Chemical solution used for cleaning or etching a ruthenium-containing layer, and method for manufacturing a ruthenium wiring

Abstract

To provide a chemical solution used for cleaning or etching a ruthenium-containing layer, capable of obtaining a ruthenium-containing layer with reduced surface roughness while maintaining a good etching rate for ruthenium, and a manufacturing method of a ruthenium wiring using the chemical solution.SOLUTION: A chemical solution is used for cleaning or etching a ruthenium-containing layer containing orthoperiodic acid (A), a base component (B), and a compound (C) selected from the group consisting of a nitrogen-containing heterocyclic compound, an organic phosphonic acid, and an organic carboxylic acid.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a chemical solution used for cleaning or etching a ruthenium-containing layer, and a method for producing a ruthenium wiring. [Background technology]

[0002] In the front-end manufacturing process of semiconductor devices, there are two processes for forming metal wiring on the wafer surface: MOL (Middle of the Line) and BEOL (Back End of the Line). Plugs are formed in MOL, while metal wiring and vias are formed in BEOL. In recent years, advances in lithography technology have led to rapid progress in the miniaturization of patterns in the manufacturing of semiconductor devices and liquid crystal display devices. As wiring patterns become finer, it has become more difficult to ensure sufficient alignment margins, resulting in issues such as resistance fluctuations and deterioration of reliability. As a measure to ensure alignment margins, a method has been developed in which metal wiring is selectively etched (recessed) after chemical mechanical polishing (CMP), and this method is called FSAV (Fully Self Aligned Via) (for example, Patent Document 1). Copper, tungsten, cobalt, etc. have been used as wiring materials, but as patterns become finer, the use of ruthenium, which has lower resistance, is being considered. When applying FSAV to form ruthenium wiring, a chemical solution suitable for recess formation is required.

[0003] In addition, in the BEOL, the conventional dual damascene structure using copper as the metal wiring material has problems such as patterning variations and resistance increases approaching the limit, so a semi-damascene structure using ruthenium, a low-resistivity metal, has been proposed. When forming the semi-damascene structure, the ruthenium layer formed on the surface of the substrate is dry-etched. When dry-etching is performed, a reaction product between ruthenium and the etching gas (hereinafter, sometimes simply referred to as "ruthenium residue") is formed on the surface of the ruthenium layer and other exposed surface films. Therefore, a chemical solution capable of cleaning and removing the ruthenium residue formed by dry etching is also desired.

[0004] As a method for etching ruthenium, for example, an etching method using an etching solution containing orthoperiodic acid as an oxidizing agent and having a pH of 8 or higher has been proposed (Patent Document 2). However, when ruthenium is etched using the etching solution described in Patent Document 2, intergranular corrosion occurs, and it may be difficult to control roughness. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2019-220690 [Patent Document 2] Japanese Patent Publication No. 2020-087945 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made in view of the above circumstances, and has an object to provide a chemical solution used for cleaning or etching a ruthenium-containing layer, which can obtain a ruthenium-containing layer with reduced surface roughness while maintaining a good etching rate for ruthenium, and a method for manufacturing a ruthenium wiring using the chemical solution. [Means for solving the problem]

[0007] The present inventors have found that the above-mentioned problems can be solved by further blending a compound (C) selected from the group consisting of a nitrogen-containing heterocyclic compound, an organic phosphonic acid, and an organic carboxylic acid in a chemical solution containing orthoperiodic acid and a base component, and have completed the present invention.

[0008] The first aspect of the present invention is a method for producing a soluble ... a base component (B) (provided that the base component (B) does not fall under any of the compound (C), the pH buffer component (D), and the organic amine oxide (E)); a compound (C) selected from the group consisting of nitrogen-containing heterocyclic compounds, organic phosphonic acids, and organic carboxylic acids; The chemical solution used to clean or etch the ruthenium-containing layer includes:

[0009] A second aspect of the present invention is a method for manufacturing a semiconductor device, comprising the steps of: forming an insulating film having a trench on a substrate; forming a ruthenium-containing layer using a conductive material containing ruthenium so as to fill the trench; planarizing the surfaces of the ruthenium-containing layer and the insulating film; forming a recess by etching the planarized surface of the ruthenium-containing layer using the chemical solution according to the first aspect; The present invention relates to a method for manufacturing a ruthenium wiring, comprising the steps of: [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a chemical solution used for cleaning or etching a ruthenium-containing layer, which can obtain a ruthenium-containing layer with reduced surface roughness while maintaining a good etching rate for ruthenium, and a method for manufacturing a ruthenium wiring using the chemical solution. DETAILED DESCRIPTION OF THE INVENTION

[0011] <Chemical solution> The chemical solution contains orthoperiodic acid (A), a base component (B), and a compound (C) selected from the group consisting of nitrogen-containing heterocyclic compounds, organic phosphonic acids, and organic carboxylic acids. The chemical solution is used to clean or etch the ruthenium-containing layer. By using such a chemical solution, it is possible to obtain a ruthenium-containing layer with reduced surface roughness while maintaining a good etching rate for ruthenium.

[0012] (orthoperiodic acid (A)) Ruthenium combines with four oxygen atoms to form ruthenium tetroxide (RuO4). Orthoperiodic acid (A) (H5IO6) is an oxidizing agent that releases oxygen atoms to oxidize ruthenium. The redox potential of orthoperiodic acid (A) is high enough to oxidize ruthenium. Therefore, orthoperiodic acid (A) can efficiently oxidize, dissolve, and etch ruthenium.

[0013] The content of orthoperiodic acid (A) is, for example, 0.01 to 8 mass % relative to the total mass of the chemical solution, preferably 0.02 to 7 mass %, and more preferably 0.03 to 5 mass %. When the content of orthoperiodic acid is within the above range, the etching rate for ruthenium is further improved.

[0014] (Base component (B)) The base component (B) is a component that adjusts the pH of the chemical solution to a desired range. As the base component (B), either an organic base component or an inorganic base component can be used. Suitable examples of the organic base component include quaternary ammonium salts such as organic quaternary ammonium hydroxides; alkanolamines; and organic amines other than alkanolamines, such as primary amines, secondary amines, and tertiary amines. The base component (B) is a component that does not fall under any of the compounds (C), pH buffer components (D), and organic amine oxides (E) described below.

[0015] Examples of organic quaternary ammonium hydroxides include tetramethylammonium hydroxide, bis(2-hydroxyethyl)dimethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, methyltriethylammonium hydroxide, trimethyl(hydroxyethyl)ammonium hydroxide, and triethyl(hydroxyethyl)ammonium hydroxide.

[0016] Examples of alkanolamines include monoethanolamine, diethanolamine, monoisopropanolamine, diisopropanolamine, methylethanolamine, N-methylethanolamine, and aminoethylethanolamine.

[0017] Other organic amines include, for example, diazabicycloundecene.

[0018] Examples of inorganic basic compounds include inorganic compounds containing ammonia, alkali metals, or alkaline earth metals, and salts thereof. Specific examples of inorganic compounds containing alkali metals or alkaline earth metals and salts thereof include lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, and cesium hydroxide.

[0019] The base component (B) may be used alone or in combination of two kinds. The content of the base component (B) is preferably 0.01% by mass or more and 20% by mass or less, and more preferably 0.1% by mass or more and 10% by mass or less, based on the total mass of the chemical solution.

[0020] (Compound (C)) The compound (C) is selected from the group consisting of nitrogen-containing heterocyclic compounds, organic phosphonic acids, and organic carboxylic acids. Among these, nitrogen-containing heterocyclic compounds are more preferred from the viewpoint of significantly reducing the increase in roughness.

[0021] The nitrogen-containing heterocyclic compound is a compound containing a nitrogen-containing heterocycle. Examples of the nitrogen-containing heterocycle include a triazole ring, an imidazole ring, a pyridine ring, a phenanthroline ring, a tetrazole ring, a pyrazole ring, and a pyrimidine ring. The nitrogen-containing heterocyclic compound can be a compound consisting of any of these nitrogen-containing heterocycles, or a compound in which any of these nitrogen-containing heterocycles is bonded to one or more other rings.

[0022] The compounds containing a triazole ring include triazoles and benzotriazoles, such as 1,2,3-triazole, 1,2,4-triazole, 3-amino-1H-1,2,4-triazole, 1-acetyl-1H-1,2,3-triazolo[4,5-b]pyridine, 1H-1,2,3-triazolo[4,5-b]pyridine, 1,2,4-triazolo[4,3-a]pyridin-3(2H)-one, and 3H-1,2,3-triazolo[4,5-b]pyridin-3-ol. Examples of benzotriazoles include 1,2,3-benzotriazole, 5-methyl-1H-benzotriazole, 1-hydroxybenzotriazole, 1-dihydroxypropylbenzotriazole, 2,3-dicarboxypropylbenzotriazole, 4-hydroxybenzotriazole, 4-carboxyl-1H-benzotriazole, 4-carboxyl-1H-benzotriazole methyl ester, 4-carboxyl-1H-benzotriazole butyl ester, 4-carboxyl-1H-benzotriazole octyl ester, 5-hexylbenzotriazole, [1,2,3-benzotriazolyl-1-methyl][1,2,4-triazolyl-1-methyl][2-ethylhexyl]amine, tolyltriazole, naphthotriazole, bis[(1-benzotriazolyl)methyl]phosphonic acid, and 3-aminotriazole. Among these, 1,2,3-benzotriazole and 5-methyl-1H-benzotriazole are preferred.

[0023] Compounds containing an imidazole ring include imidazoles and biimidazoles. Examples of imidazoles include 2-methylimidazole, 2-ethylimidazole, 2-isopropylimidazole, 2-propylimidazole, 2-butylimidazole, 4-methylimidazole, 2,4-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, and 2-aminoimidazole. The biimidazoles include 2,2'-biimidazole.

[0024] Compounds containing a pyridine ring include pyridines and bipyridyls. Examples of pyridines include 1H-1,2,3-triazolo[4,5-b]pyridine, 1-acetyl-1H-1,2,3-triazolo[4,5-b]pyridine, 3-aminopyridine, 4-aminopyridine, 3-hydroxypyridine, 4-hydroxypyridine, 2-acetamidopyridine, 4-pyrrolidinopyridine, and 2-cyanopyridine. Examples of bipyridyls include 2,2'-bipyridyl, 2,2'-bipyridine-4,4'-dicarboxylic acid, 4,4'-dimethyl-2,2'-bipyridyl, 4,4'-di-tert-butyl-2,2'-bipyridyl, and 4,4-dinonyl-2,2-bipyridyl. Among these, bipyridyls are preferred, and 2,2'-bipyridyl and 2,2'-bipyridine-4,4'-dicarboxylic acid are more preferred, from the viewpoint of facilitating improvement in the storage stability of the drug solution.

[0025] An example of a compound containing a phenanthroline ring is 1,10-phenanthroline.

[0026] Examples of compounds containing a tetrazole ring include 1H-tetrazole, 5-amino-1H-tetrazole, 5-methyl-1H-tetrazole, 5-phenyl-1H-tetrazole, and 1-(2-diaminoethyl)-5-mercaptotetrazole.

[0027] Examples of compounds containing a pyrazole ring include 3,5-dimethylpyrazole, 3-amino-5-methylpyrazole, 4-methylpyrazole, and 3-amino-5-hydroxypyrazole.

[0028] Examples of compounds containing a pyrimidine ring include pyrimidine, 1,2,4-triazolo[1,5-a]pyrimidine, 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine, 1,3-diphenyl-pyrimidine-2,4,6-trione, 1,4,5,6-tetrahydropyrimidine, 2,4,5,6-tetraaminopyrimidine sulfate, 2,4,5-trihydroxypyrimidine, 2,4,6-triaminopyrimidine, 2,4,6-trichloropyrimidine, 2,4,6-trimethoxypyrimidine, and 2,4,6-triaminopyrimidine. Examples thereof include phenylpyrimidine, 2,4-diamino-6-hydroxylpyrimidine, 2,4-diaminopyrimidine, 2-acetamidopyrimidine, 2-aminopyrimidine, 2-methyl-5,7-diphenyl-(1,2,4)triazolo(1,5-a)pyrimidine, 2-methylsulfanyl-5,7-diphenyl-(1,2,4)triazolo(1,5-a)pyrimidine, 2-methylsulfanyl-5,7-diphenyl-4,7-dihydro-(1,2,4)triazolo(1,5-a)pyrimidine, and 4-aminopyrazolo[3,4-d]pyrimidine.

[0029] The organic phosphonic acid is a compound represented by the following formula (a1). R 1 -P(=O)(OH)2 (a1) (In formula (a1), R 1 is an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0030] In the organic phosphonic acid represented by formula (a1), R 1 The aliphatic hydrocarbon group is preferably an aliphatic hydrocarbon group having 1 to 18 carbon atoms. The aliphatic hydrocarbon group may be linear or branched. In the organic phosphonic acid represented by formula (a1), R 1The aromatic hydrocarbon group is preferably an aromatic hydrocarbon group having 6 to 12 carbon atoms.

[0031] R 1 Suitable examples of the linear or branched aliphatic hydrocarbon group having from 1 to 18 carbon atoms as the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a neopentyl group, a cyclopentyl group, an n-hexyl group, a 2-ethylhexyl group, a cyclohexyl group, an n-heptyl group, a cycloheptyl group, an n-octyl group, a cyclooctyl group, an n-nonyl group, an n-decyl group, an n-undecyl group, an n-dodecyl group, and an n-octadecyl group.

[0032] R 1 Suitable examples of the aromatic hydrocarbon group having 6 to 12 carbon atoms as the alkyl group include a phenyl group, a 2-methylphenyl group, a 3-methylphenyl group, a 4-methylphenyl group, a 2-ethylphenyl group, a 3-ethylphenyl group, a 4-ethylphenyl group, an α-naphthyl group, a β-naphthyl group, and a biphenylyl group.

[0033] Of the aliphatic hydrocarbon groups and aromatic hydrocarbon groups explained above, n-butyl group, n-hexyl group, cyclohexyl group, n-octyl group, n-decyl group, and phenyl group are preferred.

[0034] Specific examples of the phosphonic acid represented by formula (a1) include n-butylphosphonic acid, n-hexylphosphonic acid, n-octylphosphonic acid, n-decylphosphonic acid, and n-octadecylphosphonic acid.

[0035] The organic carboxylic acid is a carboxylic acid having a saturated or unsaturated aliphatic group, and examples of the organic carboxylic acid include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, n-heptanoic acid, lauric acid, palmitic acid, stearic acid, acrylic acid, oleic acid, oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, succinic acid, adipic acid, citric acid, and tartaric acid.

[0036] The compound (C) may be used alone or in combination of two kinds. The content of the compound (C) is preferably 0.001% by mass or more and 10% by mass or less, and more preferably 0.001% by mass or more and 1% by mass or less, based on the total mass of the chemical solution.

[0037] (Other ingredients) The chemical solution may contain other components in addition to the above components, such as water, a pH buffer component (D), an organic amine oxide (E), and a surfactant, as long as the effects of the present invention are not impaired.

[0038] The chemical solution preferably contains water as a solvent, and the water is preferably purified water such as distilled water, ion-exchanged water, or ultrapure water, and more preferably ultrapure water commonly used in semiconductor manufacturing. The water content is not particularly limited, but is preferably 50% by mass or more, more preferably 80% by mass or more, based on the total mass of the chemical solution. The upper limit is not particularly limited, but is preferably less than 99.95% by mass, more preferably 99.9% by mass or less.

[0039] The pH buffer component (D) is a component that has the effect of suppressing a sudden change in the pH of the chemical solution. By including the pH buffer component (D) in the chemical solution, the pH of the chemical solution can be prevented from shifting to the acidic side even when the chemical solution is stirred for a long period of time, and fluctuations in the etching rate for ruthenium can be suppressed.

[0040] Examples of the pH buffer component (D) include citrate, acetate, phosphate, borate, carbonate, bicarbonate, and sulfate.

[0041] Specific examples of the pH buffer component (D) include triammonium citrate, ammonium phosphate, ammonium acetate, ammonium sulfate, and ammonium hydrogen carbonate.

[0042] The pH buffer component (D) may be used alone or in combination of two kinds. The content of the pH buffer component (D) is preferably 0.001% by mass or more and 1% by mass or less, more preferably 0.01% by mass or more and 0.8% by mass or less, based on the total mass of the drug solution.

[0043] By including the organic amine oxide (E) in the chemical solution, it is expected that the wettability of the chemical solution to the ruthenium-containing layer will be improved. Examples of the organic amine oxide (E) include oxides of aliphatic amines and oxides of cyclic amines. Examples of the oxides of aliphatic amines include trimethylamine N-oxide and triethylamine N-oxide. Examples of the oxides of cyclic amines include N-methylmorpholine N-oxide, pyridine N-oxide, 2,6-dimethylpyridine N-oxide, and 4-(dimethylamino)pyridine N-oxide.

[0044] The organic amine oxide (E) may be used alone or in combination of two kinds. The content of the organic amine oxide (E) is preferably 0.01% by mass or more, more preferably 0.05% by mass or more and 20% by mass or less, based on the total mass of the chemical solution.

[0045] The pH of the chemical solution is not particularly limited, but from the viewpoint of maintaining a good etching rate, it is preferably 8 or more and 12 or less, and more preferably 8 or more and 11 or less at 20°C.

[0046] (Method of manufacturing chemical solution) The chemical solution can be obtained by mixing the above-mentioned orthoperiodic acid (A), the base component (B), the compound (C), and, if necessary, other components, by a known method.

[0047] (Application) The chemical solution is used to clean or etch a ruthenium-containing layer. More specifically, the chemical solution is used to clean or etch a ruthenium-containing layer on a substrate as an object to be processed in the manufacture of semiconductor devices.

[0048] (Object to be treated) An example of an object to be cleaned or etched is a substrate after dry etching or chemical mechanical polishing of a ruthenium-containing layer located at the top surface of the substrate.

[0049] The substrate to be subjected to the dry etching or chemical mechanical polishing has a ruthenium-containing layer as its outermost layer. The method for forming the ruthenium-containing layer on the substrate is not particularly limited, and known methods can be used, such as physical vapor deposition (PVD) methods such as sputtering, chemical vapor deposition (CVD) methods, and atomic layer deposition (ALD) methods. The process of performing dry etching or chemical mechanical polishing on the substrate is not particularly limited, but preferably includes a process of using ruthenium as the metal wiring material and forming a metal wiring pattern on the substrate by a semi-damascene method or an FSAV method, a process of forming MOL contact wiring, and a process of forming a buried power rail.

[0050] (Cleaning process, etching process) To perform cleaning or etching with a chemical solution, the ruthenium-containing layer of the workpiece is brought into contact with the chemical solution. The method for bringing the ruthenium-containing layer of the workpiece into contact with the chemical solution is not particularly limited, and any known method can be used. Examples of such methods include, but are not limited to, a spray method, an immersion method, and a puddle method. In the spray method, for example, the object to be treated is transported or rotated in a predetermined direction, and the chemical solution is sprayed toward the transported or rotated object to bring the chemical solution into contact with the object to be treated. In the immersion method, the object to be treated is immersed in the chemical solution to bring the object into contact with the chemical solution. In the puddle method, the chemical solution is poured onto the object to be treated, and the object to be treated is brought into contact with the chemical solution. These treatment methods can be appropriately selected depending on the structure, material, etc. of the object to be treated. In the case of the spray method or the puddle method, the amount of the chemical solution supplied to the object to be treated may be an amount that sufficiently wets the surface of the object to be treated with the chemical solution.

[0051] A specific example of the cleaning treatment is cleaning of ruthenium residues formed on the surface of a ruthenium layer after dry etching of the ruthenium layer when forming a ruthenium-containing wiring by a semi-damascene method. A specific example of the etching process is a recess etching process for a ruthenium-containing wiring disposed on a substrate when forming a ruthenium-containing wiring by the FSAV method. The "recess etching process" refers to a process for forming a recess in the portion of the substrate where the ruthenium-containing wiring is disposed by etching the ruthenium-containing wiring disposed on the substrate (manufacturing a ruthenium-containing wiring having a recess).

[0052] The treatment temperature is not particularly limited, but is preferably from 15° C. to 85° C., and more preferably from 20° C. to 70° C. The cleaning treatment time is not particularly limited, but is preferably from 30 seconds to 30 minutes, and more preferably from 1 minute to 10 minutes.

[0053] <Ruthenium Wiring Manufacturing Method> The method for manufacturing ruthenium wiring includes the steps of forming an insulating film having a trench on a substrate; forming a ruthenium-containing layer using a conductive material containing ruthenium so as to fill the trench; planarizing the surfaces of the ruthenium-containing layer and the insulating film; and etching the planarized surface of the ruthenium-containing layer using the chemical solution to form a recess. The method for manufacturing ruthenium wiring is a method for manufacturing ruthenium wiring to which the above-mentioned FSAV is applied.

[0054] (Step of forming an insulating film having a trench on a substrate) The substrate may be, for example, a semiconductor substrate having one or more semiconductor processing layers formed thereon. The insulating film may be, for example, an oxide film or a low-k layer. The insulating film may be formed of, for example, SiOCH, doped silicon dioxide, spin-on polymers (including organic and silicon-based polymers), porous oxide, etc. The trench may be formed by known etching methods, etc.

[0055] (Step of forming a ruthenium-containing layer) A ruthenium-containing layer is formed using a conductive material containing ruthenium so as to fill the trench. It is preferable to form the ruthenium-containing layer after providing a barrier layer or a liner layer on the surface of the insulating film and the trench. The method for forming the ruthenium-containing layer is not particularly limited, and known film formation methods such as CVD can be used. The barrier layer or liner layer can be formed from, for example, titanium nitride (TiN).

[0056] (flattening process) The ruthenium-containing layer and the insulating film are polished by chemical mechanical polishing or the like until the surface of the insulating film is exposed, thereby flattening each surface.

[0057] (Recess formation process) The planarized surface of the ruthenium-containing layer is etched using the aforementioned chemical solution to form a recess of a desired depth. The depth of the recess is not particularly limited, but can be, for example, 1 to 20 nm. This allows the ruthenium-containing layer to form a ruthenium wiring. [Example]

[0058] The present invention will be described in more detail below based on examples and comparative examples, but the present invention is not limited to the following examples.

[0059] [Examples 1 to 23 and Comparative Example 1] (Preparation of drug solution) Orthoperiodic acid (A), the following compound (C), the following pH buffer component (D), and the following organic amine oxide (E) were uniformly mixed in water in the amounts shown in Table 1 below, and the following base component (B) was further added to adjust the pH to 9 to 9.5 to prepare the chemical solutions of Examples 1 to 23 and Comparative Example 1. As the base component (B), the following B1 was used. B1: Ammonia As the compound (C), the following compounds C1 to C8 were used. C1: 1,2,3-benzotriazole C2: 5-methyl-1H-benzotriazole C3: 2,2'-bipyridyl C4: 2,2'-bipyridine-4,4'-dicarboxylic acid C5: 1,2,4-triazole C6: n-butylphosphonic acid C7: n-octylphosphonic acid C8: n-heptanoic acid As the pH buffer component (D), the following D1 to D3 were used. D1: Triammonium citrate D2: Ammonium acetate D3: Ammonium sulfate As the organic amine oxide (E), the following E1 was used. E1: N-methylmorpholine N-oxide

[0060] (Preparation of test substrate) A CVD-Ru substrate (Ru film thickness: 30 nm) formed by CVD was cut into a 2 cm x 2 cm square to prepare a test substrate.

[0061] (Etching rate measurement) The chemical solutions of Examples 1 to 23 and Comparative Example 1 were placed in a beaker, and each test substrate was immersed in each chemical solution, and chemical treatment was carried out for 5 minutes at 23° C. while stirring each chemical solution at 300 rpm. After the chemical treatment, each substrate was washed with water and dried under a nitrogen stream. The Ru film thickness of the test substrate after the chemical treatment was measured by X-ray fluorescence analysis. The Ru film thickness was also measured for the test substrate before the chemical treatment. The Ru etching rate (Å / min) was calculated from the Ru film thickness before and after the chemical treatment. The results are shown in Table 1 as "ER."

[0062] (Measurement of increase in roughness) The chemical solutions of Examples 1 to 23 and Comparative Example 1 were placed in a beaker, and each test substrate was immersed in each chemical solution. While stirring the chemical solution at 300 rpm, chemical treatment was performed at 23°C. The treatment time for each chemical solution was set based on the etching rate of each chemical solution obtained in the etching rate measurement described above, so that the etching depth of the Ru film would be 10 nm. After the chemical treatment, each substrate was washed with water and dried in a nitrogen stream. The surface of the test substrate before and after the chemical treatment was observed using an AFM (Atomic Force Microscope: Dimension Icon manufactured by Bruker) (measurement area: 2 μm × 2 μm), and the root mean square roughness (surface roughness) Rq (nm) per 1 μm square was determined. The increase in roughness due to the chemical treatment of the test substrate was calculated using the following formula and evaluated according to the following criteria. This is shown in Table 1 as the "roughness increase." Roughness increase (X) = Rq (nm) after chemical treatment - Rq (nm) before chemical treatment Evaluation criteria A:X≦0.5nm B: 0.5 nm <X≦1.0nm C: 1.0 nm <X

[0063] (Measurement of rate fluctuations due to stirring) The chemical solutions of Examples 1 to 23 and Comparative Example 1 were placed in a beaker, and each chemical solution was stirred at 300 rpm for 3 hours at 23° C. The pH of the chemical solution was measured before and after stirring. Each test substrate was immersed in each of the stirred chemical solutions and treated with the chemical solution at 23°C for 5 minutes while stirring the solution at 300 rpm. After the chemical treatment, each substrate was washed with water and dried under a nitrogen stream. The Ru film thickness of the test substrate after the chemical treatment was measured by fluorescent X-ray analysis. The Ru film thickness was also determined for the test substrate before the chemical treatment. The Ru etching rate (Å / min) was calculated from the Ru film thickness before and after the chemical treatment. The stability of each chemical solution was evaluated according to the following criteria, which are shown in Table 1 as "agitation rate fluctuation." A: The etching rate fluctuation is less than 10%. B: The variation in etching rate is 10% or more and less than 20%. C: The etching rate fluctuates by 20% or more.

[0064] (Shelf life measurement) The chemical solutions of Examples 1 to 23 and Comparative Example 1 were placed in 100 ml PFA bottles and left to stand at room temperature for 30 days, after which the chemical solutions were placed in beakers and each test substrate was immersed in each chemical solution, and chemical treatment was carried out for 5 minutes at 23° C. while stirring each chemical solution at 300 rpm. After the chemical treatment, each substrate was washed with water and dried in a nitrogen stream. The Ru film thickness of the test substrate after the chemical treatment was measured by fluorescent X-ray analysis. The Ru film thickness was also measured for the test substrate before the chemical treatment. The Ru etching rate (Å / min) was calculated from the Ru film thickness before and after the chemical treatment. The stability of each drug solution was evaluated according to the following criteria, which are shown in Table 1 as "Shelf life." A: The etching rate fluctuation is less than 10%. B: The variation in etching rate is 10% or more and less than 20%. C: The etching rate fluctuates by 20% or more.

[0065] [Table 1]

[0066] It can be seen from Table 1 that the chemical solutions of Examples 1 to 8 containing compound (C) suppressed the increase in roughness compared to the chemical solution of Comparative Example 1 not containing compound (C). Furthermore, the chemical solutions of Examples 1 to 8 also had good etching rates. Furthermore, as shown in Examples 9 to 18, when the pH buffer component (D) is added, rate fluctuations during stirring are suppressed.

Claims

1. Orthoperiodic acid (A), a base component (B) (provided that the base component (B) does not fall under any of the nitrogen-containing heterocyclic compound (C), the pH buffer component (D), and the organic amine oxide (E)); a nitrogen-containing heterocyclic compound (C); A chemical solution used to clean or etch a ruthenium-containing layer, comprising: the nitrogen-containing heterocyclic compound (C) is a compound containing a pyridine ring in its structure, The compound containing a pyridine ring is 1H-1,2,3-triazolo[4,5-b]pyridine, 1-acetyl-1H-1,2,3-triazolo[4,5-b]pyridine, 3-aminopyridine, 4-aminopyridine, 3-hydroxypyridine, 4-hydroxypyridine, 2-acetamidopyridine, 4-pyrrolidinopyridine, 2-cyanopyridine, 2,2'-bipyridyl, 2,2'-bipyridine-4,4'-dicarboxylic acid, 4,4'-dimethyl-2,2'-bipyridyl, 4,4'-di-tert-butyl-2,2'-bipyridyl, or 4,4-dinonyl-2,2-bipyridyl.

2. The chemical solution according to claim 1 , wherein the pH of the chemical solution is 8 or more and 10 or less.

3. The drug solution according to claim 1 or 2, further comprising a pH buffer component (D).

4. 4. The drug solution according to claim 3, wherein the pH buffer component (D) is at least one selected from the group consisting of citrates, acetates, phosphates, borates, carbonates, bicarbonates, and sulfates.

5. The chemical solution according to any one of claims 1 to 4, further comprising an organic amine oxide (E).

6. forming an insulating film having a trench on a substrate; forming a ruthenium-containing layer using a conductive material containing ruthenium so as to fill the trench; planarizing the surfaces of the ruthenium-containing layer and the insulating film; forming a recess by etching the planarized surface of the ruthenium-containing layer using the chemical solution according to any one of claims 1 to 5; A method for producing a ruthenium wiring, comprising:

Images