Etchant composition

Abstract

To provide an etchant composition which hardly impairs glossiness of a metal film after etching.SOLUTION: In one embodiment, the present disclosure relates to an etchant composition for etching a metal film formed on a substrate. The etchant composition contains a phosphoric acid, a nitric acid, a non-organic cationic component, an etching inhibitor, and water. The metal film includes at least one kind of metal selected from among tungsten, tantalum, zirconium, hafnium, molybdenum, niobium, ruthenium, osmium, rhenium, rhodium, copper, nickel, cobalt, titanium, titanium nitride, alumina, aluminum, and iridium.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to an etching solution composition and an etching method using the same. [Background technology]

[0002] In the manufacturing process of a semiconductor device, a step is carried out in which a film to be etched, which contains at least one metal such as tungsten, tantalum, zirconium, hafnium, molybdenum, niobium, ruthenium, osmium, rhenium, rhodium, copper, nickel, cobalt, titanium, titanium nitride, alumina, aluminum, and iridium, is etched and processed into a predetermined pattern shape. In recent years, the semiconductor industry has seen increasing integration density, which has led to demands for more complex and finer wiring. This has led to increased demands for pattern processing techniques and etching solutions, and various etching methods have been proposed.

[0003] For example, Patent Documents 1 and 2 propose that an etching composition containing phosphoric acid, nitric acid, organic acid (e.g., acetic acid) and cationic components (e.g., ammonium ions) be used for a laminated film including an aluminum-based metal film and a molybdenum-based metal film, thereby controlling the laminated film to have a good tapered shape. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2003 / 036707 [Patent Document 2] Japanese Patent Application Laid-Open No. 2003-13261 Summary of the Invention [Problem to be solved by the invention]

[0005] In conventional etching methods, when a film containing metals such as tungsten is etched at a high speed, uneven etching can occur, resulting in a loss of gloss. In particular, loss of gloss can interfere with laser scattering measurement devices, making it difficult to accurately measure surface cleanliness, shape, and other parameters. In the semiconductor wafer manufacturing process, from the standpoints of productivity and yield, an etching solution that does not impair gloss is needed.

[0006] Therefore, in one aspect, the present disclosure provides an etching solution composition that is less likely to impair the gloss of a metal film after etching. [Means for solving the problem]

[0007] In one aspect, the present disclosure relates to an etching solution composition for etching a metal film formed on a substrate, the etching solution composition comprising phosphoric acid, nitric acid, an organic acid, a non-organic cation component, an etching inhibitor, and water, wherein the metal film is a metal film containing at least one metal selected from tungsten, tantalum, zirconium, hafnium, molybdenum, niobium, ruthenium, osmium, rhenium, rhodium, copper, nickel, cobalt, titanium, titanium nitride, alumina, aluminum, and iridium.

[0008] In one aspect, the present disclosure relates to an etching method comprising the step of etching a metal film containing at least one metal using the etching solution composition of the present disclosure.

[0009] In one aspect, the present disclosure relates to a substrate processing method, which includes a step of etching a metal film formed on a substrate using the etching solution composition of the present disclosure, wherein the substrate is at least one type of substrate selected from a semiconductor wafer, a substrate for a liquid crystal display device, a substrate for a plasma display, a substrate for an FED (Field Emission Display), a substrate for an optical disk, a substrate for a magnetic disk, a substrate for a magneto-optical disk, a substrate for a photomask, a ceramic substrate, and a substrate for a solar cell.

[0010] In one aspect, the present disclosure relates to a method for producing the etching solution composition of the present disclosure, the method including a step of blending a mixed acid composition containing phosphoric acid, nitric acid, and an organic acid, a non-organic cation component, and an etching inhibitor to obtain the etching solution composition. In one aspect, the present disclosure relates to a mixed acid composition for use in a method for producing an etching solution composition of the present disclosure, the mixed acid composition comprising phosphoric acid, nitric acid, and an organic acid. [Effects of the Invention]

[0011] According to one aspect of the present disclosure, an etching solution composition can be provided that is less likely to impair the gloss of a metal film after etching. DETAILED DESCRIPTION OF THE INVENTION

[0012] In one aspect, the present disclosure is based on the finding that the decrease in gloss of a metal film due to etching can be suppressed by using an etching solution containing phosphoric acid, nitric acid, an organic acid, a non-organic cation component, an etching inhibitor, and water.

[0013] In one aspect, the present disclosure relates to an etching solution composition for etching a metal film formed on a substrate, the etching solution composition comprising phosphoric acid, nitric acid, an organic acid, a non-organic cation component, an etching inhibitor, and water, wherein the metal film is a metal film containing at least one metal selected from tungsten, tantalum, zirconium, hafnium, molybdenum, niobium, ruthenium, osmium, rhenium, rhodium, copper, nickel, cobalt, titanium, titanium nitride, alumina, aluminum, and iridium (hereinafter also referred to as the "etching solution composition of the present disclosure"). According to the etching solution composition of the present disclosure, it is possible to provide an etching solution composition that is less likely to impair the gloss of a metal film after etching.

[0014] Although the details of the mechanism by which the effects of the present disclosure are manifested are not clear, it is presumed as follows. In the present disclosure, the etching inhibitor tightly coats the surface of the metal film, which is the film to be etched, or forms a thick protective film, thereby gently etching the metal film while protecting the surface, thereby suppressing the progression of uneven etching and preventing a decrease in the gloss of the metal film due to etching. Furthermore, by including a non-organic cation component, a portion of the strong acid is neutralized, reducing the frequency with which excess strong acid ions come into contact with the surface of the metal film to be etched, thereby suppressing uneven etching and preventing a decrease in the gloss of the metal film due to etching. From the above, it is believed that the gloss of the metal film is less likely to be impaired after etching. However, the present disclosure need not be construed as being limited to these mechanisms.

[0015] [phosphoric acid] The amount of phosphoric acid in the etching solution composition of the present disclosure is preferably 35% by mass or more, more preferably 40% by mass or more, preferably 45% by mass or more, more preferably 50% by mass or more, and even more preferably 55% by mass or more, from the viewpoint of suppressing a decrease in glossiness, and is preferably 90% by mass or less, more preferably 85% by mass or less, and even more preferably 80% by mass or less, from the viewpoint of suppressing a decrease in glossiness.

[0016] [nitric acid] The amount of nitric acid in the etching solution composition of the present disclosure is preferably 0.5% by mass or more, more preferably 1% by mass or more, and even more preferably 1.5% by mass or more, from the viewpoint of suppressing a decrease in glossiness, and is preferably 20% by mass or less, more preferably 10% by mass or less, and even more preferably 7% by mass or less, from the viewpoint of suppressing a decrease in glossiness.

[0017] [Organic acid] Examples of organic acids contained in the etching solution composition of the present disclosure include at least one selected from formic acid, acetic acid, propionic acid, butyric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, maleic acid, fumaric acid, phthalic acid, trimellitic acid, hydroxyacetic acid, lactic acid, salicylic acid, malic acid, tartaric acid, citric acid, aspartic acid, and glutamic acid. From the viewpoint of suppressing a decrease in gloss, the organic acid is preferably a monovalent organic acid having 1 to 10 carbon atoms, more preferably a monovalent carboxylic acid having 1 to 10 carbon atoms, and even more preferably at least one of acetic acid and propionic acid. The organic acids may be used alone or in combination of two or more.

[0018] The amount of organic acid in the etching solution composition of the present disclosure is preferably 1% by mass or more, more preferably 3% by mass or more, and even more preferably 5% by mass or more, from the viewpoint of etching inhibition rate, and is preferably 70% by mass or less, more preferably 60% by mass or less, and even more preferably 40% by mass or less, from the viewpoint of etching inhibition rate. When two or more organic acids are used in combination, the amount of organic acid is the total amount of the organic acids.

[0019] From the viewpoint of suppressing a decrease in gloss, the total blend amount of phosphoric acid, nitric acid, and organic acid in the etching solution composition of the present disclosure is preferably 70% by mass or more, more preferably 75% by mass or more, and even more preferably 80% by mass or more, and from the same viewpoint, it is preferably 98% by mass or less, more preferably 95% by mass or less, and even more preferably 90% by mass or less. From the same viewpoint, the total blend amount of phosphoric acid, nitric acid, and organic acid in the etching solution composition of the present disclosure is preferably 70% by mass or more and 98% by mass or less, more preferably 75% by mass or more and 95% by mass or less, and even more preferably 80% by mass or more and 90% by mass or less.

[0020] [Non-organic cationic components] In one or more embodiments, the non-organic cationic component contained in the etching solution composition of the present disclosure is at least one selected from ammonium ions and alkali metal ions, and among these, ammonium ions are preferred, from the viewpoint of suppressing a decrease in gloss. The non-organic cationic component may be one type or a combination of two or more types. Examples of sources of non-organic cation components include ammonia; ammonium salts such as ammonium hydroxide; and alkali metal salts such as sodium hydroxide and potassium hydroxide. Among these, ammonia or ammonium salts are preferred as sources of non-organic cation components from the viewpoint of reducing the amount of metal. The sources of non-organic cation components may be one type or a combination of two or more types.

[0021] The amount of the non-organic cationic component in the etching solution composition of the present disclosure is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1% by mass or more, from the viewpoint of suppressing a decrease in gloss, and is preferably 20% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less, from the viewpoint of cost. When two or more non-organic cationic components are used in combination, the amount of the non-organic cationic component is the total amount of the non-organic cationic component. In one or more embodiments, the amount of the non-organic cationic component in the present disclosure refers to the amount of a supply source of the non-organic cationic component.

[0022] [Etching inhibitor] The etching inhibitor contained in the etching liquid composition of the present disclosure may be used alone or in combination of two or more types.

[0023] From the viewpoint of suppressing a decrease in gloss, the etching inhibitor in the present disclosure preferably has an etching inhibition rate of 20% or more, more preferably 30% or more, even more preferably 40% or more, even more preferably 50% or more, even more preferably 60% or more, even more preferably 70% or more, even more preferably 80% or more, even more preferably 85% or more, even more preferably 90% or more, and even more preferably 94% or more.

[0024] In the present disclosure, the etching inhibition rate refers to the rate of decrease in the etching rate when an etching inhibitor is used relative to the etching rate when no etching inhibitor is used. In one or more embodiments, the etching inhibition rate can be calculated by subtracting the relative etching rate A of the etching rate of an aqueous mixed acid solution comprising phosphoric acid, nitric acid, acetic acid, and water, the mass ratio of the phosphoric acid, nitric acid, and acetic acid being the same as the mass ratio of the phosphoric acid, nitric acid, and acetic acid in the etching solution composition, and the total amount of the phosphoric acid, nitric acid, and acetic acid being 85 mass%, from 100. The mass ratio of the amounts of the components in the aqueous mixed acid solution can be appropriately set. In one or more embodiments, the etching inhibition rate can be measured by adjusting the operating conditions, such as temperature, to the etching conditions. Specifically, the etching inhibition rate can be determined by the method described in the Examples. The conditions for measuring the etching inhibition rate vary depending on the metal contained in the layer to be etched. Preferred ranges of temperature and time for measuring the etching inhibition rate include the preferred ranges of etching temperature and etching time in the etching process of the present disclosure described below in one or more embodiments. For example, the predetermined temperature and predetermined time for measuring the etching inhibition rate can be 90°C for 120 minutes if the metal plate used for measurement is a tungsten plate, 40°C for 10 minutes if the metal plate used for measurement is a molybdenum plate, or 40°C for 10 minutes if the metal plate used for measurement is a nickel plate. The shape of the metal plate used for measurement can be, for example, a plate-like body measuring 2 cm in length, 2 cm in width, and 0.1 mm in thickness. Specifically, the etching inhibition rate can be determined by the method described in the Examples.

[0025] In one or more embodiments, the etching inhibitor in the present disclosure may be an organic amine compound, such as at least one organic amine compound selected from polyalkyleneimine, a polymer having a constitutional unit derived from diallylamine, polyalkylenepolyamine, and an amino acid. Among these, in one or more embodiments, at least one of polyalkyleneimine and polyalkylenepolyamine is preferred as the etching inhibitor from the viewpoint of suppressing a decrease in gloss. Examples of the polyalkyleneimine include polyethyleneimine. Examples of the polymer containing a constitutional unit derived from diallylamine include diallylamine / sulfur dioxide copolymers. An example of the polyalkylene polyamine is diethylenetriamine. Examples of amino acids include arginine and aspartic acid.

[0026] When the etching inhibitor is a polyalkyleneimine, the number average molecular weight of the etching inhibitor is preferably 300 or more, more preferably 600 or more, and even more preferably 1,200 or more from the viewpoint of suppressing a decrease in gloss, and from the viewpoint of viscosity, it is preferably 100,000 or less, more preferably 10,000 or less, more preferably 5,000 or less, and even more preferably 3,000 or less. From the same viewpoint, the number average molecular weight of the etching inhibitor is preferably 300 or more and 100,000 or less, more preferably 600 or more and 5,000 or less, and even more preferably 1,200 or more and 3,000 or less. When the etching inhibitor is a polymer containing a structural unit derived from diallylamine, the weight average molecular weight of the etching inhibitor is preferably 2,000 or more, more preferably 3,000 or more, still more preferably 4,000 or more, from the viewpoint of suppressing the decrease in glossiness. From the same viewpoint, it is preferably 50,000 or less, more preferably 10,000 or less, still more preferably 7,000 or less. From the same viewpoint, the weight average molecular weight of the etching inhibitor is preferably 2,000 or more and 50,000 or less, more preferably 3,000 or more and 10,000 or less, still more preferably 4,000 or more and 7,000 or less. When the etching inhibitor is a polyalkylene polyamine, the number average molecular weight or molecular weight of the etching inhibitor is preferably 50 or more, more preferably 80 or more, still more preferably 100 or more, from the viewpoint of suppressing the decrease in glossiness. From the same viewpoint, it is preferably 1,000 or less, more preferably 500 or less, still more preferably 300 or less. From the same viewpoint, the number average molecular weight or molecular weight of the etching inhibitor is preferably 50 or more and 100,000 or less, more preferably 80 or more and 7,000 or less, still more preferably 100 or more and 4,000 or less. From the same viewpoint, the number average molecular weight or molecular weight of the etching inhibitor is preferably 50 or more and 1,000 or less, more preferably 80 or more and 500 or less, still more preferably 100 or more and 300 or less.

[0027] In the present disclosure, the average molecular weight can be measured by gel permeation chromatography (GPC).

[0028] Examples of the method for measuring the average molecular weight of the etching inhibitor of the present disclosure are shown below. <GPC conditions (polyalkyleneimine)> Sample solution: adjusted to a concentration of 0.1 wt% Apparatus / detector: HLC-8320GPC (integrated GPC) manufactured by Tosoh Corporation Column: α-M + α-M (manufactured by Tosoh Corporation) Eluent: 0.15 mol / L Na2SO4, 1% CH3COOH / water Column temperature: 40 °C Flow rate: 1.0 mL / min Sample solution injection volume: 100 μL Standard polymer: Pullulan with known molecular weight (Shodex P-5, P-50, P-200, P-800) <GPC conditions (polymer containing structural units derived from diallylamine)> Sample solution: Adjusted to a concentration of 0.1 wt% Detector: HLC-8320GPC (integrated GPC), manufactured by Tosoh Corporation Column: α-M + α-M (manufactured by Tosoh Corporation) Eluent: 0.15 mol / L Na2SO4, 1% CH3COOH / water Column temperature: 40 °C Flow rate: 1.0 mL / min Sample solution injection volume: 100 μL Standard polymer: Pullulan with known molecular weight (Shodex P-5, P-50, P-200, P-800)

[0029] As the etching inhibitor in the present disclosure, in one or more embodiments, from the viewpoint of suppressing the decrease in glossiness, it is preferably an organic amine compound having an etching inhibition rate of 20% or more. Therefore, in one aspect, the present disclosure relates to an etching solution composition for etching a metal film formed on a substrate, the etching solution composition containing phosphoric acid, nitric acid, an organic acid, an inorganic cation component, an etching inhibitor, and water, and the etching inhibitor being an organic amine compound having an etching inhibition rate of 20% or more determined under the following conditions. Here, the etching inhibition rate is defined as the value obtained by subtracting the relative rate A of the etching rate of the etching solution composition from 100, where the relative rate A is the etching rate of the etching solution composition when the etching rate of a mixed acid aqueous solution composed of phosphoric acid, nitric acid, acetic acid, and water, with the mass ratio of the blending amounts of the phosphoric acid, nitric acid, and acetic acid being the same as the mass ratio of the blending amounts of the phosphoric acid, nitric acid, and acetic acid in the etching solution composition and the total blending amount of the phosphoric acid, nitric acid, and acetic acid being 85% by mass, is set to 100.

[0030] The amount of etching inhibitor in the etching solution composition of the present disclosure is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and even more preferably 0.5% by mass or more, from the viewpoint of suppressing a decrease in gloss. From the same viewpoint, the amount is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 3% by mass or less. From the same viewpoint, the amount of etching inhibitor in the etching solution composition of the present disclosure is preferably 0.01% by mass or more and 10% by mass or less, more preferably 0.1% by mass or more and 5% by mass or less, and even more preferably 0.5% by mass or more and 3% by mass or less. When two or more etching inhibitors are used in combination, the amount of etching inhibitor is the total amount of the combined etching inhibitors.

[0031] [water] In one or more embodiments, the etching solution composition of the present disclosure contains water. Examples of water contained in the etching solution of the present disclosure include distilled water, ion-exchanged water, pure water, and ultrapure water.

[0032] From the viewpoint of suppressing a decrease in gloss, the blending amount of water in the etching solution composition of the present disclosure is preferably 2% by mass or more, more preferably 5% by mass or more, and even more preferably 7% by mass or more, and from the same viewpoint, it is preferably 30% by mass or less, more preferably 25% by mass or less, and even more preferably 20% by mass or less. From the same viewpoint, the blending amount of water in the etching solution composition of the present disclosure is preferably 2% by mass or more and 30% by mass or less, more preferably 5% by mass or more and 25% by mass or less, and even more preferably 7% by mass or more and 20% by mass or less.

[0033] [Other ingredients] The etching solution composition of the present disclosure may further contain other components within the scope that does not impair the effects of the present disclosure, such as inorganic acids other than phosphoric acid and nitric acid, chelating agents, surfactants, solubilizing agents, preservatives, rust inhibitors, disinfectants, antibacterial agents, antioxidants, etc.

[0034] From the viewpoint of reducing etching unevenness, the etching solution composition of the present disclosure preferably does not substantially contain hydrogen peroxide. Here, "substantially does not contain" means that the amount of hydrogen peroxide in the etching solution composition is preferably 3% by mass or less, more preferably 1% by mass or less, even more preferably 0.1% by mass or less, even more preferably 0.01% by mass or less, and even more preferably 0% by mass, i.e., the etching solution composition does not contain any hydrogen peroxide.

[0035] [Method of manufacturing the etching solution composition] In one or more embodiments, the etching solution composition of the present disclosure is obtained by blending phosphoric acid, nitric acid, an organic acid, a non-organic cation component, an etching inhibitor, water, and, if desired, the optional components described above, by a known method. Thus, in one aspect, the present disclosure relates to a method for producing an etching solution composition (hereinafter also referred to as the "etching solution production method of the present disclosure"), which includes a step of blending at least phosphoric acid, nitric acid, an organic acid, a non-organic cation component, an etching inhibitor, and water. In the present disclosure, "blending at least phosphoric acid, nitric acid, an organic acid, a non-organic cation component, an etching inhibitor, and water" means, in one or more embodiments, simultaneously or sequentially mixing phosphoric acid, nitric acid, an organic acid, a non-organic cation component, an etching inhibitor, water, and, if necessary, the optional components described above. The order of mixing is not particularly limited. The blending can be performed using a mixer such as a propeller-type agitator, a pump-based liquid circulation agitator, a homomixer, a homogenizer, an ultrasonic disperser, or a wet ball mill. The preferred amount of each component in the method for producing an etching solution according to the present disclosure may be the same as the preferred amount of each component in the etching solution composition according to the present disclosure described above.

[0036] In the present disclosure, the "amount of each component in the etching solution composition" refers, in one or more embodiments, to the amount of each component in the etching solution composition used in the etching step, i.e., at the time of starting use in the etching treatment (at the time of use). In one or more embodiments, the blending amount of each component in the etching solution composition of the present disclosure can be considered to be the content of each component in the etching solution composition of the present disclosure. However, if there is an effect of neutralization, the blending amount and the content may differ.

[0037] In one or more embodiments, the etching solution composition of the present disclosure can be obtained by blending a mixed acid composition containing phosphoric acid, nitric acid, and an organic acid, a non-organic cation component, and an etching inhibitor. Accordingly, in one aspect, the present disclosure relates to a method for producing the etching solution composition of the present disclosure, the method comprising blending a mixed acid composition containing phosphoric acid, nitric acid, and an organic acid, a non-organic cation component, and an etching inhibitor to obtain the etching solution composition of the present disclosure. The mixed acid composition may contain water and, if necessary, other components described above. The mixed acid composition, the non-organic cation component, and the etching inhibitor may be mixed using the mixer described above. The amount of phosphoric acid in the mixed acid composition is preferably 25% by mass or more and 90% by mass or less, more preferably 30% by mass or more and 85% by mass or less, and even more preferably 35% by mass or more and 80% by mass or less, from the viewpoint of suppressing a decrease in gloss. The amount of nitric acid in the mixed acid composition is preferably 0.5% by mass or more and 20% by mass or less, more preferably 1% by mass or more and 15% by mass or less, and even more preferably 2% by mass or more and 10% by mass or less, from the viewpoint of suppressing a decrease in gloss. The amount of the organic acid in the mixed acid composition is preferably 10% by mass or more and 70% by mass or less, more preferably 15% by mass or more and 65% by mass or less, and even more preferably 20% by mass or more and 60% by mass or less, from the viewpoint of suppressing a decrease in gloss. The mass ratio of phosphoric acid, organic acid, and nitric acid in the mixed acid composition (phosphoric acid / organic acid / nitric acid) is preferably 25-90 / 8-70 / 0.5-20, more preferably 30-85 / 8-65 / 1-15, and even more preferably 35-80 / 8-60 / 2-10, from the viewpoint of suppressing a decrease in gloss. The amount of water in the mixed acid composition is preferably 1% by mass or more and 30% by mass or less, more preferably 3% by mass or more and 25% by mass or less, and even more preferably 5% by mass or more and 20% by mass or less, from the viewpoint of suppressing a decrease in gloss. In one or more embodiments, the mixed acid composition is used to produce the etching solution composition of the present disclosure. Accordingly, in one aspect, the present disclosure relates to a mixed acid composition for use in the method for producing the etching solution composition of the present disclosure, the mixed acid composition comprising phosphoric acid, nitric acid, and an organic acid.

[0038] The etching solution composition of the present disclosure may be a so-called one-component type, in which all components are premixed and supplied to the market, or a so-called two-component type, in which components are mixed at the time of use. Examples of two-component etching solution compositions include those in which water is separated into a first component and a second component, and phosphoric acid, nitric acid, an organic acid, a non-organic cation component, and an etching inhibitor are contained in either or both of the first and second components, and the first and second components are mixed at the time of use. The first and second components may each contain the optional components described above, as necessary.

[0039] From the viewpoint of suppressing a decrease in gloss, the pH of the etching solution composition of the present disclosure is preferably 1 or less, more preferably 0 or less, even more preferably less than 0, and even more preferably about -1. The pH of the etching solution composition of the present disclosure can be preferably -5 or more, more preferably -3 or more. In the present disclosure, the pH of the etching solution composition is a value at 25°C and can be measured using a pH meter, specifically, by the method described in the Examples.

[0040] The etching solution composition of the present disclosure may be stored and supplied in a concentrated state as long as its stability is not impaired. This is preferable in that production and transportation costs can be reduced. The concentrated solution can then be used in the etching process after being appropriately diluted with water or an aqueous acid solution, as needed. The dilution ratio can be, for example, 3 to 100 times.

[0041] [kit] In another aspect, the present disclosure relates to a kit for producing the etching liquid composition of the present disclosure (hereinafter also referred to as the "kit of the present disclosure"). In one or more embodiments, the kit of the present disclosure includes a kit (two-component etching solution) that contains a first liquid and a second liquid in a mutually unmixed state, and in which phosphoric acid, nitric acid, an organic acid, a non-organic cation component, and an etching inhibitor are contained in either one or both of the first and second liquids, and the first and second liquids are mixed at the time of use. After the first and second liquids are mixed, they may be diluted with water or an aqueous acid solution as needed. The first or second liquid may contain all or a portion of the water used to prepare the etching solution. The first and second liquids may each contain the optional components described above as needed. An example of the kit of the present disclosure is a kit (two-component etching solution) that contains a solution (Liquid 1a) containing a non-organic cation component and an etching inhibitor and a mixed acid composition (Liquid 2a) containing phosphoric acid, nitric acid, and an organic acid in a mutually unmixed state, and that is mixed at the time of use. After Liquid 1a and Liquid 2a are mixed, they may be diluted with water or an aqueous acid solution as needed. Liquid 1a or Liquid 2a may contain all or a portion of the water used to prepare the etching solution. The acid contained in Liquid 2a may be all or a portion of the acid used to prepare the etching solution. Liquid 1a may contain an acid. Liquid 1a and Liquid 2a may each contain the optional components described above as needed. According to the kit of the present disclosure, an etching solution can be obtained that is less likely to impair the gloss of a metal film after etching.

[0042] [Film to be etched] In one or more embodiments, the film to be etched using the etching solution composition of the present disclosure is a metal film containing at least one metal. The metal is not particularly limited as long as the effects of the present disclosure are achieved, but examples include at least one metal selected from tungsten, tantalum, zirconium, hafnium, molybdenum, niobium, ruthenium, osmium, rhenium, rhodium, copper, nickel, cobalt, titanium, titanium nitride, alumina, aluminum, and iridium. Among these, in one or more embodiments, the etching solution composition of the present disclosure is preferably used for etching a metal film containing at least one metal selected from tungsten, tantalum, zirconium, molybdenum, niobium, and nickel, and in one or more embodiments, is suitably used for etching a tungsten film, a molybdenum film, or a nickel film. That is, in one or more embodiments, the film to be etched is a tungsten film, a molybdenum film, or a nickel film.

[0043] [Etching method] In one aspect, the present disclosure relates to an etching method (hereinafter also referred to as the "etching method of the present disclosure") that includes a step of etching a metal film containing at least one metal using an etching solution composition of the present disclosure (hereinafter also referred to as the "etching step of the present disclosure"). The etching method of the present disclosure can provide an etching method that is less likely to impair the gloss of the metal film after etching.

[0044] In the etching step of the present disclosure, examples of the etching method include immersion etching and single wafer etching.

[0045] In one or more embodiments, when the film to be etched is a tungsten film, the temperature (etching temperature) of the etching solution composition in the etching step of the present disclosure is, from the viewpoint of reducing etching unevenness, preferably 0° C. or higher, more preferably 50° C. or higher, even more preferably 70° C. or higher, and preferably 150° C. or lower, more preferably 130° C. or lower, and even more preferably 110° C. or lower. From the same viewpoint, in one or more embodiments, when the film to be etched is a tungsten film, the etching temperature is preferably 0° C. or higher and 150° C. or lower, more preferably 50° C. or higher and 130° C. or lower, and even more preferably 70° C. or higher and 110° C. or lower. In one or more embodiments, when the film to be etched is a molybdenum film, the temperature of the etching solution composition in the etching step of the present disclosure (etching temperature) is, from the viewpoint of reducing etching unevenness, preferably 0° C. or higher, more preferably 15° C. or higher, even more preferably 25° C. or higher, and preferably 80° C. or lower, more preferably 65° C. or lower, and even more preferably 50° C. or lower. From the same viewpoint, in one or more embodiments, when the film to be etched is a molybdenum film, the etching temperature is preferably 0° C. or higher and 80° C. or lower, more preferably 15° C. or higher and 65° C. or lower, and even more preferably 25° C. or higher and 50° C. or lower. In one or more embodiments, when the film to be etched is a nickel film, the temperature (etching temperature) of the etching solution composition in the etching step of the present disclosure is, from the viewpoint of reducing etching unevenness, preferably 0° C. or higher, more preferably 15° C. or higher, even more preferably 30° C. or higher, and preferably 80° C. or lower, more preferably 65° C. or lower, and even more preferably 50° C. or lower. From the same viewpoint, in one or more embodiments, when the film to be etched is a nickel film, the etching temperature is preferably 0° C. or higher and 80° C. or lower, more preferably 15° C. or higher and 65° C. or lower, and even more preferably 30° C. or higher and 50° C. or lower.

[0046] In the etching step of the present disclosure, the etching time can be set to, for example, 1 minute or more and 180 minutes or less.

[0047] In one or more embodiments, when the film to be etched is a tungsten film, the etching rate in the etching step of the present disclosure is, from the viewpoint of improving productivity, preferably 0.0001 mg / min or more, more preferably 0.0005 mg / min or more, and even more preferably 0.001 mg / min or more, and, from the viewpoint of reducing etching unevenness, preferably 10 mg / min or less, more preferably 1 mg / min or less, and even more preferably 0.1 mg / min or less. In one or more embodiments, when the film to be etched is a molybdenum film, the etching rate in the etching step of the present disclosure is preferably 0.01 mg / min or more, more preferably 0.03 mg / min or more, and even more preferably 0.05 mg / min or more, from the viewpoint of improving productivity, and is preferably 10 mg / min or less, more preferably 3 mg / min or less, and even more preferably 1 mg / min or less, from the viewpoint of reducing etching unevenness. In one or more embodiments, when the film to be etched is a nickel film, the etching rate in the etching step of the present disclosure is, from the viewpoint of improving productivity, preferably 0.001 mg / min or more, more preferably 0.005 mg / min or more, and even more preferably 0.01 mg / min or more, and from the viewpoint of reducing etching unevenness, preferably 10 mg / min or less, more preferably 1 mg / min or less, and even more preferably 0.5 mg / min or less.

[0048] In one or more embodiments, the etching liquid composition and etching method of the present disclosure can be used to etch metals in the manufacturing process of electronic devices, particularly semiconductor wafers. In one or more embodiments, the etching solution composition and etching method of the present disclosure can be suitably used for preparing at least one substrate selected from semiconductor wafers, liquid crystal display substrates, plasma display substrates, FED (Field Emission Display) substrates, optical disk substrates, magnetic disk substrates, magneto-optical disk substrates, photomask substrates, ceramic substrates, and solar cell substrates. That is, in one aspect, the present disclosure relates to a substrate processing method (hereinafter also referred to as the "substrate processing method of the present disclosure") that includes a step of etching a metal film formed on a substrate using the etching solution composition or etching method of the present disclosure, wherein the substrate is at least one substrate selected from semiconductor wafers, liquid crystal display substrates, plasma display substrates, FED (Field Emission Display) substrates, optical disk substrates, magnetic disk substrates, magneto-optical disk substrates, photomask substrates, ceramic substrates, and solar cell substrates. The substrate processing method of the present disclosure prevents loss of gloss of the metal film after etching, thereby improving productivity and yield. In one or more embodiments, the etching solution composition and the etching method of the present disclosure can be used to etch electrodes in the manufacturing process of electronic devices, particularly semiconductor memories such as nonvolatile memories including NAND flash memories. In one or more embodiments, the etching solution composition and the etching method of the present disclosure can be suitably used for producing a pattern having a three-dimensional structure, thereby enabling the production of advanced devices such as high-capacity memories. The etching solution composition and the etching method of the present disclosure can be used, for example, in an etching method such as that disclosed in JP 2020-145412 A. [Example]

[0049] The present disclosure will be specifically described below using examples, but the present disclosure is not limited to these examples in any way.

[0050] 1. Preparation of Etching Solution (Examples 1 to 6, Comparative Examples 1 to 3) Etching solutions (pH: -1) of Examples 1 to 6 and Comparative Examples 1 to 3 were obtained by blending phosphoric acid, nitric acid, an organic acid shown in Table 1, a non-organic cationic component shown in Table 1, an etching inhibitor shown in Table 1, and water. The amount of each component (mass %, active content) in the prepared etching solution is shown in Table 1. The amount of water in Table 1 also includes the amount of water contained in the acid aqueous solution, etc.

[0051] The following components were used to prepare the etching solution. Phosphoric acid [Rinkagaku Kogyo Co., Ltd., concentration 85%] Nitric acid [Fujifilm Wako Pure Chemical Corporation, concentration 70%] (organic acid) Acetic acid [Fujifilm Wako Pure Chemical Corporation, concentration 100%] Propionic acid [Fujifilm Wako Pure Chemical Corporation, concentration 98%] (Source of non-organic cationic components) Ammonium hydroxide [aqueous ammonia, 29% concentration] (etching inhibitor) Polyethyleneimine [number average molecular weight 1,800, "Epomin SP-018" manufactured by Nippon Shokubai Co., Ltd.] Diethylenetriamine [molecular weight 103, "DETA" from Tosoh Corporation] (water) Water [ultrapure water produced using a continuous pure water production system (Pure Conti PC-2000VRL) and a subsystem (MacAce KC-05H) manufactured by Kurita Water Industries Ltd.]

[0052] 2.Method for measuring the pH of etching solution The pH value of the etching solution at 25° C. was measured using a pH meter (manufactured by DKK-Toa Corporation), and was the value measured one minute after the electrode of the pH meter was immersed in the etching solution.

[0053] 3.Evaluation of etching solutions [Evaluation of etching rate and etching inhibition rate of tungsten plate] A tungsten plate with a length of 2 cm, a width of 2 cm, and a thickness of 0.1 mm, the weight of which had been measured in advance, was immersed in the etching solution prepared for each composition (Examples 1 to 6 and Comparative Examples 1 to 3), and the tungsten plate was etched at 90°C for 120 minutes. After rinsing with water, the tungsten plate was again weighed, and the difference was taken as the amount of etching. A precision balance was used to measure the weight. The etching rate was then calculated using the following formula: Etching rate (mg / min) = Etching amount (mg) / Etching time (min) The results of the etching rate of the tungsten plate are shown in Table 1. The etching rate of the tungsten plate in Comparative Example 1 was taken as 100, and the relative rate in each example was subtracted from 100 to obtain the etching inhibition rate (%), which is also shown in Table 1. [Evaluation of etching rate and etching inhibition rate of nickel plate] The nickel plate was etched in the same manner as the tungsten etching method described above, except that a nickel plate measuring 2 cm in length, 2 cm in width, and 0.1 mm in thickness was used instead of the tungsten plate, and the etching conditions were changed to an etching temperature of 40°C and an etching time of 10 minutes, and the etching rate of the nickel plate was measured. The results of the etching rate of the nickel plate are shown in Table 1. In addition, the etching inhibition rate (%) was calculated by subtracting the relative rate of each example, where the etching rate of the nickel plate in Comparative Example 1 was set to 100, and this value is shown in Table 1. [Evaluation of etching rate and etching inhibition rate of molybdenum plate] The molybdenum plate was etched in the same manner as the tungsten etching method described above, except that a molybdenum plate measuring 2 cm in length, 2 cm in width, and 0.1 mm in thickness was used instead of the tungsten plate, and the etching conditions were changed to an etching temperature of 40°C and an etching time of 10 minutes, and the etching rate of the molybdenum plate was measured. The results of the etching rate of the molybdenum plate are shown in Table 1. In addition, the etching inhibition rate (%) was calculated by subtracting the relative rate of each example from 100, where the etching rate of the molybdenum plate in Comparative Example 1 was taken as 100, and this value is shown in Table 1.

[0054] [Gloss evaluation] The appearance of the tungsten plate, nickel plate, and molybdenum plate after etching with each etching solution was visually inspected, and the gloss after etching was evaluated according to the following criteria. The results are shown in Table 1. <Evaluation criteria> 5: The entire board is mirror-finished 4: Most of the plate is mirror-finished, but some corrosion marks are visible. 3: Half of the plate is mirror-finished, but the other half shows signs of corrosion. 2: Most of the board shows signs of corrosion 1: The entire plate is cloudy and there is no mirror finish at all

[0055] [Table 1]

[0056] As shown in Table 1, the etching solutions of Examples 1 to 6 containing an etching inhibitor exhibited slower etching rates for tungsten plates, nickel plates, and molybdenum plates than the etching solutions of Comparative Examples 1 to 3 containing no etching inhibitor, and the decrease in gloss due to etching was suppressed. It can be seen that these are etching compositions that are less likely to impair the gloss of metal films after etching. [Industrial Applicability]

[0057] The etching solution composition of the present disclosure is useful for etching metal films on semiconductor wafers, liquid crystal display device substrates, plasma display substrates, FED (Field Emission Display) substrates, optical disk substrates, magnetic disk substrates, magneto-optical disk substrates, photomask substrates, ceramic substrates, and solar cell substrates, because the gloss of the metal film is unlikely to be impaired after etching.

Claims

1. An etching solution composition for etching a metal film formed on a substrate, comprising: phosphoric acid, nitric acid, an organic acid, an inorganic cation component, an etching inhibitor, and water; wherein the metal film is a metal film containing at least one metal selected from tungsten, tantalum, zirconium, hafnium, molybdenum, niobium, ruthenium, osmium, rhenium, rhodium, copper, nickel, cobalt, titanium, titanium nitride, alumina, aluminum, and iridium. The etching solution composition.

2. The etching solution composition according to claim 1, wherein the inorganic cation component is at least one selected from ammonium ions and alkali metal ions.

3. The etching solution composition according to claim 1, wherein the etching inhibitor is an organic amine compound.

4. The etching solution composition according to claim 1, wherein the etching inhibitor is at least one organic amine compound selected from polyalkyleneimine, a polymer containing a structural unit derived from diallylamine, polyalkylene polyamine, and amino acid.

5. The etching solution composition according to claim 1, wherein the organic acid is at least one selected from formic acid, acetic acid, propionic acid, butyric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, maleic acid, fumaric acid, phthalic acid, trimellitic acid, hydroxyacetic acid, lactic acid, salicylic acid, malic acid, tartaric acid, citric acid, aspartic acid, and glutamic acid.

6. The etching solution composition according to claim 1, wherein the blending amount of the inorganic cation component is 0.1% by mass or more and 20% by mass or less.

7. An etching method comprising a step of etching a metal film containing at least one metal using the etching solution composition according to any one of claims 1 to 6.

8. A step of etching a metal film formed on a substrate using the etching liquid composition according to any one of claims 1 to 6 is included. The substrate is at least one substrate selected from a semiconductor wafer, a substrate for a liquid crystal display device, a substrate for a plasma display, a substrate for an FED (Field Emission Display), a substrate for an optical disk, a substrate for a magnetic disk, a substrate for a magneto-optical disk, a substrate for a photomask, a ceramic substrate, and a substrate for a solar cell. A substrate processing method.

9. A method for producing the etching liquid composition according to any one of claims 1 to 6, A method for producing an etching liquid composition, including a step of obtaining the etching liquid composition by blending a mixed acid composition containing phosphoric acid, nitric acid, and an organic acid, a non-organic cation component, and an etching inhibitor.

10. A mixed acid composition for use in the method for producing the etching liquid composition according to claim 9, A mixed acid composition containing phosphoric acid, nitric acid, and an organic acid.