Etchant composition

Abstract

To provide an etchant composition with which a metal film is less likely to lose glossiness after being etched.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 phosphoric acid, nitric acid, organic acid with solubility in water at 20°C of 1,100 g / L or less, and water. A blending amount of the organic acid is 65 mass% or more and 99 mass% or less. When a represents a blending amount (mass%) of organic acid with solubility in water at 20°C of 1,100 g / L or less, and b represents a blending amount (mass%) of inorganic acid, an organic acid rate represented by a formula: a / b×100 is 250% or more.SELECTED DRAWING: None

Description

[Technical field]

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

[0002] In the manufacturing process of a semiconductor device, a process is performed 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 into a predetermined pattern shape. As an etching solution, a mixed acid solution containing phosphoric acid, nitric acid, and acetic acid is generally used. In recent years, the semiconductor field has seen an increase in integration density, which has led to a demand for more complex and finer wiring. This has resulted in increased demands for pattern processing techniques and etching solutions, and various etching solution compositions have been proposed.

[0003] For example, Patent Document 1 proposes an etching solution composition for use in etching a Cu / Mo bilayer film, the etching solution composition containing about 50 to 80% by weight of phosphoric acid, about 0.5 to 10% by weight of nitric acid, about 4 to 30% by weight of acetic acid, about 0.5 to 6% by weight of a chlorine-containing compound, and the balance being water. Patent Document 2 proposes an etching solution composition for forming a predetermined pattern by etching a multilayer metal film in which a molybdenum film is laminated on the surface of an aluminum or aluminum alloy film formed on a substrate, the etching solution composition having a phosphoric acid concentration of 40 to 70 mass%, a nitric acid concentration of 0.5 to 10 mass%, an acetic acid concentration of 50 to 15 mass%, and the remainder being water. Patent Document 3 proposes an etching solution composition for treating a substrate having a laminated film including a molybdenum film, the etching solution containing an oxidizing agent (e.g., nitric acid), a catalyst (e.g., phosphoric acid), and a moisture regulator (e.g., an organic acid such as acetic acid). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2014-27274 A [Patent Document 2] JP 2008-244205 A [Patent Document 3] JP 2021-114569 A 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, the etching may progress non-uniformly and the glossiness may be lost. In particular, the loss of glossiness may cause problems with laser scattering measuring instruments, making it impossible to accurately measure the surface cleanliness, shape, etc. In the manufacturing process of semiconductor wafers, from the viewpoints of productivity and yield, an etching solution that does not easily lose glossiness is required.

[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 having a solubility in water at 20° C. of 1100 g / L or less, and water, the organic acid being present in an amount of 65 mass % or more and 99 mass % or less, and an organic acid ratio represented by the formula a / b×100 is 250% or more, where a is the amount (mass %) of the organic acid having a solubility in water at 20° C. of 1100 g / L or less, and b is the amount (mass %) of the inorganic acid.

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

[0009] In one aspect, the present disclosure relates to a substrate processing method, comprising a step of etching a metal film formed on a substrate with an etching solution composition of the present disclosure, the substrate being 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. Effect of the Invention

[0010] 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 PREFERRED EMBODIMENTS

[0011] In one aspect, the present disclosure is based on the finding that the decrease in gloss of a metal film caused by etching can be suppressed by using an etching solution that contains phosphoric acid, nitric acid, an organic acid having a solubility in water at 20°C of 1100 g / L or less, and water, and has an organic acid ratio (amount of organic acid in etching solution composition / amount of inorganic acid in etching solution composition×100) of 250% or more.

[0012] 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 having a solubility in water at 20° C. of 1100 g / L or less, and water, the organic acid being present in an amount of 65 mass % or more and 99 mass % or less, and an organic acid ratio represented by the formula: a / b×100, where a is the amount (mass %) of the organic acid having a solubility in water at 20° C. of 1100 g / L or less and b is the amount (mass %) of the inorganic acid being present, is 250% or more (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.

[0013] Although the details of the mechanism by which the effects of the present disclosure are manifested are not clear, it is presumed as follows. It is believed that increasing the organic acid ratio in the etching solution composition reduces the frequency of contact of the substrate with nitric acid, phosphoric acid, and water, which affect the etching reaction, and decreases the etching rate, resulting in an improvement in gloss. However, the present disclosure need not be construed as being limited to these mechanisms.

[0014] [phosphoric acid] The amount of phosphoric acid 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 glossiness, and is preferably 35% by mass or less, more preferably 25% by mass or less, and even more preferably 20% by mass or less, from the viewpoint of suppressing a decrease in glossiness. More specifically, the amount of phosphoric acid in the etching solution composition of the present disclosure is preferably 0.1% by mass or more and 35% by mass or less, more preferably 0.5% by mass or more and 25% by mass or less, and even more preferably 1% by mass or more and 20% by mass or less.

[0015] [nitric acid] The amount of nitric acid in the etching solution composition of the present disclosure is preferably 0.1% by mass or more, more preferably 1% by mass or more, and even more preferably 2% by mass or more from the viewpoint of reducing the etching rate, 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 suppressing the decrease in gloss. More specifically, the amount of nitric acid in the etching solution composition of the present disclosure is preferably 0.1% by mass or more and 20% by mass or less, more preferably 1% by mass or more and 10% by mass or less, and even more preferably 2% by mass or more and 5% by mass or less.

[0016] [Organic acid] Examples of organic acids having a solubility of 1100 g / L or less in water at 20° C. and contained in the etching solution composition of the present disclosure include acetic acid (solubility: 1000 g / L), methoxyacetic acid (solubility: 485 g / L), citric acid (solubility: 592 g / L), succinic acid (solubility: 58 g / L), 3-methoxybutyl acetate (solubility: 4.6 g / L), etc. The organic acids having a solubility of 1100 g / L or less in water at 20° C. may be used alone or in combination of two or more.

[0017] The amount of the organic acid having a solubility of 1100 g / L or less in water at 20° C. in the etching solution composition of the present disclosure is 65% by mass or more, preferably 70% by mass or more, more preferably 75% by mass or more, and even more preferably 80% by mass or more, from the viewpoint of reducing the etching rate, and is 99% by mass or less, preferably 98% by mass or less, more preferably 97% by mass or less, and even more preferably 95% by mass or less, from the viewpoint of ease of blending. More specifically, the amount of the organic acid having a solubility of 1100 g / L or less in water at 20° C. in the etching solution composition of the present disclosure is 65% by mass or more and 99% by mass or less, preferably 70% by mass or more and 98% by mass or less, more preferably 75% by mass or more and 97% by mass or less, and even more preferably 80% by mass or more and 95% by mass or less. When two or more organic acids having a solubility of 1100 g / L or less in water at 20° C. are combined, the amount of the organic acid having a solubility of 1100 g / L or less in water at 20° C. is the total amount of the organic acids.

[0018] In the etching solution composition of the present disclosure, when the blending amount (mass%) of the organic acid having a solubility in water at 20°C of 1100 g / L or less is a and the blending amount (mass%) of the inorganic acid is b, the organic acid ratio represented by the formula: a / b×100 is, from the viewpoint of reducing the etching rate, 250% or more, preferably 300% or more, more preferably 400% or more, even more preferably 500% or more, even more preferably 600% or more, and even more preferably 800% or more, and from the viewpoint of ease of blending, is preferably 10,000% or less, more preferably 5,000% or less, even more preferably 3,000% or less, even more preferably 2,500% or less, and even more preferably 2,000% or less. More specifically, the organic acid ratio is preferably 300% to 10,000%, more preferably 400% to 5,000%, even more preferably 500% to 3,000%, even more preferably 600% to 2,500%, and even more preferably 800% to 2,000%. In one or more embodiments, the amount b of inorganic acid is the total amount of phosphoric acid and nitric acid, and in one or more other embodiments, it is the total amount of phosphoric acid, nitric acid, and inorganic acid other than phosphoric acid and nitric acid that may be added if desired.

[0019] The total amount of phosphoric acid, nitric acid, and organic acid having a solubility of 1100 g / L or less in water at 20° C. 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, from the viewpoint of suppressing a decrease in glossiness, and from the same viewpoint, it is preferably 99.9% by mass or less, more preferably 99% by mass or less, and even more preferably 98% by mass or less. The total amount of phosphoric acid, nitric acid, and organic acid having a solubility of 1100 g / L or less in water at 20° C. in the etching solution composition of the present disclosure is preferably 70% by mass or more and 99.9% by mass or less, more preferably 75% by mass or more and 99% by mass or less, and even more preferably 80% by mass or more and 98% by mass or less.

[0020] [water] In one or more embodiments, the etching solution composition of the present disclosure contains water. Examples of the water contained in the etching solution of the present disclosure include distilled water, ion-exchanged water, pure water, and ultrapure water. The amount of water 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, more preferably 1% by mass or more, and even more preferably 2% by mass or more, from the viewpoint of suppressing the decrease in glossiness, and from the same viewpoint, it is preferably 35% by mass or less, more 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 amount of water in the etching solution composition of the present disclosure is preferably 0.1% by mass or more and 35% by mass or less, more preferably 0.5% by mass or more and 30% by mass or less, more preferably 1% by mass or more and 25% by mass or less, and even more preferably 2% by mass or more and 20% by mass or less.

[0021] [Other ingredients] The etching solution composition of the present disclosure may further contain other components within the scope of the present disclosure, such as inorganic acids other than phosphoric acid and nitric acid, organic acids other than those having a solubility in water at 20° C. of 1100 g / L or less, chelating agents, surfactants, solubilizing agents, preservatives, rust inhibitors, germicides, antibacterial agents, antioxidants, etc.

[0022] From the viewpoint of suppressing the decrease in glossiness, the etching solution composition of the present disclosure preferably does not contain hydrogen peroxide. Here, in one or more embodiments, "does not contain hydrogen peroxide" includes not containing hydrogen peroxide, not containing substantially hydrogen peroxide, or not containing an amount of hydrogen peroxide that affects the etching result. The amount of hydrogen peroxide blended in the etching solution composition of the present disclosure is not particularly limited, but is preferably less than 1 mass%, more preferably 0.5 mass% or less, even more preferably 0.1 mass% or less, even more preferably 0.01 mass% or less, and even more preferably 0 mass% (i.e., not contained).

[0023] [Method of manufacturing the etching solution composition] In one embodiment, the etching solution composition of the present disclosure is obtained by blending phosphoric acid, nitric acid, an organic acid having a solubility of 1100 g / L or less in water at 20° C., water, and, if desired, the above-mentioned optional components, by a known method. Thus, in one embodiment, 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") that includes a step of blending at least phosphoric acid, nitric acid, an organic acid having a solubility of 1100 g / L or less in water at 20° C., and water. In the present disclosure, "blending at least phosphoric acid, nitric acid, an organic acid having a solubility in water at 20°C of 1100 g / L or less, and water" includes, in one or more embodiments, simultaneously or sequentially mixing phosphoric acid, nitric acid, an organic acid having a solubility in water at 20°C of 1100 g / L or less, water, and, as necessary, the above-mentioned optional components. The order of mixing is not particularly limited. The blending can be performed using a mixer such as a propeller-type agitator, liquid circulation agitation by a pump, a homomixer, a homogenizer, an ultrasonic disperser, and a wet ball mill. In the method for producing an etching solution according to the present disclosure, the preferred amount of each component may be the same as the preferred amount of each component in the etching solution composition according to the present disclosure described above.

[0024] 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 when the use in the etching treatment is started (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 regarded as the content of each component in the etching solution composition of the present disclosure. However, when the component is affected by neutralization, the blending amount and the content may differ.

[0025] The embodiment of the etching solution composition of the present disclosure may be a so-called one-liquid type in which all components are mixed in advance and supplied to the market, or a so-called two-liquid type in which components are mixed at the time of use. An example of a two-liquid type etching solution composition is one in which water is separated into a first liquid and a second liquid, phosphoric acid, nitric acid, and an organic acid having a solubility in water at 20°C of 1100 g / L or less are contained in either one or both of the first liquid and the second liquid, and the first liquid and the second liquid are mixed at the time of use. Each of the first liquid and the second liquid may contain the above-mentioned optional components as necessary.

[0026] From the viewpoint of suppressing the decrease in glossiness, 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 or -2. 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.

[0027] The etching solution composition of the present disclosure may be stored and supplied in a concentrated state to the extent that its storage stability is not impaired. In this case, it is preferable in that the manufacturing and transportation costs can be reduced. Then, this concentrated solution can be appropriately diluted with water or an acid aqueous solution as necessary and used in the etching process. The dilution ratio can be, for example, 3 to 100 times.

[0028] [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-liquid etching solution) that contains a first liquid and a second liquid in a mutually unmixed state, and phosphoric acid, nitric acid, and an organic acid having a solubility of 1100 g / L or less in water at 20° C. are contained in either one or both of the first liquid and the second liquid, and the first liquid and the second liquid are mixed when used. After the first liquid and the second liquid are mixed, they may be diluted with water or an acid aqueous solution as necessary. The first liquid or the second liquid may contain all or a part of the water used to prepare the etching solution. The first liquid and the second liquid may each contain the above-mentioned optional components as necessary. 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.

[0029] [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. Here, the metal film is not particularly limited as long as the effects of the present disclosure are achieved, but examples thereof include metal films 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. In one or more embodiments, the metal film does not contain silver. In one or more embodiments, the etching solution composition of the present disclosure is preferably used for etching a metal film (not including silver) containing at least one metal selected from tungsten, tantalum, zirconium, molybdenum, niobium, and nickel, and is preferably used for etching a tungsten film, a molybdenum film, or a nickel film in one or more embodiments. That is, the film to be etched is a tungsten film, a molybdenum film, or a nickel film in one or more embodiments.

[0030] [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 the etching solution composition of the present disclosure (hereinafter also referred to as the "etching step of the present disclosure"). According to the present disclosure, an etching method can be provided that does not easily impair the gloss of the metal film after etching.

[0031] In the etching step of the present disclosure, examples of the etching method include immersion etching and single wafer etching.

[0032] 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 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 viewpoint of suppressing a decrease in glossiness. 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 suppressing a decrease in glossiness, 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 of the etching solution composition in the etching step of the present disclosure (etching temperature) is, from the viewpoint of suppressing a decrease in glossiness, 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.

[0033] In the etching process of the present disclosure, the etching time can be set to, for example, 1 minute or more and 180 minutes or less.

[0034] In one or a plurality of embodiments, when the film to be etched is a tungsten film, from the viewpoint of suppressing a decrease in glossiness, the etching rate in the etching step of the present disclosure is 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 suppressing a decrease in glossiness, 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 a plurality of embodiments, when the film to be etched is a molybdenum film, the etching rate in the etching step of the present disclosure is, from the viewpoint of suppressing a decrease in glossiness, 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, and from the viewpoint of suppressing a decrease in glossiness, preferably 10 mg / min or less, more preferably 3 mg / min or less, and even more preferably 2 mg / min or less. 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 suppressing a decrease in glossiness, 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 suppressing a decrease in glossiness, preferably 10 mg / min or less, more preferably 1 mg / min or less, and even more preferably 0.5 mg / min or less.

[0035] In one or a plurality of embodiments, the etching solution composition and the 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 of the present disclosure and the etching method of the present disclosure can be suitably used for the preparation of at least one substrate selected from a semiconductor wafer, a substrate for a liquid crystal display device, a substrate for a plasma display device, 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. 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 of the present disclosure or the etching method of the present disclosure, and 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 device, 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. According to the substrate processing method of the present disclosure, the gloss of the metal film is unlikely to be impaired after etching, thereby improving productivity and yield. In one or a plurality of 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 making it possible to obtain an advanced device such as a large-capacity memory. 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 JP2020-145412A. EXAMPLES

[0036] The present disclosure will be specifically described below with reference to examples, but the present disclosure is not limited to these examples in any way.

[0037] 1. Preparation of Etching Solution (Examples 1 to 3, Comparative Examples 1 to 2) Phosphoric acid, nitric acid, an organic acid shown in Table 1, and water were mixed to obtain etching solutions (pH: -2 to 0) of Examples 1 to 3 and Comparative Examples 1 and 2. The amount of each component (mass %, active content) in the prepared etching solutions is shown in Table 1. The amount of water in Table 1 includes the amount of water contained in the acid aqueous solution, etc.

[0038] 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%, solubility in water at 20°C: 1000g / L] (water) Water [Ultrapure water produced using a continuous pure water production system (Pure Conti PC-2000VRL type) and subsystem (Macace KC-05H type) manufactured by Kurita Water Industries Ltd.]

[0039] 2. How to measure parameters [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.

[0040] 3.Evaluation of etching solutions [Evaluation of tungsten plate etching rate and etching inhibition rate] 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 3 and Comparative Examples 1 to 2), and the tungsten plate was etched at 90°C for 180 minutes. After that, the tungsten plate was washed with water and then weighed again, 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) = amount etched (g) / 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 of 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 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 is shown in Table 1.

[0041] [Gloss rating] 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 has no mirror finish

[0042] [Table 1]

[0043] As shown in Table 1, the etching solutions of Examples 1 to 3, in which the amount of organic acid (acetic acid) having a solubility in water at 20°C of 1100 g / L or less is within the range of 65 to 99 mass% and the organic acid ratio is 250% or more, have a slower etching rate for tungsten plate and molybdenum plate and suppress the decrease in glossiness due to etching, compared to Comparative Examples 1 and 2, in which the amount of organic acid (acetic acid) having a solubility in water at 20°C of 1100 g / L or less is less than 65 mass% and the organic acid ratio is less than 250%, and it is clear that these are etching compositions that are less likely to impair the glossiness of the metal film after etching. [Industrial Applicability]

[0044] The etching solution composition of the present disclosure is useful for etching metal films on semiconductor wafers, substrates for liquid crystal displays, substrates for plasma displays, substrates for FEDs (Field Emission Displays), substrates for optical disks, substrates for magnetic disks, substrates for magneto-optical disks, substrates for photomasks, ceramic substrates, and substrates for solar cells.

Claims

1. An etching liquid composition for etching a metal film formed on a substrate, comprising: phosphoric acid, nitric acid, an organic acid having a solubility in water at 20 °C of 1100 g / L or less, and water, wherein the blending amount of the organic acid is 65% by mass or more and 99% by mass or less, and when the blending amount (mass%) of the organic acid having a solubility in water at 20 °C of 1100 g / L or less is a and the blending amount (mass%) of the inorganic acid is b, the organic acid ratio represented by the formula: a / b × 100 is 250% or more. The etching liquid composition.

2. The etching liquid composition according to claim 1, 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.

3. The etching liquid composition according to claim 1, wherein the organic acid is acetic acid.

4. The etching liquid composition according to claim 1, wherein 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.

5. The etching liquid composition according to claim 1, wherein the blending amount of hydrogen peroxide is less than 1% by mass.

6. An etching method comprising a step of etching a metal film containing at least one metal using the etching liquid composition according to any one of claims 1 to 5.

7. A method comprising a step of etching a metal film formed on a substrate using the etching liquid composition according to any one of claims 1 to 5, The substrate processing method, wherein 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.