Chemicals and treatment methods

Abstract

Provided is a chemical solution having excellent etching ability with respect to an Al oxide on a substrate and also having excellent etching selectivity between an Al oxide and a specific metal oxide. Also provided is a treatment method using the abovementioned chemical solution. A chemical solution according to the present invention is alkaline and contains: at least one hydroxy acid selected from the group consisting of hydroxy acids and salts thereof; a quaternary ammonium compound; trialkylamine; and water.

Description

[Technical Field]

[0001] The present invention relates to a chemical solution and a processing method. [Background technology]

[0002] As semiconductor products become increasingly miniaturized, there is an increasing demand for highly efficient and accurate removal of unwanted transition metal inclusions from substrates during the semiconductor product manufacturing process. For example, as a process for removing unnecessary Al-containing metal oxides (hereinafter also referred to as "Al oxides") on a substrate, methods such as etching using a chemical solution that dissolves the unnecessary Al oxides or removing foreign matter attached to a solid surface are widely known.

[0003] For example, Patent Document 1 discloses "a cleaning solution for removing plasma etching residues and / or ashing residues formed on semiconductor substrates, characterized by comprising (component a) water, (component b) hydroxylamine and / or a salt thereof, (component c) a basic organic compound, and (component d) an organic acid, and having a pH of 7 to 9." [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-094100 Summary of the Invention [Problem to be solved by the invention]

[0005] The present inventors have investigated the chemicals and the like described in Patent Document 1 and have found that they are inferior in at least one of their etching ability and etching selectivity for unnecessary Al oxide on the substrate. Etching selectivity refers to the ability to selectively etch a compound to be removed when treating a workpiece with a chemical solution. More specifically, when removing Al oxide, the ratio of the etching ability of the Al oxide to be removed to the etching ability of a specific metal oxide that is not the target of removal (etching ability of Al oxide / etching ability of specific metal oxide) is large (e.g., greater than 1). The specific metal oxide is a metal oxide containing at least one selected from the group consisting of Zn, Hf, and In.

[0006] Therefore, an object of the present invention is to provide a chemical solution that has excellent etching ability for Al oxide on a substrate and excellent etching selectivity between Al oxide and a specific metal oxide. Another object of the present invention is to provide a processing method using the above chemical solution. [Means for solving the problem]

[0007] As a result of extensive research into solving the above problems, the present inventors have found that the above problems can be solved by the following configuration.

[0008] [1] The composition comprises at least one hydroxy acid selected from the group consisting of hydroxy acids and salts thereof, a quaternary ammonium compound, a trialkylamine, and water; An alkaline chemical solution. [2] The chemical solution according to [1], wherein the content of the trialkylamine is 100 ppt by mass to 200 ppm by mass relative to the total mass of the chemical solution. [3] The chemical solution according to [1] or [2], wherein the content of the trialkylamine is 100 ppt by mass to 100 ppm by mass relative to the total mass of the chemical solution. [4] The mass ratio of the content of the trialkylamine to the content of the hydroxy acids is 1.0 × 10 -8 The drug solution according to any one of [1] to [3], wherein the β-glucan group is 0.1 or less. [5] The mass ratio of the content of the trialkylamine to the content of the hydroxy acids is 1.0 × 10 -8 The drug solution according to any one of [1] to [4], wherein the pH is 0.01 or less. [6] The chemical solution according to any one of [1] to [5], further comprising at least one metal component selected from the group consisting of Co and Ti. [7] The chemical solution according to [6], wherein the content of the metal component is 0.1 mass ppt to 0.1 mass ppm relative to the total mass of the chemical solution. [8] The mass ratio of the content of the metal component to the content of the trialkylamine is 1.0 × 10 -8 The drug solution according to [6] or [7], wherein the pH is 1.0 or less. [9] The mass ratio of the content of the metal component to the content of the trialkylamine is 1.0 × 10 -6 The drug solution according to any one of [6] to [8], wherein the β-glucan is 0.1 or less.

[10] The medicinal solution according to any one of [1] to [9], wherein the hydroxy acids include at least one selected from the group consisting of citric acid, lactic acid, tartaric acid, glyceric acid, and salts thereof.

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

[10] , wherein the content of the hydroxy acids per 1 L of the chemical solution is 0.01 to 0.20 mol / L.

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

[11] , which has a pH of 7.5 to 14.0.

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

[12] , which has a pH of 11.0 to 13.0.

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

[13] , wherein the quaternary ammonium compound comprises at least one selected from the group consisting of tetramethylammonium hydroxide, ethyltrimethylammonium hydroxide, diethyldimethylammonium hydroxide, triethylmethylammonium hydroxide, tetraethylammonium hydroxide, and tetrabutylammonium hydroxide.

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

[14] , further comprising a nitrogen-containing aromatic ring compound.

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

[15] , further comprising an alkanolamine.

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

[16] , further comprising at least one selected from the group consisting of hydroxyamine, diethylhydroxyamine, ascorbic acid, pyrocatechol, and pyrogallol.

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

[17] , further comprising a tertiary amine other than the trialkylamine.

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

[18] is used for a processing object having a substrate and a metal oxide containing Al and a metal oxide containing at least one selected from the group consisting of Zn, Hf, and In, disposed on the substrate.

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

[19] , which is used as an etching solution. 〔twenty one〕 A processing method comprising a step of contacting a substrate, a processing object having a metal oxide containing Al and a metal oxide containing at least one selected from the group consisting of Zn, Hf, and In, arranged on the substrate, with the chemical solution according to any one of [1] to

[20] . 〔twenty two〕 The treatment method according to

[21] , wherein the temperature of the chemical solution is 40 to 80°C. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a chemical solution that has excellent etching ability for Al oxide on a substrate and excellent etching selectivity between Al oxide and a specific metal oxide. Furthermore, the present invention can provide a method for treating a substrate using the above chemical solution. DETAILED DESCRIPTION OF THE INVENTION

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

[0011] The meaning of each description in this specification is as follows. A numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits. "Preparation" includes not only preparing specific materials by synthesizing or compounding them, but also procuring specified items by purchasing them, etc. When two or more types of a component are present, the "content" of that component means the total content of those two or more components, unless otherwise specified. The term "major component" refers to the component that is contained in the greatest amount.

[0012] "ppm" stands for parts per million (10 -6 ) "ppb" means parts-per-billion (10 -9 ) "ppt" means parts-per-trillion (10 -12 ) means "Radiation" refers to the emission line spectrum of a mercury lamp, far ultraviolet light typified by an excimer laser, extreme ultraviolet light (EUV light), X-rays, or electron beams. "Light" means actinic rays or radiation. Unless otherwise specified, "exposure" includes exposure to the bright line spectrum of a mercury lamp, far ultraviolet light represented by an excimer laser, X-rays or EUV light, and drawing with particle beams such as electron beams or ion beams.

[0013] In the notation of "group (atomic group)," if there is no indication of substituted or unsubstituted, it includes both unsubstituted and substituted groups unless otherwise specified. For example, the notation of "hydrocarbon group" includes both hydrocarbon groups without substituents (unsubstituted hydrocarbon groups) and hydrocarbon groups with substituents (substituted hydrocarbon groups). This also applies to each compound. In the description of a compound, unless otherwise specified, the compound may include isomers (compounds with the same number of atoms but different structures), optical isomers, and isotopes. In addition, the compound may include one or more types of isomers and isotopes. Unless otherwise specified, the bonding direction of a divalent group (for example, -COO-) may be either "XO-CO-Z" or "X-CO-OZ" when Y in a compound represented by "XYZ" is -COO-.

[0014] [Chemical solution] The chemical solution contains at least one hydroxy acid selected from the group consisting of hydroxy acids and salts thereof, a quaternary ammonium compound, a trialkylamine, and water, and is alkaline. The mechanism by which the above-mentioned problem is solved by the drug solution having the above-mentioned structure is not entirely clear, but the present inventors believe it to be as follows. It is believed that the chemical solution, under alkaline conditions, improves the etching ability of Al oxide with the quaternary ammonium compound and trialkylamine, and suppresses the etching ability of specific metal oxides with hydroxy acids, resulting in excellent etching ability for Al oxide on the substrate and excellent etching selectivity between Al oxide and specific metal oxides. Hereinafter, the effect of the present invention will be referred to as being superior when at least one of the effects of the etching ability for Al oxide on the substrate and the etching selectivity between Al oxide and the specific metal oxide is superior.

[0015] 〔component〕 The components that may be contained in the chemical solution will be described in detail below.

[0016] <Hydroxy acids> The chemical solution contains hydroxy acids. The hydroxy acids are at least one selected from the group consisting of hydroxy acids and salts thereof. The term "hydroxy acid" refers to a compound having one or more hydroxy groups and one or more carboxy groups in the molecule. The number of hydroxy groups that the hydroxy acids have is 1 or more, preferably 1 to 3, and more preferably 1 or 2. The number of carboxy groups that the hydroxy acids have is 1 or more, preferably 1 to 5, and more preferably 1 to 3. The total number of hydroxy groups and carboxy groups contained in the hydroxy acids is 2 or more, preferably 2 to 6, and more preferably 2 to 4.

[0017] As the hydroxy acids, a compound represented by formula (H) is preferred, and a compound represented by formula (H1) is more preferred. HO-L 1 -COOH(H) In formula (H), L 1 represents a divalent linking group. Examples of the divalent linking group include an ether group, a carbonyl group, an ester group, a thioether group, -SO2-, -NT-, a divalent hydrocarbon group (e.g., an alkylene group, an alkenylene group, an alkynylene group, and an arylene group), and a group formed by combining these groups. T represents a hydrogen atom or a substituent. The divalent linking group may further have a substituent. Examples of the substituent include an alkyl group, an aryl group, a hydroxy group, a carboxy group, an amino group, a halogen atom, and a group formed by combining these groups. A hydroxy group, a carboxy group, an alkyl group having a hydroxy group, or an alkyl group having a carboxy group is preferred. Among them, L 1 As the alkyl group, a divalent hydrocarbon group is preferable, and an alkylene group which may have a substituent is more preferable. The divalent linking group preferably has 0 to 5 substituents, and more preferably 1 to 3 substituents. The divalent linking group preferably has 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms, and even more preferably 1 to 5 carbon atoms.

[0018] [ka]

[0019] In formula (H1), R h1 represents a hydroxy group, a carboxy group, an alkyl group which may have a hydroxy group, or an alkyl group which may have a carboxy group. h2 ~R h4 each independently represents a hydrogen atom, a hydroxy group, a carboxy group, an alkyl group which may have a hydroxy group, or an alkyl group which may have a carboxy group. n represents an integer of 1 to 3. m represents an integer of 0 to 3.

[0020] The alkyl group may be straight-chain, branched-chain, or cyclic, and is preferably straight-chain. The alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, further preferably 1 to 3 carbon atoms, and particularly preferably 1 or 2 carbon atoms.

[0021] R h1 As the alkyl group, a carboxy group, an alkyl group which may have a hydroxy group, or an alkyl group which may have a carboxy group is preferred. R h2 is preferably a hydrogen atom, a hydroxy group or a carboxy group, more preferably a hydrogen atom or a carboxy group. R h3 and R h4 is preferably a hydrogen atom, a hydroxy group, a carboxy group or an alkyl group which may have a carboxy group, more preferably a hydrogen atom, a hydroxy group or a carboxy group, and even more preferably a hydrogen atom.

[0022] R h1 ~R h4 The total number of hydroxy groups contained in is preferably 0 to 2, and more preferably 0 to 1. R h1 ~Rh4 The total number of carboxy groups contained in is preferably 0 to 4, more preferably 0 to 2, and even more preferably 1. R h1 ~R h4 The total number of hydroxy groups and carboxy groups contained in the alkyl group is preferably 0 to 4, and more preferably 0 to 2. Multiple Rs h1 Comrade, R h2 Comrade, R h3 Comrades and R h4 The two may be the same or different.

[0023] n represents an integer of 1 to 3. m represents an integer of 0 to 3. n is preferably 1 or 2, and more preferably 1. m is preferably 0 or 2, and more preferably 0 or 1.

[0024] Examples of hydroxy acids include aliphatic hydroxy acids, aromatic hydroxy acids, and salts thereof. Examples of aliphatic hydroxy acids and their salts include citric acid, lactic acid, tartaric acid, glyceric acid, glycolic acid, tartronic acid, leucinic acid, malic acid, gluconic acid, isocitric acid, mevalonic acid, pantoic acid, hydroxypentanoic acid, hydroxyhexanoic acid, hydroxyethyliminodiacetic acid, hydroxyiminodisuccinic acid, quinic acid, and their salts. Examples of aromatic hydroxy acids and their salts include salicylic acid, 4-hydroxyphthalic acid, 4-hydroxyisophthalic acid, creosote acid, vanillic acid, syringic acid, resorcylic acid, protocatechuic acid, gentisic acid, orsellinic acid, gallic acid, mandelic acid, atrolactic acid, mellotic acid, phloretic acid, coumaric acid, umbellic acid, caffeic acid, and their salts. The hydroxy acids may be amino acids having a hydroxyl group. Examples include serine, threonine, tyrosine, hydroxyproline, hydroxylysine, homoserine, allothreonine, N-acyl-N-(2-hydroxyethyl)-β-alanine, and salts thereof. Among these, the hydroxy acids preferably include an aliphatic hydroxy acid and a salt thereof, more preferably include at least one selected from the group consisting of citric acid, lactic acid, tartaric acid, glyceric acid, glycolic acid, and a salt thereof, still more preferably include at least one selected from the group consisting of citric acid, lactic acid, tartaric acid, glyceric acid, and a salt thereof, and particularly preferably include citric acid and a salt thereof.

[0025] Examples of the salts of hydroxy acids include metal salts, and salts of alkali metals such as sodium and potassium, and salts of alkaline earth metals such as calcium and magnesium are preferred.

[0026] The molecular weight of the hydroxy acids is preferably 30-3,000, more preferably 50-1,000, and even more preferably 50-300.

[0027] The hydroxy acids may be used alone or in combination of two or more. The content of the hydroxy acids is preferably 0.0001 to 1.00 mol / L per 1 L of the chemical solution, more preferably 0.001 to 0.20 mol / L, and even more preferably 0.01 to 0.20 mol / L, in terms of better effects of the present invention.

[0028] <Quaternary ammonium compounds> The chemical solution contains a quaternary ammonium compound. Examples of the quaternary ammonium compound include compounds having one quaternary ammonium cation in the molecule and salts thereof. The quaternary ammonium compound is not particularly limited as long as it is a compound having one quaternary ammonium cation in which four hydrocarbon groups are substituted on a nitrogen atom, or a salt thereof. The hydrocarbon group is preferably an alkyl group or an aryl group. Examples of quaternary ammonium compounds include quaternary ammonium hydroxides, quaternary ammonium fluorides, quaternary ammonium bromides, quaternary ammonium iodides, quaternary ammonium acetates, and quaternary ammonium carbonates.

[0029] The quaternary ammonium compound is preferably a quaternary ammonium hydroxide, and more preferably a compound represented by formula (A).

[0030] [ka]

[0031] In formula (A), R a1 ~R a4 R each independently represents an alkyl group having 1 to 16 carbon atoms, an aryl group having 6 to 16 carbon atoms, an aralkyl group having 7 to 16 carbon atoms, or an alkyl group having 1 to 16 carbon atoms and a hydroxy group. a1 ~R a4 At least two of these may be bonded to each other to form a ring structure.

[0032] The alkyl group may be straight-chain, branched-chain, or cyclic. The alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and even more preferably 1 to 4 carbon atoms.

[0033] Examples of quaternary ammonium compounds that can be used, in terms of availability, include tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide (TEAH), tetrapropylammonium hydroxide, tetrabutylammonium hydroxide (TBAH), methyltripropylammonium hydroxide, methyltributylammonium hydroxide, diethyldimethylammonium hydroxide (DEDMAH), triethylmethylammonium hydroxide (TEMAH), ethyltrimethylammonium hydroxide (ETMAH), dimethyldiethylammonium hydroxide, benzyltrimethylammonium hydroxide (BzTMAH), hexadecyltrimethylammonium hydroxide, (2-hydroxyethyl)trimethylammonium hydroxide, and spiro-(1,1')-bipyrrolidinium hydroxide. Among these, the quaternary ammonium compound preferably includes at least one selected from the group consisting of tetramethylammonium hydroxide, ethyltrimethylammonium hydroxide, diethyldimethylammonium hydroxide, triethylmethylammonium hydroxide, tetraethylammonium hydroxide, and tetrabutylammonium hydroxide.

[0034] The quaternary ammonium compounds may be used alone or in combination of two or more. The content of the quaternary ammonium compound is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, based on the total mass of the chemical solution, and the upper limit is preferably 20.0% by mass or less, based on the total mass of the chemical solution. It is also preferable to adjust the content of the quaternary ammonium compound so that it falls within a suitable range for the pH of the chemical solution, which will be described later.

[0035] <Trialkylamine> The chemical solution includes a trialkylamine. Trialkylamines are compounds that have a tertiary amino group in which three alkyl groups are substituted on the nitrogen atom. The trialkylamine is preferably a compound represented by formula (B).

[0036] [ka]

[0037] In formula (B), R b1 ~R b3 each independently represents an alkyl group. The alkyl group may be linear, branched, or cyclic. The alkyl group preferably has 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, even more preferably 1 to 10 carbon atoms, even more preferably 1 to 5 carbon atoms, and particularly preferably 1 or 2 carbon atoms. R b1 ~R b3 It is preferred that at least two of R b1 ~R b3It is more preferable that all of the groups are the same. R b1 ~R b3 At least two of these may be bonded to each other to form a ring structure.

[0038] Examples of trialkylamines include trimethylamine, triethylamine, tripropylamine, tributylamine, dimethylethylamine, dimethylpropylamine, dimethylbutylamine, diethylmethylamine, diethylpropylamine, diethylbutylamine, dipropylmethylamine, dipropylethylamine, dipropylbutylamine, dibutylmethylamine, dibutylethylamine, and dibutylpropylamine. Of these, at least one selected from the group consisting of trimethylamine, diethylmethylamine, triethylamine and tributylamine is preferred, and trimethylamine is more preferred.

[0039] The trialkylamines may be used alone or in combination of two or more. The content of trialkylamine is preferably 1 ppt to 1000 ppm by mass relative to the total mass of the chemical solution, and from the viewpoint of better effects of the present invention, more preferably 100 ppt to 200 ppm by mass, and further preferably 100 ppt to 100 ppm by mass. The mass ratio of the trialkylamine content to the hydroxy acid content (trialkylamine content / hydroxy acid content) was 1.0 x 10 -10 It is preferable that the ratio is 1.0×10 to 1.0, and from the viewpoint of the effect of the present invention being more excellent, it is preferable that the ratio is 1.0×10 to 1.0. -8 1.0×10 to 0.1 is more preferable, and 1.0×10 to 0.1 is more preferable because the defect suppression is more excellent. -8 ~0.01 is more preferred.

[0040] <Water> The chemical solution includes water. The water may be, for example, ultrapure water used in the manufacture of semiconductor devices. The water is preferably water in which inorganic anions and metal ions have been reduced, more preferably water in which the concentrations of ions derived from metal atoms such as Fe, Co, Na, K, Ca, Cu, Mg, Mn, Li, Al, Cr, Ni, and Zn have been reduced, and even more preferably water that has been adjusted to the order of mass ppt or less (for example, a metal content of less than 0.001 mass ppt) when used to prepare the chemical solution. Examples of the preparation method include the methods described in paragraphs

[0074] to

[0084] of JP-A No. 2011-110515 and the methods described in JP-A No. 2007-254168, and purification using a filtration membrane or an ion exchange membrane or distillation purification is preferred.

[0041] The water used in the embodiment of the present invention is preferably the water obtained as described above. The water is preferably used for washing a container, which will be described later. The water is also preferably used in the manufacturing process of the chemical solution, for measuring the components of the chemical solution, and for evaluating the chemical solution.

[0042] The water content is preferably 50% by mass or more, more preferably 65% ​​by mass or more, and even more preferably 70% by mass or more, based on the total mass of the chemical solution. The upper limit of the water content is preferably 99.99% by mass or less, more preferably 99.9% by mass or less, based on the total mass of the chemical solution.

[0043] <ph> The chemical solution is alkaline. The pH of the chemical solution is preferably more than 7.0 and not more than 14.0, and in terms of better effects of the present invention, it is more preferably 7.5 to 14.0, even more preferably 8.5 to 13.5, even more preferably 11.0 to 13.0, and particularly preferably 11.5 to 12.5. The pH of the chemical solution is a value obtained by measurement at 25°C using a known pH meter.

[0044] <Optional ingredients> The chemical solution may further contain optional components in addition to the above components. Optional components that may be contained in the drug solution are described in detail below. The chemical solution preferably contains at least one selected from the group consisting of hydroxyamine, diethylhydroxyamine, ascorbic acid, pyrocatechol, and pyrogallol.

[0045] (Co and Ti) The chemical solution may contain at least one metal component (hereinafter also referred to as "specific metal component") selected from the group consisting of Co (cobalt) and Ti (titanium). The specific metal component may be either metal particles or metal ions. The chemical solution may contain metal particles or metal ions of the specific metal component, or may contain both.

[0046] The metal particles of the specific metal component may be either a simple substance or an alloy, or may be in a form in which the metal is associated with an organic substance. The specific metal component may be any of a specific metal component that is inevitably contained in each component (raw material) contained in the chemical solution, a specific metal component that is inevitably contained during the production, storage and / or transportation of the chemical solution, and a specific metal component that is intentionally added.

[0047] The specific metal component may be used alone or in combination of two or more. When the chemical solution contains a specific metal component, the content of the specific metal component is preferably 0.01 ppt to 10 ppm by mass, and more preferably 0.1 ppt to 0.1 ppm by mass, relative to the total mass of the chemical solution. The "content of the specific metal component" means the total content of metal particles of the specific metal component and metal ions of the specific metal component. When the chemical solution contains a metal component containing Co (hereinafter also referred to as "Co metal component"), the content of the Co metal component is preferably 1000 mass ppt or less, more preferably 100 mass ppt or less, and even more preferably 1 mass ppt or less, relative to the total mass of the chemical solution. The upper limit is preferably 0 mass ppt or more, more preferably more than 0 mass ppt, and even more preferably 0.01 mass ppt or more, relative to the total mass of the chemical solution. When the chemical solution contains a metal component containing Ti (hereinafter also referred to as "Ti metal component"), the content of the Ti metal component is preferably 100 mass ppm or less, more preferably 1 mass ppm or less, and even more preferably 0.1 mass ppm or less, relative to the total mass of the chemical solution. The upper limit is preferably 0 mass ppt or more, more preferably more than 0 mass ppt, and even more preferably 0.01 mass ppt or more, relative to the total mass of the chemical solution.

[0048] The mass ratio of the specific metal component content to the trialkylamine content (specific metal component content / trialkylamine content) is 1.0 x 10 -8 The effect of the present invention is more excellent in a range of 1.0×10 to 10.0. -8 1.0×10 to 1.0 is more preferable, and 1.0×10 to 1.0 is more preferable because the defect suppression is more excellent. -6 More preferably, 1.0×10 -5 A value of 0.01 is particularly preferred.

[0049] The type and content of specific metal components can be measured by SP-ICP-MS (Single Nano Particle Inductively Coupled Plasma Mass Spectrometry). The "SP-ICP-MS method" uses the same equipment as the ICP-MS method (inductively coupled plasma mass spectrometry), but the only difference is the data analysis. Data analysis for the SP-ICP-MS method can be performed using commercially available software. In ICP-MS, the content of a specific metal component is measured regardless of its form. Therefore, the total mass of metal particles and metal ions of the specific metal component is quantified as the content of the specific metal component.

[0050] Methods for adjusting the content of a specific metal component include, for example, a method of performing a known process to remove the specific metal from the chemical solution, a method of performing a known process to remove the specific metal from raw materials containing each component used to prepare the chemical solution, or a method of adding a compound containing a metal ion of the specific metal component to the chemical solution.

[0051] The chemical solution may contain other metal components in addition to the specific metal component. Examples of other metal components include transition metal components other than the specific metal components.

[0052] (organic solvent) The chemical solution may contain an organic solvent. The organic solvent is preferably a hydrophilic organic solvent. The term "hydrophilic organic solvent" refers to an organic solvent that dissolves at least 0.1 g in 100 g of water at 25°C. As the hydrophilic organic solvent, an organic solvent that can be mixed uniformly with water at any mixing ratio is preferred. Examples of hydrophilic organic solvents include glycol-based solvents, glycol ether-based solvents, amide-based solvents, alcohol-based solvents, and sulfoxide-based solvents.

[0053] Examples of glycol-based solvents include ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, and tetraethylene glycol.

[0054] Examples of glycol ether solvents include glycol monoethers. Examples of glycol monoethers include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol monoisopropyl ether, ethylene glycol mono-n-butyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, 1-methoxy-2-propanol, 2-methoxy-1-propanol, 1-ethoxy-2-propanol, 2-ethoxy-1-propanol, propylene glycol mono-n-propyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, tripropylene glycol monoethyl ether, tripropylene glycol monomethyl ether, ethylene glycol monobenzyl ether, and diethylene glycol monobenzyl ether.

[0055] Examples of amide solvents include N,N-dimethylformamide, 1-methyl-2-pyrrolidone, 2-pyrrolidinone, 1,3-dimethyl-2-imidazolidinone, formamide, N-methylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, N-methylpropanamide, and hexamethylphosphoric triamide.

[0056] Examples of alcohol-based solvents include alkanediols, alkoxy alcohols, saturated aliphatic monohydric alcohols, and unsaturated non-aromatic monohydric alcohols. Examples of alkanediols include 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, and pinacol. Alkoxy alcohols include, for example, 3-methoxy-3-methyl-1-butanol, 3-methoxy-1-butanol, and 1-methoxy-2-butanol. Examples of saturated aliphatic monohydric alcohols include methanol, ethanol, n-propyl alcohol, isopropanol (isopropyl alcohol), 1-butanol, 2-butanol, isobutyl alcohol, tert-butyl alcohol, 2-pentanol, t-pentyl alcohol, and 1-hexanol. Examples of unsaturated non-aromatic monohydric alcohols include allyl alcohol, propargyl alcohol, 2-butenyl alcohol, 3-butenyl alcohol, and 4-penten-2-ol. Examples of low molecular weight alcohols containing a ring structure include tetrahydrofurfuryl alcohol, furfuryl alcohol, and 1,3-cyclopentanediol.

[0057] An example of the sulfoxide solvent is dimethyl sulfoxide.

[0058] The organic solvents may be used alone or in combination of two or more. The content of the organic solvent is preferably 0.001 to 10 mass %, more preferably 0.01 to 3 mass %, based on the total mass of the chemical solution.

[0059] (basic compounds) The chemical solution may contain a basic compound. By "basic compound" is meant a compound that, when dissolved in water, gives a solution pH greater than 7. The basic compound has the function of removing residues such as etching residues and ashing residues, and also functions as a pH adjuster that adjusts the pH of the chemical solution. Examples of basic compounds include ammonium hydroxide (NH4OH) and amine compounds.

[0060] When the chemical solution contains ammonium hydroxide, the content of ammonium hydroxide is preferably 0.01 to 10 mass %, more preferably 0.05 to 5 mass %, relative to the total mass of the chemical solution.

[0061] The amine compound is a compound having an amino group in the molecule. The above quaternary ammonium compounds and the above trialkylamines are not included in the basic compounds. Examples of amine compounds include primary amines having a primary amino group (-NH2) in the molecule, secondary amines having a secondary amino group (>NH) in the molecule, tertiary amines having a tertiary amino group (>N-) in the molecule, and salts thereof. Examples of salts of amine compounds include salts with inorganic acids in which at least one nonmetal selected from the group consisting of Cl, S, N, and P is bonded to hydrogen, and hydrochlorides, sulfates, or nitrates are preferred. The amine compound is preferably a water-soluble amine that can dissolve 50 g or more in 1 L of water. Examples of the amine compound include alicyclic amine compounds, alkanolamines, hydroxyamine compounds, and hydrazide compounds.

[0062] Alicyclic amine compounds are amine compounds that have an alicyclic structure in the molecule and are different from the nitrogen-containing aromatic ring compounds described below. Examples of the alicyclic amine compounds include 1,8-diazabicyclo[5.4.0]-7-undecene (DBU), ε-caprolactam, the following compound 1, the following compound 2, the following compound 3, 1,4-diazabicyclo[2.2.2]octane (DABCO), tetrahydrofurfurylamine, N-(2-aminoethyl)piperazine, hydroxyethylpiperazine, piperazine, 2-methylpiperazine, trans-2,5-dimethylpiperazine, and cis-2,6-dimethylpiperazine. perazine, 2-piperidinemethanol, N-(2-hydroxyethylmorpholine), 4-(2-cyanoethyl)morpholine, N,N',N''-tris(3-dimethylaminopropyl)-hexahydro-s-triazine, N-methyl-N'-(2-dimethylaminoethyl)piperazine, N,N-bis(3-aminopropylpiperazine), N-aminoethylpiperazine, cyclohexylamine, and 1,5-diazabicyclo[4,3,0]-5-nonene.

[0063] [ka]

[0064] Alkanolamines are amine compounds that have at least one hydroxyalkyl group in the molecule. The alkanolamine may have any of a primary amino group, a secondary amino group, and a tertiary amino group, and preferably has a primary amino group. Examples of alkanolamines include monoethanolamine (MEA), diethanolamine (DEA), triethanolamine (TEA), N-methyldiethanolamine, 2-(dimethylamino)-2-methyl-1-propanol (DMAMP), diethylene glycolamine (DEGA), trishydroxymethylaminomethane (Tris), 2-amino-2-methyl-1-propanol (AMP), 2-amino-2-methyl-1,3-dipropanol (AMPD), and 2-amino-2-ethyl-1,3-dipropanol. Examples of the ethylenediamine-based ethanol include 2-(aminoethoxy)ethanol (AEPD), 2-(methylamino)-2-methyl-1-propanol (N-MAMP), N,N-dimethylaminoethoxyethanol, 1,1-((3-(dimethylamino)propylimino)-bis-2-propanol, N,N,N'-trimethylaminoethylethanolamine, a propylene oxide adduct of ethylenediamine, 2-(aminoethoxy)ethanol (AEE), and N-(2-aminoethyl)ethanolamine (AEEA), of which N-methyldiethanolamine, AEE, or AEEA is preferred.

[0065] The hydroxyamine compound is at least one compound selected from the group consisting of hydroxyamine (NH2OH), hydroxyamine derivatives, and salts thereof. The hydroxyamine compound has the function of promoting the decomposition and solubilization of residues and removing residues such as etching residues and ashing residues.

[0066] Examples of hydroxyamine derivatives include O-methylhydroxyamine, O-ethylhydroxyamine, N-methylhydroxyamine, N,N-dimethylhydroxyamine, N,O-dimethylhydroxyamine, N-ethylhydroxyamine, N,N-diethylhydroxyamine, N,O-diethylhydroxyamine, O,N,N-trimethylhydroxyamine, N,N-dicarboxyethylhydroxyamine, and N,N-disulfoethylhydroxyamine.

[0067] Salts of hydroxyamine and hydroxyamine derivatives include, for example, inorganic acid salts and organic acid salts. Inorganic acid salts formed by bonding a nonmetallic atom of Cl, S, N, or P with a hydrogen atom are preferred, and salts of any of hydrochloric acid, sulfuric acid, and nitric acid are more preferred. Preferred inorganic acid salts of hydroxyamine and hydroxyamine derivatives are hydroxyamine nitrate, hydroxyamine sulfate, hydroxyamine hydrochloride, hydroxyamine phosphate, N,N-diethylhydroxyamine sulfate, N,N-diethylhydroxyamine nitrate, or mixtures thereof. Examples of organic acid salts of hydroxyamine and hydroxyamine derivatives include hydroxyammonium citrate, hydroxyammonium oxalate, and hydroxyammonium fluoride, with hydroxyamine being preferred.

[0068] The content of the hydroxyamine compound is preferably 0.01 to 30% by mass, more preferably 0.5 to 25% by mass, based on the total mass of the chemical solution.

[0069] Examples of primary amines other than alicyclic amine compounds, alkanolamines, and hydroxyamine compounds include methylamine, ethylamine, propylamine, butylamine, pentylamine, methoxyethylamine, and methoxypropylamine. Examples of secondary amines other than alicyclic amine compounds, alkanolamines, and hydroxyamine compounds include dimethylamine, diethylamine, dipropylamine, and dibutylamine (DBA).

[0070] A hydrazide compound refers to a compound in which the hydroxy group of an acid is replaced with a hydrazino group (-NH-NH2) and its derivatives (compounds in which the hydrazino group is substituted with at least one substituent). The hydrazide compound may have two or more hydrazino groups. Examples of the hydrazide compound include carboxylic acid hydrazides and sulfonic acid hydrazides, with carbohydrazide (CHZ) being preferred.

[0071] The basic compound is preferably an amine compound, more preferably an alkanolamine or hydroxyamine compound, and even more preferably monoethanolamine or hydroxyamine.

[0072] The basic compounds may be used alone or in combination of two or more. The content of the basic compound is preferably 0.01 to 30 mass %, more preferably 0.1 to 20 mass %, based on the total mass of the chemical solution.

[0073] (acidic compound) The chemical solution may contain an acidic compound to adjust the pH of the chemical solution. The acidic compound may be either an inorganic acid or an organic acid. The acidic compounds do not include the above-mentioned hydroxy acids. Examples of inorganic acids include sulfuric acid, hydrochloric acid, acetic acid, nitric acid, and phosphoric acid, with sulfuric acid, hydrochloric acid, or acetic acid being preferred. Examples of organic acids include lower (1 to 4 carbon atoms) aliphatic monocarboxylic acids such as formic acid, acetic acid, propionic acid, and butyric acid.

[0074] When an acidic compound is used so that the pH of the chemical solution is in the preferred range described below, the type of acidic compound to be used can be appropriately selected and the content can be adjusted depending on the type and content of the components contained in the chemical solution.

[0075] (Nitrogen-containing aromatic ring compound) The chemical solution may contain a nitrogen-containing aromatic ring compound. A nitrogen-containing aromatic ring compound is a compound that has one or more aromatic rings containing a nitrogen atom in the molecule. The aromatic ring may contain two or more nitrogen atoms. The nitrogen-containing aromatic ring compound is a compound different from the various components described above. The nitrogen-containing aromatic ring compound is preferably an azole compound.

[0076] An azole compound is a compound having one or more five-membered aromatic rings containing a nitrogen atom. Examples of the azole compound include an imidazole compound, a pyrazole compound, a thiazole compound, a triazole compound, and a tetrazole compound. The azole compound may have a substituent on the aromatic five-membered ring, such as a hydroxy group, a carboxy group, a mercapto group, an amino group, an alkyl group having 1 to 4 carbon atoms which may have an amino group, and a 2-imidazolyl group.

[0077] Examples of imidazole compounds include imidazole, 1-methylimidazole, 2-methylimidazole, 5-methylimidazole, 1,2-dimethylimidazole, 2-mercaptoimidazole, 4,5-dimethyl-2-mercaptoimidazole, 4-hydroxyimidazole, 2,2'-biimidazole, 4-imidazolecarboxylic acid, histamine, benzimidazole, and purine compounds, with imidazole or purine compounds being preferred.

[0078] The purine compound means a compound containing at least one selected from the group consisting of purine and purine derivatives. Examples of purine compounds include purine, adenine, guanine, hypoxanthine, xanthine, theobromine, caffeine, uric acid, isoguanine, adenosine, enprofylline, xanthosine, 7-methylxanthosine, 7-methylxanthine, theophylline, eritadenine, paraxanthine, 3-methyladenine, 3-methylxanthine, 1,7-dimethylxanthine, and 1-methylxanthine.

[0079] (reducing compounds) The chemical solution may contain a reducing compound. Reducing compounds have an oxidizing effect and react with OH contained in the chemical solution. - It is a compound that has the function of oxidizing ions or dissolved oxygen, and is also called an oxygen scavenger. The reducing compound is a compound different from the various components described above. Examples of reducing compounds include ascorbic acid compounds, catechol compounds, and reducing sulfur compounds. The reducing compound preferably includes at least one selected from the group consisting of ascorbic acid, pyrocatechol, and pyrogallol.

[0080] The ascorbic acid compound means at least one selected from the group consisting of ascorbic acid, ascorbic acid derivatives, and salts thereof. Examples of ascorbic acid derivatives include ascorbic acid phosphate and ascorbic acid sulfate. The ascorbic acid compound is preferably ascorbic acid, ascorbic acid phosphate, or ascorbic acid sulfate, and more preferably ascorbic acid.

[0081] The catechol compound means at least one selected from the group consisting of pyrocatechol (benzene-1,2-diol) and catechol derivatives. The term "catechol derivative" refers to a compound in which pyrocatechol is substituted with at least one substituent. The substituents of the catechol derivative include a hydroxyl group, a carboxylic acid ester group, a sulfo group, a sulfonate ester group, an alkyl group, and an aryl group. The sulfo group of the catechol derivative as a substituent may be a salt with a cation. Examples of catechol compounds include pyrocatechol, 4-tert-butylcatechol, pyrogallol, methyl gallate, 1,2,4-benzenetriol, and tiron.

[0082] The reducing sulfur compound is a compound that contains a sulfur atom and functions as a reducing agent. Examples of reducing sulfur compounds include cysteine, mercaptosuccinic acid, dithiodiglycerol, bis(2,3-dihydroxypropylthio)ethylene, sodium 3-(2,3-dihydroxypropylthio)-2-methyl-propylsulfonate, 1-thioglycerol, sodium 3-mercapto-1-propanesulfonate, 2-mercaptoethanol, thioglycolic acid, and 3-mercapto-1-propanol. The reducing sulfur compound is preferably a compound having an SH group (mercapto compound), more preferably cysteine, 1-thioglycerol, sodium 3-mercapto-1-propanesulfonate, 2-mercaptoethanol, 3-mercapto-1-propanol or thioglycolic acid, and even more preferably cysteine.

[0083] The reducing compounds may be used alone or in combination of two or more. The content of the reducing compound is preferably 0.01 to 30 mass %, more preferably 0.01 to 20 mass %, based on the total mass of the chemical solution.

[0084] (Tertiary amine compounds other than trialkylamines) The chemical solution may contain a tertiary amine compound other than the above trialkylamine. The tertiary amine compound is a compound that has a tertiary amino group and is different from trialkylamines and various other components. The number of tertiary amino groups that the tertiary amine compound has is preferably 1 or more, more preferably 2 or more, and more preferably 2 to 5. The number of nitrogen atoms contained in the tertiary amine compound is preferably 1 or more, more preferably 2 or more, and more preferably 2 to 5. Tertiary amine compounds include, for example, and aliphatic tertiary amine compounds. In addition, some of the methylene groups (-CH2-) in the aliphatic tertiary amine compound may be replaced with heteroatoms (for example, oxygen atoms, sulfur atoms, etc.). Examples of tertiary amine compounds include N,N,N',N'-tetramethylethylenediamine, bis(2-dimethylaminoethyl)ether, 3-(dimethylamino)propylamine, N,N,N',N'-tetramethylhexamethylenediamine, N,N,N',N'',N''-pentamethyldiethylenetriamine, N,N,N',N'',N'''',N'''-hexamethyltriethylenetetramine, and 1,3-bis(dimethylamino)butane, with N,N,N',N'',N''-pentamethyldiethylenetriamine being preferred.

[0085] (surfactant) The chemical solution may contain a surfactant. Examples of surfactants include compounds having a hydrophilic group and a hydrophobic group (lipophilic group) in the molecule, and specific examples include anionic surfactants, cationic surfactants, and nonionic surfactants.

[0086] Examples of the hydrophobic group contained in the surfactant include an aliphatic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these groups. When the hydrophobic group has an aromatic hydrocarbon group, the number of carbon atoms in the hydrophobic group is preferably 6 or more, and more preferably 10 or more. When the hydrophobic group does not contain an aromatic hydrocarbon group and is composed only of an aliphatic hydrocarbon group, the number of carbon atoms in the hydrophobic group is preferably 8 or more, and more preferably 10 or more. The upper limit is preferably 24 or less, and more preferably 20 or less.

[0087] Examples of the anionic surfactant include anionic surfactants having at least one hydrophilic group selected from the group consisting of a sulfonic acid group, a carboxy group, a sulfate ester group, and a phosphonic acid group in the molecule.

[0088] Examples of anionic surfactants having a sulfonic acid group include alkyl sulfonic acids, alkyl benzene sulfonic acids, alkyl naphthalene sulfonic acids, alkyl diphenyl ether sulfonic acids, fatty acid amide sulfonic acids, and salts thereof. Examples of anionic surfactants having a carboxy group include polyoxyethylene alkyl ether carboxylic acids, polyoxyethylene alkyl ether acetic acids, polyoxyethylene alkyl ether propionic acids, fatty acids, and salts thereof. Examples of salts of anionic surfactants include ammonium salts, sodium salts, potassium salts, and tetramethylammonium salts.

[0089] Examples of cationic surfactants include compounds having a cationic hydrophilic group and the above-mentioned hydrophobic group, and specific examples include quaternary ammonium salt surfactants and alkylpyridinium surfactants.

[0090] One or more surfactants may be used. The surfactant content is preferably 0.01% by mass or more, more preferably 0.03% by mass or more, based on the total mass of the chemical solution, and the upper limit is preferably 10% by mass or less, more preferably 5% by mass or less, based on the total mass of the chemical solution, in order to suppress foaming of the chemical solution.

[0091] [Physical properties of chemical solution] <Coarse particles> It is preferable that the chemical solution is substantially free of coarse particles. "Coarse particles" refers to particles with a diameter of 0.2 μm or more when the particle shape is considered to be spherical. Furthermore, "substantially free of coarse particles" means that when the liquid is measured using a commercially available measuring device that uses a light scattering liquid particle measurement method, there are 10 or fewer particles with a diameter of 0.2 μm or more per mL of the liquid. The lower limit is preferably 0 or more. 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 materials, 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 these particles ultimately remain as particles in the chemical solution without dissolving. The method for measuring the content of coarse particles includes, for example, a method of measuring in the liquid phase using a commercially available measuring device of a light scattering type liquid particle measuring method using a laser as a light source. As a method for removing coarse particles, for example, a filtering process can be mentioned.

[0092] [Method of manufacturing chemical solution] <Chemical solution preparation process> As a method for producing the chemical solution, for example, a known production method can be used. The method for producing the chemical solution may include a chemical solution preparation step. The chemical solution preparation step may include, for example, a method of preparing the above-mentioned hydroxy acids, the above-mentioned quaternary ammonium compound, the above-mentioned trialkylamine, the above-mentioned water, and any optional components, and then mixing the above-mentioned components to prepare the chemical solution. In the chemical solution preparation step, the order in which the components are mixed is not particularly limited. The method for producing the chemical solution may include a dilution step of diluting the chemical solution. That is, the chemical solution may be used after being diluted with a diluent such as water.

[0093] <Filtration process> The method for producing the chemical solution may include a filtration step of filtering the chemical solution to remove foreign matter, coarse particles, and the like from the chemical solution. Examples of the filtration method include known filtration methods, and filtering using a filter is preferred.

[0094] Examples of filters used for filtering include filters used for known filtering. Examples of materials that can be used to form the filter include fluororesins such as PTFE (polytetrafluoroethylene), polyamide resins such as nylon, and polyolefin resins (including high density and ultra-high molecular weight) such as polyethylene and polypropylene (PP), with polyamide resins, PTFE, or polypropylene (including high density polypropylene) being preferred. By using a filter made of the above material, highly polar foreign matter that is likely to cause defects can be more effectively removed from the chemical solution.

[0095] The critical surface tension of the filter is preferably 70 mN / m or more, and the upper limit is preferably 95 mN / m or less, with 75 to 85 mN / m being more preferred. The critical surface tension value is the nominal value provided by the manufacturer. By using a filter with a critical surface tension in the above range, highly polar foreign matter that is likely to cause defects can be more effectively removed from the chemical solution.

[0096] The pore size of the filter is preferably 0.001 to 1.0 μm, more preferably 0.02 to 0.5 μm, and even more preferably 0.01 to 0.1 μm. When the pore size of the filter is within the above range, fine foreign matter can be removed from the chemical solution while preventing clogging.

[0097] The filter may be a combination of two or more types of filters. The filtering using the first filter may be performed once or twice or more times. When a first filter and a second filter different from the first filter are combined to perform filtering two or more times, the filters may be identical or different, and preferably different, and the first filter and the second filter preferably differ in at least one of pore size and constituent material. It is preferable that the pore size of the second or subsequent filtering be the same as or smaller than the pore size of the first filtering. Also, first filters with different pore sizes may be combined within the above range of filter pore sizes. The nominal pore size can be referenced from the filter manufacturer. Examples of the filters include those manufactured by Nippon Pall Corporation, Advantec Toyo Co., Ltd., Nippon Entegris Co., Ltd., and Kitz Microfilter Co., Ltd. Specifically, these include polyamide P-nylon filters (pore size 0.02 μm, critical surface tension 77 mN / m, manufactured by Nippon Pall Corporation), high-density polyethylene PE clean filters (pore size 0.02 μm, manufactured by Nippon Pall Corporation), and high-density polyethylene PE clean filters (pore size 0.01 μm, manufactured by Nippon Pall Corporation).

[0098] The second filter may be, for example, a filter made of the same material as the first filter. The pore size of the second filter may be the same as the pore size of the first filter. When the pore size of the second filter is smaller than that of the first filter, the ratio of the pore size of the second filter to the pore size of the first filter (pore size of second filter / pore size of first filter) is preferably 0.01 to 0.99, more preferably 0.1 to 0.9, and even more preferably 0.3 to 0.9. When the pore size of the second filter is within the above range, fine foreign matter mixed in the chemical solution can be more effectively removed.

[0099] Filtering using the first filter may be performed, for example, on a mixed liquid containing some of the components of the drug solution, and after mixing this with the remaining components to prepare the drug solution, filtering using the second filter may be performed.

[0100] The filter to be used is preferably washed before filtering the chemical solution. The cleaning treatment is preferably a cleaning treatment using a liquid, and more preferably a cleaning treatment using a chemical solution or a liquid containing a component contained in the chemical solution.

[0101] The temperature of the chemical solution during filtering is preferably room temperature (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. At the above temperature, the amount of particulate matter and / or impurities contained in the chemical solution is reduced, allowing for more efficient filtering.

[0102] <Dilution process> The chemical solution may be used as a diluted chemical solution (diluted chemical solution) after undergoing a dilution step in which the chemical solution is diluted with a diluent such as water. In addition, a diluted chemical solution is also one form of the chemical solution of the present invention as long as it satisfies the requirements of the present invention.

[0103] The dilution ratio of the chemical solution in the dilution step may be adjusted as appropriate depending on the type and content of each component, etc. The ratio of the diluted chemical solution to the chemical solution before dilution (dilution factor) is preferably 10 to 10,000 times, more preferably 20 to 3,000 times, and even more preferably 50 to 1,000 times in mass ratio or volume ratio (volume ratio at 23°C). A chemical solution (diluted chemical solution) containing each component in an amount obtained by dividing the preferred content of each component (excluding water) that can be contained in the above chemical solution by a dilution ratio (for example, 100) within the above range can also be suitably used. In other words, the preferred content of each component (excluding water) relative to the total mass of the diluted chemical solution is, for example, the amount described as the preferred content of each component relative to the total mass of the chemical solution (chemical solution before dilution) divided by the dilution ratio in the above range (for example, 100).

[0104] The change in pH before and after dilution (the difference between the pH of the chemical solution before dilution and the pH of the diluted chemical solution) is preferably 2.0 or less, more preferably 1.8 or less, and even more preferably 1.5 or less. The pH of the chemical solution before dilution and the pH of the diluted chemical solution are preferably in the above-mentioned preferred embodiments.

[0105] The specific method of the dilution step of diluting the chemical solution may be performed in accordance with the above-mentioned chemical solution preparation step. The stirring device and stirring method used in the dilution step may also be the same as those used in the above-mentioned chemical solution preparation step.

[0106] <Static elimination process> The method for producing the chemical solution may further include a static elimination step of eliminating static electricity from the chemical solution.

[0107] Each step in the method for producing the chemical solution is preferably carried out in a clean room. The clean room preferably meets the 14644-1 clean room standard, and also preferably meets any one 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.

[0108] <Container> As the container for storing the chemical solution, for example, a known container can be used. The container is preferably one designed for semiconductor applications, has a high degree of cleanliness within, and leaches out little impurities. Examples of containers include the "Clean Bottle" series (manufactured by Aicello Chemical Co., Ltd.) and the "Pure Bottle" (manufactured by Kodama Resin Industry Co., Ltd.) In addition, from the viewpoint of preventing impurities from being mixed in (contaminated) with the raw materials and chemical solutions, 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 seven-layer structure made of seven types of resin. Examples of multilayer containers include the containers described in JP 2015-123351 A, the contents of which are incorporated herein by reference. Examples of materials for the container inner wall include at least one first resin selected from the group consisting of polyethylene resin, polypropylene resin, and polyethylene-polypropylene resin, a second resin different from the first resin, and metals such as stainless steel, Hastelloy, Inconel, Monel, etc. The container inner wall is preferably formed or coated with the above materials.

[0109] The second resin is preferably a fluorine-based resin (perfluororesin). When a fluorine-based resin is used, it is possible to suppress the elution of ethylene or propylene oligomers. Examples of the container include FluoroPure PFA composite drums (manufactured by Entegris), and the containers described on page 4 of Published Japanese Translation of PCT International Publication No. 3-502677, page 3 of International Publication No. 2004 / 016526, and pages 9 and 16 of International Publication No. 99 / 046309.

[0110] As the inner wall of the container, in addition to the above-mentioned fluorine-based resin, quartz and electrolytically polished metal materials (metal materials that have been electrolytically polished) are also preferred. The metal material used for the electropolished metal material preferably contains at least one selected from the group consisting of chromium (Cr) and nickel (Ni), and the total content of Cr and Ni is more than 25 mass% based on the total mass of the metal material, such as stainless steel and Ni-Cr alloy. The total content of Cr and Ni in the metal material is preferably 25 mass % or more, more preferably 30 mass % or more, based on the total mass of the metal material, and the upper limit is preferably 90 mass % or less, based on the total mass of the metal material.

[0111] Examples of stainless steel include known stainless steels. Among these, stainless steel containing 8 mass % or more of Ni is preferred, and austenitic stainless steel containing 8 mass % or more of Ni is more preferred. Examples of austenitic stainless steel include SUS (Steel Use Stainless) 304 (Ni content: 8 mass%, Cr content: 18 mass%), SUS304L (Ni content: 9 mass%, Cr content: 18 mass%), SUS316 (Ni content: 10 mass%, Cr content: 16 mass%), and SUS316L (Ni content: 12 mass%, Cr content: 16 mass%).

[0112] Examples of Ni-Cr alloys include known Ni-Cr alloys. Among these, a Ni-Cr alloy having an Ni content of 40 to 75 mass % and a Cr content of 1 to 30 mass % is preferred. Examples of Ni-Cr alloys include Hastelloy, Monel, and Inconel, specifically Hastelloy C-276 (Ni content: 63 mass%, Cr content: 16 mass%), Hastelloy-C (Ni content: 60 mass%, Cr content: 17 mass%), and Hastelloy C-22 (Ni content: 61 mass%, Cr content: 22 mass%). The Ni-Cr alloy may further contain boron, silicon, tungsten, molybdenum, copper and cobalt in addition to the above alloy, if necessary.

[0113] Methods for electrolytically polishing metal materials include, for example, known methods. Specifically, the methods described in paragraphs

[0011] to

[0014] of Japanese Patent Application Laid-Open No. 2015-227501 and paragraphs

[0036] to

[0042] of Japanese Patent Application Laid-Open No. 2008-264929 can be mentioned, the contents of which are incorporated herein by reference.

[0114] It is presumed that the chromium content in the surface passive layer of a metal material becomes higher than the chromium content in the parent phase due to electrolytic polishing. Therefore, it is presumed that metal elements are less likely to leak into the chemical solution from the inner wall coated with the electrolytically polished metal material, making it possible to obtain a chemical solution with reduced levels of specific metal elements. The metal material is preferably buffed. The buffing method may be, for example, a known method. The size of the abrasive grains used in the buffing finish is preferably #400 or less, as this tends to reduce the surface irregularities of the metal material. Buffing is preferably carried out before electrolytic polishing. The metal material may be treated by one or a combination of two or more of multiple steps of buffing using different grit sizes of abrasive grains, acid washing, and magnetic fluid polishing.

[0115] It is preferable to clean the inside of the container before filling it with the drug solution. The liquid used for cleaning can be appropriately selected depending on the application, and is preferably the above-mentioned chemical solution or a liquid containing at least one of the components added to the above-mentioned chemical solution.

[0116] To prevent changes in the components of the chemical solution during storage, the atmosphere inside the container may be purged with an inert gas (e.g., nitrogen or argon) with a purity of 99.99995% by volume or higher. Gases with low moisture content are particularly preferred. Furthermore, during transport and storage of the container containing the chemical solution, the temperature may be either room temperature or controlled. In particular, to prevent deterioration, it is preferable to control the temperature within the range of -20 to 20°C.

[0117] [Application] The chemical solution is preferably used for semiconductor devices. "For semiconductor devices" means used in the manufacture of semiconductor devices. The chemical solution can also be used in processes for manufacturing semiconductor devices, and can be used to treat, for example, transition metal-containing substances, insulating films, resist films, anti-reflective films, etching residues, ashing residues (hereinafter simply referred to as "residues") present on a substrate. The chemical solution can also be used to treat a substrate after chemical mechanical polishing.

[0118] [Processing object] The chemical solution is preferably used to remove Al oxides on the substrate. The term "on the substrate" includes any of the front and back surfaces, side surfaces, and inside grooves of the substrate. Furthermore, "Al oxide on a substrate" includes both cases where Al oxide is present directly on the surface of the substrate and cases where Al oxide is present on the substrate via another layer.

[0119] The object to be treated may include an object to be treated that includes a substrate and an Al oxide and a specific metal oxide disposed on the substrate.

[0120] The Al oxide is not particularly limited as long as it is an oxide containing Al (Al atoms), and may contain other metals. The content of Al atoms in the Al oxide is preferably 10 to 70 mass %, more preferably 20 to 60 mass %, based on the total mass of the Al oxide.

[0121] The specific metal oxide is a metal oxide containing at least one selected from the group consisting of Zn, Hf, and In. Examples of the specific metal oxide include an oxide containing Zn (hereinafter also referred to as "Zn oxide"), an oxide containing Hf (hereinafter also referred to as "Hf oxide"), and an oxide containing In (hereinafter also referred to as "In oxide"). The content of Zn atoms in the Zn oxide is preferably 20 to 80 mass %, more preferably 30 to 70 mass %, based on the total mass of the Zn oxide. The content of Hf atoms in the Hf oxide is preferably 5 to 65 mass %, more preferably 15 to 55 mass %, based on the total mass of the Hf oxide. The content of In atoms in the In oxide is preferably 20 to 80 mass %, more preferably 30 to 70 mass %, based on the total mass of the In oxide.

[0122] The substrate is preferably a semiconductor substrate. Examples of the semiconductor substrate include semiconductor wafers, glass substrates for photomasks, glass substrates for liquid crystal displays, glass substrates for plasma displays, substrates for FEDs (Field Emission Displays), substrates for optical disks, substrates for magnetic disks, and substrates for magneto-optical disks. Materials that may comprise the semiconductor substrate include silicon, silicon germanium, and III-V compounds such as GaAs, as well as combinations thereof.

[0123] Examples of applications of the processed object include DRAM (Dynamic Random Access Memory), FRAM (registered trademark) (Ferroelectric Random Access Memory), MRAM (Magnetoresistive Random Access Memory), PRAM (Phase change Random Access Memory), logic circuits, and processors.

[0124] The Al oxide on the substrate may be in any of the following forms: a film, a wiring, or particles. The specific metal oxide on the substrate may be in any of the following forms: a film, a wiring, or particles.

[0125] When the Al oxide is in the form of a film, the thickness of the Al oxide film is preferably 200 nm or less, more preferably 100 nm or less, and even more preferably 50 nm or less. The lower limit is preferably 0.1 nm or more. The Al oxide and the specific metal oxide may be disposed on only one or both of the main surfaces of the substrate, and the Al oxide may be disposed over the entire main surface of the substrate or over a portion of the main surface of the substrate.

[0126] The object to be treated may contain layers and / or structures other than Al oxide and specific metal oxide as desired. For example, metal wiring, a gate electrode, a source electrode, a drain electrode, an insulating layer, a ferromagnetic layer, and / or a non-magnetic layer may be disposed on the substrate. The substrate may include an exposed integrated circuit structure. The integrated circuit structure may include interconnect mechanisms such as metal wiring and dielectric materials. Metals and alloys used in the interconnect mechanisms may include, for example, aluminum, copper-aluminum alloys, copper, titanium, tantalum, cobalt, silicon, titanium nitride, tantalum nitride, and tungsten. The substrate may include layers of silicon oxide, silicon nitride, silicon carbide, and / or carbon-doped silicon oxide.

[0127] The size, thickness, shape and layer structure of the substrate can be appropriately selected as desired.

[0128] [Substrate processing method] The processing method of the present invention (hereinafter also referred to as "the processing method") includes a step A of contacting a substrate, an object to be processed having Al oxide and a specific metal oxide arranged on the substrate, with the above-mentioned chemical solution. By carrying out the processing method, the Al oxide on the substrate is selectively removed. The object to be treated in this treatment method is as described above.

[0129] Examples of contacting methods include immersing the object to be treated in a chemical solution placed in a tank, spraying the chemical solution onto the object to be treated, flowing the chemical solution onto the object to be treated, and combinations of these. The method of immersing the object to be treated in the chemical solution is preferred.

[0130] Additionally, mechanical agitation may be used to further enhance the cleaning ability of the chemical solution. Examples of mechanical stirring methods include a method of circulating a chemical solution over the workpiece, a method of passing or spraying a chemical solution over the workpiece, and a method of stirring a chemical solution using ultrasound or megasonics.

[0131] The treatment time of step A can be adjusted as appropriate. The treatment time (contact time between the chemical solution and the object to be treated) is preferably 0.25 to 10 minutes, more preferably 0.5 to 2 minutes. The temperature of the chemical solution during treatment is preferably 20 to 100°C, more preferably 40 to 80°C.

[0132] In step A, a treatment of adding a solvent (preferably water) to the chemical solution may be carried out as necessary while measuring the concentrations of the hydroxy acids, quaternary ammonium compounds, trialkylamines and / or optional components in the chemical solution. By carrying out this treatment, the concentrations of the components in the chemical solution can be stably maintained within a predetermined range.

[0133] <Other processes> The present treatment method may include other steps in addition to the step A. Other processes include, for example, processes for forming each structure such as metal wiring, gate structure, source structure, drain structure, insulating layer, ferromagnetic layer and / or non-magnetic layer (e.g., layer formation, etching, chemical mechanical polishing and modification), resist formation process, exposure process and removal process, heat treatment process, cleaning process, and inspection process. This processing method may be performed at any stage of the back end of the line (BEOL), middle end of the line (MOL), or front end of the line (FEOL), and is preferably performed in the front end or middle process. [Example]

[0134] 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 construed as being limited by the following examples.

[0135] [Preparation of drug solution] Each of the components shown in Tables 1 and 2 was prepared and mixed in the proportions shown in Tables 1 and 2 to prepare each of the liquid medicines of the Examples and Comparative Examples. The contents of each component in each liquid medicine are as shown in the tables. The amount of quaternary ammonium compound was adjusted to achieve the pH shown in the table. Water constitutes the remainder other than the various components shown in the table. The various components shown in Tables 1 and 2 were all classified as semiconductor grade or equivalent high purity grade. In addition, the concentrations of the Ti metal component and the Co metal component in the chemical solution were appropriately adjusted to the values ​​in the table described below by adding these components to the chemical solution or by filtering the chemical solution.

[0136] <Ingredients> The components listed in the table below are described below.

[0137] (hydroxy acids) Citric acid Lactic acid ·Tartaric acid Glyceric acid Glycolic acid

[0138] (Quaternary ammonium compounds) TMAH: Tetramethylammonium hydroxide ETMAH: Ethyltrimethylammonium hydroxide DEDMAH: Diethyldimethylammonium hydroxide ·TEMAH: Triethylmethylammonium hydroxide TEAH: Tetraethylammonium hydroxide TBAH: Tetrabutylammonium hydroxide

[0139] (trialkylamine) Trimethylamine Diethylmethylamine Triethylamine Tributylamine

[0140] (Other ingredients) Xanthine Adenine Imidazole ·uric acid N-methyldiethanolamine Hydroxyamine N,N-Diethylhydroxyamine Ascorbic acid Pyrogallol PMDETA: N,N,N',N'',N''-pentamethyldiethylenetriamine DMAMP: 2-(dimethylamino)-2-methyl-1-propanol

[0141] (water) ·Ultra pure water

[0142] [evaluation] [Measurement of Ti and Co Contents] The Ti and Co contents in the chemical solution were measured under the following measurement conditions. The chemical solutions of each of the Examples and Comparative Examples were measured using an Agilent 8800 triple quadrupole ICP-MS (for semiconductor analysis, option #200).

[0143] (Measurement conditions) For the measurement of the chemical solutions in the examples and comparative examples, a quartz torch, a coaxial PFA (perfluoroalkoxyalkane) nebulizer (for self-suction), and a platinum interface cone were used. The measurement parameters under cool plasma conditions were as follows: RF (Radio Frequency) Output (W): 600 Carrier gas flow rate (L / min): 0.7 Make-up gas flow rate (L / min): 1 Sampling depth (mm): 18

[0144] [Etching ability (AlOx)] A commercially available silicon wafer (diameter: 12 inches) was prepared with an AlOx layer formed by the ALD method, and a 2 cm square chip was cut from the wafer to serve as the test piece. The thickness of the AlOx layer was 10 nm. The obtained test pieces were placed in a container filled with the chemical solutions of the Examples and Comparative Examples and stirred at 250 rpm at a treatment temperature of 50° C. for 10 seconds. The etching rate (unit: Å / min) was calculated by measuring the film thickness before and after treatment using ellipsometry (a spectroscopic ellipsometer, J.A. Woollam Japan Vase) and evaluated based on the following criteria: The average value of five points was used (measurement conditions, measurement range: 1.2–2.5 eV, measurement angle: 70°, 75°). (Evaluation criteria) A: AlOx etching rate is 100Å / min or more B: The etching rate of AlOx is 50 Å / min or more and less than 100 Å / min C: The etching rate of AlOx is 10 Å / min or more and less than 50 Å / min D: The etching rate of AlOx is less than 10 Å / min

[0145] [Etching selectivity (AlOx / ZnOx)] A commercially available silicon wafer (diameter: 12 inches) was prepared as a substrate by forming a ZnOx layer by the PVD method, and a chip of 2 cm square was cut from the wafer to be used as a test piece. The thickness of the ZnOx layer was 10 nm. For ZnOx, the etching rate (unit: Å / min) was calculated using the same procedure as in the evaluation of the above [Etching ability (AlOx)], and the ratio of the etching rate of AlOx to the etching rate of ZnOx (etching rate of AlOx / etching rate of ZnOx) was determined and evaluated according to the following criteria. (Evaluation criteria) A: The etching rate ratio of AlOx / ZnOx is 50 or more B: The etching rate ratio of AlOx / ZnOx is 25 or more and less than 50 C: The etching rate ratio of AlOx / ZnOx is 10 or more and less than 25 D: The etching rate ratio of AlOx / ZnOx is less than 10

[0146] [Defect suppression] While rotating a wafer prepared in the same manner as in the evaluation of the ZnOx etching rate, 0.5 mL of each chemical solution was spin-discharged. The wafer was then spin-dried, and the number of defects on the wafer was counted using a wafer surface inspection device (SP-5, manufactured by KLA-Tencor Corporation) and evaluated based on the following criteria. (Evaluation criteria) A: There are almost no defects on the wafer (less than 1000 defects). B: Although it is within the acceptable level, there are many defects on the wafer (the number of defects is 1000 or more).

[0147] In the table, each description indicates the following. The "Content (mol / L)" column of "Hydroxy acids" indicates the content (mol / L) of hydroxy acids per 1 L of the chemical solution. The "Content (mass ppb)" column for "Trialkylamine" indicates the content (mass ppb) of trialkylamine relative to the total mass of the chemical solution. The "mass ppt" column for "Ti" or "Co" indicates the Ti content (mass ppt) or Co content (mass ppt) relative to the total mass of the chemical solution. The column "A / H" indicates the mass ratio of the trialkylamine content to the hydroxyacid content (trialkylamine content / hydroxyacid content). The column "T / A" indicates the mass ratio of the content of the specific metal component to the content of the trialkylamine (content of the specific metal component / content of the trialkylamine). The notation "En" in the figures in the "A / H" and "T / A" columns is "10 -n " n represents an integer of 1 or more. Specifically, "1.6E-05" in the "A / H" column in Example 1 means "1.6×10 -5 " indicates. The notation "E+n" in the "Content" value in the "Other compounds" column means "10 n " n represents an integer of 1 or more. Specifically, in Example 28, "2.0E+03" in the "Content" column of the "Other compounds" column means "2.0 × 10 3 " indicates.

[0148] [Table 1]

[0149] [Table 2]

[0150] From the results in Tables 1 and 2, it was confirmed that the chemical solution had excellent etching ability for Al oxide on the substrate, and also had excellent etching selectivity between Al oxide and the specific metal oxide. It was confirmed that the etching ability was better when the trialkylamine content was 100 mass ppt to 200 mass ppm relative to the total mass of the chemical solution, and that the etching ability for Al oxide and defect suppression ability were better when the trialkylamine content was 100 mass ppt to 100 mass ppm relative to the total mass of the chemical solution (comparison between Example 1 and Examples 21 to 24). Furthermore, from a similar comparison, it was confirmed that the mass ratio of the trialkylamine content to the hydroxy acids content (trialkylamine content / hydroxy acids content) was 1.0×10 -8 It has been confirmed that the etching ability is superior when the mass ratio is 1.0×10 -8 It was confirmed that when the ratio is 0.01 or less, the etching ability for Al oxide and the defect suppression ability are superior. It was confirmed that when the content of the specific metal component is 0.1 mass ppt to 0.1 mass ppm relative to the total mass of the chemical solution, the defect suppression property is more excellent (comparison of Example 1, etc. and Examples 25 to 27). Furthermore, from the same comparison, it was confirmed that the mass ratio of the content of the specific metal component to the content of trialkylamine (content of specific metal component / content of trialkylamine) is 1.0 × 10 -8 It has been confirmed that the etching ability is superior when the mass ratio is 1.0×10 -6 It was confirmed that when the ratio was 0.1 or less, the defect suppression was superior (comparison of Example 1 and Examples 21 to 27). It was confirmed that when the hydroxy acids contained at least one selected from the group consisting of citric acid, lactic acid, tartaric acid, glyceric acid, and salts thereof, the etching selectivity was superior (comparison of Examples 1 to 5). It was confirmed that when the content of hydroxy acids is 0.001 to 0.20 mol / L per 1 L of the chemical solution, the etching ability is better, and when the content of hydroxy acids is 0.01 to 0.20 mol / L per 1 L of the chemical solution, the etching selectivity is better (comparison between Example 1 and Examples 13 to 17). It was confirmed that the effects of the present invention are better when the pH of the drug solution is 7.5 to 14.0, and that the effects of the present invention are even better when the pH of the drug solution is 11.0 to 13.0 (comparison between Example 1 and Examples 18 to 20).

[0151] A chemical solution was prepared in the same manner as in Example 19, except that trimethylamine was changed to a mixture of triethylamine and diethylmethylamine (mass ratio 6:4). The obtained chemical solution was evaluated in the same manner as in Example 19, and the same results as in Example 19 were obtained, except that the etching ability changed from C to B.

[0152] A drug solution was prepared in the same manner as in Example 2, except that lactic acid was changed to serine (hydroxyamino acid). The obtained drug solution was evaluated in the same manner as in Example 2, and the same results as in Example 2 were obtained.< / ph>

Claims

1. at least one hydroxy acid selected from the group consisting of hydroxy acids and salts thereof, a quaternary ammonium compound, a trialkylamine, and water; An alkaline chemical solution.

2. The chemical solution according to claim 1, wherein the content of the trialkylamine is 100 ppt by mass to 200 ppm by mass relative to the total mass of the chemical solution.

3. The chemical solution according to claim 1 or 2, wherein the content of the trialkylamine is 100 ppt by mass to 100 ppm by mass relative to the total mass of the chemical solution.

4. The mass ratio of the content of the trialkylamine to the content of the hydroxy acids is 1.0 × 10 －８ The drug solution according to any one of claims 1 to 3, wherein the pH is 0.1 or less.

5. The mass ratio of the content of the trialkylamine to the content of the hydroxy acids is 1.0 × 10 －８ The drug solution according to any one of claims 1 to 4, wherein the pH is 0.01 or less.

6. The chemical solution according to any one of claims 1 to 5, further comprising at least one metal component selected from the group consisting of Co and Ti.

7. The chemical solution according to claim 6, wherein the content of the metal component is 0.1 mass ppt to 0.1 mass ppm relative to the total mass of the chemical solution.

8. The mass ratio of the content of the metal component to the content of the trialkylamine is 1.0 × 10 －８ The drug solution according to claim 6 or 7, wherein the pH is 1.0 or less.

9. The mass ratio of the content of the metal component to the content of the trialkylamine is 1.0 × 10 －６ The drug solution according to any one of claims 6 to 8, wherein the pH is 0.1 or less.

10. The medicinal solution according to any one of claims 1 to 9, wherein the hydroxy acids include at least one selected from the group consisting of citric acid, lactic acid, tartaric acid, glyceric acid, and salts thereof.

11. The chemical solution according to any one of claims 1 to 10, wherein the content of the hydroxy acids per 1 L of the chemical solution is 0.01 to 0.20 mol / L.

12. The drug solution according to any one of claims 1 to 11, having a pH of 7.5 to 14.

0.

13. The drug solution according to any one of claims 1 to 12, having a pH of 11.0 to 13.

0.

14. The chemical solution according to any one of claims 1 to 13, wherein the quaternary ammonium compound comprises at least one selected from the group consisting of tetramethylammonium hydroxide, ethyltrimethylammonium hydroxide, diethyldimethylammonium hydroxide, triethylmethylammonium hydroxide, tetraethylammonium hydroxide, and tetrabutylammonium hydroxide.

15. The chemical solution according to any one of claims 1 to 14, further comprising a nitrogen-containing aromatic ring compound.

16. The drug solution according to any one of claims 1 to 15, further comprising an alkanolamine.

17. The drug solution according to any one of claims 1 to 16, further comprising at least one selected from the group consisting of hydroxyamine, diethylhydroxyamine, ascorbic acid, pyrocatechol, and pyrogallol.

18. The chemical solution according to any one of claims 1 to 17, further comprising a tertiary amine compound other than the trialkylamine.

19. A substrate; a metal oxide containing Al and a metal oxide containing at least one selected from the group consisting of Zn, Hf, and In, disposed on the substrate; The chemical solution according to any one of claims 1 to 18, which is used for a treatment object having the following:

20. The chemical solution according to any one of claims 1 to 20, which is used as an etching solution.

21. A processing method comprising the step of contacting a substrate, a processing object having a metal oxide containing Al and a metal oxide containing at least one selected from the group consisting of Zn, Hf, and In, arranged on the substrate, with the chemical solution according to any one of claims 1 to 20.

22. The treatment method according to claim 21, wherein the temperature of the chemical solution is 40 to 80°C.

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