Processing liquid, method for processing semiconductor substrate, and method for manufacturing semiconductor

Abstract

Provided are: a processing liquid containing a compound capable of releasing fluoride ions, an oxidizing agent, and an anionic compound; a method for processing a semiconductor substrate; and a method for manufacturing a semiconductor.

Description

Treatment liquid, semiconductor substrate treatment method, and semiconductor manufacturing method

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

[0002] Traditionally, scaling of features within integrated circuits has allowed for an increased density of functional units on a semiconductor chip: for example, shrinking transistor size has allowed more memory elements to be integrated onto a chip, leading to the production of products with increased capacity.

[0003] The wiring formation process used in the manufacture of such products involves, for example, (i) forming a hard mask layer (HM layer) as a protective film on an interlayer insulating film formed by laminating a substrate, a metal wiring layer, and an interlayer insulating film made of a silicon (Si)-based material or the like in this order, and then etching this hard mask layer to form a prototype of a wiring pattern, and then (ii) dry-etching the interlayer insulating film using the etched HM layer as a mask layer to produce a wiring pattern such as metal wiring.

[0004] On the other hand, in the manufacture of field effect transistors (FETs) for integrated circuit devices, silicon germanium-based materials such as silicon germanium alloys are used as one of the semiconductor materials other than silicon-based materials. Silicon germanium (SiGe)-based materials have various excellent properties, such as improved carrier mobility and excellent switching operation, by adding germanium (Ge) to silicon (Si). Due to these properties, semiconductor substrates using silicon germanium-based materials and silicon-based materials are used as materials for high-frequency circuits, amplifier circuits, etc. in various miniaturized communication devices, etc.

[0005] As a technique for manufacturing such a semiconductor substrate, for example, Patent Document 1 discloses a method for manufacturing a semiconductor substrate using a compound of the general formula Si １－ｘ Ge ｘ (where x is greater than 0 and less than 1), the etching solution contains periodic acid and a fluoride.

[0006] Japanese Patent Application Laid-Open No. 2020-107724

[0007] However, in the manufacturing process of the above-mentioned silicon-germanium-based material and semiconductor substrates using the silicon-based material, when using the above-mentioned treatment solution, it is required that the silicon-germanium-based material can be selectively removed while suppressing damage to the silicon-based material. However, the inventors have found that, while treatment solutions containing fluorine compounds and oxidizing agents may be expected to remove the silicon-germanium-based material to some extent, they also have the problem of damaging the silicon-based material, and that there is room for improvement in this respect in practical use. Furthermore, the inventors have also found that there is room for improvement in achieving both suppression of damage to the silicon-based metal and selectivity for silicon-germanium-based metal / silicon-based metal.

[0008] The present invention has been made in view of the above-mentioned circumstances, and aims to provide a processing solution that can suppress damage to silicon-based materials and selectively remove silicon germanium-based materials, as well as a semiconductor substrate processing method and semiconductor manufacturing method using the same.

[0009] As a result of intensive research into achieving the above-mentioned object, the present inventors have discovered that a treatment solution containing a compound capable of releasing fluoride ions, an oxidizing agent, and an anionic compound can be prepared, and have thus completed the present invention.

[0010] [1] A treatment liquid containing a compound capable of releasing fluoride ions, an oxidizing agent, and an anionic compound. [2] The treatment liquid according to [1], wherein the anionic compound is a sulfonic acid-based compound. [3] The treatment liquid according to [1], wherein the content of the anionic compound is 0.000001 to 5 mass %. [4] The treatment liquid according to [1], further containing water. [5] The treatment liquid according to [1], wherein the ratio of the content of the oxidizing agent to the content of the anionic compound is 0.01 to 300,000. [6] The treatment liquid according to [1], wherein the treatment liquid is a treatment liquid for semiconductor substrates, the semiconductor substrate including a substrate and a film formed on the substrate, the film containing SiGe. [7] A method for treating a semiconductor substrate having a protective film, comprising the step of removing impurities from the semiconductor substrate by contacting the protective film with the treatment liquid according to [1]. [8] A method for manufacturing a semiconductor, comprising: preparing a semiconductor substrate having a substrate and a protective film provided on the substrate; etching the protective film; and, after the etching, removing impurities from the semiconductor substrate by bringing the treatment liquid according to [1] into contact with the semiconductor substrate.

[0011] According to the present invention, it is possible to provide a processing solution that can suppress damage to silicon-based materials and selectively remove silicon germanium-based materials, as well as a semiconductor substrate processing method and semiconductor manufacturing method using the same.

[0012] 1 and 2 are cross-sectional views showing an example of a semiconductor substrate before and after etching, respectively.

[0013] 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 implemented 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.

[0014] 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.

[0015] <Processing liquid>

[0016] The treatment liquid according to this embodiment contains a compound capable of releasing fluoride ions, an oxidizing agent, and an anionic compound, and by using such a treatment liquid, damage to silicon-based materials can be suppressed and silicon-germanium-based materials can be selectively removed.

[0017] The silicon-based material refers to a material containing at least silicon (Si), other than the silicon germanium-based material described below. The silicon-based material may contain other elements such as oxygen, nitrogen, boron, phosphorus, arsenic, antimony, and gallium in addition to silicon.

[0018] The term "silicon germanium-based material (SiGe-based material)" refers to a material containing at least silicon (Si) and germanium (Ge). Examples of silicon germanium-based materials include those represented by the general formula Si １－ｘ Ge ｘ where x is greater than 0 and less than 1. Ge has several advantages over silicon in some cases, including high charge carrier (hole) mobility, band gap offset, different lattice constant, and the ability to alloy with silicon to form the semiconducting binary alloy SiGe.

[0019] The treatment liquid according to this embodiment can be suitably used as a treatment liquid for removing etching residues containing inorganic substances. In this case, it can be suitably used as a treatment liquid for cleaning semiconductors, etc. The treatment liquid may also be called a cleaning liquid, etc.

[0020] The inorganic substance referred to here is a compound containing a metal, such as a metal, a metal oxide, a metal nitride, a metal chloride, or a metal fluoride. That is, the treatment liquid according to this embodiment can efficiently remove etching residues containing such inorganic substances. Examples of inorganic substances other than metals include silicon (Si) and its oxides.

[0021] More specifically, the treatment solution according to this embodiment is expected to efficiently remove metal residues, and in addition, the treatment solution according to this embodiment is expected to efficiently remove inorganic residues derived from metal wiring layers, including metals described below, and one selected from the group consisting of metal oxides, metal nitrides, metal chlorides, and metal fluorides of these metals.

[0022] Examples of the metal include molybdenum (Mo), tungsten (W), ruthenium (Ru), copper (Cu), iron (Fe), gold (Au), silver (Ag), nickel (Ni), aluminum (Al), lead (Pb), zinc (Zn), tin (Sn), tantalum (Ta), magnesium (Mg), cobalt (Co), bismuth (Bi), cadmium (Cd), titanium (Ti), 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, and metal fluorides thereof.

[0023] Examples of the metal oxide include oxides of the metal atoms described above. Specific examples of the metal oxide include TiO. ｘ , TaO ｘ , CuO ｘ , CoO ｘ , RuOｘ , AlO ｘ , W.O. ｘ , MoO ｘ , AuO ｘ , AgO ｘ , FeO ｘ , NiO ｘ , (unless otherwise specified, x represents a number), etc., but are not limited to these.

[0024] Examples of the metal nitride include metal nitrides of the above-mentioned metal atoms. Specific examples of the metal nitride include TiN. ｘ , TaN ｘ , CuN ｘ , CoN ｘ , RuN ｘ , AlN ｘ , W.N. ｘ , MoN ｘ , AuN ｘ , AgN ｘ , FeN ｘ , NiN ｘ These include, but are not limited to:

[0025] Examples of metal chlorides include metal chlorides of the above-mentioned metal atoms. Specific examples of metal chlorides include TiCl. ｘ , TaCl ｘ , CuCl ｘ , CoCl ｘ , RuCl ｘ , AlCl ｘ , WCl ｘ , MoCl ｘ , AuCl ｘ , AgCl ｘ , FeCl ｘ , NiCl ｘ These include, but are not limited to:

[0026] Examples of the metal fluoride include metal fluorides of the above-mentioned metal atoms. Specific examples of the metal fluoride include TiF ｘ , TaF ｘ , CuF ｘ , CoF ｘ , RuF ｘ , AlF ｘ , W.F. ｘ , MoF ｘ , AuFｘ , AgF ｘ , FeF ｘ , NiF ｘ These include, but are not limited to:

[0027] 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.

[0028] For example, the treatment solution according to this embodiment can be expected to effectively remove metal residues derived from HM layers such as protective films that adhere during wiring processes, and etching residues containing inorganic substances derived from metal wiring layers. In particular, metal residues that adhere to semiconductor substrates after dry etching have high wet resistance and are difficult to remove by cleaning processes. The treatment solution according to this embodiment can also efficiently clean such residues.

[0029] The components of the treatment liquid according to this embodiment will be described below.

[0030] ((A) Compound capable of releasing fluoride ions)

[0031] The (A) compound capable of releasing fluoride ions may be any compound capable of releasing fluoride ions in water. Specific examples of compounds capable of releasing fluoride ions include hydrogen fluoride (HF), hexafluorosilicic acid (HFSA), aluminum fluoride, titanium fluoride, ammonium fluoride, and tetrabutylammonium fluoride. The (A) compound capable of releasing fluoride ions may be contained in the form of a salt thereof (e.g., sodium salt, potassium salt, calcium salt, barium salt, ammonium salt, tetraalkylammonium salt, etc.). Among these, it is preferable to contain at least one selected from the group consisting of hydrogen fluoride and hexafluorosilicic acid.

[0032] For example, in the case of hexafluorosilicic acid, it may be added as a hexafluorosilicate salt, or as a hydrate, aqueous solution, etc. Specific examples of hexafluorosilicic acid salts include potassium hexafluorosilicate, sodium hexafluorosilicate, magnesium hexafluorosilicate, etc. In the case of hydrogen fluoride, hydrofluoric acid (aqueous solution of hydrogen fluoride) may be added when producing the treatment liquid according to this embodiment.

[0033] The component (A) may be used alone or in combination of two or more types.

[0034] The content of component (A) in the treatment liquid according to this embodiment is not particularly limited, but is preferably 0.05 to 10 mass %. The upper limit of the content of component (A) is more preferably 5 mass % or less, even more preferably 4 mass % or less, and even more preferably 3 mass % or less. The lower limit of the content of component (A) is more preferably 0.1 mass % or more, even more preferably 0.15 mass % or more, and even more preferably 0.2 mass % or more. By keeping the content of component (A) within the above range, damage to silicon-based materials can be suppressed, and the selectivity of silicon-germanium-based materials relative to silicon-based materials (SiGe / Si) can be further improved, i.e., the selectivity of silicon-germanium-based materials relative to silicon-based materials can be selectively removed.

[0035] ((B) Oxidizing Agent)

[0036] Specific examples of the oxidizing agent (B) include halogen oxidizing agents (hypochlorous acid, chlorous acid, chloric acid, perchloric acid, hypobromous acid, bromous acid, bromic acid (HBrO ３ ), perbromic acid, hypoiodous acid, iodic acid, iodic acid (HIO ３ ), periodic acid (H ５ IO ６ ) etc.), boric acid (H ３ BO ３ , B(OH) ３ ), silicic acid, nitrous acid, nitric acid (HNO ３ ), sulfuric acid, sulfurous acid, hydrogen peroxide (H ２ O ２), and salts thereof. That is, the treatment liquid according to this embodiment may contain these salts (for example, sodium salts, potassium salts, calcium salts, barium salts, ammonium salts, tetraalkylammonium salts, etc.).

[0037] Among the above oxidizing agents, at least one selected from halogen oxidizing agents, silicic acid, nitrous acid, nitric acid, sulfuric acid, sulfurous acid, hydrogen peroxide, and salts thereof is preferred; and at least one selected from halogen oxidizing agents, nitrous acid, nitric acid, sulfuric acid, sulfurous acid, hydrogen peroxide, and salts thereof is more preferred.

[0038] Among halogen oxidizing agents, hypobromous acid, bromous acid, bromic acid (HBrO ３ ), perbromic acid, hypoiodous acid, iodic acid, iodic acid (HIO ３ ), and periodic acid (H ５ IO ６ ) is at least one selected from the group consisting of

[0039] In the treatment liquid according to this embodiment, the above-mentioned oxidizing agents may be used alone or in combination of two or more.

[0040] The content of component (B) in the treatment solution according to this embodiment is not particularly limited, but is preferably 0.05 to 30 mass %. The upper limit of the content of component (B) is more preferably 27 mass % or less, even more preferably 25 mass % or less, even more preferably 23 mass % or less, and even more preferably 22 mass % or less. The lower limit of the content of component (B) is more preferably 0.1 mass % or more, even more preferably 0.3 mass % or more, and even more preferably 0.5 mass % or more. By keeping the content of component (B) within the above range, damage to silicon-based materials can be suppressed, and the selectivity of silicon-germanium-based materials relative to silicon-based materials (SiGe / Si) can be further improved, i.e., the selectivity of silicon-germanium-based materials relative to silicon-based materials can be selectively removed.

[0041] ((C) Anionic Compound)

[0042] The anionic compound (C) is contained in the treatment liquid according to this embodiment as a component other than the compound (A) that releases fluoride ions. Such anionic compounds include, for example, compounds that can be ionized in a solvent such as water (D) or an organic solvent (E) described below and that exhibit anionic properties after ionization.

[0043] Examples of the anionic compound (C) include sulfonic acid compounds, carboxylic acid compounds, and phosphoric acid compounds. These may be contained in the form of their salts (e.g., sodium salts, potassium salts, calcium salts, barium salts, ammonium salts, tetraalkylammonium salts, etc.). Among these, sulfonic acid compounds are preferred.

[0044] The sulfonic acid compounds include those having a sulfo group (-SO ３ H group), and sulfo anion (-SO ３ -) and the like.

[0045] Specific examples of sulfonic acid compounds include aromatic ring-containing sulfonic acids, alkylsulfonic acids, and salts thereof (e.g., sodium salts, potassium salts, calcium salts, barium salts, ammonium salts, tetraalkylammonium salts, etc.).

[0046] Specific examples of aromatic ring-containing sulfonic acids include alkylbenzenesulfonic acids, alkylnaphthalenesulfonic acids, alkyldiphenylethersulfonic acids, and polystyrenesulfonic acids.

[0047] Specific examples of alkylbenzenesulfonic acids include dodecyl(sulfophenoxy)benzenesulfonic acid, diammonium dodecyl(sulfophenoxy)benzenesulfonate (DADDSPBS), 4-dodecylbenzenesulfonic acid (DDBSA), and 4-ethylbenzenesulfonic acid (EBSA).

[0048] Specific examples of alkylnaphthalenesulfonic acids include naphthalenesulfonic acids such as 1-naphthalenesulfonic acid (1NSA) and 2-naphthalenesulfonic acid; butylnaphthalenesulfonic acids such as 4-butyl-1-naphthalenesulfonic acid (1BNSA); dibutylnaphthalenesulfonic acids such as 4,7-dibutyl-1-naphthalenesulfonic acid; isopropylnaphthalenesulfonic acids such as 4-isopropyl-1-naphthalenesulfonic acid (1IPNSA); and diisopropylnaphthalenesulfonic acids such as 4,7-diisopropyl-1-naphthalenesulfonic acid.

[0049] Specific examples of alkyldiphenyl ether sulfonic acids include dodecyldiphenyloxide disulfonic acid and nonyldiphenyloxide disulfonic acid.

[0050] Specific examples of polystyrene sulfonic acids include poly(4-styrene sulfonic acid).

[0051] Specific examples of alkylsulfonic acids include 1-dodecanesulfonic acid (DDSA), hexadecanesulfonic acid, and nonanesulfonic acid.

[0052] A specific example of the carboxylic acid compound is decanecarboxylic acid.

[0053] Specific examples of the phosphoric acid compound include tetradecyl phosphoric acid, polyvinyl phosphoric acid, and octadecyl phosphoric acid.

[0054] The content of component (C) in the treatment liquid according to this embodiment is not particularly limited, but is preferably 0.000001 to 5 mass %. The upper limit of the content of component (C) is more preferably 3 mass % or less, even more preferably 2 mass % or less, and even more preferably 1 mass % or less. The lower limit of the content of component (C) is more preferably 0.00001 mass % or more, and even more preferably 0.0001 mass % or more. By keeping the content of component (C) within the above range, when used in combination with components (A) and (B), damage to silicon-based materials can be suppressed and the selectivity of silicon-germanium-based materials relative to silicon-based materials (SiGe / Si) can be further improved, i.e., silicon-germanium-based materials can be selectively removed.

[0055] The ratio of the content of the oxidizing agent (B) to the content of the anionic compound (C) (B / C, mass ratio) is not particularly limited, but is preferably 0.01 to 300,000. The upper limit of this ratio is more preferably 100,000 or less, even more preferably 20,000 or less, and still more preferably 10,000 or less. The lower limit of this ratio is more preferably 0.1 or more, even more preferably 0.5 or more, and still more preferably 1 or more. By keeping this ratio within the above range, damage to the silicon-based material can be suppressed, and the selectivity of the silicon-germanium-based material to the silicon-based material (SiGe / Si) can be further improved, that is, the silicon-germanium-based material can be selectively removed.

[0056] ((D) Water)

[0057] (D) Water that can be used includes, for example, deionized water (DIW), ultrapure water (UPW), pure water, high-purity ionized water, etc., from the viewpoint of suitability for manufacturing semiconductor devices.

[0058] The water content of the treatment liquid according to this embodiment is not particularly limited, but is preferably 0.1 to 99.999 mass %. When the water content is high, the treatment liquid can be suitably used as a so-called aqueous treatment liquid, but the water content can also be selected according to the application, taking into consideration the type of metal to be cleaned, etc.

[0059] The treatment liquid according to this embodiment is preferably an aqueous treatment liquid. In this case, the content of (D) water is preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, and even more preferably 90% by mass or more. The content of (E) organic solvent, which will be described later, is preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 10% by mass or less.

[0060] ((E) Organic Solvent)

[0061] The treatment liquid according to this embodiment preferably contains an organic solvent depending on the application and conditions. The treatment liquid according to this embodiment can be suitably used as a solvent-based treatment liquid containing more organic solvent than water, or as an aqueous treatment liquid containing more water than organic solvent.

[0062] Specific examples of organic solvents are not particularly limited, but are preferably at least one selected from the group consisting of alcohol-based solvents, glycol ester-based solvents, sulfoxide-based solvents, sulfone-based solvents, amide-based solvents, lactone-based solvents, imidazolidinone-based solvents, nitrile-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, pyrrolidone-based solvents, and urea-based solvents. Furthermore, the treatment liquid according to this embodiment preferably contains only at least one organic solvent selected from the group consisting of alcohol-based solvents, glycol ester-based solvents, sulfoxide-based solvents, sulfone-based solvents, amide-based solvents, lactone-based solvents, imidazolidinone-based solvents, nitrile-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, pyrrolidone-based solvents, and urea-based solvents, and more preferably does not contain any other solvents. Furthermore, when the treatment liquid according to this embodiment contains an organic solvent, it is preferable to use a water-soluble organic solvent from the viewpoint of the water solubility of the treatment liquid.

[0063] Specific examples of alcohol-based solvents include aliphatic alcohols such as methanol, ethanol, denatured ethanol, isopropanol, n-propanol, n-butanol, and 3-methoxy-3-methyl-1-butanol; and glycols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, glycerin, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, furfuryl alcohol, and hexylene glycol.

[0064] Specific examples of glycol ester solvents include ethylene glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, diethylene glycol monomethyl ether, diethylene glycol dimethyl ether, triethylene glycol monomethyl ether, triethylene glycol dimethyl ether, ethylene glycol monoethyl ether, ethylene glycol diethyl ether, ethylene glycol monobutyl ether, ethylene glycol dibutyl ether, diethylene glycol monobutyl ether, diethylene glycol dibutyl ether, triethylene glycol monobutyl ether, triethylene glycol dibutyl ether, ethylene glycol monohexyl ether, ethylene glycol dihexyl ether, diethylene glycol monohexyl ether, diethylene glycol dihexyl ether, and ethylene glycol phenyl ether; ethylene glycol ether acetates such as ethylene glycol monobutyl ether acetate and diethylene glycol monobutyl ether acetate; propylene glycol propylene-based glycol ethers such as propylene glycol monomethyl ether (PGME), propylene glycol dimethyl ether, dipropylene glycol monomethyl ether (DPM), dipropylene glycol dimethyl ether, tripropylene glycol monomethyl ether, tripropylene glycol dimethyl ether, propylene glycol monoethyl ether, propylene glycol diethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol diethyl ether, tripropylene glycol monoethyl ether, tripropylene glycol diethyl ether, propylene glycol monopropyl ether, propylene glycol dipropyl ether, dipropylene glycol monopropyl ether, dipropylene glycol dipropyl ether, propylene glycol monobutyl ether, propylene glycol dibutyl ether, dipropylene glycol monobutyl ether, dipropylene glycol dibutyl ether, tripropylene glycol monobutyl ether, tripropylene glycol dibutyl ether, and propylene glycol phenyl ether;Examples include propylene-based glycol ether acetates such as propylene glycol methyl ether acetate, dipropylene glycol methyl ether acetate, and propylene glycol diacetate.

[0065] Specific examples of sulfoxide solvents include dimethyl sulfoxide (DMSO), diethyl sulfoxide, dipropyl sulfoxide, diphenyl sulfoxide, and thiophene.

[0066] Specific examples of sulfone solvents include dimethyl sulfone, diethyl sulfone, tetramethylene sulfone, dipropyl sulfone, sulfolane (also known as tetramethylene sulfone), 3-methyl sulfolane, 2,4-dimethyl sulfolane, 3,4-dimethyl sulfolane, diphenyl sulfolane, 3,4-diphenylmethyl sulfolane, sulfolene, 3-methyl sulfolene, and 3-ethyl sulfolene.

[0067] Specific examples of amide solvents include dimethylformamide (DMF), diethylformamide (DEF), dimethylacetamide (DMAc), N-methylpyrrolidine (MPD), and hexamethylphosphoric triamide (HMPA).

[0068] Specific examples of lactone solvents include γ-butyrolactone, α-methyl-γ-butyrolactone, β-propiolactone, γ-valerolactone, δ-valerolactone, γ-caprolactone, ε-caprolactone, γ-laurolactone, and hexanolactone.

[0069] Specific examples of imidazolidinone solvents include 2-imidazolidinone, 1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2-imidazolidinone, 1,3-dipropyl-2-imidazolidinone, and 1,3-diisopropyl-2-imidazolidinone.

[0070] Specific examples of nitrile solvents include acetonitrile, propionitrile, valeronitrile, and butyronitrile.

[0071] Specific examples of ketone solvents include acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), diisobutyl ketone, cyclohexanone, diacetone alcohol, 1-hexanone, 2-hexanone, 4-heptanone, 2-heptanone (methyl amyl ketone), 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetylacetone, acetonylacetone, phenylacetone, acetophenone, methyl naphthyl ketone, methylcyclohexanone, ionone, isophorone, propylene carbonate (propylene carbonate), diacetonyl alcohol, and acetylcarbinol.

[0072] Specific examples of the ether solvent include diisopropyl ether, 1,4-dioxane, methyl tert-butyl ether (MTBE), dimethyl ether, diethyl ether, dipropyl ether, and methyl phenyl ether.

[0073] Specific examples of ester solvents include methyl acetate, ethyl acetate, butyl acetate, amyl acetate, propyl acetate, isopropyl acetate, methyl lactate, ethyl lactate, butyl lactate, ethyl methoxyacetate, ethyl ethoxyacetate, 2-methoxybutyl acetate (2-methoxybutyl acetate), 3-methoxybutyl acetate (3-methoxybutyl acetate), 4-methoxybutyl acetate (4-methoxybutyl acetate), 3-methoxy-3-methylbutyl acetate (3-methoxy-3-methylbutyl acetate), 3-ethyl-3-methoxybutyl acetate (3-ethyl-3-methoxybutyl acetate), and 4-methyl-4-methoxypentyl acetate. methyl formate, ethyl formate, propyl formate, butyl formate, ethyl lactate (EL), propyl lactate, butyl lactate, ethyl carbonate, propyl carbonate, butyl carbonate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, methyl-3-methoxypropionate, ethyl-3-methoxypropionate, ethyl-3-ethoxypropionate, and propyl-3-methoxypropionate.

[0074] Specific examples of pyrrolidone solvents include N-methylpyrrolidone (NMP), 2-pyrrolidone, and N-vinyl-2-pyrrolidone.

[0075] Specific examples of urea-based solvents include 1,3-dimethylurea, 1,3-diethylurea, 1,3-dipropylurea, 1,3-diisopropylurea, tetramethylurea, tetraethylurea, tetrapropylurea, tetraisopropylurea, and N,N-dimethylpropyleneurea.

[0076] The organic solvent (E) may be used alone or in combination of two or more kinds.

[0077] Although the treatment liquid according to this embodiment can achieve a sufficient effect even without containing an organic solvent, it can also achieve a sufficient effect if it contains an organic solvent. For example, the content of the organic solvent in this embodiment can be 0 to 95% by mass. The lower limit of the content of the treatment liquid may be, for example, 5% by mass or more, 10% by mass or more, 20% by mass or more, 30% by mass or more, 40% by mass or more, or 50% by mass or more, depending on the components of the treatment liquid. The upper limit of the content of the treatment liquid may be, for example, 90% by mass or less, 80% by mass or less, 70% by mass or less, 60% by mass or less, or 50% by mass or less.

[0078] On the other hand, the treatment liquid according to this embodiment can achieve sufficient effects even if the type and content of the organic solvent are changed depending on the application and mode of use. For example, in the case of acetate, it may be possible to reduce the acetate content. Specifically, it is preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 2% by mass or less. It is more preferably substantially free, and preferably 0% by mass (nothing at all).

[0079] In the case of acetic acid and peracetic acid, it may be possible to reduce the content of acetic acid and peracetic acid. Specifically, it is preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 2% by mass or less, and more preferably substantially free of acetic acid and peracetic acid, and it is preferably 0% by mass (free of acetic acid and peracetic acid).

[0080] The treatment solution according to this embodiment may or may not contain components other than those described above, as necessary. Examples of such components include anticorrosive agents, pH adjusters, buffers, surfactants, solvents, etc. Furthermore, the treatment solution according to this embodiment may contain metal impurities, as described below, within a range in which the action and effect of the treatment solution can be obtained.

[0081] ((F) Corrosion inhibitor)

[0082] The treatment solution according to this embodiment preferably contains an anticorrosive agent when it is desired to further improve the anticorrosive properties of the metal layer. The treatment solution according to this embodiment is expected to have the advantage that, even when an anticorrosive agent is used in combination, the anticorrosive effect of the anticorrosive agent is not reduced and a high anticorrosion effect can be maintained. Note that the anticorrosive agent can be appropriately selected depending on the type of metal layer to be protected, etc.

[0083] Specific examples of the anticorrosive agent include, but are not limited to, at least one selected from the group consisting of a nitrogen-containing heterocycle-containing compound, a mercapto group-containing compound, an aliphatic amine compound, and a salt thereof. Among these, the treatment liquid according to the present embodiment preferably contains a nitrogen-containing heterocycle-containing compound and a salt thereof.

[0084] Specific examples of nitrogen-containing heterocycle-containing compounds include imidazole ring-containing compounds, triazole ring-containing compounds, pyridine ring-containing compounds, pyrimidine ring-containing compounds, phenanthroline ring-containing compounds, tetrazole ring-containing compounds, pyrazole ring-containing compounds, and purine ring-containing compounds. Among these, tetrazole ring-containing compounds are preferred. By using a tetrazole ring-containing compound, the corrosion resistance of a layer containing, for example, a metal component such as cobalt or copper as a main component (e.g., a metal wiring layer, an etching stop layer, an interlayer insulating film, or other functional layer) can be further improved. That is, when the treatment solution according to this embodiment is used, damage (film loss) to a layer containing cobalt, copper, or the like can be more effectively reduced.

[0085] Specific examples of the imidazole ring-containing compound include 1-decyl-3-methylimidazolium chloride, 2-ethyl-4-methylimidazole, 2-methylimidazole, 2-ethylimidazole, 2-isopropylimidazole, 2-propylimidazole, 2-butylimidazole, 4-methylimidazole, 2,4-dimethylimidazole, 2-undecylimidazole, 2-aminoimidazole, and 2,2'-biimidazole.

[0086] Specific examples of the triazole ring-containing compound include 1,2,4-triazole, 1,2,3-benzotriazole, 1,2,3-triazole, 3-amino-1H-1,2,4-triazole, 5-methyl-1H-benzotriazole, 1-hydroxybenzotriazole, 1-hydroxypropylbenzotriazole, 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.

[0087] Specific examples of the pyridine ring-containing compound include 1H-1,2,3-triazolo[4,5-b]pyridine, 1,2,4-triazolo[4,3-a]pyridin-3(2H)-one, 3H-1,2,3-triazolo[4,5-b]pyridin-3-ol, 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, 4,4'-dimethyl-2,2'-bipyridyl, 4,4'-di-tert-butyl-2,2'-bipyridyl, and 4,4'-dinonyl-2,2'-bipyridyl.

[0088] Specific examples of the pyrimidine ring-containing compound 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. 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, 4-aminopyrazolo[3,4-d]pyrimidine, and the like.

[0089] Specific examples of phenanthroline ring-containing compounds include 1,10-phenanthroline.

[0090] Specific examples of the tetrazole ring-containing compound include 1H-tetrazole, 5-amino-1H-tetrazole, 5-methyl-1H-tetrazole, 5-phenyl-1H-tetrazole, and 1-(2-diaminoethyl)-5-mercaptotetrazole.

[0091] Specific examples of the pyrazole ring-containing compound include 3,5-dimethylpyrazole, 3-amino-5-methylpyrazole, 4-methylpyrazole, and 3-amino-5-hydroxypyrazole.

[0092] Specific examples of purine ring-containing compounds include purine.

[0093] Specific examples of the mercapto group-containing compound include 1-thioglycerol, 3-(2-aminophenylthio)-2-hydroxypropyl mercaptan, 3-(2-hydroxyethylthio)-2-hydroxypropyl mercaptan, 2-mercaptopropionic acid, and 3-mercaptopropionic acid.

[0094] Specific examples of the aliphatic amine compound include alkylamines, dialkylamines, and trialkylamines.

[0095] The anticorrosive agent may also be a salt of the above-mentioned compound. Specific examples of the salt include, but are not limited to, sodium salt, potassium salt, ammonium salt, alkylammonium salt (e.g., tetramethylammonium salt), etc. The anticorrosive agent may also be a hydrate of the above-mentioned compound.

[0096] The concentration of the anticorrosive agent in the treatment solution according to this embodiment is preferably 0.0001 to 10% by mass. The upper limit of the concentration of the anticorrosive agent is more preferably 6% by mass or less, and even more preferably 3% by mass or less. The lower limit of the concentration of the anticorrosive agent is more preferably 0.001% by mass or more, even more preferably 0.01% by mass or more, and still more preferably 0.1% by mass or more. When two or more types of anticorrosive agents are contained, it is preferable that the total amount thereof is within the above range.

[0097] (pH adjuster)

[0098] The treatment liquid according to this embodiment may contain a pH adjuster to adjust the pH to a desired level. As the pH adjuster, an inorganic acid, an organic acid, an organic basic compound, or an inorganic basic compound can be appropriately used.

[0099] The pH of the treatment liquid according to this embodiment is not particularly limited, and a suitable pH value can be selected as appropriate taking into consideration the intended use, the components contained, etc. The pH of the treatment liquid may be, for example, 1 to 7.

[0100] (Buffering agent)

[0101] The treatment liquid according to this embodiment may contain a buffer. The buffer is a compound that has the effect of suppressing changes in the pH of the treatment liquid. The buffer is not particularly limited as long as it is a compound that has pH buffering ability.

[0102] Examples of buffers include Good's buffers, such as tricine, bicine, and bis(2-hydroxyethyl)aminotris(hydroxymethyl)methane (Bis-Tris).

[0103] The buffering agent may be used alone or in combination of two or more. Alternatively, the treatment liquid according to this embodiment may not contain a buffering agent.

[0104] (Surfactant)

[0105] The treatment liquid according to this embodiment may contain a surfactant for the purpose of adjusting the wettability of the treatment liquid with respect to the substrate, etc. Examples of the surfactant include a nonionic surfactant, an anionic surfactant, a cationic surfactant, and an amphoteric surfactant.

[0106] 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.

[0107] Examples of anionic surfactants include polyoxyethylene alkyl ether acetic acid, polyoxyethylene alkyl ether propionic acid, and salts of fatty acids. The salts of these include, but are not limited to, sodium salts, potassium salts, ammonium salts, and alkylammonium salts (e.g., tetramethylammonium salts).

[0108] Examples of cationic surfactants include alkylpyridium surfactants and quaternary ammonium salt surfactants.

[0109] Examples of amphoteric surfactants include betaine surfactants, amino acid surfactants, imidazoline surfactants, and amine oxide surfactants.

[0110] These surfactants are generally commercially available. The surfactants may be used alone or in combination of two or more.

[0111] When the treatment liquid according to this embodiment contains a surfactant, the content of the surfactant is not particularly limited, but is, for example, preferably 0.0001% by mass to 5% by mass relative to the total mass of the treatment liquid. The lower limit of the content is more preferably 0.0002% by mass or more, and even more preferably 0.002% by mass or more. The upper limit of the content is more preferably 3% by mass or less, even more preferably 1% by mass or less, and even more preferably 0.2% by mass or less.

[0112] 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.

[0113] (Impurities, etc.)

[0114] The treatment liquid according to this embodiment may contain metal impurities containing at least one metal atom selected from the group consisting of, for example, Fe atoms, Cr atoms, Ni atoms, Zn atoms, Ca atoms, and Pb atoms.

[0115] The total content of metal atoms in the treatment liquid according to this embodiment is preferably 100 mass ppt or less, relative to the total mass of the treatment liquid. The lower limit of the total content of metal atoms is preferably as low as possible, and may be, for example, 0.001 mass ppt or more. The total content of metal atoms may be, for example, 0.001 mass ppt to 100 mass ppt. By setting the total content of metal atoms to the above-mentioned preferred upper limit or less, it is believed that the defect suppression and residue suppression properties of the treatment liquid are improved. By setting the total content of metal atoms to the above-mentioned preferred lower limit or more, it is believed that metal atoms are less likely to be isolated and present in the system, and that adverse effects on the overall production yield of the object to be cleaned are less likely to be exerted.

[0116] 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.

[0117] The treatment liquid according to this embodiment may contain, for example, impurities derived from organic substances (organic impurities). The total content of the above-mentioned 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, but may be, for example, 0.1 ppm by mass or more. The total content of organic impurities may be, for example, 0.1 ppm by mass to 5000 ppm by mass.

[0118] 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 the lower limit being, for example, 1 or more. It is believed that by keeping the number of countable entities in the treatment liquid within the above-mentioned range, the metal corrosion inhibitory effect of the treatment liquid is improved.

[0119] 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 inevitable mixing in the treatment liquid during the manufacturing process 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).

[0120] 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.

[0121] The treatment solution according to this embodiment can be used for various purposes. Among these, from the viewpoint of effectively utilizing the effects and advantages of this embodiment, it is particularly suitable for cleaning semiconductor substrates on which a film containing a silicon-germanium-based material is formed, and is more suitable for cleaning semiconductor substrates on which a film containing a silicon-based material and a film containing a silicon-germanium-based material are formed. More specifically, a suitable example of this embodiment is a treatment solution for semiconductor substrates, the semiconductor substrate including a substrate and a film formed on the substrate, the film containing a silicon-based material. A more suitable example of this embodiment is a treatment solution for semiconductor substrates, the semiconductor substrate including a substrate and a film formed on the substrate, the film containing a silicon-based material and a film containing a silicon-germanium-based material. Note that the treatment solution according to this embodiment can provide the various effects described above even without containing tetraethoxysilane (TEOS). Alternatively, the treatment solution according to this embodiment can provide the various effects described above even without containing tetramethoxysilane (TMOS).

[0122] Here, an example of a semiconductor substrate for which the treatment liquid according to this embodiment can be used will be described.

[0123] FIG. 1 is a cross-sectional view showing an example of a semiconductor substrate before etching, and FIG. 2 is a cross-sectional view showing an example of a semiconductor substrate after etching.

[0124] The semiconductor substrate 1 before etching shown in FIG. 1 has, on a substrate 10, a layer of silicon germanium-based material 20, a layer of silicon germanium-based material 30, a layer of silicon germanium-based material 20, a layer of silicon germanium-based material 30, a layer of silicon germanium-based material 20, and an oxide film 40, in this order (substrate 10 / layer of silicon germanium-based material 20 / layer of silicon germanium-based material 30 / layer of silicon germanium-based material 20 / layer of silicon germanium-based material 30 / layer of silicon germanium-based material 20 / oxide film 40).

[0125] The substrate 10 may be made of a material such as silicon, amorphous silicon, or glass.

[0126] The material of the silicon germanium-based material layer 20 may be any silicon germanium-based material, for example, a silicon germanium-based material represented by the general formula Si １－ｘ Ge ｘ (where x is greater than 0 and less than 1).

[0127] Examples of the material for the silicon-based material layer 30 include silicon (Si), SiN, and SiO. ２ , Low-k films (SiOC films, SiCOH films, etc.), etc. The silicon-based material layer 30 can be used, for example, as an interlayer insulating film, an etching stopper film, or a transistor channel (for example, a Si channel, etc.). For example, in the case of an interlayer insulating film, a silicon-based material having insulating properties can be selected, and a suitable material can be selected as appropriate in consideration of manufacturing conditions, etc.

[0128] The oxide film 40 can function as a protective film against etching. In this case, the oxide film 40 may be made of any material that is resistant to etching, and the material is not particularly limited. A suitable material can be selected in consideration of manufacturing conditions, etc., for example, SiO ２ Examples of the silicon oxide film include a silicon oxide film such as the one shown in FIG. 1. The silicon oxide film can function as a protective film for silicon-based materials and silicon germanium-based materials. Examples of the silicon oxide film include a thermal oxide film.

[0129] Although not shown, a metal wiring layer made of another metal material may be provided as a layer other than the silicon germanium-based material layer 20 and the silicon-based material layer 30 . The metal wiring layer is a wiring layer containing at least one of metals such as molybdenum (Mo), tungsten (W), ruthenium (Ru), copper (Cu), iron (Fe), gold (Au), silver (Ag), nickel (Ni), aluminum (Al), lead (Pb), zinc (Zn), tin (Sn), tantalum (Ta), magnesium (Mg), cobalt (Co), bismuth (Bi), cadmium (Cd), titanium (Ti), 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, and metal fluorides thereof.

[0130] The metal wiring layer is not limited to wiring, but also broadly includes functional layers such as electrodes, insulating layers, low-dielectric layers, and various conductor layers, and includes layers formed by using the above-mentioned various metals as well as their metal oxides, metal nitrides, metal chlorides, and metal fluorides.

[0131] Then, the semiconductor substrate 1 is etched by a known method, the details of which will be described later, but dry etching is preferred.

[0132] The semiconductor substrate 2 after etching shown in FIG. 2 has, on the substrate 10, a layer 22 of silicon-germanium-based material, a layer 30 of silicon-based material, a layer 22 of silicon-germanium-based material, a layer 30 of silicon-germanium-based material, a layer 22 of silicon-based material, and an oxide film 40, in this order (substrate 10 / layer 22 of silicon-germanium-based material / layer 30 of silicon-germanium-based material / layer 22 of silicon-based material / layer 30 of silicon-germanium-based material / layer 22 of silicon-germanium-based material / oxide film 40).

[0133] The processing solution according to this embodiment can suppress damage to silicon-based materials and selectively remove silicon-germanium-based materials, and therefore, as shown in FIG. 2 , it is possible to suppress damage to the silicon-based material layer 30 and selectively remove only the silicon-germanium-based material layer 20, leaving a silicon-germanium-based material layer 22 after processing.

[0134] <Processing method>

[0135] The treatment solution according to the present embodiment can be suitably used as a method for treating a semiconductor substrate. The treatment method according to the present embodiment is a method for treating a semiconductor substrate having a protective film, and includes a step of removing impurities from the semiconductor substrate by bringing the treatment solution into contact with the protective film.

[0136] The protective film preferably includes a film containing the above-mentioned silicon-based material, and more preferably includes a film containing the above-mentioned silicon-based material and a film containing the above-mentioned silicon germanium-based material.

[0137] 1 and the semiconductor substrate 2 shown in Fig. 2, the protective film corresponds to the oxide film 40. Hereinafter, cleaning of the semiconductor substrate 2 shown in Fig. 2 will be described as an example.

[0138] The processing method according to this embodiment is a step of cleaning the semiconductor substrate 2 after etching (e.g., dry etching) in the wiring process using the above-described processing solution. The processing method is not particularly limited, and a known processing method can be used.

[0139] When the processing solution is brought into contact with the semiconductor substrate 2 to be cleaned, the processing solution may be diluted 2 to 2000 times to obtain a diluted solution, and then cleaning may be performed using this diluted solution.

[0140] Examples of cleaning operations include a method of continuously applying a treatment solution onto the semiconductor substrate 2 rotating at a constant speed (spin coating method), a method of immersing the semiconductor substrate 2 in the treatment solution for a certain period of time (dipping method), and a method of spraying the treatment solution onto the surface of the semiconductor substrate 2 (spray method).

[0141] The temperature at which the cleaning treatment is carried out is not particularly limited, but is preferably carried out under conditions of 10 to 80°C. The lower limit of the cleaning treatment temperature (temperature of the treatment liquid) is more preferably 20°C or higher, and even more preferably 40°C or higher. The upper limit of the cleaning treatment temperature (temperature of the treatment liquid) is more preferably 75°C or lower, and even more preferably 70°C or lower. By setting the lower limit of the cleaning treatment temperature within the above-mentioned range, the removability of etching residues can be further improved. Furthermore, by setting the upper limit of the cleaning treatment temperature within the above-mentioned range, unintended composition changes in the treatment liquid can be more effectively suppressed, and cleaning can be carried out more efficiently in terms of workability, safety, cost, etc.

[0142] The cleaning time can be appropriately selected so as to be sufficient to remove etching residues, impurities, etc. adhering to the surface of the semiconductor substrate 2. The cleaning time is not limited to these values, but is, for example, 10 seconds to 30 minutes.

[0143] By cleaning the semiconductor substrate 2 after dry etching with the treatment solution according to this embodiment, it is possible to selectively remove silicon-germanium-based material originating from the silicon-germanium-based material layer 20 while suppressing damage to the silicon-based material layer 30. Furthermore, it is expected that dry etching residues originating from the oxide film 40, which serves as a protective film, can also be cleaned away. Additionally, by using the treatment solution according to this embodiment, damage to various functional layers (e.g., metal wiring layers, etching stop layers, interlayer insulating films, etc.) other than the oxide film 40, which serves as a protective film, can also be suppressed. The treatment solution according to this embodiment has at least the advantages of being able to suppress damage to silicon-based materials and selectively remove silicon-germanium-based materials, and is therefore particularly suitable for selective etching.

[0144] <Semiconductor manufacturing method>

[0145] The treatment liquid according to this embodiment and the treatment method using the same can be suitably used as a method for manufacturing a semiconductor. A suitable example of the method for manufacturing a semiconductor according to this embodiment includes the steps of preparing a semiconductor substrate having a substrate and a protective film provided on the substrate, etching the protective film, and, after etching, removing impurities from the semiconductor substrate by contacting the semiconductor substrate with the treatment liquid described above.

[0146] As in the description of the processing method, the protective film corresponds to, for example, the oxide film 40. Hereinafter, the processing of the semiconductor substrate 2 after etching shown in FIG. 2 will be described as an example.

[0147] (1) A step of preparing a substrate having a protective film

[0148] In step (1), a substrate having at least a protective film is prepared, which is a semiconductor substrate 1 (substrate 10 / silicon germanium-based material layer 20 / silicon-based material layer 30 / silicon germanium-based material layer 20 / silicon-based material layer 30 / silicon germanium-based material layer 20 / oxide film 40) before etching.

[0149] The method for sequentially stacking the silicon germanium-based material layer 20, the silicon-based material layer 30, and the oxide film 40 corresponding to the protective film on the substrate 10 is not particularly limited, and any known method can be used.

[0150] (2) Etching the protective film

[0151] Next, the protective film is etched. The etching method is not particularly limited, and may be wet etching or dry etching, but dry etching is preferable. 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 concerned in that it can cause relatively large damage to the substrate, etc., but by using the treatment solution according to this embodiment, such damage can be effectively suppressed, which is desirable in that it can more effectively reflect the advantages of this embodiment.

[0152] In the case of dry etching, plasma can be used. Usually, when plasma etching is performed, there are problems such as the substrate being easily damaged and the plasma etching residue being generated, which must be cleaned with a treatment liquid. However, the use of the treatment liquid according to the present embodiment is preferable in that such problems can be effectively suppressed.

[0153] (3) After etching, the process of removing impurities from the substrate by bringing the above-mentioned treatment liquid into contact with the substrate.

[0154] The above-described treatment method can be used for the step (3). This allows the desired semiconductor substrate to be obtained. Furthermore, if necessary, known post-treatments can be performed after cleaning.

[0155] As described above, the treatment solution according to this embodiment can suppress damage to silicon-based materials and selectively remove silicon-germanium-based materials. It can be suitably used, for example, as an etching treatment solution for removing residues generated in semiconductor etching processes, and is particularly suitable for removing residues generated by dry etching. The treatment solution according to this embodiment can be expected to efficiently remove metal residues, and furthermore, when used in combination with a corrosion inhibitor, it can be expected to provide further corrosion resistance.

[0156] The present invention will be explained in more detail with reference to the following examples and comparative examples, but the present invention is not limited to these examples in any way.

[0157] 1. Preparation of processing solution

[0158] <Each Example and Each Comparative Example> Treatment solutions having the compositions shown in Tables 1 and 2 were prepared. For example, in Example 1, H ５ IO ６ The treatment liquid was an aqueous solution containing 5% by mass of HCl, 0.2% by mass of HF, 0.01% by mass of DADDSPBS, and the remainder being water (see Table 1).

[0159] The abbreviations in the table are as follows: (A) Compounds capable of releasing fluoride ions HF: Hydrogen fluoride HFSA: Hexafluorosilicic acid (B) Oxidizing agents H ５ IO ６ : Periodic acid KBrO ３ : Potassium bromate ・HIO ３ : Iodic acid ・HNO ３ : Nitric acid ・H ２ O ２ : Hydrogen peroxide (C) Anionic compounds DADDSPBS: DiAmmonium DoDecyl(SulphonatoPhenoxy)BenzeneSulphonate DDBSA: 4-Dodecylbenzenesulfonic acid DDSA: 1-Dodecanesulfonic acid EBSA: 4-Ethylbenzenesulfonic acid 1NSA: 1-naphthalenesulfonic acid 1IPNSA: 4-Isopropyl-1-naphthalenesulfonic acid 1BNSA: 4-Butyl-1-naphthalenesulfonic acid

[0160] 2. Evaluation of film loss (SiGe, Si (SOI))

[0161] The film loss in each example and comparative example was evaluated by the following method.

[0162] First, stacks (substrates having films) with each metal layer were fabricated as follows: - A stack (SIO substrate) was prepared by depositing a metal layer of Si (SIO: silicon on insulator) (100 nm thick) on a substrate (12-inch silicon substrate) by CVD. - A stack was prepared by depositing a metal layer of SiGe (100 nm thick) on a substrate (12-inch silicon substrate) by CVD.

[0163] Next, each obtained laminate (substrate with film) was cut into a 2 cm x 2 cm piece in top view to obtain a test sample (wafer coupon). Then, 80 mL of the cleaning solution for each example and comparative example was placed in a 100 mL cup. The sample was then placed in the cup and immersed in the cleaning solution. In the case of Si in each table, the sample was immersed for 10 minutes at 25°C. The cleaning solution was stirred at 300 rpm during immersion. In the case of SiGe in each table, the sample was immersed for 2 minutes at 25°C. The cleaning solution was stirred at 300 rpm during immersion. After immersion, each sample was removed from the cleaning solution, rinsed with water at room temperature for 30 seconds, and dried with nitrogen.

[0164] The film thickness of the sample was measured before and after immersion in the cleaning solution. The difference (nm) between the two was calculated as the amount of change in film thickness, and the difference was divided by the processing time (min) to calculate the film loss (nm / min). It was evaluated that the smaller the amount of film loss of the Si (SOI) film, the more successfully damage to the Si was suppressed. For example, in Example 1, the amount of film loss of the Si (SOI) film was 0.02 nm / min, and the amount of film loss of the SiGe film was 6.9 nm / min (see Table 3).

[0165] The film thickness was measured by the following method. The film thickness of the Si (SOI) film was measured using an ellipsometer ("L115S300 STOKES WAFERSKAN", manufactured by Gaertner Scientific Corporation). The unit of film thickness is angstrom unless otherwise specified. The film thickness of the SiGe film was measured using a scanning X-ray fluorescence analyzer ("ZSX Primus IV", manufactured by Rigaku Corporation).

[0166] 3. Selectivity evaluation (Selectivity of SiGe over Si; SiGe / Si)

[0167] The selectivity of SiGe to Si (SiGe / Si) was calculated by calculating the ratio of the SiGe film loss to the Si film loss (SiGe / Si). The higher the selectivity (SiGe / Si), the better the selectivity of SiGe to Si was evaluated. For example, in Example 1, the selectivity of SiGe to Si (SiGe / Si) was 345 (= 6.9 nm / min ÷ 0.02 nm / min) (see Table 3).

[0168] The compositions of the treatment solutions of the examples and comparative examples are shown in Tables 1 and 2. Table 3 shows the evaluation results of the examples and comparative examples.

[0169]

[0170]

[0171]

[0172] From the above, it has been confirmed that the treatment solution according to this example can suppress damage to silicon-based materials and selectively remove silicon-germanium-based materials. Such treatment solution can be suitably used in semiconductor substrate treatment methods and semiconductor manufacturing methods.

[0173] This application claims priority to U.S. Provisional Application No. 63 / 614,132, filed with the U.S. Patent and Trademark Office on December 22, 2023, the contents of which are incorporated herein by reference.

[0174] REFERENCE SIGNS LIST 1 semiconductor substrate before etching 2 semiconductor substrate after etching 10 substrate 20 silicon germanium-based material layer (before etching) 22 silicon germanium-based material layer (after etching) 30 silicon-based material layer 40 oxide film

Claims

1. A treatment liquid containing: a compound capable of releasing fluoride ions; an oxidizing agent; and an anionic compound.

2. The treatment liquid according to claim 1, wherein the anionic compound is a sulfonic acid compound.

3. The treatment liquid according to claim 1, wherein the content of the anionic compound is 0.000001 to 5 mass %.

4. The treatment liquid according to claim 1, further comprising water.

5. The treatment liquid according to claim 1, wherein the ratio of the content of said oxidizing agent to the content of said anionic compound is 0.01 to 300,000.

6. The processing liquid according to claim 1, wherein the processing liquid is a processing liquid for a semiconductor substrate, the semiconductor substrate including a substrate and a film formed on the substrate, and the film contains SiGe.

7. A method for treating a semiconductor substrate having a protective film, comprising the step of removing impurities from the semiconductor substrate by contacting the protective film with the treatment liquid according to claim 1.

8. A method for manufacturing a semiconductor, comprising: preparing a semiconductor substrate having a substrate and a protective film provided on the substrate; etching the protective film; and removing impurities from the semiconductor substrate after the etching by contacting the semiconductor substrate with the treatment liquid according to claim 1.

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