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

Abstract

To provide a processing liquid that excels in both copper corrosion protection and aluminum etching, and a method for processing substrates and a method for manufacturing a semiconductor substrate.SOLUTION: A processing liquid containing (a) a compound or salt thereof capable of releasing a fluoride anion, (b) a water-soluble organic solvent, (c) water, and (d) a nitrogen-containing aromatic compound, wherein the anion content of the nitrogen-containing aromatic compound at 25°C is between 5 ppm and 30 ppm, and a method for processing a substrate and a method for manufacturing the semiconductor, are provided.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Semiconductor elements such as ICs and LSIs and liquid crystal panel elements are manufactured, for example, by (i) uniformly applying a resist onto an insulating film such as a metal film or SiO2 film deposited on a substrate by CVD, (ii) selectively exposing and developing the resist to form a resist pattern, (iii) selectively etching the substrate on which the CVD-deposited metal film or SiO2 film is formed using this pattern as a mask to form a fine circuit, and (iv) thereafter removing unnecessary resist layers, etc. In addition to CVD, the metal film can be formed by ALD, CVC, PVD, sputtering, metal plating, etc.

[0003] Various types of metal films are used as the above-mentioned metal films. These metal films are laminated in a single layer or in multiple layers on a substrate.

[0004] Meanwhile, with the recent trend toward higher density integrated circuits, dry etching, which allows finer etching at higher density, has become mainstream. However, such etching treatment can leave residues such as altered films or residues derived from other components on the sides and bottom of the pattern. In addition, deposition occurs when the metal film is removed during etching. If such residues and depositions are not sufficiently removed, problems such as a decrease in the yield of semiconductor manufacturing occur. For this reason, a processing liquid (sometimes called a cleaning liquid, a stripping liquid, etc.) is used to remove such residues and depositions.

[0005] Dry etching residues have conventionally been removed by a cleaning process. As a cleaning solution for removing dry etching residues, a cleaning solution containing a peroxide as a residue remover is used (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2016 / 076033 Summary of the Invention [Problem to be solved by the invention]

[0007] However, a wide variety of metals are used for the above-mentioned substrate, depending on the type of metal formed on the substrate, the type of insulating film, the type of resist used, etc. Therefore, depending on the type of metal used, the corrosion resistance and etching properties may be insufficient, and there is room for further improvement of the treatment liquid depending on the type of metal used. However, such detailed consideration is not currently given. The inventors have focused on this current situation and conducted extensive research, and as a result, have found that there is room for further improvement, particularly in terms of achieving both the corrosion resistance of copper and the etching properties of aluminum.

[0008] The present invention has been made in consideration of the above-mentioned circumstances, and has an object to provide a treatment liquid, a substrate treatment method, and a semiconductor substrate manufacturing method that are excellent in both copper corrosion resistance and aluminum etching properties. [Means for solving the problem]

[0009] As a result of intensive research by the present inventors to achieve the above-mentioned object, they discovered that a treatment liquid containing (a) a compound or a salt thereof capable of releasing a fluoride anion, (b) a water-soluble organic solvent, (c) water, and (d) a nitrogen-containing aromatic compound, in which the content of the anion of the nitrogen-containing aromatic compound at 25° C. is 5 ppm or more and 30 ppm or less, led to the completion of the present invention. That is, the present invention is as follows.

[0010] [1] A treatment liquid comprising: (a) a compound or a salt thereof capable of releasing a fluoride anion; (b) a water-soluble organic solvent; (c) water; and (d) a nitrogen-containing aromatic compound, the content of the anion of the nitrogen-containing aromatic compound at 25°C being 5 ppm or more and 30 ppm or less. [2] The treatment liquid according to [1], further comprising (e) ammonium hydroxide. [3] The treatment liquid according to [1], wherein the (b) water-soluble organic solvent contains at least one selected from the group consisting of dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, ethylene glycol, and diethylene glycol monobutyl ether. [4] The treatment liquid according to [1], wherein the (d) nitrogen-containing aromatic compound contains at least one selected from the group consisting of an imidazole ring-containing compound, a triazole ring-containing compound, a carbazole ring-containing compound, a pyridine ring-containing compound, a pyrimidine ring-containing compound, a tetrazole ring-containing compound, a pyrazole ring-containing compound, a purine ring-containing compound, and a phenanthroline ring-containing compound. [5] The treatment liquid according to [1], wherein the total content of the solvent is 60% by mass or more and 99.9% by mass or less. [6] The treatment liquid according to [1], which is a post-etching treatment liquid for a substrate having a first metal atom-containing layer containing copper atoms and a second metal atom-containing layer containing aluminum atoms or cobalt atoms. [7] The treatment liquid according to [1], which is a post-etching treatment liquid for a substrate having a first metal atom-containing layer containing copper atoms, a second metal atom-containing layer containing aluminum atoms, and a third metal atom-containing layer containing cobalt atoms. [8] A method for treating a substrate, comprising a step of treating an etched substrate having a first metal atom-containing layer containing copper atoms and a second metal atom-containing layer containing aluminum atoms or cobalt atoms, with the treatment liquid according to [1] at a temperature of 20°C or higher and lower than 30°C. [9] A method for treating a substrate, comprising a step of treating an etched substrate having a first metal atom-containing layer containing copper atoms, a second metal atom-containing layer containing aluminum atoms, and a third metal atom-containing layer containing cobalt atoms, with the treatment liquid according to [1] at a temperature of 20°C or higher and lower than 30°C.

[10] A method for producing a semiconductor substrate, comprising the steps of: etching a substrate having a first metal atom-containing layer containing copper atoms and a second metal atom-containing layer containing aluminum atoms or cobalt atoms; ashing the etched substrate; and treating the ashed substrate at a temperature of 20°C or higher and lower than 30°C using the treatment liquid according to [1].

[11] A method for producing a semiconductor substrate, comprising the steps of: etching a substrate having a first metal atom-containing layer containing copper atoms, a second metal atom-containing layer containing aluminum atoms, and a third metal atom-containing layer containing cobalt atoms; ashing the etched substrate; and treating the ashed substrate at a temperature of 20°C or higher and lower than 30°C using the treatment liquid described in [1]. Effect of the Invention

[0011] According to the present invention, it is possible to provide a processing liquid, a substrate processing method, and a semiconductor substrate manufacturing method that are excellent in both copper corrosion prevention properties and aluminum etching properties. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a cross-sectional view showing an example of an element to be cleaned after dry etching. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment for carrying out the present invention (hereinafter, simply referred to as "the present embodiment") will be described in detail. The 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 carried out by appropriately modifying it within the scope of its gist.

[0014] In the drawings, the same elements are given the same reference numerals, and duplicated explanations are 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 solution>

[0016] The treatment liquid according to the present embodiment contains (a) a compound or a salt thereof capable of releasing fluoride anions, (b) a water-soluble organic solvent, (c) water, and (d) a nitrogen-containing aromatic compound, and has a content of the anions of the nitrogen-containing aromatic compound of 5 ppm or more and 30 ppm or less by mass at 25° C. By using such a treatment liquid, it is possible to unexpectedly achieve at least the effect of excellent both in copper corrosion resistance and aluminum etching properties.

[0017] The treatment liquid according to the present embodiment can be suitably used as a treatment liquid for removing etching residues containing inorganic substances, and in that case, can be suitably used as a treatment liquid for cleaning semiconductors, etc.

[0018] The inorganic substance referred to in this embodiment is a compound containing a metal, and examples thereof include metals, metal oxides, metal nitrides, metal chlorides, and metal fluorides. That is, the treatment liquid according to this embodiment is expected to have excellent anticorrosive properties and etching properties as described above, and also to efficiently remove etching residues containing such inorganic substances. Examples of inorganic substances other than metals include silicon (Si) and its oxides (SiO x ; Unless otherwise specified, x represents a number. ), nitrides (SiN x ), chloride (SiCl x ), and fluoride (SiFx ) etc.

[0019] Regarding removal of residues, for example, the treatment liquid according to the present embodiment is expected to efficiently remove residues contained in a hard mask layer (HM layer) and other layers. In addition, the treatment liquid according to the present embodiment is expected to efficiently remove inorganic-containing residues derived from a metal wiring layer, including metals described below, and one selected from the group consisting of metal oxides, metal nitrides, metal chlorides, and metal fluorides thereof.

[0020] Examples of metals include molybdenum (Mo), tungsten (W), ruthenium (Ru), copper (Cu), gold (Au), silver (Ag), iron (Fe), 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.

[0021] Examples of the metal oxide include metal oxides of the above-mentioned metal atoms. Specific examples of the metal oxide include TiO x , TaO x , CuO x , CoO x , RuO x , AlO x , WO 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.

[0022] The metal nitride may be any of the metal nitrides of the above-mentioned metal atoms. Specific examples of metal nitrides 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, the following.

[0023] The 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, the following.

[0024] The metal fluoride may be a metal fluoride 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 , AuF x , AgF x , FeF x , NiF x These include, but are not limited to, the following.

[0025] The treatment liquid according to the present embodiment is suitable for removing etching residues, and is particularly suitable for removing dry etching residues. In general, dry etching residues are removed before the next process in order to improve semiconductor yields and prevent deterioration of electrical properties. For example, the treatment liquid according to the present embodiment is suitable for cleaning semiconductor substrates after dry etching in a wiring process.

[0026] (Component a)

[0027] The treatment liquid according to the present embodiment contains a compound capable of releasing fluoride anions or a salt thereof. Examples of the component (a) include one or more compounds selected from the group consisting of hydrogen fluoride (HF), ammonium fluoride, and salts thereof.

[0028] Hydrogen fluoride may be blended in the form of hydrofluoric acid (hydrogen fluoride aqueous solution) or the like. Examples of hydrogen fluoride salts include tetraalkylammonium salts and trialkylamine salts. Specific examples of hydrogen fluoride salts include tetrabutylammonium dihydrogen trifluoride, tetraethylammonium fluoride tetrahydrofluoride, tetraethylammonium fluoride trihydrofluoride, triethylamine pentahydrofluoride, and triethylamine trihydrofluoride.

[0029] It is preferable that the treatment liquid according to the present embodiment does not contain hydroxylamine. And, it is preferable that the treatment liquid according to the present embodiment does not contain a thiol-containing compound. Also, it is preferable that the treatment liquid according to the present embodiment does not contain a phosphinic acid-containing compound. Furthermore, it is preferable that the treatment liquid according to the present embodiment does not contain a phosphonic acid-containing compound. Furthermore, it is preferable that the treatment liquid according to the present embodiment does not contain a peroxide. Even if the treatment liquid according to the present embodiment does not contain such a compound, it can be expected that both the corrosion prevention property and the etching property are excellent. From this viewpoint, it is more preferable that the treatment liquid according to the present embodiment does not contain hydroxylamine, a thiol-containing compound, a phosphinic acid-containing compound, a phosphonic acid-containing compound, and a peroxide.

[0030] The component a may be used alone or in combination of two or more kinds.

[0031] (b component)

[0032] The treatment liquid according to the present embodiment contains a water-soluble organic solvent. The treatment liquid according to the present embodiment, which contains a water-soluble organic solvent and water described below, is suitable as a so-called aqueous treatment liquid.

[0033] Specific examples of the water-soluble organic solvent 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, it is more preferable that the treatment liquid according to this embodiment does not contain any solvent other than 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 as an organic solvent. 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. Furthermore, it is preferable to use only a water-soluble organic solvent as the organic solvent.

[0034] 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 (also known as 1,2-ethanediol, monoethylene glycol), diethylene glycol (also known as 2,2'-oxydiethanol, diethyl glycol), propylene glycol (also known as propane-1,2-diol), dipropylene glycol, glycerin, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, furfuryl alcohol, and hexylene glycol (also known as 2-methyl-2,4-pentanediol).

[0035] Specific examples of glycol ester-based solvents include 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 polypropylene 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 of the propylene glycol ether acetates include propylene glycol methyl ether acetate, dipropylene glycol methyl ether acetate, and propylene glycol diacetate.

[0036] Specific examples of sulfoxide solvents include dimethyl sulfoxide (DMSO), diethyl sulfoxide, dipropyl sulfoxide, diphenyl sulfoxide, and thiophene.

[0037] Specific examples of sulfone-based 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.

[0038] Specific examples of amide solvents include N,N-dimethylformamide (DMF), diethylformamide (DEF), N,N-dimethylacetamide (DMAc), N-methylpyrrolidine (MPD), and hexamethylphosphoric triamide (HMPA).

[0039] Specific examples of lactone solvents include γ-butyllactone, α-methyl-γ-butyrolactone, β-propiolactone, γ-valerolactone, δ-valerolactone, γ-caprolactone, ε-caprolactone, γ-laurolactone, and hexanolactone.

[0040] Specific examples of the imidazolidinone solvent include 2-imidazolidinone, 1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2-imidazolidinone, 1,3-dipropyl-2-imidazolidinone, and 1,3-diisopropyl-2-imidazolidinone.

[0041] Specific examples of the nitrile solvent include acetonitrile, propionitrile, valeronitrile, and butyronitrile.

[0042] 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, diacetonyl alcohol, and acetyl carbinol.

[0043] 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.

[0044] Specific examples of ester-based 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), 4-methyl-4-methoxy Examples of the alkoxysilane include pentyl acetate, methyl formate, ethyl formate, propyl formate, butyl formate, propyl 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.

[0045] Specific examples of pyrrolidone-based solvents include N-methyl-2-pyrrolidone (NMP), 2-pyrrolidone, and N-vinyl-2-pyrrolidone.

[0046] 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.

[0047] Among the above, suitable examples of the water-soluble organic solvent are, for example, at least one selected from the group consisting of dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, ethylene glycol, and diethylene glycol monobutyl ether, and more preferably dimethyl sulfoxide. By using these, for example, the corrosion resistance of a layer containing a metal component such as cobalt or copper as a main component (for example, a metal wiring layer, an etching stop layer, an interlayer insulating film, or other functional layers, etc.) can be further improved. That is, when the treatment liquid according to this embodiment is used, damage (amount of film loss) given to a layer containing copper, cobalt, etc. can be further effectively reduced.

[0048] By using such a suitable solvent, it is possible to further improve the corrosion resistance of a layer (e.g., a metal wiring layer, an etching stop layer, an interlayer insulating film, or other functional layers) containing, as a main component, a metal component such as copper, cobalt, tungsten, ruthenium, aluminum, molybdenum, etc. In other words, when such a solvent is used, it is possible to maintain both the corrosion resistance and the etching property at a high level.

[0049] The component b may be used alone or in combination of two or more.

[0050] Moreover, the treatment liquid according to the present embodiment is expected to obtain the desired effect without using a halogen-based solvent. That is, the treatment liquid according to the present embodiment can be used as an environmentally friendly halogen-free treatment liquid. From such a viewpoint, a suitable example of the treatment liquid according to the present embodiment is one that does not substantially contain halogen atoms, and furthermore, one that does not contain any halogen atoms. Note that "substantially does not contain" does not exclude the case where the component is inevitably blended as an impurity. For example, the content of the component in the treatment liquid is preferably 1 mass % or less, more preferably 0.5 mass % or less, even more preferably 0.3 mass % or less, even more preferably 0.1 mass % or less, and even more preferably 0 mass %.

[0051] The ratio of the content of component b to the total content of component b and component c (water) (b / (b+c)) is preferably 0.05 to 50 mass%. The lower limit of this ratio may be, for example, 0.1 mass% or more. The upper limit of this ratio is more preferably 30 mass% or less, even more preferably 20 mass% or less, and even more preferably 10 mass% or less. By setting the ratio as above, a water-soluble mixed solvent can be obtained as the solvent, which is preferable in that higher water solubility can be imparted to the treatment liquid.

[0052] (c component)

[0053] The treatment liquid according to the present embodiment contains water. As the water, for example, deionized water (DIW), ultrapure water (UPW), pure water, high-purity ionized water, etc. can be used from the viewpoint of suitability for manufacturing semiconductor devices.

[0054] The water content in the treatment liquid according to the present embodiment is not particularly limited, but is preferably 1 to 50 mass%. The lower limit of this content is more preferably 5 mass% or more, even more preferably 10 mass% or more, and even more preferably 15 mass% or more, from the viewpoint of being able to maintain high levels of residue removability and corrosion prevention while imparting water solubility as an aqueous treatment liquid. The upper limit of this content is more preferably 45 mass% or less, even more preferably 40 mass% or less, and even more preferably 35 mass% or less, from the viewpoint of being able to maintain high levels of residue removability and corrosion prevention while imparting water solubility as an aqueous treatment liquid. By having the water content within the above-mentioned range, other components can be dissolved uniformly and stably.

[0055] The total content of the solvent is not particularly limited, but is preferably 60% by mass or more and 99.9% by mass or less. The lower limit of this content is 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 upper limit of this content is more preferably 99.7% by mass or less, even more preferably 99.5% by mass or less, and even more preferably 99.0% by mass or less. By setting the total amount of the solvent within the above range, it is possible to maintain high levels of corrosion prevention and residue removability while imparting water solubility as an aqueous treatment liquid. The total amount of the solvent here means the total of the water-soluble organic solvent, water, and other solvents. For example, when only the water-soluble organic solvent and water are used as the solvent, it is the total of the b component and the c component.

[0056] (d component)

[0057] The treatment liquid according to the present embodiment contains a nitrogen-containing aromatic compound. The treatment liquid according to the present embodiment has an anion content of the nitrogen-containing aromatic compound at 25° C. of 5 ppm or more and 30 ppm or less on a molar mass basis (ppm by mass). The lower limit of the anion content is preferably 6 ppm or more, more preferably 6.5 ppm or more, and even more preferably 7 ppm or more. The upper limit of the anion content is preferably 25 ppm or less, more preferably 20 ppm or less, and even more preferably 15 ppm or less. The mass-based anion content (ppm by mass, etc.) can be calculated using web software "Sparc" provided by ARChem (URL: http: / / archemcalc.com / sparc-web / calc).

[0058] As the nitrogen-containing aromatic compound, for example, a nitrogen atom-containing anticorrosive agent can be used.As the nitrogen-containing aromatic compound, for example, it is preferable to be at least one selected from the group consisting of imidazole ring-containing compound, triazole ring-containing compound, carbazole ring-containing compound, pyridine ring-containing compound, pyrimidine ring-containing compound, tetrazole ring-containing compound, pyrazole ring-containing compound, purine ring-containing compound, and phenanthroline ring-containing compound.

[0059] Examples of the imidazole ring-containing compound include imidazole, 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.

[0060] Examples of the triazole ring-containing compound include 1,2,4-triazole (TAZ), 1,2,3-benzotriazole (BTA), 1,2,3-triazole, 3-amino-1H-1,2,4-triazole, 5-methyl-1H-benzotriazole (5MBTA), 1-hydroxybenzotriazole, 1-hydroxypropylbenzotriazole, 2,3-dicarboxypropylbenzotriazole, 4-hydroxybenzotriazole, 4-carboxyl-1H-benzotriazole, 4- Examples of such an amine include 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.

[0061] Examples of the carbazole ring-containing compound include 9H-carbazole, 4-hydroxycarbazole, 1-methyl-carbazole, 3-methyl-9H-carbazole, 9-methyl-1H-carbazole, 2-methoxycarbazole, 1-bromocarbazole, 2-bromocarbazole, 3-bromocarbazole, 4-bromocarbazole, 2-chlorocarbazole, 3-chlorocarbazole, 2-fluorocarbazole, 3-fluorocarbazole, 2-iodocarbazole, 3-iodocarbazole, 9-acetylcarbazole, 2 ,7-dibromocarbazole, 3,6-dibromocarbazole, 3,6-dichlorocarbazole, 2,3-benzcarbazole, 9-acetyl-3,6-diiodocarbazole, 2-bromo-7-methoxy-9H-carbazole, 3,6-dimethylcarbazole, 2,7-dimethylcarbazole, 3,6-diaminocarbazole, 3-amino-ethylcarbazole, 3,6-dimethoxy-9H-carbazole, 2,7-dimethoxy-9H-carbazole, 3,3'-bicarbazole, 7H-benzo[c]carbazole, and the like.

[0062] Examples of the pyridine ring-containing compound include 4-(3-phenylpropyl)pyridine, 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.

[0063] Specific examples of pyrimidine ring-containing compounds include pyrimidine, 4-methylpyrimidine, 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, 2,4 ,6-triphenylpyrimidine, 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.

[0064] 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.

[0065] Examples of the pyrazole ring-containing compound include 3,5-dimethylpyrazole, 3-amino-5-methylpyrazole, 4-methylpyrazole, and 3-amino-5-hydroxypyrazole.

[0066] Examples of the purine ring-containing compound include purine, adenine, and N6-benzoyladenine.

[0067] Examples of the phenanthroline ring-containing compound include 1,10-phenanthroline and 5-amino-1,10-phenanthroline.

[0068] In addition, the component d may 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, and alkylammonium salt (e.g., tetramethylammonium salt, etc.). In addition, the component d may be a hydrate of the above-mentioned compound.

[0069] The component d may be used alone or in combination of two or more kinds.

[0070] (e component)

[0071] The treatment liquid according to the present embodiment preferably further contains (e) ammonium hydroxide, which may be added in the form of a salt. The ammonium hydroxide may be added, for example, as an ammonia water solution or ammonia.

[0072] (Other Ingredients)

[0073] The treatment liquid according to the present embodiment is expected to obtain a predetermined effect even if it does not contain any component other than those described above. Of course, the treatment liquid according to the present embodiment may contain any component other than the a component and the d component other than the solvent as necessary, or may not contain any component other than the a component and the d component. For example, when the d component functions as a corrosion inhibitor, it may further contain a corrosion inhibitor other than the d component. In addition, other than the corrosion inhibitor, a pH adjuster, a surfactant, etc. may be further contained, but since sufficient effects can be expected even without these, they may not be contained. In addition, the treatment liquid according to the present embodiment may contain metal impurities described later as long as the action and effect can be obtained.

[0074] (Buffer)

[0075] The treatment liquid according to the present 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. By containing a buffering agent, the pH value of the treatment liquid can be efficiently controlled to be smaller than the acid dissociation constant. In addition, by containing a buffering agent, the pH of the treatment liquid can be efficiently controlled to be a predetermined value. The buffering agent is not particularly limited as long as it is a compound having pH buffering ability.

[0076] Examples of the buffer include Good's buffers. Examples of the Good's buffer include 3-cyclohexylaminopropanesulfonic acid (CAPS), N-tris(hydroxymethyl)methyl-3-aminopropanesulfonic acid (TAPS), 4-(cyclohexylamino)-1-butanesulfonic acid (CABS), tricine, bicine, 2-morpholinoethanesulfonic acid monohydrate (MES), bis(2-hydroxyethyl)aminotris(hydroxymethyl)methane (Bis-Tris), N-(2-acetamido)iminodiacetic acid (ADA), piperazine-1,4-bis(2-ethanesulfonic acid) (PIPES), N-(2-acetamido)-2-aminoethanesulfonic acid (ACES), 2-hydroxyethylaminotris(hydroxymethyl)methane (Bis-Tris), and the like. Examples of such sulfonic acids include hydroxy-3-morpholinopropanesulfonic acid (MOPSO), N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid (BES), N-tris(hydroxymethyl)methyl-2-aminoethanesulfonic acid (TES), 2-[4-(2-hydroxyethyl)-1-piperazinyl]ethanesulfonic acid (HEPES), piperazine-1,4-bis(2-hydroxypropanesulfonic acid) (POPSO), 4-(2-hydroxyethyl)piperazine-1-(2-hydroxypropane-3-sulfonic acid) (HEPSO), and 4-(2-hydroxyethyl)-1-piperazinepropanesulfonic acid (EPPS).

[0077] The buffering agent may be used alone or in combination of two or more kinds. Alternatively, the treatment liquid according to the present embodiment may not contain a buffering agent.

[0078] (Surfactant)

[0079] The treatment liquid according to the present 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.

[0080] 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-type phenyl ether surfactants, polyalkylene tribenzyl phenyl ether surfactants, and acetylene polyalkylene oxide surfactants.

[0081] Examples of anionic surfactants include alkylsulfonic acid, alkylbenzenesulfonic acid, alkylnaphthalenesulfonic acid, alkyldiphenylethersulfonic acid, fatty acid amidesulfonic acid, polyoxyethylene alkylether carboxylic acid, polyoxyethylene alkylether acetic acid, polyoxyethylene alkylether propionic acid, alkylphosphonic acid, and fatty acid salts. These salts are not particularly limited, but include, for example, sodium salts, potassium salts, ammonium salts, and alkylammonium salts (e.g., tetramethylammonium salts).

[0082] Examples of cationic surfactants include alkylpyridinium surfactants and quaternary ammonium salt surfactants.

[0083] Examples of amphoteric surfactants include betaine type surfactants, amino acid type surfactants, imidazoline type surfactants, and amine oxide type surfactants.

[0084] These surfactants are generally commercially available. The surfactants may be used alone or in combination of two or more.

[0085] When the treatment liquid according to the present 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.

[0086] The treatment liquid according to the present embodiment may not contain one or more 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 the present embodiment may not contain a surfactant.

[0087] (pH adjuster)

[0088] The treatment liquid according to the present 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.

[0089] (Impurities, etc.)

[0090] The treatment liquid according to this embodiment may contain metal impurities including at least one type of metal atom selected from the group consisting of, for example, Fe atoms, Cr atoms, Ni atoms, Zn atoms, Ca atoms, and Pb atoms.

[0091] The total content of metal atoms in the treatment liquid according to this embodiment is preferably 100 mass ppt or less with respect 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 to 100 mass ppt. By making the total content of metal atoms equal to or less than the above-mentioned preferable upper limit, the defect suppression and residue suppression properties of the treatment liquid are improved. By making the total content of metal atoms equal to or more than the above-mentioned preferable lower limit, it is considered that metal atoms are less likely to be isolated and present in the system, and thus are less likely to adversely affect the overall manufacturing yield of the object to be cleaned (however, the action and effect of this embodiment are not limited to these).

[0092] The content of metal impurities can be adjusted, for example, by a purification treatment such as filtering. The purification treatment such as filtering may be performed on a part or all of the raw material before preparing the treatment liquid, or may be performed after preparing the treatment liquid.

[0093] The treatment liquid according to the present embodiment may contain, for example, impurities derived from organic matter (organic impurities). The total content of the above-mentioned organic impurities in the treatment liquid according to the present embodiment is preferably 5000 mass ppm or less. The lower limit of the content of the organic impurities is preferably as low as possible, and may be, for example, 0.1 mass ppm or more. The total content of the organic impurities may be, for example, 0.1 to 5000 mass ppm.

[0094] The treatment liquid according to this embodiment may contain countable objects of a size that can be counted by, for example, a light scattering type liquid particle counter. The size of the countable objects is, for example, 0.04 μm or more. The number of countable objects in the treatment liquid according to this embodiment is, for example, 1,000 or less per 1 mL of treatment liquid, and the lower limit is, for example, 1 or more. It is believed that the metal corrosion suppression effect of the treatment liquid is improved by keeping the number of countable objects in the treatment liquid within the above-mentioned range.

[0095] The organic impurities and / or counted bodies 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 organic impurities contained in raw materials (e.g., organic solvents) used in the manufacturing of the treatment liquid, and mixing from the external environment during the manufacturing process of the treatment liquid (e.g., contamination), but are not limited to the above.

[0096] When the objects to be counted are added to the treatment liquid, the abundance ratio may be adjusted for each specific size, taking into consideration the surface roughness of the object to be cleaned, etc.

[0097] The treatment liquid according to the present embodiment can be used for various purposes, among which, from the viewpoint of effectively utilizing the effects and advantages of the present embodiment, it is suitable as a treatment liquid for post-etching a substrate having a first metal atom-containing layer containing copper atoms and a second metal atom-containing layer containing aluminum atoms or cobalt atoms. An example of such a substrate is a copper-based substrate for semiconductor manufacturing.

[0098] Furthermore, the treatment liquid according to the present embodiment is suitable as a treatment liquid for a substrate having a first metal atom-containing layer containing copper atoms, a second metal atom-containing layer containing aluminum atoms, and a third metal atom-containing layer containing cobalt atoms after etching. An example of such a substrate is a copper-based substrate for semiconductor manufacturing.

[0099] Here, an example of a semiconductor substrate for which the treatment liquid according to this embodiment can be used will be described.

[0100] FIG. 1 is a cross-sectional view showing an example of an element (semiconductor substrate) after dry etching, which is to be treated (cleaned).

[0101] The semiconductor element 100 shown in FIG. 1 includes a substrate 10, a metal wiring layer 20, an etching stop layer 30, and an interlayer insulating film 40 stacked in this order, and a hard mask layer (HM layer) 50 formed on the interlayer insulating film 40 (substrate 10 / metal wiring layer 20 / etching stop layer 30 / interlayer insulating film 40 / HM layer 50).

[0102] This semiconductor element 100 is in a state after dry etching has been performed in a wiring process, that is, after dry etching of the interlayer insulating film 40 has been performed using the HM layer 50 on which a prototype of the wiring pattern has been formed by dry etching as a mask. Dry etching residues 60 are attached to the side surfaces of the HM layer 50 and the interlayer insulating film 40. Note that, although the case of etching by dry etching is described here as an example, when etching is performed by wet etching, for example, the resulting residues will be wet etching residues.

[0103] In the spaces between the interlayer insulating films 40 in the wiring pattern, the metal wiring layer 20 is exposed and dry etching residues 60 are also attached.

[0104] The substrate 10 may be made of a material such as silicon, amorphous silicon, or glass.

[0105] The metal wiring layer 20 is a wiring layer containing one of metals such as molybdenum (Mo), tungsten (W), ruthenium (Ru), copper (Cu), gold (Au), silver (Ag), iron (Fe), 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.

[0106] The metal wiring layer 20 is not limited to wiring, but 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 and metal nitrides.

[0107] The material of the interlayer insulating film 40 is not particularly limited as long as it has insulating properties, and a suitable material can be selected in consideration of manufacturing conditions, etc. As the interlayer insulating film 40, for example, a layer containing a silicon-based material such as SiO2, SiN, SiOC, or SiOCN can be used.

[0108] The material of the HM layer 50 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. The treatment liquid according to this embodiment can efficiently remove residues (see dry etching residues 60) generated from the HM layer.

[0109] The dry etching residue 60 includes, for example, the above-mentioned etching residue containing inorganic substances.

[0110] <Processing method>

[0111] The treatment liquid according to the present embodiment can be suitably used as a method for treating a substrate. The treatment method is a treatment for removing residues generated after etching from a substrate. A suitable example of the treatment method according to the present embodiment is a method for treating a substrate, which includes a step of treating an etched substrate having a first metal atom-containing layer containing copper atoms and a second metal atom-containing layer containing aluminum atoms or cobalt atoms, at a temperature of 20° C. or more and less than 30° C. using the treatment liquid described above. The substrate may have the above-described configuration.

[0112] Another preferred example of the processing method according to this embodiment is a method for processing a substrate, comprising a step of processing an etched substrate having a first metal atom-containing layer containing copper atoms, a second metal atom-containing layer containing aluminum atoms, and a third metal atom-containing layer containing cobalt atoms, at a temperature of 20° C. or higher and lower than 30° C., using the above-mentioned processing liquid. The substrate may have the above-mentioned configuration.

[0113] The processing method according to this embodiment is a process of processing (cleaning) the semiconductor element 100 after dry etching in the wiring process using the above-mentioned processing liquid. The cleaning method is not particularly limited, and a known cleaning method can be used. As an example, the case of cleaning the semiconductor element 100 shown in FIG. 1 will be described.

[0114] When the treatment liquid is brought into contact with the semiconductor element 100 to be cleaned, the treatment liquid may be diluted 2 to 2000 times to obtain a diluted liquid, and then the cleaning operation may be performed using this diluted liquid.

[0115] Examples of cleaning operations include a method in which a treatment liquid is continuously applied onto the semiconductor element 100 rotating at a constant speed (spin coating method), a method in which the semiconductor element 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 element 100 (spray method).

[0116] The treatment temperature of the treatment liquid is preferably 20°C or more and less than 30°C. The treatment liquid according to this embodiment is used for treatment in such a temperature range, so that the anticorrosive properties of copper (metal atom-containing layer having copper atoms) and the etching properties of aluminum (metal atom-containing layer having aluminum atoms) can be compatible at a higher level. Furthermore, in the case of a substrate having a metal atom-containing layer having cobalt atoms, it is expected that the anticorrosive properties of copper, the etching properties of aluminum, and the etching properties of cobalt can be compatible at a higher level. The reason for this is unclear, but it is presumed that the above-mentioned effects such as selectivity can be obtained because the metal corrosion inhibitor tends to be more strongly adsorbed to copper, cobalt, etc. than to aluminum, etc., and the anticorrosive properties of the metal corrosion inhibitor are thought to be superior to the corrosion of copper and cobalt by the etching agent, especially in the temperature range of 20°C or more and less than 30°C (however, the action and effect of this embodiment are not limited to these).

[0117] The treatment time of the treatment liquid can be appropriately selected as a time sufficient for removing etching residues, impurities, and the like adhering to the surface of the semiconductor element 100. The cleaning time is preferably, for example, 10 seconds to 30 minutes. The lower limit of the cleaning 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.

[0118] Since cleaning is performed using the treatment solution according to this embodiment, in the semiconductor element 100 with the dry etching residues 60 attached thereto, the dry etching residues 60 originating from the HM layer 50, which is a protective film, can be effectively cleaned and removed while minimizing damage to the metal wiring layer 20, such as copper or cobalt.

[0119] In addition, by using the treatment liquid according to this embodiment, damage to various functional layers (metal wiring layer 20, etching stop layer 30, interlayer insulating film 40, etc.) other than the protective film can also be suppressed.

[0120] Furthermore, the treatment solution according to the present embodiment is expected to provide a practical level of cleaning effect without using conventional general-purpose hydroxylamine or the like, and therefore has the expected advantage of enabling the manufacture of semiconductor devices and the like to be carried out more safely.

[0121] <Semiconductor manufacturing method>

[0122] 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 a step of etching a substrate having a first metal atom-containing layer containing copper atoms and a second metal atom-containing layer containing aluminum atoms or cobalt atoms; a step of ashing the etched substrate; and a step of treating the ashed substrate at a temperature of 20°C or higher and lower than 30°C using the treatment liquid described above. The treatment step using the treatment liquid can adopt the above-mentioned conditions.

[0123] Another preferred example of the method for producing a semiconductor according to this embodiment is a method for producing a semiconductor substrate, comprising the steps of: etching a substrate having a first metal atom-containing layer containing copper atoms, a second metal atom-containing layer containing aluminum atoms, and a third metal atom-containing layer containing cobalt atoms; ashing the etched substrate; and treating the ashed substrate with the above-mentioned treatment liquid at a temperature of 20° C. or higher and lower than 30° C. The above-mentioned conditions can be adopted for the step of treating with the treatment liquid.

[0124] The etching process may be carried out using known methods and conditions. For example, the above-mentioned etching techniques may be used. For example, in the case of etching aluminum, plasma etching using a halogen-containing gas such as carbon tetrachloride may be used.

[0125] The ashing process may be carried out by a known method under known conditions, for example, oxygen plasma.

[0126] Here, the method for manufacturing a semiconductor will be described by taking as an example the case of cleaning the semiconductor element 100 shown in FIG.

[0127] In this case, the method for manufacturing a semiconductor includes, for example, the steps of (1) preparing a substrate having a protective film, (2) etching the protective film, and (3) removing impurities from the substrate by contacting the substrate with the above-mentioned treatment liquid after etching. As in the explanation of the treatment method (cleaning method), the protective film corresponds to the HM layer 50 in the case of the semiconductor element 100 (semiconductor substrate) shown in Fig. 1. Hereinafter, the cleaning of the semiconductor element 100 shown in Fig. 1 will be explained as an example.

[0128] (1) preparing a substrate having a protective film

[0129] In step (1), a substrate having at least a protective film is prepared. Although not shown, in the case of Fig. 1, a laminate (substrate 10 / metal wiring layer 20 / etching stop layer 30 / interlayer insulating film 40 / HM layer 50) having a substrate 10, a metal wiring layer 20, an etching stop layer 30, an interlayer insulating film 40, and a hard mask layer (HM layer) 50 equivalent to a protective film in this order is prepared before etching.

[0130] The method for sequentially stacking the metal wiring layer 20, the etching stop layer 30, the interlayer insulating film 40, and the hard mask layer (HM layer) 50 corresponding to the protective film on the substrate 10 is not particularly limited, and any known method can be adopted.

[0131] (2) Etching the protective film

[0132] Subsequently, the protective film is etched. The etching method is not particularly limited, and may be wet etching or dry etching, but is preferably dry etching. Dry etching is advantageous in that metal wiring at the nano level is possible and the gas used can be controlled. In addition, dry etching is advantageous in that damage to the substrate and the like is relatively large, but it is desirable in that the advantage of this embodiment can be more effectively reflected from the viewpoint that such damage can be effectively suppressed by using the treatment liquid according to this embodiment.

[0133] In the case of dry etching, plasma can be used. Usually, when performing plasma etching, there are problems such as the substrate being easily damaged and the plasma etching residue being generated, which must be washed away 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.

[0134] (3) A step of removing impurities from the substrate after etching by contacting the substrate with the above-mentioned treatment liquid. The above-mentioned treatment method (cleaning method) can be used as the step (3), thereby obtaining the semiconductor element 100. Furthermore, if necessary, a known post-treatment can be performed after cleaning.

[0135] As described above, the treatment liquid according to this embodiment can be used as a treatment liquid for removing residues generated in, for example, a semiconductor etching process, and is particularly suitable for removing residues generated by dry etching. The treatment liquid according to this embodiment has the advantage of being excellent in both corrosion resistance of copper (metal layer containing copper atoms) and etching ability of aluminum (metal layer containing aluminum atoms). Furthermore, in the case of a substrate having a layer containing cobalt atoms, it can be expected to have the advantage of being excellent in corrosion resistance of cobalt (metal layer containing cobalt atoms).

[0136] When a conventionally used treatment liquid (e.g., a treatment liquid containing hydroxylamine, etc.) is used, problems such as large damage to copper (i.e., large film loss) may occur. However, the treatment liquid according to the present embodiment has excellent copper corrosion resistance, and can effectively suppress the occurrence of such problems. Furthermore, the treatment liquid according to the present embodiment is expected to have excellent corrosion resistance to versatile metal materials such as copper and cobalt. Therefore, it is preferable in that it is expected to reduce damage to substrates, metal wiring, etching stop layers, interlayer insulating films, and various other functional layers that contain copper, cobalt, etc. as metal components. On the other hand, it is preferable as a treatment liquid that has excellent etching properties for metal layers that contain aluminum, etc. as metal components.

[0137] Furthermore, since the processing liquid according to this embodiment can be a halogen-free processing liquid, it is not only environmentally friendly but also easy to use in terms of waste liquid disposal. EXAMPLES

[0138] The present invention will be described in more detail with reference to the following examples and comparative examples, but the present invention is not limited to the following examples in any way.

[0139] 1. Test 1

[0140] 1-1. Preparation of processing solution

[0141] A treatment liquid was obtained by mixing the components shown in Table 1 in the ratios shown in Table 1. The components shown in Table 2 were used as the types of "corrosion inhibitors" in Table 1. For example, Comparative Example 1 is an aqueous treatment liquid containing (a) 1.0 mass% ammonium fluoride, (d) no nitrogen atom-containing corrosion inhibitor, (c) 30.0 mass% water, and (b) dimethyl sulfoxide as an aqueous organic solvent as the balance. Example 1 is an aqueous treatment liquid containing (a) 1.0 mass% ammonium fluoride, (c) 30.0 mass% water, (d) 1,2,4-triazole as a nitrogen atom-containing corrosion inhibitor with an anion concentration of 14 ppm, and (b) dimethyl sulfoxide as an aqueous organic solvent as the balance.

[0142] The anion concentration of the anticorrosive agent in the treatment liquid of each of the Examples and Comparative Examples was determined using the web software "Sparc" provided by ARChem (URL: http: / / archemcalc.com / sparc-web / calc).

[0143] 1-2. Evaluation of copper (Cu) corrosion protection (film loss)

[0144] First, a laminate (substrate with a film) was prepared by laminating a Ta layer (20 nm thick) and a Cu layer (30 nm thick) in that order on a substrate (12-inch SiO2 substrate) in cross-sectional view by the CVD method (substrate / Ta layer / Cu layer). A test sample (wafer coupon) was prepared by cutting this laminate into a size of 2 cm x 2 cm in top view.

[0145] Next, 80 mL of the treatment solution of each Example and Comparative Example was placed in a 100 mL cup. The sample was placed therein and immersed in the treatment solution at 25° C. for 15 minutes. During immersion, the treatment solution was stirred at 300 rpm. After immersion, the sample was removed from the treatment solution, washed with water at room temperature for 30 seconds, and dried with nitrogen blow.

[0146] The film thickness of the sample was measured before and after immersion in the treatment solution, and the amount of film loss was calculated by calculating the difference between the two values ​​as the amount of change in film thickness.

[0147] 1-3. Evaluation of the corrosion protection properties (film loss) of cobalt (Co)

[0148] First, a laminate (substrate with a film) was prepared by laminating a TiN layer (20 nm thick) and a Co layer (100 nm thick) in that order on a substrate (12-inch silicon substrate) in cross-sectional view by the CVD method (substrate / TiN layer / Co layer). A test sample (wafer coupon) was prepared by cutting this laminate into a size of 2 cm x 2 cm in top view.

[0149] Next, 80 mL of the treatment solution of each Example and Comparative Example was placed in a 100 mL cup. The sample was placed therein and immersed in the treatment solution at 25° C. for 15 minutes. During immersion, the treatment solution was stirred at 300 rpm. After immersion, the sample was removed from the treatment solution, washed with water at room temperature for 30 seconds, and dried with nitrogen blow.

[0150] The film thickness of the sample was measured before and after immersion in the treatment solution, and the amount of film loss was calculated by calculating the difference between the two values ​​as the amount of change in film thickness.

[0151] 1-4. Evaluation of aluminum (Al) etching properties (film loss)

[0152] First, a layer of aluminum (50 nm thick) was formed on a substrate (12-inch silicon substrate) by CVD in cross section to prepare a laminate (substrate with a film) (substrate / Al layer). A test sample (wafer coupon) was prepared by cutting this laminate into a 2 cm x 2 cm piece in top view.

[0153] Next, 80 mL of the treatment solution of each Example and Comparative Example was placed in a 100 mL cup. The sample was placed therein and immersed in the treatment solution at 25° C. for 1 minute. During immersion, the treatment solution was stirred at 300 rpm. After immersion, the sample was removed from the treatment solution, washed with water at room temperature for 30 seconds, and dried with nitrogen blow.

[0154] The film thickness of the sample was measured before and after immersion in the treatment solution, and the amount of film loss was calculated by calculating the difference between the two values ​​as the amount of change in film thickness.

[0155] Table 1 shows the base composition of the treatment liquid for each of the Examples and Comparative Examples, and Table 2 shows the ppm concentration (by mass) of the anion of the component (d) and the evaluation results for each of the Examples and Comparative Examples.

[0156] The abbreviations in each table are as follows: DMSO: Dimethyl sulfoxide MOPS: 3-morpholinopropanesulfonic acid CHES: 2-Cyclohexylaminoethanesulfonic acid Taurine: 2-aminoethanesulfonic acid ·TAPS: N-tris(hydroxymethyl)methyl-3-aminopropanesulfonic acid TAPSO: N-[tris(hydroxymethyl)methyl]-3-aminopropanesulfonic acid HEDPA: 1-hydroxyethane-1,1-diylbis(phosphonic acid) TAZ: 1,2,4-triazole

[0157] [Table 1]

[0158] [Table 2]

[0159] 2. Test 2

[0160] The anion concentration of the (d) anticorrosive agent in the treatment solution was varied to evaluate the corrosion resistance of copper (Cu ER), the corrosion resistance of cobalt (Co ER), and the etching ability of aluminum (Al ER).

[0161] 2-1. Preparation of processing solution

[0162] Each treatment solution was prepared so that the anion concentration of 1,2,4-triazole, which is a nitrogen atom-containing anticorrosive, was as shown in Table 4 for the treatment solution containing the components shown in Table 3. For example, Comparative Example 10 is an aqueous treatment solution containing (a) 1.0 mass% ammonium fluoride, (d) no 1,2,4-triazole, (c) 30.0 mass% water, and (b) dimethyl sulfoxide as an aqueous organic solvent as the balance. Example 4 is an aqueous treatment solution containing (a) 1.0 mass% ammonium fluoride, (c) 30.0 mass% water, (d) 1,2,4-triazole so that its anion concentration is 7 ppm, and (b) dimethyl sulfoxide as an aqueous organic solvent as the balance.

[0163] 2-2.Evaluation of corrosion resistance

[0164] According to the method of Test 1, the corrosion resistance of copper (Cu ER), the corrosion resistance of cobalt (Co ER), and the etching resistance of aluminum (Al ER) were each evaluated.

[0165] Table 3 shows the base composition of the treatment liquid of each of the Examples and Comparative Examples.

[0166] [Table 3]

[0167] Table 4 shows the ppm concentration of the anion of component (d) for each example and each comparative example, and the etching rate (A / min) when immersed for 15 minutes at 25° C. as an evaluation of Cu damage using a Cu substrate. The etching rate was measured using an XRF (Rigaku Corp., “ZSX Primus IV”), and the amount of film loss per time was measured by dividing the amount of film loss obtained by the above method by the immersion time.

[0168] [Table 4]

[0169] Table 5 shows the ppm concentration of the anion of component (d) for each example and each comparative example, and the etching rate (A / min) when immersed for 15 minutes at 25° C. as an evaluation of damage to Co using a Co substrate. The etching rate was measured using an XRF (Rigaku Corp., “ZSX Primus IV”), and the amount of film loss per time was measured by dividing the amount of film loss obtained by the above method by the immersion time.

[0170] [Table 5]

[0171] Table 6 shows the ppm concentration of the anion of component (d) for each example and each comparative example, and the etching rate (A / min) when immersed for 1 minute at 25° C. as an evaluation of Al etching using an Al substrate. The etching rate was measured using an XRF (Rigaku Corp., “ZSX Primus IV”), and the amount of film loss per time was measured by dividing the amount of film loss obtained by the above method by the immersion time.

[0172] [Table 6]

[0173] 3. Test 3

[0174] The anion concentration of the (d) anticorrosive agent in the treatment solution was varied to evaluate damage to copper using a copper pattern wafer.

[0175] 3-1. Preparation of processing solution

[0176] Each treatment solution was prepared so that the anion concentration of 1,2,4-triazole, which is a nitrogen atom-containing anticorrosive, was the concentration shown in Table 8 for the treatment solution containing the components shown in Table 7. For example, Comparative Example 14 is an aqueous treatment solution containing (a) 1.0 mass% ammonium fluoride, (d) no 1,2,4-triazole, (c) 30.0 mass% water, and (b) dimethyl sulfoxide as an aqueous organic solvent as the balance. Example 6 is an aqueous treatment solution containing (a) 1.0 mass% ammonium fluoride, (c) 30.0 mass% water, (d) 1,2,4-triazole so that its anion concentration is 11 ppm, and (b) dimethyl sulfoxide as an aqueous organic solvent as the balance.

[0177] 3-2. Evaluation of copper (Cu) corrosion protection (film loss)

[0178] First, a laminate (substrate with a film) was prepared by laminating a Ta layer (20 nm thick) and a Cu layer (30 nm thick) in that order on a substrate (12-inch silicon substrate) in cross-sectional view by the CVD method (substrate / Ta layer / Cu layer). A test sample (wafer coupon) was prepared by cutting this laminate into a size of 2 cm x 2 cm in top view.

[0179] Next, 80 mL of the treatment solution of each Example and Comparative Example was placed in a 100 mL cup. The sample was placed therein and immersed in the treatment solution at 25° C. for 5 minutes. During immersion, the treatment solution was stirred at 300 rpm. After immersion, the sample was removed from the treatment solution, washed with water at room temperature for 30 seconds, and dried with nitrogen blow.

[0180] Then, using an ultra-high resolution field emission scanning electron microscope (manufactured by HITACHI, "SU8220"), the presence or absence of corrosion of the Cu pattern was evaluated based on the following criteria. A: No corrosion was observed over almost the entire surface of the Cu pattern. B: Localized corrosion was observed in part of the Cu pattern. Corrosion was observed over almost the entire surface of the C:Cu pattern.

[0181] Table 7 shows the base composition of the treatment liquid for each of the Examples and Comparative Examples. Table 8 shows the evaluation results of corrosion of the Cu patterned wafer for each of the Examples and Comparative Examples.

[0182] [Table 7]

[0183] [Table 8]

[0184] From the above, it was confirmed that the treatment liquid according to this embodiment has excellent copper corrosion prevention properties and aluminum etching properties. Such a treatment liquid can be suitably used in a substrate treatment method and a semiconductor manufacturing method.

[0185] This application claims priority to U.S. Provisional Application No. 63 / 593,081, filed with the U.S. Patent and Trademark Office on October 25, 2023, the contents of which are incorporated herein by reference. [Explanation of symbols]

[0186] 10: Substrate 20: Metal wiring layer 30: Etch stop layer 40: Interlayer insulating film 50: Hard mask layer (HM layer) 60: Dry etching residue 100: Semiconductor element (semiconductor substrate)

Claims

1. (a) a compound capable of releasing a fluoride anion or a salt thereof; (b) a water-soluble organic solvent; (c) water, and (d) nitrogen-containing aromatic compounds; The treatment liquid has an anion content of the nitrogen-containing aromatic compound of 5 ppm or more and 30 ppm or less at 25°C.

2. Further comprising (e) ammonium hydroxide, The treatment liquid according to claim 1 .

3. 2. The treatment liquid according to claim 1, wherein the (b) water-soluble organic solvent contains at least one selected from the group consisting of dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, ethylene glycol, and diethylene glycol monobutyl ether.

4. 2. The treatment liquid according to claim 1, wherein the nitrogen-containing aromatic compound (d) comprises at least one selected from the group consisting of an imidazole ring-containing compound, a triazole ring-containing compound, a carbazole ring-containing compound, a pyridine ring-containing compound, a pyrimidine ring-containing compound, a tetrazole ring-containing compound, a pyrazole ring-containing compound, a purine ring-containing compound, and a phenanthroline ring-containing compound.

5. The treatment liquid according to claim 1 , wherein the total content of the solvent is from 60% by mass to 99.9% by mass.

6. 2. The treatment liquid according to claim 1, which is a post-etching treatment liquid for a substrate having a first metal atom-containing layer containing copper atoms and a second metal atom-containing layer containing aluminum atoms or cobalt atoms.

7. 2. The treatment liquid according to claim 1, which is a post-etching treatment liquid for a substrate having a first metal atom-containing layer containing copper atoms, a second metal atom-containing layer containing aluminum atoms, and a third metal atom-containing layer containing cobalt atoms.

8. 13. A method for treating a substrate, comprising: treating an etched substrate having a first metal atom-containing layer containing copper atoms and a second metal atom-containing layer containing aluminum atoms or cobalt atoms, with the treatment liquid according to claim 1 at a temperature of 20° C. or higher and lower than 30° C.

9. 13. A method for treating a substrate, comprising: treating an etched substrate having a first metal atom-containing layer containing copper atoms, a second metal atom-containing layer containing aluminum atoms, and a third metal atom-containing layer containing cobalt atoms, with the treatment solution according to claim 1 at a temperature of 20° C. or higher and lower than 30° C.

10. Etching a substrate having a first metal atom-containing layer containing copper atoms and a second metal atom-containing layer containing aluminum atoms or cobalt atoms; ashing the etched substrate; treating the ashed substrate with the treatment liquid according to claim 1 at a temperature of 20° C. or more and less than 30° C.; A method for manufacturing a semiconductor substrate, comprising:

11. Etching a substrate having a first metal atom-containing layer containing copper atoms, a second metal atom-containing layer containing aluminum atoms, and a third metal atom-containing layer containing cobalt atoms; ashing the etched substrate; treating the ashed substrate with the treatment liquid according to claim 1 at a temperature of 20° C. or more and less than 30° C.; A method for manufacturing a semiconductor substrate, comprising:

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