Etching solution composition

Abstract

To provide an etchant composition capable of maintaining storage stability and filterability even when the etchant composition contains a phosphoric acid and a nitric acid and further contains an etching inhibitor, and an etching method and a substrate processing method in which the etchant composition is used.SOLUTION: There is provided an etchant composition for etching a metal film formed on a substrate. The etchant composition contains a phosphoric acid, a nitric acid, an organic acid with solubility in water at 20°C of 900 g / L or less, an etching inhibitor, and water. The etching inhibitor is an amine compound having no carboxyl group. 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, an etching method using the same, and a substrate processing method.

Background Art

[0002] In the manufacturing process of semiconductor devices, for example, a step of etching an etching target film containing 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 into a predetermined pattern shape is performed. As the etching solution, an aqueous mixed acid solution containing phosphoric acid, nitric acid, and acetic acid is generally used. In recent years, in the semiconductor field, high integration has been progressing, and wiring complexity and miniaturization are required. The requirements for pattern processing technology and etching solutions are also increasing, and various etching solution compositions have been proposed.

[0003] For example, Patent Document 1 proposes an etching solution composition containing phosphoric acid, nitric acid, methoxyacetic acid, and water as an etching solution composition for etching a metal thin film mainly composed of silver. Patent Document 2 proposes an etching solution composition containing at least one basic acid (such as phosphoric acid and nitric acid) and water as an etching solution composition for etching a metal oxide containing indium or a metal oxide containing zinc and indium, and having an acid dissociation constant pKa at 25 °C of 2.15 or less in any of the dissociation stages of the basic acid and a hydrogen ion concentration pH at 25 °C of 4 or less. Patent Document 3 proposes a method for collectively etching a tungsten film and a titanium nitride film using an etching solution composition containing hydrogen peroxide, phosphoric acid, an amine or an amide polymer, sulfuric acid, and deionized water.

Prior Art Documents

Patent Documents

[0004] Patent Document 1 Japanese Unexamined Patent Application Publication No. 2006-253473 Patent Document 2 Japanese Unexamined Patent Application Publication No. 2015-60937 Patent Document 3 Korean Patent Publication No. 10-2014-0065771 SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0005] As an etching solution, an aqueous mixed acid solution (strongly acidic aqueous solution) containing phosphoric acid, nitric acid, and acetic acid is generally used. Patent Document 3 proposes adding polyethyleneimine as an agent for suppressing etching and improving etching selectivity. However, when polyethyleneimine or the like is added to the aqueous mixed acid solution, turbidity occurs, and it has been found that the storage stability of the etching solution deteriorates. Furthermore, when the storage stability of the etching solution deteriorates, it affects the filterability. Therefore, there is a need for an etching solution that contains phosphoric acid and nitric acid and can maintain storage stability and filterability even when containing polyethyleneimine or the like.

[0006] Therefore, in one aspect, the present disclosure provides an etching solution composition that contains phosphoric acid and nitric acid and can maintain storage stability and filterability even when containing an etching inhibitor such as polyethyleneimine. MEANS FOR SOLVING THE PROBLEMS

[0007] In one aspect, the present disclosure relates to an etching liquid composition for etching a metal film formed on a substrate, the composition containing phosphoric acid, nitric acid, an organic acid having a solubility in water at 20°C of 900 g / L or less, an etching inhibitor, and water, wherein the etching inhibitor is an amine compound having no carboxyl group, and 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 including a step of etching a metal film containing at least one metal using the etching liquid composition of the present disclosure.

[0009] In one aspect, the present disclosure relates to a substrate processing method including a step of etching a metal film formed on a substrate using the etching liquid composition of the present disclosure, 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 a 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.

Effects of the Invention

[0010] According to the present disclosure, in one aspect, it is possible to provide an etching liquid composition containing phosphoric acid and nitric acid and further containing an etching inhibitor, while maintaining storage stability and filterability.

Modes for Carrying Out the Invention

[0011] In one aspect, the present disclosure is based on the finding that storage stability and filterability can be maintained by using an etching liquid containing phosphoric acid, nitric acid, an organic acid having a solubility in water at 20°C of 900 g / L or less, an etching inhibitor, and water.

[0012] In one aspect, the present disclosure relates to an etching liquid composition for etching a metal film formed on a substrate, which contains phosphoric acid, nitric acid, an organic acid having a solubility in water at 20 °C of 900 g / L or less, an etching inhibitor, and water. The etching inhibitor is an amine compound having no carboxyl group, and 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 liquid composition of the present disclosure"). According to the etching liquid composition of the present disclosure, even if it contains phosphoric acid and nitric acid and further contains an etching inhibitor, its storage stability and filterability can be maintained.

[0013] Although the details of the mechanism of the effect expression of the present disclosure are not clear, it is presumed as follows. When an etching inhibitor is added to an etching liquid (strongly acidic aqueous solution) containing phosphoric acid and nitric acid, the etching inhibitor and nitric acid form a hardly soluble salt, resulting in turbidity. When an organic acid having a solubility in water exceeding 900 g / L is used as the organic acid, since the organic acid has high hydrophilicity, it is considered difficult to dissolve the hardly soluble salt in the strongly acidic aqueous solution, resulting in turbidity. In addition, when the etching inhibitor is an amine compound having a carboxyl group, since many of the amine compounds have relatively high hydrophilicity, even if an organic acid having a solubility in water of 900 g / L or less is used as the organic acid, it becomes difficult to dissolve the hardly soluble salt, resulting in turbidity. In the present disclosure, it is considered that an organic acid having a solubility in water of 900 g / L or less dissolves the hardly soluble salt formed by the amine compound having no carboxyl group and nitric acid in the strongly acidic aqueous solution, suppressing the occurrence of turbidity and maintaining the storage stability and filterability of the etching liquid. However, the present disclosure may not be construed as being limited to these mechanisms.

[0014] [Phosphoric acid] The content of phosphoric acid in the etching solution composition of the present disclosure is preferably 20% by mass or more, more preferably 30% by mass or more, still more preferably 40% by mass or more, from the viewpoints of etching rate, storage stability, and maintenance of filterability, and from the viewpoint of filterability, it is preferably 90% by mass or less, more preferably 85% by mass or less, still more preferably 80% by mass or less, still more preferably 70% by mass or less, and still more preferably 65% by mass or less.

[0015] [Nitric acid] The content 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, still more preferably 1.5% by mass or more, still more preferably 2% by mass or more, still more preferably 3% by mass or more, still more preferably 4% by mass or more, from the viewpoint of etching rate, and from the viewpoint of etching unevenness, it is preferably 20% by mass or less, more preferably 10% by mass or less, still more preferably 7% by mass or less, and still more preferably 6% by mass or less.

[0016] [Organic acid] Examples of the organic acid having a solubility in water at 20°C of 900 g / L or less contained in the etching solution composition of the present disclosure include, from the viewpoints of storage stability and maintenance of filterability, for example, 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 acid having a solubility in water at 20°C of 900 g / L or less may be used alone or in combination of two or more.

[0017] From the viewpoints of storage stability and maintaining filterability, the blending amount of the organic acid having a solubility in water at 20°C of 900 g / L or less in the etching liquid composition of the present disclosure is preferably 5% by mass or more, more preferably 10% by mass or more, still more preferably 20% by mass or more, and from the same viewpoints, preferably 90% by mass or less, more preferably 80% by mass or less, still more preferably less than 70% by mass, still more preferably less than 60% by mass, still more preferably less than 50% by mass, and still more preferably less than 45% by mass. When the organic acid having a solubility in water at 20°C of 900 g / L or less is a combination of two or more kinds, the blending amount of the organic acid having a solubility in water at 20°C of 900 g / L or less is the total blending amount thereof.

[0018] From the viewpoints of storage stability and maintaining filterability, the total blending amount of phosphoric acid, nitric acid, and the organic acid having a solubility in water at 20°C of 900 g / L or less in the etching liquid composition of the present disclosure is preferably 70% by mass or more, more preferably 75% by mass or more, still more preferably 80% by mass or more, and from the same viewpoints, preferably 98% by mass or less, more preferably 95% by mass or less, still more preferably 90% by mass or less. The total blending amount of phosphoric acid, nitric acid, and the organic acid having a solubility in water at 20°C of 900 g / L or less in the etching liquid 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, still more preferably 80% by mass or more and 90% by mass or less.

[0019] [Etching inhibitor] The etching inhibitor contained in the etching liquid composition of the present disclosure is an amine compound having no carboxyl group. The etching inhibitor may be used alone or in combination of two or more kinds.

[0020] From the viewpoints of reducing etching unevenness and maintaining storage stability and filterability, the etching inhibition rate of the etching inhibitor in the present disclosure is preferably 20% or more, more preferably 30% or more, still more preferably 40% or more, still more preferably 50% or more, still more preferably 60% or more, still more preferably 70% or more, still more preferably 80% or more, still more preferably 85% or more, still more preferably 90% or more, and still more preferably 94% or more.

[0021] In the present disclosure, the etching inhibition rate indicates the reduction rate of the etching rate when an etching inhibitor is used with respect to the etching rate when no etching inhibitor is used. In one or more embodiments, the etching inhibition rate consists of phosphoric acid, nitric acid, an organic acid having a solubility in water at 20 °C of 900 g / L or less, and water, and the mass ratio of the blending amounts of the phosphoric acid, nitric acid, and the organic acid having a solubility in water at 20 °C of 900 g / L or less is the same as the mass ratio of the blending amounts of the phosphoric acid, nitric acid, and the organic acid having a solubility in water at 20 °C of 900 g / L or less in the etching liquid composition, and the total blending amount of the phosphoric acid, nitric acid, and the organic acid having a solubility in water at 20 °C of 900 g / L or less is 87% by mass. When etching is performed at a predetermined temperature and for a predetermined time using the mixed acid aqueous solution, the relative rate A of the etching rate of the etching liquid composition can be taken as the value obtained by subtracting the etching rate of the mixed acid aqueous solution, which is set to 100, from 100. Note that the mass ratio of the blending amounts of the respective components in the mixed acid aqueous solution can be set as appropriate. In one or more embodiments, the etching inhibition rate can be measured by adapting the implementation conditions such as temperature and time to the conditions for performing the etching. The measurement conditions for the etching inhibition rate vary depending on the metal contained in the layer to be etched. For example, as the preferable ranges of the temperature and time when measuring the etching inhibition rate, in one or more embodiments, the preferable ranges of the etching temperature and etching time in the etching step of the present disclosure described below can be mentioned.

[0022] The etching inhibitor in the present disclosure is an amine compound having no carboxyl group, and examples thereof include at least one selected from polyalkyleneimine and polyalkylene polyamine. Examples of the polyalkyleneimine include polyethyleneimine (PEI) and the like. Examples of the polyalkylene polyamine include pentaethylenehexamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and the like.

[0023] 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, still more preferably 1,200 or more, from the viewpoints of reducing etching non-uniformity and maintaining storage stability and filterability, and preferably 100,000 or less, more preferably 5,000 or less, still more preferably 3,000 or less, from the viewpoint of viscosity. From the same viewpoints, the number average molecular weight of the etching inhibitor is preferably from 300 to 100,000, more preferably from 600 to 5,000, still more preferably from 1,200 to 3,000. When the etching inhibitor is a polyalkylene polyamine, the weight average molecular weight of the etching inhibitor is preferably 50 or more, more preferably 80 or more, still more preferably 100 or more, from the viewpoints of reducing etching non-uniformity and maintaining storage stability and filterability, and preferably 1,000 or less, more preferably 500 or less, still more preferably 300 or less, from the same viewpoints. From the same viewpoints, the weight average molecular weight of the etching inhibitor is preferably from 50 to 1,000, more preferably from 80 to 500, still more preferably from 100 to 300.

[0024] In the present disclosure, the average molecular weight can be measured by gel permeation chromatography (GPC). Examples of the method for measuring the average molecular weight of the etching inhibitor of the present disclosure are shown below. <GPC conditions (for 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)

[0025] From the viewpoints of reducing etching non-uniformity and maintaining storage stability and filterability, the blending amount of the 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, still more preferably 0.5% by mass or more, and from the same viewpoints, preferably 10% by mass or less, more preferably 5% by mass or less, still more preferably 3% by mass or less, and still more preferably 2% by mass or less. From the same viewpoints, the blending amount of the 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, still more preferably 0.5% by mass or more and 3% by mass or less, and still more preferably 0.5% by mass or more and 2% by mass or less. When the etching inhibitor is a combination of two or more types, the blending amount of the etching inhibitor is the total blending amount thereof.

[0026] [Water] The etching solution composition of the present disclosure contains water in one or more embodiments. Examples of the water contained in the etching solution of the present disclosure include distilled water, ion-exchanged water, pure water, and ultrapure water. From the viewpoints of maintaining storage stability and filterability, 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, still more preferably 7% by mass or more, and still more preferably 10% by mass or more, and from the same viewpoints, preferably 35% by mass or less, more preferably 30% by mass or less, still more preferably 25% by mass or less, and still more preferably 20% by mass or less. From the same viewpoints, the blending amount of water in the etching solution composition of the present disclosure is preferably 2% by mass or more and 35% by mass or less, more preferably 5% by mass or more and 30% by mass or less, still more preferably 7% by mass or more and 25% by mass or less, and still more preferably 10% by mass or more and 20% by mass or less.

[0027] [Other components] The etching liquid composition of the present disclosure may further contain other components as long as the effects of the present disclosure are not impaired. Examples of other components include inorganic acids other than phosphoric acid and nitric acid, organic acids other than organic acids having a solubility in water at 20°C of 900 g / L or less, chelating agents, surfactants, solubilizing agents, preservatives, rust inhibitors, bactericides, antibacterial agents, antioxidants, and the like.

[0028] From the viewpoint of reducing etching unevenness, the etching liquid composition of the present disclosure preferably does not contain hydrogen peroxide. Here, "not containing hydrogen peroxide" includes, in one or more embodiments, not containing hydrogen peroxide, substantially not containing hydrogen peroxide, or not containing an amount of hydrogen peroxide that affects the etching result. The blending amount of hydrogen peroxide in the etching liquid composition of the present disclosure is not particularly limited, but is preferably less than 1% by mass, more preferably 0.5% by mass or less, still more preferably 0.1% by mass or less, still more preferably 0.01% by mass or less, and still more preferably 0% by mass.

[0029] In one or more embodiments, the etching liquid composition of the present disclosure does not become turbid at 25°C. The presence or absence of turbidity can be confirmed by the method described in the examples.

[0030] [Method for Producing Etching Liquid Composition] In one aspect, the etching liquid composition of the present disclosure is obtained by blending phosphoric acid, nitric acid, an organic acid having a solubility in water at 20°C of 900 g / L or less, an etching inhibitor, water, and, if desired, any of the above-described optional components by a known method. Accordingly, in one aspect, the present disclosure relates to a method for producing an etching liquid composition (hereinafter, also referred to as "the etching liquid production method of the present disclosure") including at least the steps of blending phosphoric acid, nitric acid, an organic acid having a solubility in water at 20°C of 900 g / L or less, an etching inhibitor, and water. In the present disclosure, "mixing at least phosphoric acid, nitric acid, an organic acid having a solubility in water at 20°C of 900 g / L or less, an etching inhibitor, and water" means that, in one or more embodiments, it includes mixing phosphoric acid, nitric acid, an organic acid having a solubility in water at 20°C of 900 g / L or less, an etching inhibitor, water, and, if necessary, any of the above-described optional components simultaneously or in sequence. The order of mixing may not be particularly limited. The above mixing can be carried out using a mixer such as a propeller-type stirrer, liquid circulation stirring by a pump, a homomixer, a homogenizer, an ultrasonic disperser, and a wet ball mill. In the method for manufacturing an etching solution of the present disclosure, the preferable blending amounts of the respective components can be the same as the preferable blending amounts of the respective components in the etching solution composition of the present disclosure described above.

[0031] In the present disclosure, "the blending amount of each component in the etching solution composition" means, in one or more embodiments, the blending amount of each component in the etching solution composition at the time when it is used in the etching process, that is, at the time point when the use for the etching treatment is started (when in 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 affected by neutralization, the blending amount and the content may be different.

[0032] Embodiments of the etching solution composition of the present disclosure may be of a so-called one-component type in which all components are pre-mixed and supplied to the market, or a so-called two-component type in which they are mixed at the time of use. As the two-component type etching solution composition, water is divided into the first component and the second component, and phosphoric acid, nitric acid, an organic acid having a solubility in water at 20°C of 900 g / L or less, and an etching inhibitor are each included in either one or both of the first component and the second component, and the first component and the second component are mixed at the time of use. The first component and the second component may each contain any of the above-described optional components as necessary.

[0033] From the perspective of maintaining storage stability and filterability, the pH of the etching liquid composition of the present disclosure is preferably 1 or less, more preferably 0 or less, still more preferably less than 0, and even more preferably about -1. In addition, the pH of the etching liquid composition of the present disclosure can be -5 or more, or -3 or more. In the present disclosure, the pH of the etching liquid composition is the value at 25°C, which can be measured using a pH meter, specifically, it can be measured by the method described in the examples.

[0034] The etching liquid composition of the present disclosure may be stored and supplied in a concentrated state as long as its storage stability is not impaired. In this case, it is preferable in terms of reducing manufacturing and transportation costs. And this concentrated liquid can be appropriately diluted with water or an aqueous acid solution as needed and used in the etching process. The dilution ratio can be, for example, 3 to 100 times.

[0035] [Kit] In other aspects, the present disclosure relates to a kit for manufacturing 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 first liquid and a second liquid in a state where they are not mixed with each other, and phosphoric acid, nitric acid, an organic acid having a solubility in water at 20°C of 900 g / L or less, and an etching inhibitor are each included in either one or both of the first liquid and the second liquid, and a kit (two-component etching liquid) in which the first liquid and the second liquid are mixed during use. After the first liquid and the second liquid are mixed, they may be diluted with water or an aqueous acid solution as needed. The first liquid or the second liquid may contain all or part of the total amount of water used for preparing the etching liquid. The first liquid and the second liquid may each contain the above-mentioned optional components as needed. For example, as a kit of the present disclosure, there is a kit (two-component etching solution) that includes a solution containing an etching inhibitor (first solution a) and an acidic aqueous solution containing phosphoric acid, nitric acid, and an organic acid having a solubility in water at 20°C of 900 g / L or less (second solution a), and these are included in a state where they are not mixed with each other and are mixed at the time of use. After the first solution a and the second solution a are mixed, they may be diluted with water or an acidic aqueous solution as necessary. The first solution a or the second solution a may contain all or part of the total amount of water used for preparing the etching solution. The acid contained in the second solution a may be the total amount or a part of the total amount of acid used for preparing the etching solution. The first solution a may contain an acid. The first solution a and the second solution a may each contain the above-described optional components as necessary. According to the kit of the present disclosure, an etching solution containing phosphoric acid and nitric acid and further containing an etching inhibitor can be obtained while maintaining storage stability and filterability.

[0036] [Etched film] The etched film to be etched using the etching solution composition of the present disclosure is, in one or more embodiments, a metal film containing at least one kind of metal. Here, the metal film is not particularly limited as long as the effects of the present disclosure are exhibited. For example, it includes a metal film containing at least one kind of metal selected from tungsten, tantalum, zirconium, hafnium, molybdenum, niobium, ruthenium, osmium, rhenium, rhodium, copper, nickel, cobalt, titanium, titanium nitride, alumina, aluminum, and iridium. 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 (however, not containing silver) containing at least one kind of metal selected from tungsten, tantalum, zirconium, molybdenum, niobium, and nickel in one or more embodiments, and is preferably suitably used for etching a tungsten film, a molybdenum film, or a nickel film in one or more embodiments. That is, the etched film is a tungsten film, a molybdenum film, or a nickel film in one or more embodiments.

[0037] [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") including a step of etching a metal film containing at least one metal using the etching liquid composition of the present disclosure (hereinafter also referred to as "the etching step of the present disclosure"). According to the etching method of the present disclosure, by using an etching liquid containing phosphoric acid and nitric acid and further containing an etching inhibitor, the productivity of a semiconductor substrate can be improved while maintaining storage stability and filterability.

[0038] In the etching step of the present disclosure, examples of the etching treatment method include immersion etching, single-wafer etching, and the like.

[0039] In one or more embodiments, when the film to be etched is a tungsten film, from the viewpoint of reducing etching non-uniformity, the temperature of the etching liquid composition (etching temperature) in the etching step of the present disclosure is preferably 0°C or higher, more preferably 50°C or higher, still more preferably 70°C or higher, and preferably 150°C or lower, more preferably 130°C or lower, still 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, still 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, from the viewpoint of reducing etching non-uniformity, the temperature of the etching liquid composition (etching temperature) in the etching step of the present disclosure is preferably 0°C or higher, more preferably 15°C or higher, still more preferably 25°C or higher, and preferably 80°C or lower, more preferably 65°C or lower, still 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, still 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, from the perspective of reducing etching unevenness, the temperature of the etching liquid composition (etching temperature) in the etching process of the present disclosure is preferably 0°C or higher, more preferably 15°C or higher, still more preferably 30°C or higher, and preferably 80°C or lower, more preferably 65°C or lower, still more preferably 50°C or lower. From the same perspective, 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, still more preferably 30°C or higher and 50°C or lower.

[0040] In the etching process of the present disclosure, the etching time can be set, for example, to 1 minute or more and 180 minutes or less.

[0041] In one or more embodiments, when the film to be etched is a tungsten film, from the perspective of improving productivity, the etching rate in the etching process of the present disclosure is preferably 0.0001 g / min or more, more preferably 0.0005 g / min or more, still more preferably 0.001 g / min or more, and from the perspective of reducing etching unevenness, preferably 10 g / min or less, more preferably 1 g / min or less, still more preferably 0.1 g / min or less. In one or more embodiments, when the film to be etched is a molybdenum film, from the perspective of improving productivity, the etching rate in the etching process of the present disclosure is preferably 0.01 g / min or more, more preferably 0.03 g / min or more, still more preferably 0.05 g / min or more, and from the perspective of reducing etching unevenness, preferably 10 g / min or less, more preferably 3 g / min or less, still more preferably 1 g / min or less. In one or more embodiments, when the film to be etched is a nickel film, from the perspective of improving productivity, the etching rate in the etching process of the present disclosure is preferably 0.001 g / min or more, more preferably 0.005 g / min or more, still more preferably 0.01 g / min or more, and from the perspective of reducing etching unevenness, preferably 10 g / min or less, more preferably 1 g / min or less, still more preferably 0.5 g / min or less.

[0042] The etching liquid composition of the present disclosure and the etching method of the present disclosure can be used for etching metals in the manufacturing process of electronic devices, particularly semiconductor wafers, in one or more embodiments. The etching liquid composition of the present disclosure and the etching method of the present disclosure can be suitably used in the production of at least one substrate selected from semiconductor wafers, substrates for liquid crystal display devices, substrates for plasma displays, substrates for FED (Field Emission Display), substrates for optical disks, substrates for magnetic disks, substrates for magneto-optical disks, substrates for photomasks, ceramic substrates, and substrates for solar cells in one or more embodiments. 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") including a step of etching a metal film formed on a substrate using the etching liquid composition of the present disclosure or the etching method of the present disclosure, wherein the substrate is at least one substrate selected from semiconductor wafers, substrates for liquid crystal display devices, substrates for plasma displays, substrates for FED (Field Emission Display), substrates for optical disks, substrates for magnetic disks, substrates for magneto-optical disks, substrates for photomasks, ceramic substrates, and substrates for solar cells. According to the substrate processing method of the present disclosure, by using an etching liquid composition containing phosphoric acid and nitric acid and further containing an etching inhibitor and maintaining storage stability and filterability, the productivity and yield of semiconductor substrates can be improved. The etching liquid composition of the present disclosure and the etching method of the present disclosure can be used for etching electrodes in the manufacturing process of electronic devices, particularly semiconductor memories such as non-volatile memories including NAND-type flash memories, in one or more embodiments. The etching liquid composition of the present disclosure and the etching method of the present disclosure can be suitably used for producing patterns having a three-dimensional structure in one or more embodiments. Thereby, advanced devices such as high-capacity memories can be obtained. The etching liquid composition of the present disclosure and the etching method of the present disclosure can be used in an etching method as disclosed in, for example, JP-A-2020-145412.

Example

[0043] The present disclosure will be specifically described below with reference to examples, but the present disclosure is not limited by these examples in any way.

[0044] 1. Preparation of etching solution (Examples 1-9, Comparative Examples 1-2, Reference Example 1) Phosphoric acid, nitric acid, the organic acids shown in Table 1, the etching inhibitors shown in Table 1, and water were blended to obtain the etching solutions (pH: -1) of Examples 1-9, Comparative Examples 1-2, and Reference Example 1. The blending amounts (mass%, active ingredient) of each component in the prepared etching solution are shown in Table 1. Note that the blending amount of water in Table 1 also includes the blending amount of water contained in acid aqueous solutions and the like.

[0045] The following components were used for the preparation of the etching solution. Phosphoric acid [manufactured by Phosphorus Chemical Industry Co., Ltd., concentration 85%] Nitric acid [manufactured by Fujifilm Wako Pure Chemical Corporation, concentration 70%] (Organic acid) Acetic acid [manufactured by Fujifilm Wako Pure Chemical Corporation, concentration 100%, solubility in water at 20°C: 1000 g / L] Methoxyacetic acid [manufactured by Fujifilm Wako Pure Chemical Corporation, concentration 95%, solubility in water at 20°C: 485 g / L] (Etching inhibitor) Polyethyleneimine [number average molecular weight 1,800, "Epomin SP-018" manufactured by Nippon Shokubai Co., Ltd.] Pentaethylenehexamine ["PEHA" manufactured by Tosoh Corporation] (Water) Water [ultrapure water produced using a continuous ultrapure water production apparatus (Pure Conty PC-2000VRL type) and a subsystem (Mac Ace KC-05H type) manufactured by Kurita Water Industries, Ltd.]

[0046] 2. Measurement method of parameters [pH of etching solution] The pH value of the etching solution at 25°C was measured using a pH meter (manufactured by Toa DKK Corporation), and it is the value one minute after immersing the electrode of the pH meter in the etching solution.

[0047] 3. Evaluation of the etching solution [Presence or absence of turbidity (storage stability)] The presence or absence of turbidity in the etching solution composition immediately after preparation was visually confirmed under the following conditions. The results are shown in Table 1. <Conditions and equipment> Temperature of the liquid composition: 25°C Container: 100 ml transparent glass container Mixing method of the liquid composition: For phosphoric acid, nitric acid, organic acid with a solubility of 900 g / L or less in water at 20°C, etching inhibitor, and water described in the examples, a predetermined amount was mixed while stirring at 200 rpm using a magnetic stirrer. The mixing order may be changed. Confirmation of turbidity generation: After stirring at 200 rpm for 30 minutes using a magnetic stirrer, it was allowed to stand for 5 minutes, and then the generation of turbidity in the etching solution composition was visually confirmed. The visual judge was one experienced researcher.

[0048] [Filterability] The etching solution composition was passed through a filter under the following conditions. Those that could pass the entire 50 kg of the charge scale were rated as filterability "A", those with a flow-through volume of 20 kg or more and less than 50 kg were rated as filterability "B", those with a flow-through volume of 5 kg or more and less than 20 kg were rated as filterability "C", and those where the filter became clogged and filtration was impossible (less than 5 kg of the charge scale) were rated as filterability "D". <Conditions and equipment> Liquid temperature: 25°C Filtration pressure: 0.3 MPa Filtration flow rate: 5 kg / min Scale: 50 kg of the etching solution composition Pump: Diaphragm pump DP-10BPT (manufactured by Yamada Corporation) Piping: PFA piping (outer diameter 19φ, manufactured by Fluorochemical Co., Ltd.) Filter: Kuran Filter (made of PTFE, pore size 0.05 μm, manufactured by Kurashiki Boseki Co., Ltd.) Container: 10L container

[0049]

Table 1

[0050] As shown in Table 1, the etching solutions of Examples 1 to 9 using a combination of an organic acid (methoxyacetic acid) having a solubility in water at 20°C of 900 g / L or less and an etching inhibitor did not show turbidity and maintained storage stability and filterability, and it was found that clogging of the filter during use of the etching solution could be suppressed.

Industrial Applicability

[0051] The etching solution composition of the present disclosure is useful for etching metal films on semiconductor wafers, substrates for liquid crystal display devices, substrates for plasma displays, substrates for FED (Field Emission Display), 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 solution 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 900 g / L or less, an etching inhibitor, and water, wherein the etching inhibitor is an amine compound having no carboxyl group and is at least one selected from polyalkyleneimine and polyalkylene polyamine, wherein the blending amount of the organic acid is 20% by mass or more, 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. An etching solution composition.

2. The etching solution composition according to Claim 1, wherein the blending amount of the phosphoric acid is 20% by mass or more and 90% by mass or less.

3. The etching solution composition according to Claim 1 or 2, wherein the organic acid is methoxyacetic acid.

4. The etching solution composition according to any one of Claims 1 to 3, wherein the etching solution does not become turbid at 25 °C.

5. The etching solution composition according to any one of Claims 1 to 4, wherein the etching inhibitor is at least one selected from polyethyleneimine, pentaethylenehexamine, diethylenetriamine, triethylenetetramine, and tetraethylenepentamine.

6. 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. The etching solution composition according to any one of Claims 1 to 5.

7. The etching solution composition according to any one of Claims 1 to 6, wherein the blending amount of hydrogen peroxide is less than 1% by mass.

8. 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 7.

9. An etching method comprising a step of etching a metal film formed on a substrate using the etching solution composition according to any one of Claims 1 to 7, 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.

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