Etching solution composition

Abstract

In one embodiment, an etching solution composition is provided that can improve the etching uniformity of a member containing a titanium-based metal, a tungsten-based metal, a titanium / tungsten-based metal, or a nitride thereof. [Solution] In one aspect, the present disclosure relates to an etching solution composition for etching a member containing a titanium-based metal, a tungsten-based metal, a titanium / tungsten-based metal, or a nitride thereof, the etching solution composition comprising the following components A, B, and D, and having a mass ratio A / D of 1 or more and 4 or less: Component A: Phosphoric acid Component B: Nitric acid Component D: Aprotic polar solvent

Description

[Technical Field]

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

[0002] 2. Description of the Related Art In the manufacturing process of a semiconductor device, a step is carried out in which a member containing at least one of tungsten, titanium, titanium nitride, etc. 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 and etching solutions have been proposed.

[0003] For example, Patent Document 1 proposes an etching solution suitable for both tungsten-containing metals and TiN-containing materials, which contains at least one or more components selected from water, an oxidizing agent, a fluorine-containing etching compound, an organic solvent, a chelating agent, a corrosion inhibitor, and a surfactant. Patent Document 2 proposes a liquid etching solution containing a fluorine-containing compound such as hydrofluoric acid, ammonium fluoride, ammonium hydrogen difluoride, fluoroboric acid, or fluorosulfonic acid; and an oxidizing agent such as nitric acid, nitrous acid, hydrogen peroxide, ozone, perchloric acid, or percarboxylic acid. The document also describes that the liquid etching solution may further contain an additive selected from inorganic oxygen-containing acids (e.g., phosphoric acid), carboxylic acids (e.g., acetic acid), aromatic carboxylic acids, hydroxycarboxylic acids, percarboxylic acids, carboxylic acid esters, carboxylic acid peresters, carboxylic acid amides, or dipolar solvents (e.g., dimethyl sulfoxide). Patent Document 3 proposes an etching composition containing 65 to 90% by weight of phosphoric acid, 0.01 to 4% by weight of acetic acid, and 0.01 to 5% by weight of nitric acid. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-165225 [Patent Document 2] Special Publication No. 2008-512862 [Patent Document 3] Special Publication No. 2022-502835 Summary of the Invention [Problem to be solved by the invention]

[0005] As an etching solution, a mixed acid aqueous solution (strong acid aqueous solution) containing phosphoric acid, nitric acid, and acetic acid is commonly used. However, during the etching process of a member containing titanium-based metals, tungsten-based metals, titanium-tungsten-based metals, or their nitrides, a chemical reaction such as oxidation of the titanium-based metals, tungsten-based metals, titanium-tungsten-based metals, or their nitrides by the etching solution may occur, which may result in the surface of the member containing titanium-based metals, tungsten-based metals, titanium-tungsten-based metals, or their nitrides not being etched uniformly, resulting in the formation of an uneven surface or a phenomenon in which etching does not proceed.

[0006] Therefore, the present disclosure provides an etching solution composition that can improve the uniformity of etching for a member containing a titanium-based metal, a tungsten-based metal, a titanium / tungsten-based metal, or a nitride thereof, as well as an etching method and a method for manufacturing a semiconductor substrate that use the same. [Means for solving the problem]

[0007] In one aspect, the present disclosure relates to an etching solution composition for etching a member containing a titanium-based metal, a tungsten-based metal, a titanium / tungsten-based metal, or a nitride thereof, the etching solution composition comprising the following components A, B, and D, wherein the mass ratio A / D is 1 or more and 4 or less: Component A: Phosphoric acid Component B: Nitric acid Component D: Aprotic polar solvent

[0008] In one aspect, the present disclosure relates to an etching method including a step of etching a member containing a titanium-based metal, a tungsten-based metal, a titanium / tungsten-based metal, or a nitride thereof using the etching solution composition of the present disclosure.

[0009] In one aspect, the present disclosure relates to a method for manufacturing a semiconductor substrate that includes the etching method of the present disclosure. [Effects of the Invention]

[0010] According to one aspect of the present disclosure, an etching solution composition can be provided that can improve the etching uniformity of a member containing a titanium-based metal, a tungsten-based metal, a titanium / tungsten-based metal, or a nitride thereof. DETAILED DESCRIPTION OF THE INVENTION

[0011] As a result of extensive research, the present inventors have found that by using an etching solution containing an aprotic polar solvent, the wettability of a member containing a titanium-based metal, a tungsten-based metal, a titanium / tungsten-based metal, or a nitride thereof is improved, allowing the member to be etched well and improving the uniformity of etching of the member.

[0012] In one aspect, the present disclosure relates to an etching solution composition for etching a member containing a titanium-based metal, a tungsten-based metal, a titanium / tungsten-based metal, or a nitride thereof, the etching solution composition comprising the following components A, B, and D, in which the mass ratio A / D is 1 or more and 4 or less (hereinafter also referred to as the “etching solution composition of this aspect 1”). Component A: Phosphoric acid Component B: Nitric acid Component D: Aprotic polar solvent

[0013] The etching solution composition of this embodiment 1 has improved wettability to a member containing a titanium-based metal, a tungsten-based metal, a titanium / tungsten-based metal, or a nitride thereof, and therefore can etch the member well and improve the etching uniformity of the member, thereby improving the smoothness and in-plane uniformity of the etched surface of the member.

[0014] In another aspect, the present disclosure relates to an etching solution composition for etching a member containing a titanium-based metal, a tungsten-based metal, a titanium / tungsten-based metal, or a nitride thereof, the etching solution composition including the following components A, B, C, and D, in which the mass ratio A / D is 1 or more and 10 or less (hereinafter also referred to as the "etching solution composition of this aspect 2"). Component A: Phosphoric acid Component B: Nitric acid Component C: Monocarboxylic acid with 1 to 10 carbon atoms Component D: Aprotic polar solvent

[0015] The etching solution of this embodiment 2 has improved wettability to a member containing a titanium-based metal, a tungsten-based metal, a titanium / tungsten-based metal, or a nitride thereof, and therefore can etch the member well and improve the etching uniformity of the member, thereby improving the smoothness and in-plane uniformity of the member surface after etching.

[0016] 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 etching process of a member containing a titanium-based metal, a tungsten-based metal, a titanium / tungsten-based metal, or a nitride thereof, the nitric acid in the etching solution oxidizes the surface of the member, and the oxidized surface of the member is then etched by phosphoric acid. When a chemical reaction such as oxidation of a component by nitric acid occurs, gas (bubbles) may be generated. However, if the wettability of the etching solution with the surface of a component containing titanium-based metals, tungsten-based metals, titanium-tungsten-based metals, or their nitrides is low, it is thought that the bubbles generated by the chemical reaction are less likely to escape. If bubbles continue to adsorb to the surface of a component containing titanium-based metals, tungsten-based metals, titanium-tungsten-based metals, or their nitrides, it is thought that this can cause the component surface to be etched unevenly, resulting in the formation of an uneven surface or a phenomenon in which etching does not proceed smoothly. Therefore, in the present disclosure, by using an aprotic polar solvent as a wettability improver, or by using a monocarboxylic acid having 1 to 10 carbon atoms in combination with an aprotic polar solvent as a wettability improver, the wettability of the etching solution with a member containing a titanium-based metal, a tungsten-based metal, a titanium / tungsten-based metal, or a nitride thereof can be improved, the surface of the member can be etched well, and the etching uniformity of the member can be improved. Furthermore, it is believed that the smoothness and in-plane uniformity of the member surface after etching can be improved. However, the present disclosure need not be construed as being limited to these mechanisms.

[0017] Hereinafter, the etching solution composition of Aspect 1 and the etching solution composition of Aspect 2 will also be collectively referred to as the "etching solution composition of the present disclosure."

[0018] [Component] In one or more embodiments, the member to be etched using the etching solution composition of the present disclosure is a member containing a titanium-based metal, a tungsten-based metal, a titanium / tungsten-based metal, or a nitride thereof. In one or more embodiments, the member is preferably a member containing at least one titanium-based metal selected from titanium and titanium nitride. Among these, a member containing titanium nitride is preferred. Therefore, in one or more embodiments, the etching solution composition of the present disclosure is preferably an etching solution composition for etching a member containing titanium nitride. In one or more embodiments, the member may be a layer or a film.

[0019] [Component A: Phosphoric acid] The amount of phosphoric acid (hereinafter also referred to as "component A") in the etching solution composition of the present disclosure is preferably 30% by mass or more, more preferably 40% by mass or more, and even more preferably 50% by mass or more, from the viewpoint of improving the etching rate, and from the same viewpoint, is preferably 80% by mass or less, more preferably 70% by mass or less, and even more preferably 60% by mass or less. More specifically, the amount of phosphoric acid (component A) in the etching solution composition of the present disclosure is preferably 30% by mass or more and 80% by mass or less, more preferably 40% by mass or more and 70% by mass or less, and even more preferably 50% by mass or more and 60% by mass or less.

[0020] [Component B: Nitric acid] The amount of nitric acid (hereinafter also referred to as "component B") in the etching solution composition of the present disclosure is preferably 1% by mass or more, more preferably 1.5% by mass or more, and even more preferably 2% by mass or more, from the viewpoint of oxidizing titanium-based metals, tungsten-based metals, titanium / tungsten-based metals, or their nitrides, and is preferably 10% by mass or less, more preferably 8% by mass or less, and even more preferably 5% by mass or less, from the viewpoint of improving the etching rate. More specifically, the amount of nitric acid (component B) in the etching solution composition of the present disclosure is preferably 1% by mass or more and 10% by mass or less, more preferably 1.5% by mass or more and 8% by mass or less, and even more preferably 2% by mass or more and 5% by mass or less.

[0021] The mass ratio A / B of component A to component B (amount of component A blended / amount of component B blended) in the etching solution composition of the present disclosure is preferably 1 or more, more preferably 5 or more, and even more preferably 10 or more from the viewpoint of improving the etching rate, and from the viewpoint of oxidation of titanium-based metals, tungsten-based metals, titanium / tungsten-based metals, or nitrides thereof, is preferably 50 or less, more preferably 30 or less, and even more preferably 28 or less. More specifically, the mass ratio A / B is preferably 1 or more and 50 or less, more preferably 5 or more and 30 or less, and even more preferably 10 or more and 28 or less.

[0022] [Component C: Organic acid] In one or more embodiments, the etching solution composition of Aspect 1 may further contain an organic acid (hereinafter also referred to as "Component C"). Examples of Component C 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. Among these, from the viewpoint of uniform etching of the layer to be etched, 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, even more preferably one containing acetic acid, and even more preferably acetic acid. In one or more embodiments, the etching solution composition of Aspect 2 contains a monocarboxylic acid (component C) having from 1 to 10 carbon atoms. From the viewpoint of uniform etching of the layer to be etched, component C in the etching solution composition of Aspect 2 preferably contains acetic acid, and more preferably is acetic acid. In the etching liquid composition of the present disclosure, Component C may be one type or a combination of two or more types. When the etching solution composition of the present disclosure contains component C, the blending amount of component C in the etching solution composition of the present disclosure is preferably 1% by mass or more, more preferably 2% by mass or more, and even more preferably 3% by mass or more, from the viewpoint of improving the etching rate, and from the same viewpoint, is preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less. More specifically, the blending amount of component C in the etching solution composition of the present disclosure is preferably 1% by mass or more and 20% by mass or less, more preferably 2% by mass or more and 15% by mass or less, and even more preferably 3% by mass or more and 10% by mass or less. When component C is a combination of two or more types, the blending amount of component C is the total blending amount of the two or more types.

[0023] The total amount of components A and B or the total amount of components A, B, and C in the etching solution composition of the present disclosure is preferably 40% by mass or more or 50% by mass or more, more preferably 55% by mass or more, and even more preferably 60% by mass or more, from the viewpoint of improving the etching rate. From the viewpoint of improving the wettability of the etching solution with a member containing a titanium-based metal, a tungsten-based metal, a titanium / tungsten-based metal, or a nitride thereof, the total amount is preferably 90% by mass or less, more preferably 80% by mass or less, and even more preferably 70% by mass or less. More specifically, the total amount of components A and B or the total amount of components A, B, and C in the etching solution composition of the present disclosure is preferably 40% by mass or more and 90% by mass or less, or 50% by mass or more and 90% by mass or less, more preferably 55% by mass or more and 80% by mass or less, and even more preferably 60% by mass or more and 70% by mass or less.

[0024] When the etching solution composition of the present disclosure contains component C, the mass ratio A / C of component A to component C (amount of component A blended / amount of component C blended) is preferably 1 or more, more preferably 5 or more, and even more preferably 8 or more, from the viewpoint of improving the etching rate, and is preferably 20 or less, more preferably 18 or less, and even more preferably 15 or less, from the viewpoint of improving the etching rate. More specifically, the mass ratio A / C is preferably 1 or more and 20 or less, more preferably 5 or more and 18 or less, and even more preferably 8 or more and 15 or less.

[0025] When the etching solution composition of the present disclosure contains component C, the mass ratio B / C of components B to C (amount of component B blended / amount of component C blended) is preferably 0.01 or more, more preferably 0.1 or more, and even more preferably 0.2 or more from the viewpoint of improving the etching rate, and is preferably 1 or less, more preferably 0.5 or less, and even more preferably 0.3 or less from the viewpoint of improving the etching rate. More specifically, the mass ratio B / C is preferably 0.01 or more and 1 or less, more preferably 0.1 or more and 0.5 or less, and even more preferably 0.2 or more and 0.3 or less.

[0026] [Component D: Aprotic polar solvent] The aprotic polar solvent (hereinafter also referred to as "component D") contained in the etching solution composition of the present disclosure may be, for example, a sulfoxide solvent such as dimethyl sulfoxide (DMSO). Component D may be one type or a combination of two or more types.

[0027] The amount of component D in the etching solution composition of the present disclosure is preferably 1% by mass or more, more preferably 2% by mass or more, even more preferably 5% by mass or more, even more preferably 10% by mass or more, and even more preferably 15% by mass or more, from the viewpoint of improving the wettability of a member containing a titanium-based metal, a tungsten-based metal, a titanium / tungsten-based metal, or a nitride thereof with the etching solution, and from the viewpoint of improving the wettability of a member containing a titanium-based metal, a tungsten-based metal, a titanium / tungsten-based metal, or a nitride thereof with the etching solution and increasing the etching rate, preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less. More specifically, the amount of component D in the etching solution composition of the present disclosure is preferably 1% by mass or more and 50% by mass or less, more preferably 2% by mass or more and 40% by mass or less, even more preferably 5% by mass or more and 30% by mass or less, even more preferably 10% by mass or more and 30% by mass or less, and even more preferably 15% by mass or more and 30% by mass or less. When Component D is a combination of two or more types, the blending amount of Component D is the total blending amount of those.

[0028] The mass ratio A / D of component A to component D (amount of component A blended / amount of component D blended) in the etching solution composition of this embodiment 1 is 1 or more, preferably 1.5 or more, and more preferably 2 or more, from the viewpoints of improving the wettability of the etching solution with a member containing a titanium-based metal, a tungsten-based metal, a titanium / tungsten-based metal, or a nitride thereof, and of improving the etching rate, and from the same viewpoints, is 4 or less, preferably 3 or less. More specifically, the mass ratio A / D is 1 or more and 4 or less, preferably 1.5 or more and 4 or less, more preferably 2 or more and 4 or less, and even more preferably 2 or more and 3 or less. The mass ratio A / D of component A to component D (amount of component A blended / amount of component D blended) in the etching solution composition of this embodiment 2 is 1 or more, preferably 1.5 or more, and more preferably 2 or more, from the viewpoints of improving the wettability of the etching solution with a member containing a titanium-based metal, a tungsten-based metal, a titanium / tungsten-based metal, or a nitride thereof, and of improving the etching rate, and from the same viewpoints, is 10 or less, preferably 7 or less, and more preferably 5 or less. More specifically, the mass ratio A / D is 1 or more and 10 or less, preferably 1.5 or more and 7 or less, and more preferably 2 or more and 5 or less.

[0029] The mass ratio B / D of component B to component D (amount of component B blended / amount of component D blended) in the etching solution composition of the present disclosure is preferably 0.01 or more, more preferably 0.025 or more, and even more preferably 0.05 or more, from the viewpoints of improving the wettability of a member containing a titanium-based metal, a tungsten-based metal, a titanium / tungsten-based metal, or a nitride thereof with the etching solution and improving the etching rate, and from the same viewpoints, is preferably 1 or less, more preferably 0.5 or less, and even more preferably 0.3 or less. More specifically, the mass ratio B / D is preferably 0.01 or more and 1 or less, more preferably 0.025 or more and 0.5 or less, and even more preferably 0.05 or more and 0.3 or less.

[0030] When the etching solution composition of the present disclosure contains component C, the mass ratio C / D of component C to component D (amount of component C blended / amount of component D blended) is preferably 0.01 or more, more preferably 0.025 or more, and even more preferably 0.05 or more, from the viewpoints of improving the wettability of a member containing a titanium-based metal, a tungsten-based metal, a titanium / tungsten-based metal, or a nitride thereof with the etching solution and improving the etching rate, and from the same viewpoints, is preferably 1 or less, more preferably 0.75 or less, and even more preferably 0.5 or less. More specifically, the mass ratio C / D is preferably 0.01 or more and 1 or less, more preferably 0.025 or more and 0.75 or less, and even more preferably 0.05 or more and 0.5 or less.

[0031] [Component E: Water] In one or more embodiments, the etching solution composition of the present disclosure further contains water (hereinafter also referred to as "component E"). Examples of component E include distilled water, ion-exchanged water, pure water, and ultrapure water. When the etching solution composition of the present disclosure contains component E, the blending amount of component E 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 from the viewpoint of improving storage stability, and 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 viewpoint of uniform etching of a member containing a titanium-based metal, a tungsten-based metal, a titanium / tungsten-based metal, or a nitride thereof. More specifically, the blending amount of component E 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.

[0032] When the etching solution composition of the present disclosure contains Component E, the mass ratio E / A of Component E to Component A (amount of Component E blended / amount of Component A blended) is, from the viewpoint of improving storage stability, preferably 0.1 or more, more preferably 0.2 or more, and even more preferably 0.3 or more, and, from the viewpoint of improving etching rate, is preferably 2 or less, more preferably 1.5 or less, and even more preferably 1 or less. More specifically, the mass ratio E / A is preferably 0.1 or more and 2 or less, more preferably 0.2 or more and 1.5 or less, and even more preferably 0.3 or more and 1 or less.

[0033] When the etching solution composition of the present disclosure contains component E, the mass ratio E / D of components E to D (amount of component E blended / amount of component D blended) is preferably 0.1 or more, more preferably 0.5 or more, and even more preferably 0.8 or more from the viewpoint of improving storage stability, and is preferably 5 or less, more preferably 2.5 or less, and even more preferably 2 or less from the viewpoint of improving wettability. More specifically, the mass ratio E / D (amount of component E blended / amount of component D blended) is preferably 0.1 or more and 5 or less, more preferably 0.5 or more and 2.5 or less, and even more preferably 0.8 or more and 2 or less.

[0034] [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. Examples of other components include acids other than Components A to C, solvents other than Component D, chelating agents, surfactants, solubilizers, preservatives, rust inhibitors, disinfectants, antibacterial agents, antioxidants, etc.

[0035] In one or more embodiments, the etching solution composition of the present disclosure may be substantially free of a fluorine-containing compound. The amount of the fluorine-containing compound in the etching solution composition of the present disclosure is preferably less than 0.001% by mass, more preferably 0.0001% by mass or less, and even more preferably 0% by mass (i.e., no compound is contained). In one or more embodiments, the present disclosure may be substantially free of azoles. The amount of azoles in the etching solution composition of the present disclosure is preferably less than 0.005% by mass, more preferably 0.001% by mass or less, and even more preferably 0% by mass (i.e., no azoles are contained).

[0036] [Method of manufacturing the etching solution composition] In one embodiment, the etching solution composition of Aspect 1 is obtained by blending Components A, B, and D, and, if desired, the optional components described above (Components C, E, and other 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 Components A, B, and D. In one embodiment, the etching solution composition of Aspect 2 is obtained by blending phosphoric acid (component A), nitric acid (component B), a monocarboxylic acid having from 1 to 10 carbon atoms (component C), an aprotic polar solvent (component D), and, if desired, the optional components described above, by a known method. Thus, in another 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"), which includes a step of blending at least phosphoric acid (component A), nitric acid (component B), a monocarboxylic acid having from 1 to 10 carbon atoms (component C), and an aprotic polar solvent (component D). In this aspect 1, "blending at least component A, component B, and component D" includes, in one or more embodiments, simultaneously or sequentially mixing component A, component B, component D, and, if necessary, the optional components described above (component C, component E, and other components). In this aspect 2, "blending at least component A, component B, component C, and component D" includes, in one or more embodiments, simultaneously or sequentially mixing components A, B, C, and D, and, as necessary, the optional components described above. The mixing order is not particularly limited. The blending can be carried out using a mixer such as a propeller-type mixer, a liquid circulation mixer using a pump, 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.

[0037] In the present disclosure, the term "amount of each component in the etching solution composition" refers, in one or more embodiments, to the amount of each component of 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.

[0038] An embodiment of the etching solution composition of the present disclosure may be a so-called one-component type, in which all components are supplied to the market in a premixed state, or a so-called two-component type, in which components are mixed at the time of use. One embodiment of a two-component etching solution composition is composed of a solution (first component) containing components A and B and a solution (second component) containing component D, and the first and second components are mixed at the time of use. After the first and second components are mixed, they may be diluted with water or an aqueous acid solution as needed. The first or second component may contain all or a portion of the water used to prepare the etching solution. The first and second components may each contain the optional components described above (component C, component E, and other components) as needed.

[0039] In one or more embodiments, the pH of the etching solution composition of the present disclosure is preferably 2 or less, and more preferably 1 or less. In one or more embodiments, the pH of the etching solution composition of the present disclosure may be −2 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, 5 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"). An example of the kit of the present disclosure is a kit (two-component etching solution) that contains a solution (first liquid) containing components A and B and a solution (second liquid) containing component D in a mutually unmixed state, and that is mixed at the time of 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 a portion of the water used to prepare the etching solution. The first liquid and the second liquid may each contain the above-mentioned optional components (component C, component E, other components) as needed. The kit of the present disclosure makes it possible to prepare an etching solution that can improve the uniformity of etching for a member containing a titanium-based metal, a tungsten-based metal, a titanium / tungsten-based metal, or a nitride thereof.

[0042] [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 member containing a titanium-based metal, a tungsten-based metal, a titanium / tungsten-based metal, or a nitride thereof using an etching solution composition of the present disclosure (hereinafter also referred to as the "etching step of the present disclosure"). Examples of members containing a titanium-based metal, a tungsten-based metal, a titanium / tungsten-based metal, or a nitride thereof include the members described above. In one or more embodiments, use of the etching method of the present disclosure can improve the etching uniformity of members containing a titanium-based metal, a tungsten-based metal, a titanium / tungsten-based metal, or a nitride thereof, thereby improving semiconductor substrate productivity.

[0043] In the etching step of the present disclosure, examples of the etching method include immersion etching and single wafer etching.

[0044] The temperature of the etching solution composition in the etching step of the present disclosure (etching temperature) is preferably 40° C. or higher, more preferably 50° C. or higher, and even more preferably 60° C. or higher, and is preferably 120° C. or lower, more preferably 110° C. or lower, and even more preferably 100° C. or lower. More specifically, the etching temperature is preferably 40° C. or higher and 120° C. or lower, more preferably 50° C. or higher and 110° C. or lower, and even more preferably 60° C. or higher and 100° C. or lower.

[0045] In the etching step of the present disclosure, the etching time can be set to, for example, 1 minute or more and 330 minutes or less.

[0046] In one or more embodiments, the etching solution composition and the etching method of the present disclosure can be used to etch a member containing a titanium-based metal, a tungsten-based metal, a titanium / tungsten-based metal, or a nitride thereof in the manufacturing process of an electronic device, particularly a semiconductor substrate. In one or more embodiments, the etching solution composition and etching method of the present disclosure can be suitably used for producing at least one substrate selected from semiconductor substrates, 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. This can improve the etching performance of members containing titanium-based metals, tungsten-based metals, titanium / tungsten-based metals, or nitrides thereof, thereby increasing productivity and yield. In one or more embodiments, the etching solution composition and etching method of the present disclosure can be used to etch electrodes in the manufacturing process of electronic devices, particularly semiconductor memories such as DRAMs and 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.

[0047] [Method of manufacturing semiconductor substrate] The etching solution composition and etching method of the present disclosure can be suitably used in the production of semiconductor substrates. Thus, in one aspect, the present disclosure relates to a method for manufacturing a semiconductor substrate (hereinafter also referred to as the "method for manufacturing a semiconductor substrate of the present disclosure"), which includes the etching method of the present disclosure. In one or more embodiments, the method for manufacturing a semiconductor substrate of the present disclosure includes a step of etching a substrate having a member containing a titanium-based metal, a tungsten-based metal, a titanium / tungsten-based metal, or a nitride thereof, using the etching solution composition of the present disclosure. The treatment method and treatment conditions in the etching step may be the same as those used in the etching step of the etching method of the present disclosure described above. In one or more embodiments, the substrate having a member containing a titanium-based metal, a tungsten-based metal, a titanium / tungsten-based metal, or a nitride thereof may be a substrate having a member containing a titanium-based metal, a tungsten-based metal, a titanium / tungsten-based metal, or a nitride thereof, and an insulating member. In one or more embodiments, the member containing a titanium-based metal, a tungsten-based metal, a titanium / tungsten-based metal, or a nitride thereof may be any of the members described above, and a preferred example is titanium nitride. The substrate may be, for example, a semiconductor substrate such as a silicon wafer. The insulating member may be, for example, silicon dioxide (SiO2). An example of a substrate having a component containing a titanium-based metal, a tungsten-based metal, a titanium tungsten-based metal, or a nitride thereof is a substrate in which a silicon oxide film (SiO2 film) is formed on a silicon wafer and a titanium nitride film (TiN film) is further formed on the SiO2 film.

[0048] The present disclosure further relates to one or more of the following embodiments. <1> An etching solution composition for etching a member containing a titanium-based metal, a tungsten-based metal, a titanium / tungsten-based metal, or a nitride thereof, comprising: Contains the following components A, B, and D, An etching solution composition having a mass ratio A / D of 1 or more and 4 or less. Component A: Phosphoric acid Component B: Nitric acid Component D: Aprotic polar solvent <2> An etching solution composition for etching a member containing a titanium-based metal, a tungsten-based metal, a titanium / tungsten-based metal, or a nitride thereof, comprising: Contains the following components A, B, C, and D, An etching solution composition having a mass ratio A / D of 1 or more and 10 or less. Component A: Phosphoric acid Component B: Nitric acid Component C: Monocarboxylic acid with 1 to 10 carbon atoms Component D: Aprotic polar solvent <3> Further containing an organic acid (component C), <1> The etching solution composition according to claim 1. <4> An etching solution composition for etching a member containing titanium nitride, <1> from <3> The etching solution composition according to any one of the preceding claims. <5> Component D is dimethyl sulfoxide; <1> from <4> The etching solution composition according to any one of the preceding claims. <6> The organic acid (component C) includes 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; <2> from <5> The etching solution composition according to any one of the preceding claims. <7> the mass ratio A / C of component A to component C is 1 or more, or 5 or more, or 8 or more, and 20 or less, or 18 or less, or 15 or less; <2> from <6> The etching solution composition according to any one of the preceding claims. <8> the mass ratio A / D of component A to component D is 1 or more, or 1.5 or more, or 2 or more, and 10 or less, or 4 or less, or 3 or less; <1> from <7> The etching solution composition according to any one of the preceding claims. <9> The mass ratio B / D of component B to component D is 0.01 or more, or 0.025 or more, or 0.05 or more, and 1 or less, or 0.5 or less, or 0.3 or less. <1> from <8> The etching solution composition according to any one of the preceding claims. <10> the mass ratio A / B of component A to component B is 1 or more, or 5 or more, or 10 or more, and 50 or less, or 30 or less, or 28 or less; <1> from <9> The etching solution composition according to any one of the preceding claims. <11> the mass ratio C / D of component C to component D is 0.01 or more, or 0.025 or more, or 0.05 or more, and is 1 or less, or 0.75 or less, or 0.5 or less; <2> from <10> The etching solution composition according to any one of the preceding claims. <12> the mass ratio B / C of component B to component C is 0.01 or more, or 0.1 or more, or 0.2 or more, and 1 or less, or 0.5 or less, or 0.3 or less; <2> from <11> The etching solution composition according to any one of the preceding claims. <13> The blending amount of component A is 30% by mass or more, or 40% by mass or more, or 50% by mass or more, and 80% by mass or less, or 70% by mass or less, or 60% by mass or less. <1> from <12> The etching solution composition according to any one of the preceding claims. <14> The blending amount of component B is 1% by mass or more, or 1.5% by mass or more, or 2% by mass or more, and 10% by mass or less, or 8% by mass or less, or 5% by mass or less. <1> from <13> The etching solution composition according to any one of the preceding claims. <15> The blending amount of component C is 1% by mass or more, or 2% by mass or more, or 3% by mass or more, and 20% by mass or less, or 15% by mass or less, or 10% by mass or less. <2> from <14> The etching solution composition according to any one of the preceding claims. <16> The blending amount of component D is 1% by mass or more, or 2% by mass or more, or 5% by mass or more, or 10% by mass or more, or 15% by mass or more, and is 50% by mass or less, or 40% by mass or less, or 30% by mass or less. <1> from <15> The etching solution composition according to any one of the preceding claims. <17> The total blending amount of component A and component B is 40% by mass or more, or 50% by mass or more, or 55% by mass or more, or 60% by mass or more, and is 90% by mass or less, or 80% by mass or less, or 70% by mass or less. <1> from <16> The etching solution composition according to any one of the preceding claims. <18> The total blending amount of component A, component B, and component C is 40% by mass or more, or 50% by mass or more, or 55% by mass or more, or 60% by mass or more, and is 90% by mass or less, or 80% by mass or less, or 70% by mass or less. <2> from <17> The etching solution composition according to any one of the preceding claims. <19> Further containing water (ingredient E), <1> from <18> The etching solution composition according to any one of the preceding claims. <20> the mass ratio E / A of component E to component A is 0.1 or more, or 0.2 or more, or 0.3 or more, and is 2 or less, or 1.5 or less, or 1 or less; <1> from <19> The etching solution composition according to any one of the preceding claims. <21> the mass ratio E / D of component E to component D is 0.1 or more, or 0.5 or more, or 0.8 or more, and 5 or less, or 2.5 or less, or 2 or less; <1> from <20> The etching solution composition according to any one of the preceding claims. <22> pH is 2 or less, or 1 or less and -2 or more; <1> from <21> The etching solution composition according to any one of the preceding claims. <23> <1> from <22> 1. An etching method comprising the step of etching a member containing a titanium-based metal, a tungsten-based metal, a titanium / tungsten-based metal, or a nitride thereof using the etching solution composition according to any one of claims 1 to 9. <24> <23> A method for manufacturing a semiconductor substrate, comprising the etching method according to claim 1. [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 4, Comparative Examples 1 to 5) The components shown in Tables 1 and 2 were blended to obtain etching solutions (pH: -1) of Examples 1 to 4 and Comparative Examples 1 to 5. The amount of each component (mass %, active content) in the prepared etching solution is shown in Tables 1 and 2. The amount of water in Tables 1 and 2 also includes the amount of water contained in the acid aqueous solution, etc.

[0051] The following components were used to prepare the etching solution. (Component A) Phosphoric acid [Rinkagaku Kogyo Co., Ltd., concentration 85%] (Component B) Nitric acid [Fujifilm Wako Pure Chemical Corporation, concentration 70%] (Component C) Acetic acid [Fujifilm Wako Pure Chemical Industries, Ltd., concentration 100%] (Component D) DMSO: Dimethyl sulfoxide [Toray Fine Chemicals Co., Ltd., 100% concentration] (Non-ingredient D) Propylene glycol [Fujifilm Wako Pure Chemical Industries, Ltd., concentration 100%] (Component E) Water [ultrapure water produced using a continuous pure water production system (Pure Conti PC-2000VRL model) and a subsystem (Macace KC-05H model) manufactured by Kurita Water Industries Ltd.]

[0052] 2. Measuring the pH of the 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 The following etching test was carried out using each of the prepared etching solutions, and the following evaluations were carried out.

[0054] [Etching test] A 1.5 x 1.5 cm TiN wafer to be etched was immersed in an etching solution heated to 70°C for a specified time (the time shown below). A water bath was used for the etching test. A glass container containing approximately 10 ml of the etching solution composition was placed in the water bath and left to stand for 30 minutes to stabilize the temperature. Then, the TiN wafer was placed in the etching solution composition and etching began. After etching was completed, the wafer was removed, washed with water, and air-dried. In order to make the etching amount uniform, the etching time was determined based on the etching rate of the etching solution, and the immersion time for Example 1 was 30 minutes, for Example 2 it was 21 minutes, for Example 3 it was 35 minutes, for Example 4 it was 14 minutes, for Comparative Example 1 it was 20 minutes, for Comparative Example 2 it was 17 minutes, for Comparative Example 3 it was 180 minutes, for Comparative Example 4 it was 14 minutes, and for Comparative Example 5 it was 10 minutes.

[0055] [Evaluation TiN wafer A] The evaluation TiN wafer A is a uniform blanket wafer in which an SiO2 film is formed on a silicon wafer and a TiN film is further formed on the SiO2 film. [Evaluation TiN wafer B] The evaluation TiN wafer B is a uniform blanket wafer in which an SiO2 film is formed on a silicon wafer, and a TiN film is further formed on the SiO2 film by a film formation method different from that of the wafer A.

[0056] [Calculation of etching amount and etching rate] The film thickness of wafers A and B before and after the etching test was measured using spectroscopic ellipsometry, and the difference was taken as the amount of etching. The equipment and measurement conditions used are as follows: <Measurement conditions> Equipment: JA Woollam M-2000D Measurement temperature: room temperature (25℃) Measurement angle: 65°, 70°, 75° Sample size: 1.5cm square Acq. Time: 2.0 seconds Sample Thickness: 1.0 mm The sample size must be larger than the light source diameter of the device. Therefore, it should be at least 1.0 cm square, and considering operability, it should be at least 1.5 cm square. The analysis was performed using CompleteEASE. The fitting model for the TiN film used was TiN(Lorentz)+SiO2-JAW+INTR_JAW. The method for calculating the thickness of the TiN film is shown below. The calculation was performed by fitting the measurement results using the fitting model described above under the condition that the SiO2-JAW value was fixed at 100.63 nm and the INTR_JAW value was fixed at 1.0 nm. The results are shown in Table 1. The etching rate was calculated by dividing the etching amount by the etching time using the following formula: Etching rate (nm / min) = etching amount (nm) / etching time (min)

[0057] [Contact angle measurement] The contact angles between the etching solution and TiN wafers A and B were measured using a contact angle meter. The equipment and measurement conditions used are as follows: <Measurement conditions> Equipment: DropMaster DMo-501 manufactured by Kyowa Interface Science Co., Ltd. Measurement method: Droplet method Measurement temperature: room temperature (25℃) Liquid volume: 3 μl Analysis software: FAMAS Analysis method: θ / 2 method The time from when the etching solution landed on TiN wafers A and B until the contact angle value was read was 60 seconds. The contact angle value was measured at five points, and the average value of the three points excluding the maximum and minimum values ​​was calculated. The results are shown in Tables 1 and 2.

[0058] [Surface roughness measurement] Etching was performed under the same conditions as in the etching test described above, and the surface roughness of TiN wafers A and B was measured using an AFM (Digital Instrument NanoScope IIIa Multi Mode AFM) when the etching depth reached 10 nm. The results are shown in Table 1. A TiN wafer was immersed in a 1% BHF (buffered hydrofluoric acid solution) for 2 minutes and then washed with water to prepare a blank TiN wafer. To confirm the reliability of the results, measurements were taken of blank TiN wafers before and after etching TiN wafers A and B to confirm that the surface roughness of the blanks had not changed. If the surface roughness of the blanks had changed by 10% or more, the reliability was judged to be low and measurements were taken again. The results are shown in Tables 1 and 2. Note that for Comparative Example 3 in Table 2, the etching rate was 0.1 nm / min or less, which was not fast enough for evaluation, so surface roughness measurements were not taken. The equipment and measurement conditions used are shown below. Equipment: Bruker Dimension Icon Cantilever: Bruker RTESPA-300 Measurement method: Peak Force Tapping Measurement temperature: room temperature (25℃) Scan Size: 10.0 μm Scan Rate: 1.00 Hz Samples / Line:512 Analysis software: NanoScope Analysis 1.5 Roughness measurement image: Height Sensor

[0059] [Table 1]

[0060] As shown in Table 1, the etching solution composition of Example 1 had a smaller contact angle than Comparative Example 1, which did not contain component D, and therefore had improved wettability to titanium nitride-containing members. Furthermore, Example 1 had reduced surface roughness after etching compared to Comparative Example 1. From these findings, it is believed that the etching solution composition of Example 1 can improve the uniformity of etching of titanium nitride-containing members by improving the wettability to titanium nitride-containing members.

[0061] [Table 2]

[0062] As shown in Table 2, the etching solution compositions of Examples 2 to 4, in which the mass ratio A / D was 1 to 4, had reduced contact angles and improved wettability to titanium nitride-containing members, compared to Comparative Example 4, in which the mass ratio A / D was outside the range of 1 to 4. Furthermore, Examples 2 to 4 had reduced surface roughness after etching, compared to Comparative Example 4. As mentioned above, in Comparative Example 3, in which the mass ratio A / D was outside the range of 1 to 4, the etching rate was 0.1 nm / min or less, which was not sufficient for evaluation, and therefore surface roughness was not measured. The etching solution composition of Example 2 containing Components A to D had a reduced contact angle and improved wettability to a titanium nitride-containing member compared to Comparative Examples 2 and 5, which did not contain Component D. Furthermore, Example 2 had reduced surface roughness after etching compared to Comparative Examples 2 and 5. From these findings, it is believed that the etching solution compositions of Examples 2 to 4 can improve the wettability to members containing titanium nitride, thereby improving the uniformity of etching of members containing titanium nitride. [Industrial Applicability]

[0063] The etching solution composition of the present disclosure is useful for manufacturing large-capacity semiconductor memories.

Claims

1. An etching solution composition for etching a member containing a titanium-based metal, a tungsten-based metal, a titanium / tungsten-based metal, or a nitride thereof, comprising: Contains the following components A, B, and D, An etching solution composition having a mass ratio A / D of 1 or more and 4 or less. Component A: Phosphoric acid Component B: Nitric acid Component D: Aprotic polar solvent

2. The etching solution composition according to claim 1, which is an etching solution composition for etching a member containing titanium nitride.

3. 2. The etching solution composition of claim 1, wherein component D is dimethyl sulfoxide.

4. The etching solution composition of claim 1 further comprising an organic acid (component C).

5. The etching solution composition of claim 4 , wherein the organic acid comprises acetic acid.

6. 2. The etching solution composition according to claim 1, wherein a mass ratio B / D of component B to component D is 0.01 or more and 1 or less.

7. 2. The etching solution composition according to claim 1, wherein a mass ratio A / B of component A to component B is 1 or more and 50 or less.

8. The etching solution composition according to claim 4, wherein a mass ratio C / D of component C to component D is 0.01 or more and 1 or less.

9. The etching liquid composition according to claim 1, wherein the blending amount of component A is 30% by mass or more and 80% by mass or less.

10. The etching liquid composition according to claim 1 , wherein the blending amount of component B is 1% by mass or more and 10% by mass or less.

11. The etching solution composition according to claim 1, wherein the blending amount of component D is 1 mass % or more and 50 mass % or less.

12. The etching liquid composition according to claim 4, wherein the blending amount of component C is 1% by mass or more and 20% by mass or less.

13. 10. The etching solution composition of claim 1, further comprising water (component E).

14. The etching solution composition according to claim 1 , wherein the pH is 2 or less.

15. An etching method comprising the step of etching a member containing a titanium-based metal, a tungsten-based metal, a titanium / tungsten-based metal, or a nitride thereof using the etching solution composition according to any one of claims 1 to 14.

16. A method for manufacturing a semiconductor substrate, comprising the etching method according to claim 15.

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