Treatment liquid, method for treating semiconductor substrate, and method for manufacturing semiconductor device

Abstract

Provided are: a treatment liquid comprising (A) an oxidizing agent, (B) a compound capable of releasing a fluoride ion, (C) at least one selected from the group consisting of pyrimidine ring-containing compounds and salts thereof, imidazole ring-containing compounds and salts thereof, and tetrazole ring-containing compounds and salts thereof as a first anticorrosive, (D) a benzotriazole ring-containing compound or a salt thereof as a second anticorrosive, and water; a method for treating a semiconductor substrate using same; and a method for manufacturing a semiconductor device using same.

Description

Treatment liquid, method for treating semiconductor substrate, and method for manufacturing semiconductor device

[0001] The present invention relates to a processing liquid, a semiconductor substrate processing method, and a semiconductor device manufacturing method.

[0002] In the manufacturing process of semiconductor devices such as semiconductor elements, a dry etching process is usually employed when forming semiconductor integrated circuits. In this dry etching process, a titanium-based hard mask (HM) such as titanium nitride (TiN) is used as a protective film for the semiconductor substrate, and this must be removed. The semiconductor substrate to be processed contains metal wiring (e.g., tungsten, molybdenum, etc.).

[0003] Examples of such processing solutions include a processing solution containing a combination of sulfuric acid and hydrogen peroxide (SPM cleaning, etc.), a cleaning solution containing a combination of hydrogen peroxide and ammonium water (SC-1 cleaning, etc.), etc. Furthermore, as a technology related to such processing solutions, for example, Patent Document 1 describes a processing solution for semiconductor devices that contains a fluorine-containing compound and a water-soluble aromatic compound that has a benzene ring but no heterocyclic group, and has a pH of 5 or less.

[0004] International Publication No. 2018 / 061582

[0005] However, conventional cleaning solutions such as those described above have the problem of damaging metal wiring even if they can remove a titanium-based hard mask layer. In particular, when processing a semiconductor substrate having a layer containing tungsten atoms (tungsten atom-containing layer) or a layer containing molybdenum atoms (molybdenum atom-containing layer) as metal wiring, even if the titanium-based hard mask layer and titanium-based residues can be removed to some extent, there is a problem of damaging these layers. Therefore, there is a demand for a solution that can sufficiently remove the titanium-based mask and titanium-based residues while suppressing corrosion of the tungsten atom-containing layer and molybdenum atom-containing layer, but the reality is that there is still room for improvement.

[0006] The present invention has been made in view of the above circumstances, and has an object to provide a processing solution that is excellent in removing titanium-based masks and titanium-based residues and also has excellent corrosion prevention properties for tungsten atom-containing layers and molybdenum atom-containing layers, as well as a semiconductor substrate processing method and a semiconductor device manufacturing method using the same.

[0007] As a result of intensive research into achieving the above-mentioned object, the present inventors unexpectedly discovered that a treatment liquid containing (A) an oxidizing agent, (B) a compound capable of releasing fluoride ions, (C) at least one compound selected from the group consisting of pyrimidine ring-containing compounds and salts thereof, imidazole ring-containing compounds and salts thereof, and tetrazole ring-containing compounds and salts thereof as a first corrosion inhibitor, and (D) a benzotriazole ring-containing compound and salts thereof, and water as a second corrosion inhibitor, led to the completion of the present invention.

[0008] That is, the present invention is as follows.<1> A treatment solution containing (A) an oxidizing agent, (B) a compound capable of releasing fluoride ions, (C) at least one first corrosion inhibitor selected from the group consisting of a pyrimidine ring-containing compound and a salt thereof, an imidazole ring-containing compound and a salt thereof, and a tetrazole ring-containing compound and a salt thereof, (D) a second corrosion inhibitor selected from the group consisting of a benzotriazole ring-containing compound and a salt thereof, and water.<2> The treatment solution according to <1>, wherein the (C) first corrosion inhibitor is at least one selected from the group consisting of an alkylpyridinium salt, an alkylmethylimidazolium salt, and a triphenyltetrazolium salt. <3> The treatment solution according to <1> or <2>, wherein the (D) second corrosion inhibitor is at least one selected from the group consisting of 5-methyl-1H-benzotriazole, 4-carboxyl-1H-benzotriazole, 5-carboxyl-1H-benzotriazole, 5-nitro-1H-benzotriazole, 5-chloro-1H-benzotriazole, 5-bromo-1H-benzotriazole, and 5-amino-1H-benzotriazole. <4> The treatment solution according to <1> or <2>, wherein the (A) oxidizing agent is contained in an amount of 0.0001 to 0.1% by mass. <5> The treatment solution according to <1> or <2>, wherein the (B) compound capable of releasing fluoride ions is contained in an amount of 0.0001 to 1% by mass. <6> The treatment solution according to <1> or <2>, wherein the (C) first corrosion inhibitor is contained in an amount of 0.0001 to 5% by mass. <7> The treatment liquid according to <1> or <2>, wherein the content of the (D) second corrosion inhibitor is 0.0001 to 10 mass %. <8> The treatment liquid according to <1> or <2>, wherein the mass ratio (D / C) of the content of the (D) second corrosion inhibitor to the content of the (C) first corrosion inhibitor is 0.1 to 2000. <9> The treatment liquid according to <1> or <2>, wherein the treatment liquid is used for treating a semiconductor substrate including a substrate, a layer containing tungsten atoms and / or a layer containing molybdenum atoms, and a layer containing titanium atoms.<10> A method for treating a semiconductor substrate, the method comprising the step of treating a semiconductor substrate including a substrate, a layer containing tungsten atoms and / or a layer containing molybdenum atoms, and a layer containing titanium atoms, with the treatment liquid according to <1> or <2>. <11> A method for manufacturing a semiconductor device, the method comprising the step of treating a semiconductor substrate including a substrate, a layer containing tungsten atoms and / or a layer containing molybdenum atoms, and a layer containing titanium atoms, with the treatment liquid according to <1> or <2>.

[0009] According to the present invention, it is possible to provide a processing solution that is excellent in removing titanium-based masks and titanium-based residues and also has excellent corrosion protection for tungsten atom-containing layers and molybdenum atom-containing layers, as well as a semiconductor substrate processing method and a semiconductor device manufacturing method that use the same.

[0010] FIG. 1 is a cross-sectional view of an example of a semiconductor substrate for which the treatment liquid according to this embodiment can be used.

[0011] Hereinafter, a mode for carrying out the present invention (hereinafter simply referred to as "the present embodiment") will be described in detail. The following present embodiment is an example for explaining the present invention, and is not intended to limit the present invention to the following content. The present invention can be practiced by appropriately modifying it within the scope of its gist. Furthermore, unless otherwise specified, the configurations and parameters disclosed in this specification can be arbitrarily combined. Furthermore, unless otherwise specified, the upper and lower limits of the values ​​disclosed in this specification can be arbitrarily combined.

[0012] In the drawings, the same elements are given the same reference numerals, and redundant explanations will be omitted. Furthermore, unless otherwise specified, the positional relationships such as up, down, left, and right are based on the positional relationships shown in the drawings. Furthermore, the dimensional ratios of the drawings are not limited to the ratios shown in the drawings.

[0013] <Processing liquid>

[0014] The treatment solution according to this embodiment is a treatment solution containing (A) an oxidizing agent, (B) a compound capable of releasing fluoride ions, (C) at least one first anticorrosive selected from the group consisting of pyrimidine ring-containing compounds and salts thereof, imidazole ring-containing compounds and salts thereof, and tetrazole ring-containing compounds and salts thereof, (D) a second anticorrosive selected from the group consisting of benzotriazole ring-containing compounds and salts thereof, and water. According to the treatment solution according to this embodiment, by combining at least the above-described components (A) to (D), it is possible to remove titanium-based hard masks and titanium-based residues while suppressing corrosion (damage) to tungsten atom-containing layers and molybdenum atom-containing layers. In this regard, while it has been particularly difficult to suppress corrosion of molybdenum atom-containing layers (e.g., molybdenum-based metal layers) in some prior art techniques, this embodiment can suppress damage even to such molybdenum atom-containing layers. Furthermore, it is expected that damage to low-k materials and the like can also be suppressed. For example, in some cases, a low-dielectric-constant film such as a low-k film may also be formed on a substrate on which the above-described tungsten atom-containing layer and / or molybdenum atom-containing layer is wired. The treatment solution according to this embodiment is expected to remove the titanium-based hard mask and titanium-based residues while suppressing damage to the low-k film.

[0015] The reason why the treatment solution according to this embodiment achieves the above-described effects is unclear, but is thought to be as follows. It is believed that by combining the above-described components (A) to (D), the first anticorrosive acts as an anchor on the surface of the molybdenum atom-containing layer, and the second anticorrosive is adsorbed or coordinated thereto, thereby suppressing corrosion (damage) of the surface of the molybdenum atom-containing layer. Furthermore, it is believed that the effective action of the first anticorrosive on the tungsten atom-containing layer suppresses corrosion (damage) of the surface of the tungsten atom-containing layer. It is presumed that, due to this action, a treatment solution containing at least components (A) to (D) can remove titanium-based hard masks and titanium-based residues from a substrate while suppressing corrosion (damage) of the tungsten atom-containing layer and molybdenum atom-containing layer (however, the functions and effects of this embodiment are not limited to these). Each component will be described below.

[0016] ((A) Oxidizing Agent)

[0017] The treatment solution according to this embodiment contains (A) an oxidizing agent. It is believed that the treatment solution according to this embodiment can efficiently remove the titanium-based hard mask and titanium-based residues by interacting with the titanium atoms of the titanium-based hard mask and titanium-based residues (however, the functions and effects of this embodiment are not limited to these). Specific examples of the oxidizing agent include oxoacids that can donate protons.

[0018] Specific examples of oxoacids include halogen oxoacids (hypochlorous acid, chlorous acid, chloric acid, perchloric acid, hypobromous acid, bromous acid, bromic acid, perbromic acid, hypoiodous acid, iodous acid, iodic acid, periodic acid, etc.), silicic acid, nitrous acid (HNO ２ ), nitric acid, etc. The treatment liquid according to this embodiment may contain a salt of these oxo acids (for example, a sodium salt, a potassium salt, a calcium salt, a barium salt, an ammonium salt, a tetraalkylammonium salt, etc.).

[0019] Preferred examples of halogen oxoacids include hypoiodous acid, iodous acid, iodic acid, and periodic acid.

[0020] From the viewpoint of a balance between the removability of the titanium-based hard mask or titanium-based residue and the corrosion prevention properties of the tungsten atom-containing layer and the molybdenum atom-containing layer, among the above-mentioned oxidizing agents, halogen oxoacids are preferred, iodine oxoacids are more preferred, and iodic acid is even more preferred.

[0021] The component (A) may be used alone or in combination of two or more types.

[0022] The content of component (A) in the treatment solution according to this embodiment is not particularly limited, but is preferably 0.0001 to 0.1 mass %. The lower limit of this content is more preferably 0.0005 mass % or more, even more preferably 0.0007 mass % or more, and even more preferably 0.001 mass % or more. The upper limit of this content is more preferably 0.05 mass % or less, even more preferably 0.008 mass % or less, and even more preferably 0.005 mass % or less. By setting the content of component (A) within this range, it is possible to further improve the balance between the removability of titanium-based hard masks and titanium-based residues and the corrosion resistance of the tungsten atom-containing layer and the molybdenum atom-containing layer.

[0023] ((B) Compound capable of releasing fluoride ions)

[0024] The treatment liquid according to this embodiment contains a compound capable of releasing fluoride ions. Component (B) may be any compound capable of releasing at least fluoride ions in the treatment liquid, and a suitable type may be selected as appropriate, taking into consideration the types of other components contained in the treatment liquid other than component (B), the structure and material of the substrate to be treated, and the like. Examples of compounds capable of releasing fluoride ions include fluorine-containing compounds.

[0025] Specific examples of the compound (B) capable of releasing fluoride ions include, but are not limited to, hydrogen fluoride, ammonium fluoride (ammonium fluoride, NH ４ F), tetraalkylammonium fluoride, hexafluorosilicic acid (HFSA), hexafluorophosphate (HPF ６ ), fluorotitanic acid (H ２ TiF６ ), tetrafluoroboric acid (HBF ４ ), triethanolamine hydrofluoride, etc. The tetraalkylammonium fluoride may, for example, be tetramethylammonium fluoride (TMAF).

[0026] Among the above, ammonium fluoride (ammonium fluoride, NH ４ F), tetraalkylammonium fluoride, hexafluorosilicic acid (HFSA), hexafluorophosphate (HPF ６ ), fluorotitanic acid (H ２ TiF ６ ), tetrafluoroboric acid (HBF ４ ) is preferable. These compounds may be salts. Furthermore, the component (B) is preferably a compound that does not contain metal ions. Furthermore, the component (B) is preferably a component other than the components (A), (C), and (D). Furthermore, the component (B) is preferably a compound that does not contain a nitrogen atom.

[0027] The component (B) may be used alone or in combination of two or more.

[0028] The content of component (B) in the treatment solution according to this embodiment is not particularly limited, but is preferably 0.0001 to 1 mass %. The lower limit of this content is more preferably 0.0005 mass % or more, even more preferably 0.001 mass % or more, and even more preferably 0.005 mass % or more. The upper limit of this content is more preferably 0.5 mass % or less, even more preferably 0.3 mass % or less, and even more preferably 0.1 mass % or less. By setting the content of component (B) within this range, it is possible to further improve the balance between the removability of titanium-based hard masks and titanium-based residues and the corrosion resistance of the tungsten atom-containing layer and the molybdenum atom-containing layer.

[0029] ((C) First Corrosion Inhibitor)

[0030] The treatment solution according to this embodiment contains, as a first anticorrosive agent (C) (sometimes abbreviated as "first anticorrosive agent"), at least one selected from the group consisting of pyrimidine ring-containing compounds and salts thereof, imidazole ring-containing compounds and salts thereof, and tetrazole ring-containing compounds and salts thereof. Examples of the salt include sodium salts, potassium salts, calcium salts, barium salts, ammonium salts, and tetraalkylammonium salts.

[0031] Examples of pyrimidine ring-containing compounds and salts thereof include pyrimidine, 4-methylpyrimidine, 1-dodecylpyrimidine, 1-dodecylpyridinium chloride (DDPy), 1-dodecylpyridinium bromide, 1-dodecylpyridinium iodide, 2-amino-4-methylpyrimidine (2A4mP), 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, and 2,4,6-triaminopyrimidine. , 2,4,6-trichloropyrimidine, 2,4,6-trimethoxypyrimidine, 2,4,6-triphenylpyrimidine, 2,4-diamino-6-hydroxypyrimidine, 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, and salts thereof.

[0032] Among the pyrimidine ring-containing compounds and salts thereof, at least one selected from the group consisting of pyrimidine, alkylpyrimidines, and alkylpyridinium salts, and aminoalkylpyrimidines and aminoalkylpyridinium salts is preferred, and at least one selected from the group consisting of alkylpyridinium salts and aminoalkylpyrimidines is more preferred.

[0033] A specific example of the alkylpyrimidine is preferably 1-dodecylpyrimidine, etc. Specific examples of the alkylpyridinium salt are preferably 1-dodecylpyridinium chloride (DDPy), 1-dodecylpyridinium bromide, 1-dodecylpyridinium iodide, etc. A specific example of the aminoalkylpyrimidine is preferably 2-amino-4-methylpyrimidine (2A4mP), etc.

[0034] Examples of the imidazole ring-containing compound and salts thereof include at least one selected from the group consisting of imidazoles such as 2-methylimidazole, 2-ethylimidazole, 2-isopropylimidazole, 2-propylimidazole, 2-butylimidazole, 4-methylimidazole, 2,4-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 2-aminoimidazole, benzimidazole, 1-hexadecyl-3-methylimidazole, 1-hexadecyl-3-methylimidazolium chloride (HDMI), 1-hexadecyl-3-methylimidazolium bromide, and 1-hexadecyl-3-methylimidazolium iodide; biimidazoles such as 2,2'-biimidazole; and salts thereof.

[0035] Among the imidazole ring-containing compounds and salts thereof, at least one selected from the group consisting of imidazole, alkylmethylimidazole, and alkylmethylimidazolium salt is preferred, and alkylmethylimidazolium salt is more preferred. Specific examples of alkylmethylimidazoles include 1-hexadecyl-3-methylimidazole, etc. Specific examples of alkylmethylimidazolium salts include 1-hexadecyl-3-methylimidazolium chloride (HDMI), 1-hexadecyl-3-methylimidazolium bromide, and 1-hexadecyl-3-methylimidazolium iodide, etc.

[0036] Examples of the tetrazole ring-containing compound and salts thereof include at least one selected from the group consisting of 1H-tetrazole, 5-amino-1H-tetrazole, 5-methyl-1H-tetrazole, 5-phenyl-1H-tetrazole, 1-(2-diaminoethyl)-5-mercaptotetrazole, triphenyltetrazole, 2,3,5-triphenyltetrazolium chloride (TpT-Cl), 2,3,5-triphenyltetrazolium bromide, 2,3,5-triphenyltetrazolium iodide, and salts thereof.

[0037] Among the tetrazole ring-containing compounds and salts thereof, at least one selected from the group consisting of triphenyltetrazole and triphenyltetrazolium salts is preferred, and triphenyltetrazolium salts are more preferred. Specific examples of triphenyltetrazolium salts include 2,3,5-triphenyltetrazolium chloride (TpT-Cl), 2,3,5-triphenyltetrazolium bromide, and 2,3,5-triphenyltetrazolium iodide.

[0038] The first corrosion inhibitor is more preferably at least one selected from the group consisting of alkylpyridinium salts, alkylmethylimidazolium salts, and triphenyltetrazolium salts, specific examples of which are described above.

[0039] The first corrosion inhibitor may be used alone or in combination of two or more kinds.

[0040] The content of component (C) in the treatment liquid according to this embodiment is not particularly limited, but is preferably 0.0001 to 5 mass% relative to the total mass of the treatment liquid. The lower limit of this content is more preferably 0.0003 mass% or more, even more preferably 0.005 mass% or more, and even more preferably 0.008 mass% or more. The upper limit of this content is more preferably 3 mass% or less, even more preferably 2 mass% or less, and even more preferably 1.5 mass% or less. By setting the content of component (C) within this range, it is possible to further improve the balance between the removability of titanium-based hard masks and titanium-based residues and the corrosion resistance of the tungsten atom-containing layer and the molybdenum atom-containing layer.

[0041] ((D) Second Corrosion Inhibitor)

[0042] The treatment solution according to this embodiment contains at least one compound selected from the group consisting of benzotriazole ring-containing compounds and salts thereof as a second corrosion inhibitor (D) (hereinafter sometimes abbreviated as "second corrosion inhibitor"). Examples of the salt include sodium salts, potassium salts, calcium salts, barium salts, ammonium salts, chloride salts, bromide salts, iodide salts, and tetraalkylammonium salts.

[0043] Examples of benzotriazole ring-containing compounds and salts thereof include 1,2,3-benzotriazole (BTA), 5-methyl-1H-benzotriazole (5M-BTA), 1-hydroxybenzotriazole, 1-hydroxypropylbenzotriazole, 2,3-dicarboxypropylbenzotriazole, 4-hydroxybenzotriazole, 4-carboxyl-1H-benzotriazole (BTA-4AC, also known as benzotriazole-4-carboxylic acid), 5-carboxyl-1H-benzotriazole (BTA-5CA, also known as benzotriazole-5-carboxylic acid), 5-nitro-1H-benzotriazole, 4 4-carboxyl-1H-benzotriazole methyl ester, 4-carboxyl-1H-benzotriazole butyl ester, 4-carboxyl-1H-benzotriazole octyl ester, 5-hexylbenzotriazole, 5-amino-1H-benzotriazole (5AM-BTA), [1,2,3-benzotriazolyl-1-methyl][1,2,4-triazolyl-1-methyl][2-ethylhexyl]amine, tolyltriazole, naphthotriazole, bis[(1-benzotriazolyl)methyl]phosphonic acid, 3-aminotriazole, and salts thereof.

[0044] Among the benzotriazole ring-containing compounds and salts thereof, at least one selected from the group consisting of 5-methyl-1H-benzotriazole (5M-BTA), 4-carboxyl-1H-benzotriazole (BTA-4AC, also known as benzotriazole-4-carboxylic acid), 5-carboxyl-1H-benzotriazole (BTA-5CA, also known as benzotriazole-5-carboxylic acid), 5-nitro-1H-benzotriazole, 5-chloro-1H-benzotriazole (5Cl-BTA), 5-bromo-1H-benzotriazole (5Br-BTA), and 5-amino-1H-benzotriazole (5AM-BTA) is preferred.

[0045] The second corrosion inhibitor may be used alone or in combination of two or more kinds.

[0046] The content of component (D) in the treatment solution according to this embodiment is not particularly limited, but is preferably 0.0001 to 10 mass% relative to the total mass of the treatment solution. The lower limit of this content is more preferably 0.0005 mass% or more, even more preferably 0.001 mass% or more, even more preferably 0.005 mass% or more, even more preferably 0.01 mass% or more, and even more preferably 0.05 mass% or more. The upper limit of this content is more preferably 6 mass% or less, even more preferably 5 mass% or less, even more preferably 3 mass% or less, even more preferably 2 mass% or less, and even more preferably 1.5 mass% or less. By setting the content of component (D) within this range, the balance between the removability of titanium-based hard masks and titanium-based residues and the corrosion resistance of the tungsten atom-containing layer and the molybdenum atom-containing layer can be further improved.

[0047] In the treatment solution according to this embodiment, the mass ratio (D / C) of the content of the second anticorrosive (D) to the content of the first anticorrosive (C) is preferably 0.1 to 2000. The lower limit of this mass ratio is more preferably 0.15 or more, and even more preferably 0.2 or more. The upper limit of this mass ratio is more preferably 1500 or less, even more preferably 1300 or less, and even more preferably 1100 or less. By setting this mass ratio within this range, the balance between the removability of the titanium-based hard mask and titanium-based residue and the corrosion resistance of the tungsten atom-containing layer and the molybdenum atom-containing layer can be further improved. The lower limit of the mass ratio (D / C) may be, for example, 0.3, 0.6, 1, 2, 4, or 6. The upper limit of the mass ratio (D / C) may be, for example, 600, 500, 300, 200, or 100.

[0048] (Other corrosion inhibitors)

[0049] The treatment solution according to this embodiment may further contain other corrosion inhibitors in addition to the first and second corrosion inhibitors, as long as the effects and advantages of this embodiment are achieved. Examples of such other corrosion inhibitors include triazole ring-containing compounds, pyridine ring-containing compounds, phenanthroline ring-containing compounds, pyrazole ring-containing compounds, purine ring-containing compounds, and salts thereof. The formulation and selection of the other corrosion inhibitors can be determined as needed, taking into account the type of substrate to be treated and the metal wiring stacked thereon. In this embodiment, sufficient corrosion resistance can be achieved without the inclusion of such other corrosion inhibitors.

[0050] Examples of the triazole ring-containing compound include 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.

[0051] Examples of the pyridine ring-containing compound include pyridines such as 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, 2,6-pyridinecarboxylic acid, and 2,4,6-trimethylpyridine; and bipyridyls such as 2,2'-bipyridyl, 4,4'-dimethyl-2,2'-bipyridyl, 4,4'-di-tert-butyl-2,2'-bipyridyl, 4,4'-dinonyl-2,2'-bipyridyl, 2,2'-bipyridine-6,6'-dicarboxylic acid, and 4,4'-dimethoxy-2,2'-bipyridyl.

[0052] An example of the phenanthroline ring-containing compound is 1,10-phenanthroline.

[0053] Examples of the pyrazole ring-containing compound include 3,5-dimethylpyrazole, 3-amino-5-methylpyrazole, 4-methylpyrazole, and 3-amino-5-hydroxypyrazole.

[0054] Examples of purine ring-containing compounds include adenine, guanine, hypoxanthine, xanthine, uric acid, and theophylline.

[0055] The above-mentioned anticorrosive agents may be used alone or in combination of two or more.

[0056] When the treatment liquid according to the present embodiment contains the first anticorrosive, the second anticorrosive, and other anticorrosives described above, the total content of these anticorrosives is not particularly limited, but is preferably 0.0001 to 20 mass% relative to the total mass of the treatment liquid.

[0057] The concentration of each component in the treatment solution according to this embodiment may be prepared in advance to the above-mentioned content, or may be distributed or supplied as a concentrated product, which may be diluted to the desired concentration when used.

[0058] ((E) Other ingredients)

[0059] The treatment solution according to this embodiment may further contain optional components other than the components described above, as long as the effects of this embodiment can be obtained. Such optional components can be appropriately selected in consideration of the composition of the treatment solution, the intended use, the material and configuration of the semiconductor substrate to be treated, and the like. Examples of such optional components include surfactants, pH adjusters, buffers, and the like.

[0060] (Surfactant)

[0061] The treatment liquid according to this embodiment may contain a surfactant for the purposes of preventing foaming, adjusting the wettability of the treatment liquid with respect to the substrate, etc. Examples of the surfactant include nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants.

[0062] Examples of nonionic surfactants include polyalkylene oxide alkyl phenyl ether surfactants, polyalkylene oxide alkyl ether surfactants, block polymer surfactants consisting of polyethylene oxide and polypropylene oxide, polyoxyalkylene distyrene-substituted phenyl ether surfactants, polyalkylene tribenzyl phenyl ether surfactants, and acetylene polyalkylene oxide surfactants.

[0063] These surfactants may be commercially available products, etc. One surfactant may be used alone, or two or more surfactants may be used in combination.

[0064] When the treatment liquid according to this embodiment contains a surfactant, the content of the surfactant is not particularly limited, but is typically 0.0001 to 5 mass % relative to the total mass of the treatment liquid. When the content of the surfactant is within this range, the bubbles generated by the foaming agent tend to be dense.

[0065] The treatment liquid according to this embodiment may not contain one or more surfactants selected from the group consisting of nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants, and may not contain one or more of the compounds exemplified above as these surfactants. The treatment liquid according to this embodiment may not contain a surfactant.

[0066] (pH adjuster)

[0067] The treatment liquid according to this embodiment may contain a pH adjuster. Examples of the pH adjuster include acidic compounds and basic compounds other than the above-mentioned components (A), (B), (C), and (D). The basic compound may be an organic basic compound or an inorganic basic compound. The treatment liquid according to this embodiment may not contain a pH adjuster. Examples of the pH adjuster include methanesulfonic acid (MSA), phosphoric acid (H ３ P.O. ４ , H ４ P ２ O ７ , H.P.O. ３ ), carboxylic acids, boric acid (H３ BO ３ , B(OH) ３ ), phosphorous acid (H ３ P.O. ３ ), carbonic acid (H ２ CO ３ ), orthocarbonate (H ４ CO ４ , C(OH) ４ CH ４ O ４ ), sulfuric acid, hydrochloric acid, etc. Carboxylic acids are acids having at least one carboxy group (—COOH). Preferred examples of carboxylic acids include monocarboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, and valeric acid; dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, and adipic acid; and tricarboxylic acids such as citric acid.

[0068] (Buffering agent)

[0069] The treatment liquid according to this embodiment may contain a buffering agent. The buffering agent is a compound that has the effect of suppressing changes in the pH of the treatment liquid. As the buffering agent, a compound having pH buffering ability can be used as appropriate.

[0070] The buffering agent may be used alone or in combination of two or more. When the treatment liquid according to this embodiment contains a buffering agent, the content of the buffering agent is not particularly limited, but is typically 0.001 to 10% by mass relative to the total mass of the treatment liquid. The treatment liquid according to this embodiment does not necessarily contain a buffering agent.

[0071] ((F)Wed)

[0072] The treatment liquid according to this embodiment contains water. Although the type of water is not particularly limited, it is preferable that the water has been subjected to distillation, ion exchange treatment, filtering, various adsorption treatments, or the like to remove or reduce metal ions, organic impurities, particle particles, and the like. Examples of the water that is preferable include pure water, ultrapure water, and deionized water.

[0073] The content of water is not particularly limited, but it is used as a solvent. As a solvent, it may be used in combination with an organic solvent described below. Water may be contained as the balance of the components described above and the components described below, and is typically 40 to 99.999% by mass relative to the total amount of the treatment liquid. The lower limit may be, for example, 80% by mass or more, 90% by mass or more, or 95% by mass or more. The upper limit may be, for example, 99.998% by mass or less, or 99.99% by mass or less.

[0074] ((G) Organic Solvent)

[0075] The treatment liquid according to this embodiment may further contain an organic solvent. In the case of an aqueous treatment liquid containing water as a solvent, a water-soluble organic solvent can be used as the organic solvent. The organic solvent may be any organic solvent that is miscible with the above-described components (A), (B), (C), and (D), and an appropriate organic solvent can be selected taking into consideration the types and contents of other components to be used.

[0076] Specific examples of the water-soluble organic solvent include alcohols such as isopropanol, ethanol, ethylene glycol, propylene glycol, glycerin, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, diethylene glycol, dipropylene glycol, furfuryl alcohol, and 2-methyl-2,4-pentanediol; ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and diethylene glycol monobutyl ether; acetates such as ethylene glycol monomethyl ether acetate and ethylene glycol monoethyl ether acetate; and dimethyl sulfoxide (DMSO). sulfoxides such as dimethyl sulfone, diethyl sulfone, bis(2-hydroxyethyl) sulfone, and tetramethylene sulfone; amides such as N,N-dimethylformamide (DMF), N-methylformamide, N,N-dimethylacetamide, N-methylacetamide, and N,N-diethylacetamide; lactams such as N-methyl-2-pyrrolidone (NMP), N-ethyl-2-pyrrolidone, N-propyl-2-pyrrolidone, N-hydroxymethyl-2-pyrrolidone, and N-hydroxyethyl-2-pyrrolidone; imidazolidinones such as 1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2-imidazolidinone, and 1,3-diisopropyl-2-imidazolidinone; lactones such as γ-butyrolactone and δ-valerolactone; and derivatives thereof. These may be used alone or in combination of two or more.

[0077] The content of the organic solvent relative to the total content of water and organic solvent is preferably 40% by mass or less, more preferably 30% by mass or less, even more preferably 20% by mass or less, and even more preferably 10% by mass or less. The lower limit of the content of the organic solvent relative to the total content of water and organic solvent is not particularly limited, but may be 0.01% by mass or more, or 0.1% by mass or more.

[0078] The treatment liquid according to the present embodiment is preferably an aqueous treatment liquid (sometimes referred to as an "aqueous treatment liquid") from the viewpoints of component solubility, environmental load reduction, cost efficiency, etc. An aqueous treatment liquid is a treatment liquid that does not contain an organic solvent, or a treatment liquid that contains water and an organic solvent and in which the organic solvent content is lower than the water content. From these viewpoints, in a more preferred embodiment, the organic solvent content in the treatment liquid according to the present embodiment is preferably 20% by mass or less, more preferably 10% by mass or less, even more preferably 5% by mass or less, even more preferably 3% by mass or less, and even more preferably 0% by mass (i.e., containing only water as the solvent).

[0079] (Impurities, etc.)

[0080] The treatment solution according to this embodiment may contain metal impurities, including metal atoms such as Fe atoms, Cr atoms, Ni atoms, Zn atoms, Ca atoms, or Pb atoms. The total content of the metal atoms in the treatment solution according to this embodiment is preferably 100 mass ppt or less, relative to the total mass of the treatment solution. The lower the lower limit of the total metal atom content, the more preferable it is, and examples thereof include 0.001 mass ppt or more. The total metal atom content may be, for example, 0.001 mass ppt to 100 mass ppt. By setting the total metal atom content to the above-mentioned preferred upper limit or less, the defect suppression and residue suppression properties of the treatment solution are improved. By setting the total metal atom content to the above-mentioned preferred lower limit or more, it is believed that metal atoms are less likely to be free and present in the system, which is less likely to adversely affect the overall manufacturing yield of the object to be cleaned.

[0081] The content of metal impurities can be adjusted, for example, by a purification treatment such as filtering, etc. The purification treatment such as filtering may be performed on a part or all of the raw materials before preparing the treatment liquid, or may be performed after preparing the treatment liquid.

[0082] The treatment liquid according to this embodiment may contain, for example, impurities derived from organic substances (organic impurities). The total content of the organic impurities in the treatment liquid according to this embodiment is preferably 5000 ppm by mass or less. The lower limit of the organic impurity content is preferably as low as possible, and may be, for example, 1 ppq by mass or more. The total content of the organic impurities may be, for example, 1 ppq by mass to 5000 ppm by mass.

[0083] The treatment liquid according to this embodiment may contain countable entities of a size that can be counted by, for example, a light-scattering liquid-borne particle counter. The size of the countable entities is, for example, 0.04 μm or more. The number of countable entities in the treatment liquid according to this embodiment is, for example, 1,000 or less per mL of treatment liquid, with a lower limit of, for example, 0.1 or more. By keeping the number of countable entities in the treatment liquid within the above-mentioned range, it is believed that the metal corrosion suppression effect and defect suppression effect of the treatment liquid are improved (however, the actions and effects of this embodiment are not limited to these).

[0084] The size of the objects to be counted may be a size that can be detected by a light scattering liquid particle counter, for example, 0.001 μm or more.

[0085] The organic impurities and / or the counted entities may be added to the treatment liquid, or may be inevitably mixed into the treatment liquid during the manufacturing process of the treatment liquid. Examples of cases where organic impurities are inevitably mixed into the treatment liquid during the manufacturing process of the treatment liquid include, but are not limited to, cases where organic impurities are contained in raw materials (e.g., organic solvents) used to manufacture the treatment liquid, and cases where organic impurities are mixed in from the external environment during the manufacturing process of the treatment liquid (e.g., contamination).

[0086] When the objects to be counted are added to the processing solution, the abundance ratio may be adjusted for each specific size, taking into consideration the surface roughness of the object to be cleaned, etc.

[0087] (pH)

[0088] The pH of the treatment liquid according to this embodiment is not particularly limited, but is preferably 0 to 4. The lower limit of the pH is more preferably 1 or more. The upper limit of the pH is more preferably 4 or less, and even more preferably 3 or less. When the pH is in this range, it is easy to achieve both corrosion prevention and cleaning properties.

[0089] <Storage method of processing solution, etc.>

[0090] The method for storing the treatment liquid according to this embodiment is not particularly limited, and a conventionally known storage container can be used. The void ratio within the container and / or the type of gas to fill the voids when storing the treatment liquid in the container may be appropriately determined so as to ensure the stability of the treatment liquid. For example, the void ratio within the storage container may be approximately 0.01 to 30% by volume.

[0091] The treatment solution according to this embodiment may be concentrated and stored as a highly concentrated solution before use (hereinafter, sometimes referred to as a "concentrated solution"). When in use, the concentrated solution may be diluted 2 to 2000 times to form a treatment solution having the desired content described above, which may be used for treating semiconductor devices. Water, for example, may be used as a diluting solvent for the concentrated solution. In this regard, the aqueous treatment solution described above is preferred because such concentration and dilution can be easily performed. When concentrating and diluting, an appropriate purification process may be performed, if necessary. A known purification method may be used depending on the type and content of the components.

[0092] <Method of using processing liquid, method of processing semiconductor devices, etc.>

[0093] The treatment solution according to this embodiment is excellent at removing at least titanium-based masks and titanium-based residues, and also has excellent corrosion protection for tungsten-atom-containing layers and molybdenum-atom-containing layers, and therefore can be suitably used for treating semiconductor substrates that include a substrate and a layer containing tungsten atoms and / or a layer containing molybdenum atoms. Furthermore, it can be more suitably used for treating semiconductor substrates that include a substrate, a layer containing tungsten atoms and / or a layer containing molybdenum atoms, and a layer containing titanium atoms. Examples of substrates to be treated are given below.

[0094] An example of the configuration of a laminated substrate for a semiconductor device is a laminated substrate in which functional layers such as a metal wiring layer, an etching stop layer, an insulating layer, and an interlayer dielectric (ILD), as well as a protective film (hard mask layer, HM layer) are laminated on a substrate.

[0095] Examples of the substrate material include silicon, amorphous silicon, polysilicon, and glass.

[0096] Examples of metals used for the metal wiring and metal layers include metals such as tungsten (W), molybdenum (Mo), cobalt (Co), ruthenium (Ru), gold (Au), silver (Ag), copper (Cu), iron (Fe), nickel (Ni), aluminum (Al), lead (Pb), zinc (Zn), tin (Sn), tantalum (Ta), magnesium (Mg), bismuth (Bi), cadmium (Cd), zirconium (Zr), antimony (Sb), manganese (Mn), beryllium (Be), chromium (Cr), germanium (Ge), vanadium (V), gallium (Ga), hafnium (Hf), indium (In), niobium (Nb), rhenium (Re), and thallium (Tl), as well as metal oxides, metal nitrides, metal chlorides, metal fluorides, and the like of these metals. In addition, examples of inorganic substances other than metals include silicon (Si) and its oxides (SiO ｘ Unless otherwise specified, x represents a number.), nitrides (SiN), chlorides (SiCl ｘ ), and fluoride (SiF). From the viewpoint of effectively utilizing the advantages of this embodiment, it is preferable that the material contains tungsten and / or molybdenum. These may be tungsten alloys or molybdenum alloys. In addition, for example, silicon-based materials such as SiN, SiO ２ , Low-k films (SiOC films, SiCOH films, etc.), ILD, etc. are examples.

[0097] Examples of materials for the etching stop layer include aluminum oxide, SiN, SiON, and SiOCN.

[0098] The material of the interlayer insulating film (ILD) is, for example, SiO ２Examples of the interlayer insulating film include silicon-based materials such as SiN, SiOC, SiOCN, etc. The interlayer insulating film can be used as a functional layer that insulates wiring between multilayer wirings made up of multiple layers.

[0099] The material of the protective film (hard mask layer, HM layer) is not particularly limited as long as it functions as a protective film against etching, and a suitable material can be selected in consideration of manufacturing conditions, etc. Examples of the material for the protective film include titanium-based materials such as Ti and TiN, SiN, and SiO. ２ Examples of the titanium-based material include silicon-based materials such as silicon nitride (SiON), silicon oxynitride (SiON), silicon oxynitride (SiCN), and combinations thereof. In this regard, the processing liquid according to this embodiment is preferably a titanium-based material from the viewpoint of excellent removability of titanium-based masks and titanium-based residues. Examples of the titanium-based material include titanium (Ti), titanium nitride (TiN), and titanium oxide (TiO ｘ (x represents a number), titanium-based materials such as titanium oxynitride (TiON) and titanium oxyfluoride (TiOF) are more preferred.

[0100] FIG. 1 is a cross-sectional view of an example of a semiconductor substrate for which the treatment liquid according to this embodiment can be used.

[0101] The semiconductor substrate 100 shown in FIG. 1 has a metal wiring layer 12, a low-k film 14, and a hard mask layer (HM layer) 16 formed on a substrate 10 (substrate 10 / metal wiring layer 12 / low-k film 14 / hard mask layer 16).

[0102] The substrate 10 can be made of the materials described above.

[0103] While the above-described materials can be used for the metal wiring layer 12, from the viewpoint of achieving the effects of this embodiment, a tungsten atom-containing layer and / or a molybdenum atom-containing layer is preferred. These include layers containing tungsten atoms and molybdenum atoms. Furthermore, the metal wiring layer may be a combination of a tungsten atom-containing layer and a molybdenum atom-containing layer, or a combination of a tungsten atom-containing layer, a molybdenum atom-containing layer, and a layer containing another metal. In this regard, in the semiconductor device manufacturing process, components are becoming increasingly lighter, thinner, and smaller, which can make handling these components difficult during the manufacturing process, and may have led to a reluctance to use tungsten or molybdenum. However, the treatment solution according to this embodiment has excellent corrosion resistance for tungsten atom-containing layers and molybdenum atom-containing layers, thereby eliminating the problem of such structural constraints.

[0104] The low-k film 14 can be made of the materials described above.

[0105] The hard mask layer 16 can be made of the above-mentioned materials, but from the viewpoint of achieving the effects of this embodiment, titanium-based materials such as titanium and titanium-based alloys are preferred.

[0106] The treatment solution according to this embodiment is suitable for removing etching residues, and is particularly suitable for removing dry etching residues. Generally, dry etching residues are removed before the next process in order to improve semiconductor yields and prevent deterioration of electrical characteristics. For example, the treatment solution according to this embodiment is suitable for cleaning semiconductor substrates after dry etching in a wiring process.

[0107] For example, the treatment liquid according to this embodiment can suitably remove residues P, such as residues of titanium-based materials (titanium-based residues; residues containing titanium and / or titanium-based alloys) that are attached to the hard mask layer 16 during the wiring process, and etching residues containing inorganic substances that are attached to the metal wiring layer. In particular, titanium-based residues that adhere to the semiconductor substrate after dry etching have high wet resistance and are difficult to remove by cleaning treatment, but the treatment liquid according to this embodiment can efficiently clean such residues.

[0108] The treatment liquid according to this embodiment can be suitably used for treating a semiconductor substrate. A suitable example of a method for treating a semiconductor substrate includes, for example, a step of treating a semiconductor substrate including a substrate, a layer containing tungsten atoms and / or a layer containing molybdenum atoms, and a layer containing titanium atoms, with the treatment liquid. The treatment method will be described below using, as an example, the case of treating the semiconductor substrate 100 shown in FIG. 1 .

[0109] The treatment method according to this embodiment is a step of treating a semiconductor substrate 100 after dry etching in a wiring process using the treatment liquid described above. The treatment method is not particularly limited, and a known treatment method can be used. When the treatment liquid is brought into contact with the semiconductor substrate 100 to be treated, the treatment liquid may be diluted 2 to 2000 times to obtain a diluted liquid of the desired concentration described above, and then the diluted liquid may be used to perform cleaning.

[0110] The treatment process using the treatment solution according to this embodiment may be a process of bringing the treatment solution into contact with the semiconductor substrate 100. For example, by bringing the treatment solution into contact with the semiconductor substrate 100 during an etching process (or a process before or after the etching process), etching residues can be removed. Furthermore, it is expected that protective films such as the hard mask layer 16 can also be removed. The etching method is not particularly limited, and may be wet etching or dry etching, but dry etching is preferred. Dry etching is advantageous in that it enables metal wiring at the nano-level and allows for control of the gas used. Furthermore, dry etching can be a concern due to the relatively large damage to the substrate, etc. However, using the treatment solution according to this embodiment is desirable in that such damage can be effectively suppressed, thereby more effectively utilizing the advantages of this embodiment.

[0111] As a method for contacting the semiconductor substrate 100, for example, the treatment liquid is placed in a container and the semiconductor substrate 100 to be cleaned is immersed in the treatment liquid to remove residues P such as dry etching residues. Alternatively, dry etching residues can be removed by treating electronic devices using a single-wafer cleaning method. The treatment liquid is preferably used as an etching liquid in addition to a dry etching residue removal liquid (cleaning liquid). Furthermore, the treatment liquid according to this embodiment can also be used as a cleaning liquid for cleaning electronic devices after a chemical mechanical polishing (CMP) process. Examples of operations in the treatment process include a method in which the treatment liquid is continuously applied onto a semiconductor substrate 100 rotating at a constant speed (spin coating method), a method in which the semiconductor substrate 100 is immersed in the treatment liquid for a certain period of time (dip method), and a method in which the treatment liquid is sprayed onto the surface of the semiconductor substrate 100 (spray method).

[0112] The treatment temperature is not particularly limited, but is preferably carried out under conditions of 10 to 80°C. The lower limit of the treatment temperature is more preferably 20°C or higher, and even more preferably 40°C or higher. The upper limit of the treatment temperature is more preferably 75°C or lower, and even more preferably 70°C or lower. By setting the lower limit of the treatment temperature within the above-mentioned range, the removability of the residue P can be further improved. Furthermore, by setting the upper limit of the treatment temperature within the above-mentioned range, unintended composition changes in the treatment liquid can be more effectively suppressed, and cleaning can be performed more efficiently from the standpoints of workability, safety, cost, etc.

[0113] The treatment time can be appropriately selected to be a time sufficient to remove etching residues, impurities, and the like adhering to the surface of the semiconductor substrate 100. The treatment time is preferably, for example, 10 seconds to 30 minutes. The lower limit of the treatment time is more preferably 20 seconds or more, and even more preferably 30 seconds or more. The upper limit of the cleaning time is more preferably 15 minutes or less, even more preferably 10 minutes or less, and even more preferably 5 minutes or less.

[0114] Before or after the treatment step, a rinsing step using an organic solvent, water, carbonated water, ammonia water, or the like may be performed.

[0115] In this way, by using the treatment liquid according to this embodiment, it is possible to effectively remove the hard mask layer 16 (e.g., a titanium-based mask containing titanium and / or a titanium alloy) and the residue P (e.g., titanium-based residue) from the semiconductor substrate 100 to which the residue P is attached, while suppressing damage to the metal wiring layer 12 (e.g., a tungsten atom-containing layer or a molybdenum atom-containing layer).

[0116] <Semiconductor device manufacturing methods, etc.>

[0117] The treatment liquid and the treatment method using the same according to this embodiment can be suitably used as a method for manufacturing a semiconductor device. The method for manufacturing a semiconductor device according to this embodiment includes a step of treating a semiconductor substrate including a substrate, a layer containing tungsten atoms and / or a layer containing molybdenum atoms, and a layer containing titanium atoms, with the treatment liquid described above.

[0118] Examples of such a semiconductor device manufacturing method include a semiconductor device manufacturing method including the steps of (1) preparing a semiconductor substrate having a protective film and (2) etching the protective film and / or removing impurities from the semiconductor substrate. The step (2) can be performed as a treatment using a treatment liquid. Furthermore, the protective film referred to here corresponds to the hard mask layer 16 in the case of the semiconductor substrate 100 shown in FIG. 1 . The following description will be given using the semiconductor substrate 100 shown in FIG. 1 as an example.

[0119] (1) A step of preparing a substrate having a protective film

[0120] In step (1), a substrate having at least a protective film is prepared. In the case of FIG. 1 , a semiconductor substrate 100 is prepared that has, in this order, a substrate 10, a metal wiring layer 12, a low-k film 14, and a hard mask layer (HM layer) 16 before etching. The method for stacking the metal wiring layer 12, the low-k film 14, and the hard mask layer (HM layer) 16 on the substrate 10 is not particularly limited, and any known method can be used.

[0121] (2) A step of etching the protective film and / or removing impurities from the semiconductor substrate

[0122] Next, the protective film is etched and / or impurities on the semiconductor substrate are removed. In the case of FIG. 1 , the hard mask layer (HM layer) 16 is etched and / or impurities P on the semiconductor substrate 100 are removed. In step (2), etching and removal of impurities P may be performed simultaneously or sequentially. Alternatively, either one of these may be performed.

[0123] The etching method is not particularly limited, and may be wet etching or dry etching, but dry etching is preferred. Dry etching is advantageous in that it allows metal wiring at the nano-level and allows control of the gas used. Furthermore, dry etching is a concern in that it can cause relatively large damage to the substrate, etc., but such damage can be effectively suppressed by using the treatment liquid according to this embodiment. Therefore, dry etching is also preferred in that it can more effectively reflect the advantages of this embodiment.

[0124] In the case of dry etching, for example, plasma can be used. Usually, when plasma etching is performed, there are problems that the substrate is easily damaged and that plasma etching residue is generated, which must be washed away with a treatment liquid. However, when the treatment liquid according to the present embodiment is used, such problems can be effectively suppressed, which is preferable.

[0125] Furthermore, as a method for removing the impurities P on the semiconductor substrate 100, a method can be adopted in which the impurities are removed from the semiconductor substrate 100 by bringing the above-described treatment liquid into contact with the semiconductor substrate 100. As this method, for example, the above-described treatment method (cleaning method) can be used. In this way, the hard mask layer 16 is removed from the semiconductor substrate 100, and the residue P is also removed, thereby obtaining a semiconductor device. Note that, if necessary, known post-treatment can be performed after cleaning.

[0126] As described above, the treatment solution according to this embodiment can be used, for example, to remove a protective film from a semiconductor substrate, and to remove or clean residues generated in an etching process, etc. In particular, the treatment solution according to this embodiment has the advantages of being excellent in removing titanium-based masks and titanium-based residues, and also excellent in corrosion prevention for both tungsten atom-containing layers and molybdenum atom-containing layers.

[0127] Furthermore, the treatment liquid according to this embodiment can achieve a sufficient effect even if it does not contain hydrogen peroxide. Furthermore, the treatment liquid according to this embodiment can achieve a sufficient effect even if it does not contain hydroxylamine. Furthermore, the treatment liquid according to this embodiment can achieve a sufficient effect even if it does not contain tetramethylammonium hydroxide (TMAH) and / or tetraethylammonium hydroxide (TEAH). From this perspective, the treatment liquid according to this embodiment may be a treatment liquid that does not contain hydrogen peroxide. The treatment liquid according to this embodiment may be a treatment liquid that does not contain hydroxylamine. The treatment liquid according to this embodiment may be a treatment liquid that does not contain tetramethylammonium hydroxide (TMAH). The treatment liquid according to this embodiment may be a treatment liquid that does not contain tetraethylammonium hydroxide (TEAH).

[0128] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0129] (Preparation of processing solution)

[0130] Treatment solutions were prepared by mixing the components to obtain the compositions shown in Tables 1 to 5. Water was prepared as the remainder of each treatment solution. For example, the treatment solution of Example 1 is an aqueous treatment solution containing 0.003 mass% iodic acid, 0.03 mass% HFSA as a fluorine-containing compound, 1.0 mass% MSA as an acid, 0.01 mass% DDPy as a first corrosion inhibitor, and 0.1 mass% 5M-BTA as a second corrosion inhibitor, and containing water as a solvent, with the mass ratio of the content of the second corrosion inhibitor to the content of the first corrosion inhibitor (second corrosion inhibitor / first corrosion inhibitor) being 10. Abbreviations and the like listed in each table are as follows:

[0131] HFSA: Hexafluorosilicic acid HPF ６ : Hexafluorophosphate · H ２ TiF ６ : Hexafluorotitanic acid HBF ４: Tetrafluoroboric acid (Tetrafluoroborate) TMAF: Tetramethylammonium fluoride NH ４ F: Ammonium fluoride, MSA: Methanesulfonic acid, DDPy: 1-Dodecylpyridinium chloride, HDMI: 1-Hexadecyl-3-methylimidazolium chloride, TpT-Cl: 2,3,5-Triphenyltetrazolium chloride, 2A4mP: 2-Amino-4-methylpyrimidine, 5M-BTA: 5-Methyl-1H-benzotriazole, BTA-5CA: Benzotriazole-5-carboxylic acid 5Cl-BTA: 5-Chrolo-1H-benzotriazole 5Br-BTA: 5-Bromo-1H-benzotriazole 5AM-BTA: 5-Amino-1H-benzotriazole

[0132] (Evaluation of removability of titanium-based mask and titanium-based residue)

[0133] By depositing TiN by CVD, the substrate (material: SiO ２A TiN substrate was prepared by forming a TiN film (film thickness: 50 nm) on a TiN substrate (film thickness: 100 nm). The substrate was then cut into a 2 cm x 2 cm sample. Subsequently, 100 mL of the treatment solution for each Example and Comparative Example was placed in a beaker, and the sample substrate was immersed in the treatment solution at 40°C for 3 minutes. The substrate was then rinsed with ultrapure water (25°C) for 3 seconds, washed with isopropyl alcohol (25°C) for 30 seconds, and dried by nitrogen blowing. The TiN etching property was evaluated based on the difference in the TiN film thickness before and after immersion in the treatment solution. The film thicknesses before and after treatment were measured by X-ray fluorescence analysis using a "ZSX Primus IV" (manufactured by RIGAKU Corporation). For example, the ER of the TiN HM (hard mask) of Example 1 was 49 Å / min, which means that 147 Å was etched in 3 minutes.

[0134] (Evaluation of tungsten corrosion resistance)

[0135] By depositing tungsten using the CVD method, the substrate (material: SiO ２ A tungsten film substrate was prepared, in which a tungsten film (thickness: 100 nm) was formed on a tungsten film (thickness: 100 nm) formed on a tungsten film (thickness: 100 nm). Then, a sample substrate was obtained by cutting it into a 2 cm x 2 cm piece. Subsequently, 100 mL of the treatment solution for each Example and Comparative Example was placed in a beaker, and the sample substrate was immersed in this treatment solution at 40°C for 3 minutes. The sample substrate was then rinsed with ultrapure water (25°C) for 3 seconds, then washed with isopropyl alcohol (25°C) for 30 seconds, and dried by nitrogen blowing. The corrosion resistance was evaluated based on the difference in the thickness of the tungsten film before and after immersion in the treatment solution. The thicknesses of each film before and after treatment were measured by X-ray fluorescence analysis using a "ZSX Primus IV" (manufactured by RIGAKU Corporation). For example, the ER of W in Example 1 was 4 Å / min, which means that 12 Å was etched in 3 minutes.

[0136] (Evaluation of the corrosion resistance of molybdenum)

[0137] By depositing molybdenum using the CVD method, the substrate (material: SiO ２A molybdenum film substrate was prepared, in which a molybdenum film (film thickness: 50 nm) was formed on a tungsten film (film thickness: 100 nm). This was then cut to a 2 cm x 2 cm sample substrate. Subsequently, 100 mL of the treatment solution for each Example and Comparative Example was placed in a beaker, and the sample substrate was immersed in this treatment solution at 40°C for 3 minutes. The sample substrate was then rinsed with ultrapure water (25°C) for 3 seconds, then washed with isopropyl alcohol (25°C) for 30 seconds, and dried by nitrogen blowing. Corrosion resistance was evaluated based on the difference in film thickness of the tungsten film before and after immersion in the treatment solution. The film thicknesses before and after treatment were measured by X-ray fluorescence analysis using a "ZSX Primus IV" (manufactured by RIGAKU Corporation). For example, the ER of Mo in Example 1 was 26 Å / min, which means that 78 Å was etched in 3 minutes.

[0138] The compositions of the examples and comparative examples are shown in Tables 1 to 5, and the evaluation results of the examples and comparative examples are shown in Tables 6 to 8.

[0139]

[0140]

[0141]

[0142]

[0143]

[0144]

[0145]

[0146]

[0147] ​​​​​​​​From the above, it was at least confirmed that the treatment liquid according to this example is excellent in removing titanium-based masks and titanium-based residues, and also has excellent corrosion resistance for tungsten atom-containing layers and molybdenum atom-containing layers.

[0148] This application claims priority to U.S. Provisional Application No. 63 / 633,930, filed with the U.S. Patent and Trademark Office on April 15, 2024, the contents of which are incorporated herein by reference.

[0149] 100: semiconductor substrate 10: substrate 12: metal wiring layer 14: low-k film 16: hard mask layer P: residue

Claims

1. A treatment solution comprising: (A) an oxidizing agent; (B) a compound capable of releasing fluoride ions; (C) as a first corrosion inhibitor, at least one selected from the group consisting of pyrimidine ring-containing compounds and salts thereof, imidazole ring-containing compounds and salts thereof, and tetrazole ring-containing compounds and salts thereof; (D) as a second corrosion inhibitor, a benzotriazole ring-containing compound and salts thereof; and water.

2. The treatment liquid according to claim 1, wherein the (C) first anticorrosive agent is at least one selected from the group consisting of alkylpyridinium salts, alkylmethylimidazolium salts, and triphenyltetrazolium salts.

3. The treatment solution according to claim 1 or 2, wherein the (D) second corrosion inhibitor is at least one selected from the group consisting of 5-methyl-1H-benzotriazole, 4-carboxyl-1H-benzotriazole, 5-carboxyl-1H-benzotriazole, 5-nitro-1H-benzotriazole, 5-chloro-1H-benzotriazole, 5-bromo-1H-benzotriazole, and 5-amino-1H-benzotriazole.

4. The treatment liquid according to claim 1 or 2, wherein the content of the oxidizing agent (A) is 0.0001 to 0.1 mass %.

5. The treatment liquid according to claim 1 or 2, wherein the content of the compound (B) capable of releasing fluoride ions is 0.0001 to 1 mass %.

6. The treatment liquid according to claim 1 or 2, wherein the content of the first anticorrosive agent (C) is 0.0001 to 5 mass %.

7. The treatment liquid according to claim 1 or 2, wherein the content of the second corrosion inhibitor (D) is 0.0001 to 10 mass %.

8. The treatment liquid according to claim 1 or 2, wherein the mass ratio (D / C) of the content of the second corrosion inhibitor (D) to the content of the first corrosion inhibitor (C) is 0.1 to 2000.

9. The treatment liquid according to claim 1 or 2, wherein the treatment liquid is used for treating a semiconductor substrate including a substrate, a layer containing tungsten atoms and / or a layer containing molybdenum atoms, and a layer containing titanium atoms.

10. A method for treating a semiconductor substrate, comprising a step of treating a semiconductor substrate comprising a substrate, a layer containing tungsten atoms and / or a layer containing molybdenum atoms, and a layer containing titanium atoms, with the treatment liquid according to claim 1 or 2.

11. A method for manufacturing a semiconductor device, comprising a step of treating a semiconductor substrate including a substrate, a layer containing tungsten atoms and / or a layer containing molybdenum atoms, and a layer containing titanium atoms, with the treatment liquid according to claim 1 or 2.

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