Circuit board processing method

Abstract

The present invention provides a substrate processing method that yields a substrate with a clean surface condition. [Solution] This disclosure relates to a method for processing a substrate, comprising the following steps I and II. Step I: A process to obtain a treatment solution by mixing a composition containing an inhibitor, carbonic acid, and water (Solution A) with a composition containing an aliphatic quaternary ammonium salt, an alkanolamine, and water (Solution B). Step II: A step of processing a substrate having a resin mask using the processing solution obtained in Step I.

Description

Technical Field

[0001] This disclosure relates to a method for processing a substrate.

Background Art

[0002] In recent years, in personal computers and various electronic devices, power consumption has been reduced, processing speed has been increased, and miniaturization has advanced. Wiring such as package substrates mounted on these devices has been becoming finer year by year. For forming such fine wiring and connection terminals such as pillars and bumps, the metal mask method has mainly been used heretofore. However, due to its low versatility and difficulty in coping with the fineness of wiring and the like, it is being replaced by other new methods.

[0003] As one of the new methods, a method of using a dry film resist instead of a metal mask as a thick film resin mask is known. Although this resin mask is finally peeled off and removed, an alkaline peeling agent composition (peeling cleaning agent) is used at that time.

[0004] For example, Patent Document 1 proposes a substrate cleaning method including a step of peeling a resin mask from a substrate having a copper-containing metal layer and a resin mask on its surface using a cleaning agent containing a specific quaternary ammonium hydroxide, a specific amine, a reducing agent, and water.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] When forming fine wiring on printed circuit boards and the like, high stripping performance (resin mask removal ability, cleaning ability) is required for the stripping agent composition (processing solution) in order to reduce not only the residue of the resin mask but also the residue of auxiliary agents contained in the solder and plating solution used for forming the fine wiring and bumps. However, as wiring becomes smaller, even the slightest foreign matter is unacceptable in order to maintain the quality and value of the package substrate. Therefore, the release agent composition (processing liquid) is required not only to remove resin masks from minute gaps, but also to achieve a cleaner surface condition. When an alkaline stripping agent composition (treatment solution) is used in a circulating manner, for example, it will come to contain carbonate ions due to reactions with carbon dioxide in the air. When using a processing solution containing carbonate ions, a problem was frequently observed where crystalline foreign matter formed on the substrate surface after processing.

[0007] Therefore, this disclosure provides a substrate processing method that yields a substrate with a clean surface condition. [Means for solving the problem]

[0008] This disclosure relates, in one embodiment, to a method for processing a substrate, including the following steps I and II. Step I: A process to obtain a treatment solution by mixing a composition containing an inhibitor, carbonic acid, and water (Solution A) with a composition containing an aliphatic quaternary ammonium salt, an alkanolamine, and water (Solution B). Step II: A step of processing a substrate having a resin mask using the processing solution obtained in Step I.

[0009] This disclosure relates, in one embodiment, to a method for manufacturing an electronic component, including a method for processing a substrate of the disclosure. [Effects of the Invention]

[0010] This disclosure provides a substrate processing method that can obtain a substrate with a clean surface condition. [Modes for carrying out the invention]

[0011] This disclosure is based on the finding that, in one or more embodiments, the cause of crystalline foreign matter contamination on the substrate surface after processing, which occurs when using an alkaline stripping agent composition containing carbonate ions, is an inhibitor that is more easily precipitated due to the influence of carbonate ions and aliphatic quaternary ammonium salts, and that the occurrence of contamination is affected by the mixing method of the aliphatic quaternary ammonium salt, carbonate ions, and inhibitor.

[0012] This disclosure relates, in one embodiment, to a substrate processing method (hereinafter also referred to as "the substrate processing method of this disclosure") which includes the following steps I and II. Step I: A process to obtain a treatment solution by mixing a composition containing an inhibitor, carbonic acid, and water (Solution A) with a composition containing an aliphatic quaternary ammonium salt, an alkanolamine, and water (Solution B). Step II: A step of processing a substrate having a resin mask using the processing solution obtained in Step I.

[0013] This disclosure provides a substrate processing method that can obtain a substrate with a clean surface condition. Furthermore, by using the substrate processing method of this disclosure, high-quality electronic components can be obtained with a high yield.

[0014] While the detailed mechanism of action by which the effects of this disclosure are manifested remains unclear, it is presumed to be as follows. Generally, a stripping agent composition (treatment solution) for removing resin mask present in the gaps of fine metal patterns contains an alkanolamine, an aliphatic quaternary ammonium salt, an inhibitor, and water. On the other hand, since the stripping agent composition (treatment solution) is alkaline, as mentioned above, it has been reported that carbon dioxide (carbonic acid gas) from the air dissolves into the solution as carbonate ions during use, and these accumulate, potentially resulting in a large amount of carbonate ions in the solution. Furthermore, it is thought that the solubility of the inhibitor decreases in the presence of a certain amount or more of aliphatic quaternary ammonium salt and a certain amount or more of carbonate ions, leading to the formation of aggregates (foreign matter). If these aggregates adhere to the substrate, they can contaminate the substrate surface. However, in this disclosure, it is believed that by preparing a composition (Solution B) containing an aliphatic quaternary ammonium salt, an alkanolamine, and some water in advance, and then mixing it with a composition (Solution A) containing an inhibitor and carbonic acid, it is possible to prevent the aggregation of the inhibitor and contamination of the substrate, thereby obtaining a substrate with a clean surface condition. However, this disclosure does not have to be interpreted as being limited to this mechanism.

[0015] In this disclosure, a resin mask is a mask that protects the surface of a material from processes such as etching, plating, and heating, that is, a mask that functions as a protective film. Examples of resin masks include, in one or more embodiments, a resist layer after exposure and development, a resist layer subjected to at least one of exposure and / or development (hereinafter also referred to as "exposed and / or developed"), or a cured resist layer. Furthermore, in one or more embodiments, the resin mask is formed using a resist whose physical properties, such as solubility in a developer solution, change when exposed to light or electron beams. Resists are broadly classified into negative and positive types based on their reaction method with light or electron beams. Negative resists have the characteristic of decreasing solubility in a developer solution when exposed, and the layer containing a negative resist (hereinafter also referred to as the "negative resist layer") is used as a resin mask in the exposed area after exposure and development. Positive resists have the characteristic of increasing solubility in a developer solution when exposed, and the layer containing a positive resist (hereinafter also referred to as the "positive resist layer") has the exposed area removed after exposure and development, and the unexposed area is used as a resin mask. By using a resin mask with such characteristics, it is possible to form fine connection parts of circuit boards such as metal wiring, metal pillars, and solder bumps. In one or more embodiments, the resin material used to form the resin mask may be a film-like photosensitive resin, a resist film, or a photoresist. A general-purpose resist film can be used.

[0016] [Process I: Mixing process] Step I in the substrate processing method of the present disclosure is a step (mixing step) of obtaining a treatment liquid by mixing a composition (liquid A) containing an inhibitor, carbonic acid, and water with a composition (liquid B) containing an aliphatic quaternary ammonium salt, an alkanolamine, and water. In one or more embodiments, step I further includes mixing a composition (liquid C) containing an alkanolamine, an inhibitor, and water. That is, in one or more embodiments, step I is a step of mixing liquid A, liquid B, and liquid C to obtain a treatment liquid. Known methods can be used for the mixing method in step I. The mixing conditions in step I can be set as appropriate. As the mixing conditions in step I, in one or more embodiments, on a scale of 500 to 5000 L of liquid A, liquid B is continuously mixed at about 2 to 200 L per hour. For example, in one or more embodiments, the mixing ratio (A / B) of liquid A to liquid B in step I is 2 to 2000, and it is preferable to mix liquid B and liquid A over 1 hour. It is more preferable that the mixing ratio (A / B) is 3 to 1000 and liquid A and liquid B are mixed over 1 hour. It is even more preferable that the mixing ratio (A / B) is 50 to 600 and liquid A and liquid B are mixed over  1 hour. For example, as the mixing conditions of liquid A, liquid B, and liquid C in step 1, in one or more embodiments, the mixing ratio (B / C) of liquid B to liquid C is 0.1 to 10, and it is preferable to mix liquid B and liquid C over 1 hour, more preferably the mixing ratio (B / C) is 0.3 to 5 and liquid B and liquid C are mixed over 1 hour, and even more preferably the mixing ratio (B / C) is 0.5 to 3 and liquid B and liquid C are mixed over 1 hour. Also, in one or more embodiments, the mixing ratio (A / C) of liquid A to liquid C is 2 to 2000, and it is preferable to mix liquid A and liquid C over 1 hour, more preferably the mixing ratio (A / C) is 3 to 1000 and liquid A and liquid C are mixed over 1 hour, and even more preferably the mixing ratio (A / C) is 50 to 600 and liquid A and liquid C are mixed over 1 hour. As the mixing conditions in the step I, in one or more other embodiments, the mixing ratio (A / B) of the liquid A and the liquid B is set based on the mass ratio (inhibitor / aliphatic quaternary ammonium salt) of the content of the inhibitor in the liquid A and the content of the aliphatic quaternary ammonium salt in the liquid B. For example, it is preferably mentioned that the liquid A and the liquid B are mixed so that the mass ratio (inhibitor / aliphatic quaternary ammonium salt) of the inhibitor and the aliphatic quaternary ammonium salt mixed per hour is 0.005 or more and 60 or less. Alternatively, as the mixing conditions in the step I, in one or more embodiments, the liquid A, the liquid B, and optionally the liquid C are mixed so that each component in the treatment liquid after mixing is within the range described below.

[0017] <Liquid A> The liquid A is a composition containing an inhibitor, carbonic acid, and water. In one or more embodiments, the liquid A further contains at least one of an organic solvent and an alkanolamine. In one or more embodiments, the liquid A can further contain an alkali metal hydroxide and / or other components. In one or more embodiments, the liquid A is a release agent composition in which carbon dioxide gas has dissolved in the treatment liquid during the treatment process or during circulation to contain carbonic acid (carbonate ions). In one or more embodiments, the liquid A can be obtained by blending an inhibitor, carbonic acid, water, and optionally an organic solvent, an alkanolamine, an alkali metal hydroxide, and other components, etc. by a known method here. Here, "blending" includes mixing an inhibitor, carbonic acid, water, and other components, etc. simultaneously or in any order. In one or more embodiments, the preferable blending amount of each component in the liquid A can be the same as the preferable content of each component in the liquid A described below.

[0018] (Inhibitor in Liquid A) Examples of inhibitors contained in solution A include compounds containing heteroatoms, specifically nitrogen, sulfur, and oxygen atom compounds. More specifically, examples include azoles, and even more specifically, at least one selected from pyrazole, methylpyrazole, thiazole, oxazole, triazole, benzotriazole, tolyltriazole, dimethylbenzotriazole, tetrazole, triazine, tetrazine, pentazole, imidazole, methylimidazole, phenylimidazole, and dimethylbenzimidazole. Among these, from the viewpoint of the cleanliness of the substrate surface, at least one inhibitor selected from triazole, benzotriazole, tolyltriazole, dimethylbenzimidazole, and at least one selected from benzotriazole, imidazole, and dimethylbenzimidazole is preferred. The inhibitor may be one type or a combination of two or more types. From the viewpoint of substrate cleanliness, the inhibitor content in solution A is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and even more preferably 0.1% by mass or more. Similarly, from the same viewpoint, it is preferably 6% by mass or less, more preferably 3% by mass or less, and even more preferably 1.5% by mass or less. More specifically, the inhibitor content in solution A is preferably 0.01% by mass or more and 6% by mass or less, more preferably 0.05% by mass or more and 3% by mass or less, and even more preferably 0.1% by mass or more and 1.5% by mass or less. If there is a combination of two or more inhibitors, the inhibitor content in solution A is the total content of those inhibitors.

[0019] (Carbon dioxide in solution A) In one or more embodiments, the carbon dioxide (carbonate ions) contained in solution A originates from carbon dioxide gas in the air, etc. The carbon dioxide concentration (content) in solution A is generally preferable to be as low as possible from the viewpoint of resin mask removal. From the viewpoint of resin mask removal, it is preferably 10 mol / L or less, more preferably 5 mol / L or less, even more preferably 1.1 mol / L or less, even more preferably 1 mol / L or less, and 0.2 mol / L or more. The carbon dioxide concentration (content) in solution A is, in one or more embodiments, 0.2 mole / L or more and 10 mole / L or less, 0.2 mole / L or more and 5 mole / L or less, 0.2 mole / L or more and 1.1 mole / L or less, or 0.2 mole / L or more and 1 mole / L or less. In this disclosure, the carbon dioxide concentration in the solution can be measured using potentiometric titration.

[0020] (Water in solution A) Examples of the water contained in solution A include ion-exchanged water, RO water, distilled water, pure water, and ultrapure water. From the viewpoint of stability and miscibility, the water content in liquid A is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more. Similarly, from the viewpoint of stability and miscibility, it is preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 85% by mass or less. More specifically, the water content in liquid A is preferably 5% by mass or more and 95% by mass or less, more preferably 10% by mass or more and 90% by mass or less, and even more preferably 15% by mass or more and 85% by mass or less.

[0021] (Organic solvent in solution A) In one or more embodiments, solution A may further contain an organic solvent. From the viewpoint of improving resin mask removal performance, the organic solvent is preferably a ketone or alcohol compound, more preferably a glycol ether, and even more preferably butyl diglycol (BDG). The organic solvent may be one type or a combination of two or more types. From the viewpoint of stability and miscibility, the content of the organic solvent in solution A is preferably 2% by mass or more, more preferably 4% by mass or more, and even more preferably 10% by mass or more. Similarly, from the viewpoint of stability and miscibility, it is preferably 50% by mass or less, more preferably 45% by mass or less, and even more preferably 40% by mass or less. More specifically, the content of the organic solvent in solution A is preferably 2% by mass or more and 50% by mass or less, more preferably 4% by mass or more and 45% by mass or less, and even more preferably 10% by mass or more and 40% by mass or less. When the organic solvent is a combination of two or more types, the content of the organic solvent in solution A refers to their total content.

[0022] (Alkanolamine in solution A) Solution A may further contain an alkanolamine in one or more embodiments. If Solution A contains an alkanolamine, the alkanolamine may be the same as the alkanolamine contained in Solution B, which will be described later. If solution A contains an alkanolamine, the alkanolamine content in solution B is preferably 2% by mass or more, more preferably 4% by mass or more, and even more preferably 6% by mass or more, and from the viewpoint of resin mask removal, preferably 20% by mass or less, more preferably 17% by mass or less, and even more preferably 15% by mass or less. More specifically, the alkanolamine content in solution B is preferably 2% by mass or more and 20% by mass or less, more preferably 4% by mass or more and 17% by mass or less, and even more preferably 6% by mass or more and 15% by mass or less. If the alkanolamines are a combination of two or more types, the alkanolamine content in solution A is the total content of those types.

[0023] (Alkali metal hydroxide in solution A) The liquid A may further contain an alkali metal hydroxide in one or more embodiments. From the perspective of resin mask removability, the alkali metal hydroxide is preferably at least one selected from lithium hydroxide, sodium hydroxide, and potassium hydroxide, more preferably at least one of sodium hydroxide and potassium hydroxide, and still more preferably potassium hydroxide. The alkali metal hydroxide may be one type or a combination of two or more types. From the perspectives of stability and miscibility, the content of the alkali metal hydroxide in the liquid A is preferably 0.3% by mass or more, more preferably 1% by mass or more, still more preferably 2% by mass or more, and from the same perspectives, preferably 10% by mass or less, more preferably 8% by mass or less, and still more preferably 5% by mass or less. More specifically, the content of the alkali metal hydroxide in the liquid A is preferably 0.3% by mass or more and 10% by mass or less, more preferably 1% by mass or more and 8% by mass or less, and still more preferably 2% by mass or more and 5% by mass or less. When the alkali metal hydroxide is a combination of two or more types, the content of the alkali metal hydroxide in the liquid A refers to their total content.

[0024] (Other components in liquid A) The liquid A may further contain other components in one or more embodiments. Examples of the other components include those that can be used in ordinary detergents, such as alkali agents other than the above-mentioned alkanolamines and alkali metal hydroxides, amines other than the above-mentioned alkanolamines, organic solvents other than the above-mentioned organic solvents, surfactants, chelating agents, thickeners, dispersants, rust inhibitors, polymer compounds, solubilizers, antioxidants, preservatives, defoamers, antibacterial agents, and the like.

[0025] <Liquid B> The liquid B is a composition containing an aliphatic quaternary ammonium salt, an alkanolamine, and water. The liquid B may contain optional components (other components described later) as required in one or more embodiments. Solution B can be obtained in one or more embodiments by combining an aliphatic quaternary ammonium salt, an alkanolamine, water, and optionally other components in a known manner. Here, "combining" includes mixing the aliphatic quaternary ammonium salt, alkanolamine, water, and optionally other components simultaneously or in any order. The preferred amounts of each component in Solution B can be the same as the preferred content of each component in Solution B described later in one or more embodiments.

[0026] (Aliphatic quaternary ammonium salt in solution B) Examples of aliphatic quaternary ammonium salts contained in solution B include quaternary ammonium hydroxides represented by the following formula (II). The aliphatic quaternary ammonium salt may be one type or a combination of two or more types. [ka] In the above equation (II), R 4 , R 5 , R 6 and R 7 Each of these groups is independently at least one selected from a methyl group, an ethyl group, a propyl group, a hydroxymethyl group, a hydroxyethyl group, and a hydroxypropyl group. Quaternary ammonium hydroxides represented by formula (II) are salts consisting of a quaternary ammonium cation and a hydroxide, and include, for example, at least one selected from tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, tetrapropylammonium hydroxide, 2-hydroxyethyltrimethylammonium hydroxide (choline), 2-hydroxyethyltriethylammonium hydroxide, 2-hydroxyethyltripropylammonium hydroxide, 2-hydroxypropyltrimethylammonium hydroxide, 2-hydroxypropyltriethylammonium hydroxide, 2-hydroxypropyltripropylammonium hydroxide, dimethylbis(2-hydroxyethyl)ammonium hydroxide, diethylbis(2-hydroxyethyl)ammonium hydroxide, dipropylbis(2-hydroxyethyl)ammonium hydroxide, tris(2-hydroxyethyl)methylammonium hydroxide, tris(2-hydroxyethyl)ethylammonium hydroxide, tris(2-hydroxyethyl)propylammonium hydroxide, tetrakis(2-hydroxyethyl)ammonium hydroxide, and tetrakis(2-hydroxypropyl)ammonium hydroxide. Among these, tetramethylammonium hydroxide (TMAH) is preferred from the viewpoint of improving resin mask removal performance. From the viewpoint of resin mask removal efficiency, the content of aliphatic quaternary ammonium salt in solution B is preferably 0.5% by mass or more, more preferably 1.5% by mass or more, and even more preferably 3% by mass or more. From the viewpoint of reducing wastewater load, it is preferably 40% by mass or less, more preferably 35% by mass or less, and even more preferably 30% by mass or less. More specifically, the content of aliphatic quaternary ammonium salt in solution B is preferably 0.5% by mass or more and 40% by mass or less, more preferably 1.5% by mass or more and 35% by mass or less, and even more preferably 3% by mass or more and 30% by mass or less. If there is a combination of two or more aliphatic quaternary ammonium salts, the content of aliphatic quaternary ammonium salt in solution B is the total content of those salts.

[0027] (Alkanolamine in solution B) Examples of alkanolamines (amino alcohols) contained in solution B include compounds represented by the following formula (I). The alkanolamine may be one type or a combination of two or more types. [ka] In the above equation (I), R 1 R represents a hydrogen atom, a methyl group, an ethyl group, or an aminoethyl group. 2 R represents a hydrogen atom, a hydroxyethyl group, a hydroxypropyl group, a methyl group, or an ethyl group. 3 This represents a hydroxyethyl group or a hydroxypropyl group. Component A can be at least one selected from, for example, monoethanolamine (MEA), monoisopropanolamine, N-methylmonoethanolamine, N-methylisopropanolamine, N-ethylmonoethanolamine, N-ethylisopropanolamine, diethanolamine, diisopropanolamine, N-dimethylmonoethanolamine, N-dimethylmonoisopropanolamine, N-methyldiethanolamine, N-methyldiisopropanolamine, N-diethylmonoethanolamine, N-diethylmonoisopropanolamine, N-ethyldiethanolamine, N-ethyldiisopropanolamine, N-(β-aminoethyl)ethanolamine, N-(β-aminoethyl)isopropanolamine, N-(β-aminoethyl)diethanolamine, and N-(β-aminoethyl)diisopropanolamine. Among these, monoethanolamine (MEA) is preferred from the viewpoint of improving resin mask removal performance. From the viewpoint of stability and miscibility, the content of alkanolamine in solution B is preferably 1% by mass or more, more preferably 2% by mass or more, and even more preferably 3% by mass or more. Similarly, from the viewpoint of stability and miscibility, it is preferably 60% by mass or less, more preferably 55% by mass or less, and even more preferably 50% by mass or less. More specifically, the content of alkanolamine in solution B is preferably 1% by mass or more and 60% by mass or less, more preferably 2% by mass or more and 55% by mass or less, and even more preferably 3% by mass or more and 50% by mass or less. If there is a combination of two or more alkanolamines, the content of alkanolamine in solution B is the total content of those two or more.

[0028] The ratio (by mass%) of the content (aliphatic quaternary ammonium salt / alkanolamine) in solution B is, in one or more embodiments, 10 / 90 to 30 / 70, 40 / 60 to 60 / 40, or 80 / 20 to 98 / 2.

[0029] (Water in solution B) From the viewpoint of substrate cleanliness, the water content in solution B is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 20% by mass or more. From the viewpoint of improving resin mask removal, it is preferably 95% by mass or less, more preferably 85% by mass or less, and even more preferably 80% by mass or less. More specifically, the water content in solution B is preferably 5% by mass or more and 95% by mass or less, more preferably 10% by mass or more and 85% by mass or less, and even more preferably 20% by mass or more and 80% by mass or less.

[0030] (Alkali metal hydroxide in solution B) In one or more embodiments, solution B may further contain an alkali metal hydroxide. From the viewpoint of resin mask removal, the alkali metal hydroxide is preferably at least one selected from lithium hydroxide, sodium hydroxide, and potassium hydroxide, more preferably at least one of sodium hydroxide and potassium hydroxide, and even more preferably potassium hydroxide. The alkali metal hydroxide may be one type or a combination of two or more types. From the viewpoint of stability and miscibility, the alkali metal hydroxide content in solution B is preferably 0.3% by mass or more, more preferably 1% by mass or more, and even more preferably 2% by mass or more. Similarly, from the viewpoint of stability and miscibility, it is preferably 10% by mass or less, more preferably 8% by mass or less, and even more preferably 5% by mass or less. More specifically, the alkali metal hydroxide content in solution A is preferably 0.3% by mass or more and 10% by mass or less, more preferably 1% 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. When there is a combination of two or more alkali metal hydroxides, the alkali metal hydroxide content in solution B refers to the total content of those alkali metal hydroxides.

[0031] (Other components in Solution B) In one or more embodiments, solution B may further contain other components. Examples of other components include those commonly used in cleaning agents, such as the aliphatic quaternary ammonium salts, alkaline agents other than the alkanolamines and alkali metal hydroxides mentioned above, amines other than the alkanolamines mentioned above, organic solvents, surfactants, chelating agents, thickeners, dispersants, rust inhibitors, polymer compounds, solubilizers, antioxidants, preservatives, defoaming agents, and antibacterial agents. In one or more embodiments, solution B does not contain the inhibitor of solution A. (Carbon dioxide in solution B) In one or more embodiments, solution B may contain carbon dioxide (carbonate ions) derived from carbon dioxide in the air. Generally, a lower carbon dioxide concentration in solution B is preferable from the viewpoint of improving resin mask removal. For example, in one or more embodiments, the carbon dioxide concentration (content) in solution B is preferably less than 0.2 mol / L, more preferably 0.15 mol / L or less, even more preferably 0.1 mol / L or less, even more preferably 0.05 mol / L or less, and even more preferably 0.01 mol / L or less. In one or more embodiments, the carbon dioxide concentration (content) in solution B may be 0 mol / L. Incidentally, the carbonic acid concentration in Liquid B can be controlled within a predetermined concentration range by manufacturing it in an inert gas environment such as nitrogen or by treating it with an ion exchange resin. From the viewpoint of preventing contact with carbon dioxide gas, Liquid B is preferably stored in a sealed container until immediately before use. An inert gas may be enclosed in the container.

[0032] <Liquid C> In one or more embodiments, Liquid C is a composition containing alkanolamine, an inhibitor, and water. In one or more embodiments, Liquid C can further contain components described later as necessary. In one or more embodiments, Liquid C can be obtained by blending an aliphatic quaternary ammonium salt, water, and other components as necessary by a known method. Here, "blending" includes mixing an aliphatic quaternary ammonium salt, water, and other components as necessary simultaneously or in any order. The preferable blending amount of each component in Liquid C can be the same as the preferable content of each component in Liquid C described later in one or more embodiments.

[0033] (Alkanolamine in Liquid C) Examples of the alkanolamine contained in Liquid C include the alkanolamine in Liquid B described above. From the viewpoints of stability and miscibility, the content of alkanolamine in Liquid C is preferably 15% by mass or more, more preferably 25% by mass or more, still more preferably 35% by mass or more, and from the same viewpoints, preferably 60% by mass or less, more preferably 55% by mass or less, still more preferably 50% by mass or less. More specifically, the content of alkanolamine in Liquid C is preferably 15% by mass or more and 60% by mass or less, more preferably 25% by mass or more and 55% by mass or less, still more preferably 35% by mass or more and 50% by mass or less. When the alkanolamine is a combination of two or more kinds, the content of alkanolamine in Liquid C is the total content thereof.

[0034] (Inhibitor in Liquid C) Examples of inhibitors contained in solution C include the inhibitors in solution A mentioned above. From the viewpoint of substrate cleanliness, the inhibitor content in solution C is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, and even more preferably 0.5% by mass or more. Similarly, from the same viewpoint, it is preferably 6% by mass or less, more preferably 3% by mass or less, and even more preferably 1.5% by mass or less. More specifically, the inhibitor content in solution C is preferably 0.05% by mass or more and 6% by mass or less, more preferably 0.1% by mass or more and 3% by mass or less, and even more preferably 0.5% by mass or more and 1.5% by mass or less. If there is a combination of two or more inhibitors, the inhibitor content in solution C is the total content of those inhibitors.

[0035] (Water in solution C) From the viewpoint of improving resin mask removal and substrate cleanliness, the water content in solution C is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more. Similarly, from the viewpoint of improving resin mask removal and substrate cleanliness, it is preferably 95% by mass or less, more preferably 85% by mass or less, and even more preferably 80% by mass or less. More specifically, the water content in solution C is preferably 5% by mass or more and 95% by mass or less, more preferably 10% by mass or more and 85% by mass or less, and even more preferably 15% by mass or more and 80% by mass or less.

[0036] (Alkali metal hydroxide in solution C) In one or more embodiments, solution C may further contain an alkali metal hydroxide. From the viewpoint of resin mask removal, the alkali metal hydroxide is preferably at least one selected from lithium hydroxide, sodium hydroxide, and potassium hydroxide, more preferably at least one of sodium hydroxide and potassium hydroxide, and even more preferably potassium hydroxide. The alkali metal hydroxide may be a single type or a combination of two or more types. From the viewpoint of stability and miscibility, the alkali metal hydroxide content in solution C is preferably 0.3% by mass or more, more preferably 1% by mass or more, and even more preferably 2% by mass or more. Similarly, from the viewpoint of stability and miscibility, it is preferably 10% by mass or less, more preferably 8% by mass or less, and even more preferably 5% by mass or less. More specifically, the alkali metal hydroxide content in solution C is preferably 0.3% by mass or more and 10% by mass or less, more preferably 1% 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. When there is a combination of two or more alkali metal hydroxides, the alkali metal hydroxide content in solution C refers to the total content of those alkali metal hydroxides.

[0037] (Organic solvent in solution C) In one or more embodiments, solution C may further contain an organic solvent. From the viewpoint of improving resin mask removal, the organic solvent is preferably a ketone or alcohol compound, more preferably a glycol ether, and even more preferably butyl diglycol (BDG). The organic solvent may be one type or a combination of two or more types. From the viewpoint of stability and miscibility, the content of the organic solvent in solution C is preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more. Similarly, from the viewpoint of stability and miscibility, it is preferably 60% by mass or less, more preferably 55% by mass or less, and even more preferably 50% by mass or less. More specifically, the content of the organic solvent in solution C is preferably 10% by mass or more and 60% by mass or less, more preferably 15% by mass or more and 55% by mass or less, and even more preferably 20% by mass or more and 50% by mass or less. When there is a combination of two or more organic solvents, the content of the organic solvent in solution C refers to their total content.

[0038] (Other components in solution C) In one or more embodiments, liquid C may further contain other components. Examples of other components include those commonly used in cleaning agents, such as alkaline agents other than the alkanolamines and alkali metal hydroxides mentioned above, amines other than the alkanolamines mentioned above, organic solvents other than the organic solvents mentioned above, surfactants, chelating agents, thickeners, dispersants, rust inhibitors, polymer compounds, solubilizers, antioxidants, preservatives, defoaming agents, and antibacterial agents.

[0039] (Carbon dioxide in solution C) In one or more embodiments, solution C may contain carbon dioxide (carbonate ions) derived from carbon dioxide in the air. Generally, a lower carbon dioxide concentration in solution C is preferable from the viewpoint of improving resin mask removal. For example, in one or more embodiments, the carbon dioxide concentration in solution C is preferably less than 0.2 mol / L, more preferably 0.15 mol / L or less, even more preferably 0.1 mol / L or less, even more preferably 0.05 mol / L or less, and even more preferably 0.01 mol / L or less. In one or more embodiments, the carbon dioxide concentration in solution C may be 0 mol / L. Furthermore, the carbon dioxide concentration in solution C can be controlled within a predetermined concentration range by manufacturing it under an inert gas environment such as nitrogen. From the viewpoint of preventing contact with carbon dioxide, it is preferable to store solution C in a sealed container until immediately before use. An inert gas may be sealed inside the container.

[0040] <Processing solution> The processing liquid obtained in step I (hereinafter also referred to as "the processing liquid of the present disclosure") is, in one or more embodiments, a mixed liquid obtained by mixing liquid A and liquid B, or a mixed liquid obtained by mixing liquid A, liquid B, and liquid C. In one or more embodiments, the processing liquid of the present disclosure is a processing liquid for use in processing a substrate having a resin mask, a cleaning agent composition for removing a resin mask for cleaning a substrate having a resin mask, or a stripping agent composition for removing a resin mask from a substrate having a resin mask. In one or more embodiments of this disclosure, Solution A is a stripping agent composition containing carbon dioxide (carbonate ions) as carbon dioxide is dissolved in the processing liquid during the processing step or circulation, while Solutions B and C are replenishment solutions for replenishing the stripping agent composition components of Solution A that have been reduced by use.

[0041] (Alkanolamines in the treatment solution) From the viewpoint of improving resin mask removal performance, the content of alkanolamine in the processing solution of this disclosure is preferably 3% by mass or more, more preferably 5% by mass or more, and even more preferably 8% by mass or more. From the same viewpoint, it is preferably 18% by mass or less, more preferably 15% by mass or less, and even more preferably 12% by mass or less. More specifically, the content of alkanolamine in the processing solution of this disclosure is preferably 3% by mass or more and 18% by mass or less, preferably 5% by mass or more and 15% by mass or less, and even more preferably 8% by mass or more and 12% by mass or less. When there is a combination of two or more alkanolamines, the content of alkanolamine in the processing solution is the total content of those alkanolamines.

[0042] (Inhibitors in the treatment solution) From the viewpoint of substrate cleanliness, the inhibitor content in the processing solution of this disclosure is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, and even more preferably 0.05% by mass or more. Similarly, from the same viewpoint, it is preferably 3% by mass or less, more preferably 1% by mass or less, and even more preferably 0.5% by mass or less. More specifically, the inhibitor content in the processing solution of this disclosure is preferably 0.01% by mass or more and 3% by mass or less, more preferably 0.02% by mass or more and 1% by mass or less, and even more preferably 0.05% by mass or more and 0.5% by mass or less. If there is a combination of two or more inhibitors, the inhibitor content in the processing solution is the total content of those inhibitors.

[0043] (Aliphatic quaternary ammonium salts in the treatment solution) From the viewpoint of improving resin mask removal performance, the content of aliphatic quaternary ammonium salts in the processing solution of this disclosure is preferably 0.5% by mass or more, more preferably 1.5% by mass or more, and even more preferably 3% by mass or more. Similarly, from the same viewpoint, it is preferably 15% by mass or less, more preferably 10% by mass or less, and even more preferably 7% by mass or less. More specifically, the content of aliphatic quaternary ammonium salts in the processing solution of this disclosure is preferably 0.5% by mass or more and 15% by mass or less, more preferably 1.5% by mass or more and 10% by mass or less, and even more preferably 3% by mass or more and 7% by mass or less. When the aliphatic quaternary ammonium salts are a combination of two or more types, the content of aliphatic quaternary ammonium salts in the processing solution refers to their total content.

[0044] (Organic solvent in the processing solution) From the viewpoint of improving resin mask removal performance, the content of the organic solvent in the processing solution of this disclosure is preferably 2% by mass or more, more preferably 3% by mass or more, and even more preferably 5% by mass or more. From the same viewpoint, it is preferably 20% by mass or less, more preferably 17% by mass or less, and even more preferably 14% by mass or less. More specifically, the content of the organic solvent in the processing solution of this disclosure is preferably 2% by mass or more and 20% by mass or less, more preferably 3% by mass or more and 17% by mass or less, and even more preferably 5% by mass or more and 14% by mass or less. When the organic solvent is a combination of two or more types, the content of the organic solvent in the processing solution refers to the total content of those organic solvents.

[0045] (Carbon dioxide in the processing solution) The carbon dioxide (carbonate ions) contained in the processing solution of this disclosure is derived from carbon dioxide gas in the air, etc., in one or more embodiments. The carbon dioxide concentration (content) in the processing solution of this disclosure is generally preferable to be lower from the viewpoint of resin mask removal. From the viewpoint of resin mask removal, it is preferably 10 ml / L or less, more preferably 5 ml / L or less, even more preferably 1 ml / L or less, and 0.1 ml / L or more. The carbon dioxide concentration in the processing solution of this disclosure can be measured using potentiometric titration.

[0046] (Water in the processing solution) The water content in the processing solution of this disclosure can be the remainder after removing the above-mentioned components (alkanolamines, inhibitors, aliphatic quaternary ammonium salts, alkali metal hydroxides, organic solvents, and other components) from the entire processing solution. Specifically, from the viewpoint of resin mask removal performance, the water content in the processing solution of this disclosure is preferably 40% by mass or more, more preferably 50% by mass or more, even more preferably 60% by mass or more, and from the same viewpoint, preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 85% by mass or less.

[0047] (Alkali metal hydroxides in the treatment solution) If the processing solution of the present disclosure contains alkali metal hydroxides, the content is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and even more preferably 0.5% by mass or more, from the viewpoint of resin mask removal, and similarly, preferably 3% by mass or less, more preferably 2% by mass or less, and even more preferably 1.5% by mass or less. More specifically, the alkali metal hydroxide content in the processing solution of the present disclosure is preferably 0.1% by mass or more and 3% by mass or less, more preferably 0.2% by mass or more and 2% by mass or less, and even more preferably 0.5% by mass or more and 1.5% by mass or less. If the alkali metal hydroxides are a combination of two or more types, the alkali metal hydroxide content in the processing solution refers to their total content.

[0048] In this disclosure, "content of each component in the processing solution" means the content of each component at the time of use, that is, at the time when the processing solution is first used for substrate processing (resin mask peeling treatment). In one or more embodiments, the content of each component in the processing solution of this disclosure can be considered as the amount of each component blended in the processing solution of this disclosure. In this disclosure, the content of each component in solution A, solution B, and solution C can be considered as the amount of each component blended in solution A, solution B, and solution C, respectively, in one or more embodiments.

[0049] (pH of the treatment solution) The pH of the processing solution in this disclosure is preferably 10 or higher, more preferably 11 or higher, and even more preferably 12 or higher, from the viewpoint of improving resin mask removal efficiency, and preferably 15 or lower, more preferably 14.7 or lower, and even more preferably 14.5 or lower, from the viewpoint of suppressing damage to the substrate resin. The pH of the processing solution is the value at 25°C and can be measured using a pH meter, specifically by the method described in the examples.

[0050] [Process II: Processing Process] Step II in the substrate processing method of this disclosure is a step (processing step) in which a substrate (object to be processed) having a resin mask is processed using the processing solution (processing solution of this disclosure) obtained in step I. In one or more embodiments, the process includes cleaning a substrate having a resin mask, peeling the resin mask off the substrate having the resin mask, and removing the resin mask from the substrate having the resin mask. Step II, in one or more embodiments, includes bringing the processing solution of the present disclosure into contact with the object to be processed.

[0051] Methods for peeling a resin mask from an object to be treated using the processing solution of the present disclosure, or methods for bringing the processing solution of the present disclosure into contact with the object to be treated, include, for example, a method of immersing the object in a washing bath containing the processing solution, a method of spraying the processing solution into contact with the object (shower method), and an ultrasonic cleaning method in which ultrasonic waves are irradiated while the object is immersed in the processing solution. The processing solution in this disclosure can be used directly for washing without dilution. Examples of materials to be processed include those described later. For example, in one or more embodiments, step II includes spraying the processing solution obtained in step I (the processing solution of the present disclosure) onto a substrate (work to be processed) having a resin mask. Examples of the time (contact time or immersion time) for contacting or immersing the processing liquid of the present disclosure with the object to be processed include 1 minute or more and 10 minutes or less, and more specifically, 2 minutes or more and 6 minutes or less. When the processing liquid of the present disclosure is sprayed and brought into contact with the surface, the spray time can be, for example, 1 minute or more and 10 minutes or less, or more specifically, 2 minutes or more and 6 minutes or less.

[0052] In step II, it is preferable to irradiate the workpiece with ultrasonic waves when the workpiece comes into contact with the workpiece with the workpiece with the workpiece with the workpiece with the workpiece with the workpiece with the workpiece with the workpiece with peeling and cleaning power (resin mask peeling ability, resin mask removal ability) of the workpiece with

[0053] In step II, the peeling and cleaning power (resin mask peeling ability, resin mask removal ability) of the processing solution of the present disclosure is easily demonstrated, so the temperature of the processing solution when used is preferably 40°C or higher, more preferably 50°C or higher, and from the viewpoint of reducing the impact on the substrate, it is preferably 70°C or lower, and more preferably 60°C or lower.

[0054] Step II in the substrate processing method of the present disclosure may, in one or more embodiments, further include bringing the object to be processed into contact with the processing solution obtained in Step I (the processing solution of the present disclosure), rinsing with water, and drying. Examples of rinsing methods include running water rinsing. Examples of drying methods include air blow drying. In one or more embodiments, step II of the substrate processing method of the present disclosure may further include bringing the object to be processed into contact with the processing solution obtained in step I (the processing solution of the present disclosure), and then rinsing it with water.

[0055] <Object to be processed> In one or more embodiments, the object to be processed is a substrate having a resin mask. Examples of the substrate include printed circuit boards, wafers, copper plates, aluminum plates, and the like. The resin mask may be, for example, a negative-type resin mask or a positive-type resin mask, and a negative-type resin mask is preferred because it is easier to achieve the effects of this disclosure. An example of a negative-type resin mask is an exposed and / or developed negative-type dry film resist. In this disclosure, a negative resin mask is formed using a negative resist, and an example of this is a negative resist layer that has been exposed and / or developed. In this disclosure, a positive resin mask is formed using a positive resist, and an example of this is a positive resist layer that has been exposed and / or developed. The thickness of the resin mask can be, for example, 5 μm to 35 μm or less.

[0056] In one or more embodiments, the substrate (workpiece) having the resin mask includes a substrate having a metal layer and a resin mask on its surface. In one or more embodiments, the metal layer is a copper plating layer. The copper plating layer can be formed, for example, by an electrolytic copper plating method. Examples of the thickness of the metal layer include 3 μm to 30 μm. In one or more embodiments, the metal layer is used as metal wiring or wiring connection.

[0057] In one or more other embodiments, the substrate (workpiece) having the resin mask may include, for example, an electronic component having a metal layer and a resin mask on its surface and an intermediate product of the same. Examples of electronic components include at least one component selected from printed circuit boards, wafers, copper plates, and aluminum plates. The intermediate product is an intermediate product in the manufacturing process of an electronic component, and includes an intermediate product after resin mask processing. Specific examples of objects to be processed include, for example, electronic components on which wiring, connection terminals, etc., are formed on the substrate surface by undergoing a process of at least one of the following: soldering using a resin mask and plating (copper plating, aluminum plating, nickel plating, tin plating, etc.). In this disclosure, soldering means creating solder in areas on the substrate where a resin mask is not present and forming solder bumps by heating. In this disclosure, plating means performing at least one plating process selected from copper plating, aluminum plating, nickel plating, and tin plating on areas on the substrate where a resin mask is not present. Areas where a resin mask is not present refer to the parts of a resist pattern (a resin mask in the shape of a pattern) formed by phenotyping a resin mask laminated to a substrate, where the resin mask has been removed by phenotyping.

[0058] In one or more other embodiments, the substrate (workpiece) having the resin mask includes a substrate having a resin mask in a fine gap. An example of a substrate having a resin mask in a fine gap is a substrate in which a non-cured resin mask is subjected to curing treatment of at least one of exposure and development on the substrate surface, the non-cured resin mask is removed, and then a circuit pattern is formed by plating. The hardened resin mask is present in the non-plated portion of the formed circuit pattern. In this disclosure, a gap refers to the distance between circuit patterns (fine wire sections) (the distance between adjacent fine wire sections) in one or more embodiments, and is also called space (S). The thickness (plating thickness) of the fine wire section is, for example, 3 μm or more and 30 μm or less. The width of the fine wire section is also called line (L). A resin mask in a fine gap refers to a resin mask that exists in a space with a space width (S) of 10 μm or less in one or more embodiments. The thickness of the resin mask is, for example, 5 μm or more and 35 μm or less. An example of a resin mask in a fine gap is a resin mask that exists in a space with a space width (S) of 4 to 7 μm.

[0059] [Process III (Recovery Process)] The substrate processing method of this disclosure may further include a step III (recovery step) in one or more embodiments. Step III in the substrate processing method of this disclosure is a step of recovering the processing liquid after step II. In one or more embodiments, at least a portion of the processing solution recovered in step III can be used (reused) as solution B in step I. Therefore, in one or more embodiments of the substrate treatment method of this disclosure, the processing solution recovered in step III can be recycled.

[0060] [Manufacturing methods for electronic components] This disclosure relates, in one embodiment, to a method for manufacturing electronic components, including a substrate processing method according to this disclosure. According to the method for manufacturing electronic components of this disclosure, the resin mask adhering to the substrate can be effectively removed, resulting in a substrate with a clean surface condition, thus enabling the manufacture of highly reliable electronic components. Furthermore, by using the electronic component processing method of this disclosure, the resin mask adhering to the substrate can be easily peeled off, resulting in a substrate with a clean surface condition, thus improving the manufacturing efficiency of electronic components. [Examples]

[0061] The present disclosure will be specifically described below with reference to examples, but the present disclosure is not limited in any way by these examples.

[0062] 1. Preparation of the carbonate source aqueous solution A tetramethylammonium bicarbonate aqueous solution with a carbon dioxide concentration of 2.7 mol / L is prepared by bubbling carbon dioxide into a 25% by mass tetramethylammonium hydroxide (TMAH) aqueous solution until the pH of the aqueous solution at 25°C reaches 8. The concentration of tetramethylammonium bicarbonate in the aqueous solution obtained by the above procedure was calculated assuming that all of the tetramethylammonium in the 25% TMAH aqueous solution used was converted to tetramethylammonium carbonate. Note that the amount of tetramethylammonium cation in the carbonate source aqueous solution is omitted in Table 1 below, but it is the same amount as the carbonate ions.

[0063] 1. Preparation of the treatment solution for Example 1 and Comparative Example 1 (mixing step) (Example 1) The inhibitors (DMBI, BTA), organic solvent (BDG), the aforementioned aqueous solution of the carbon dioxide source, and water were mixed to obtain solution A shown in Table 1 below. Solution A is intended to represent a composition (processing solution) that contains carbon dioxide as carbon dioxide gas dissolves during the processing step or circulation. Aliphatic quaternary ammonium salt (TMAH), alkanolamine (MEA), and water were mixed to obtain solution B shown in Table 1. This solution B is assumed to be a carbon dioxide-free composition (carbon dioxide concentration 0 mol / L). Solution B was stored in a sealed container to prevent contact with carbon dioxide until it was mixed with solution A. Solution A and Solution B were mixed over 1 hour according to the mixing ratio shown in Table 1 to obtain the treatment solution (pH: 12.1) of Example 1 shown in Table 2. The concentrations (amount) (mass% or mol / L, effective content) of each component in Solution A and Solution B before mixing are shown in Table 1. The concentrations listed in Table 2 are the active ingredient concentrations (mass% or mol / L) calculated from the amounts used. (Comparative Example 1) The inhibitors (DMBI, BTA), organic solvent (BDG), aliphatic quaternary ammonium salt (TMAH), alkanolamine (MEA), the aforementioned carbonate source aqueous solution, and water were simultaneously mixed to obtain the treatment solution for Comparative Example 1. Specifically, the raw materials (DMBI, BTA, BDG, TMAH, MEA, carbonate source aqueous solution, and water) equivalent to 3 kg of the treatment solution were simultaneously added to a 5 L stainless steel beaker, stirred, and mixed to prepare the treatment solution for Comparative Example 1 (pH: 12.1) shown in Table 2.

[0064] The following materials were used to prepare the treatment solutions for Example 1 and Comparative Example 1. MEA: Monoethanolamine (MEA) [Nippon Shokubai Co., Ltd.] TMAH: Tetramethylammonium hydroxide [Resonac Co., Ltd., 25% aqueous solution] BDG: Dibutyl diglycol [Nippon Emulsifier Co., Ltd.] DMBI: 5,6-Dimethylbenzimidazole [Manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.] BTA: Benzotriazole [Manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.] Carbonate source [Tetramethylammonium bicarbonate aqueous solution with a carbon dioxide concentration of 2.7 ml / L] Water [Pure water with a purity of 1 μS / cm or less, produced using Organo's G-10DSTSET pure water production system]

[0065] [pH of the treatment solution] The pH of the treatment solution at 25°C was measured using a pH meter (Toa Denpa Kogyo Co., Ltd., HM-30G), and the value was obtained 3 minutes after immersing the pH meter's electrode in the treatment solution.

[0066] [Table 1]

[0067] 2. Evaluation of the treatment solutions in Example 1 and Comparative Example 1 The following evaluations were performed on the prepared treatment solutions for Example 1 and Comparative Example 1.

[0068] [Evaluation board] The test piece for evaluating peelability is 50mm x 50mm in size and consists of a copper substrate with a 15μm thick metal layer (copper plating layer, fine lines) formed by copper plating and a 25μm thick negative-type dry film resin mask layer arranged alternately in a linear pattern (circuit pattern). The line width of the metal layer (fine lines) and the width of the resin mask layer (L / S) of the circuit pattern are 8μm / 7μm. The negative-type dry film is a cured resin mask. [Surface condition of the circuit board] (Processing steps) Three kilograms of each treatment solution were added to a five-liter stainless steel beaker. This was heated to 60°C and sprayed onto a test piece for 120 seconds while circulating through a box-type spray cleaner equipped with a single-fluid nozzle (full cone type) J020 (manufactured by Ikeuchi Co., Ltd.) as a spray nozzle (pressure: 0.03 MPa, spray distance: 8 cm). (Post-processing steps) Next, the test piece was rinsed by running water over it for 30 seconds. Furthermore, a box-type spray cleaning machine equipped with a single-fluid nozzle (full cone type) J020 (manufactured by Ikeuchi Co., Ltd.) was used to spray 10% sulfuric acid (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) for 10 seconds while circulating the solution (pressure: 0.03 MPa, spray distance: 8 cm). After that, the test piece was rinsed again by running water over it for 30 seconds and dried with a nitrogen blower. Using a scanning electron microscope (SEM, manufactured by JEOL Ltd.), the test pieces after the above treatment were magnified 2500 times and visually observed, and the surface cleanliness was evaluated based on the following criteria. The results are shown in Table 2. <Criteria for determining surface cleanliness> Clean surface condition: No contaminants are visible on the copper surface. Contamination with crystalline foreign matter: Crystalline contaminants are observed.

[0069] [Table 2]

[0070] As shown in Table 2, Example 1, obtained by mixing solution A and solution B, yielded a substrate with a cleaner surface condition compared to Comparative Example 1, obtained by mixing all components simultaneously.

[0071] 3. Preparation of the treatment solution for Example 2 The inhibitors (DMBI, BTA), organic solvent (BDG), the aforementioned aqueous solution of the carbon dioxide source, water, and alkanolamine (MEA) were mixed to obtain solution A shown in Table 3 below. The obtained solution A was colorless and transparent, and no foreign matter precipitated even in the presence of 3% by mass of alkanolamine. This solution A is intended to represent a composition (processing solution) that contains carbon dioxide due to the dissolution of carbon dioxide gas during the processing step or circulation. Mix an aliphatic quaternary ammonium salt (TMAH), an alkanolamine (MEA), and water to obtain solution B shown in Table 3. This solution B is assumed to be a carbon dioxide-free composition (carbon dioxide concentration 0 mol / L). Solution B is stored in a sealed container to prevent contact with carbon dioxide until it is mixed with solution A. Mix solution A and solution B over 1 hour according to the mixing ratios shown in Table 3 to obtain the treatment solution for Example 2. The treatment solution for Example 2 can be used to treat the substrate in the same manner as in Example 1.

[0072] [Table 3]

[0073] 4. Preparation of the treatment solution in Example 3 Solution A was obtained in the same manner as Solution A in Example 2. Solution B is obtained in the same manner as Solution B in Example 2. Solution C is obtained by mixing MEA, DMBI, BTA, and water. The content of each component in Solution C is 16% by mass of MEA, 0.4% by mass of DMBI, 0.4% by mass of BTA, and the remainder being water. The A / B / C solutions were mixed in a 50 / 25 / 25 ratio, and the A, B, and C solutions were mixed over 1 hour to obtain the treatment solution for Example 3. The treatment solution for Example 3 can be used to treat the substrate in the same manner as in Example 1. [Industrial applicability]

[0074] This disclosure provides a substrate processing method that can obtain a substrate with a clean surface condition. Furthermore, by using the substrate processing method of this disclosure, it is possible to improve the performance and reliability of the manufactured electronic components and improve the productivity of semiconductor devices.

Claims

1. A method for processing a substrate, comprising the following steps I and II. Step I: A process to obtain a treatment solution by mixing a composition containing an inhibitor, carbonic acid, and water (Solution A) with a composition containing an aliphatic quaternary ammonium salt, an alkanolamine, and water (Solution B). Step II: A step of processing a substrate having a resin mask using the processing solution obtained in Step I.

2. The treatment method according to claim 1, wherein solution A further contains at least one of an organic solvent and an alkanolamine.

3. The processing method according to claim 1, wherein step II includes spraying the processing solution obtained in step I onto a substrate having a resin mask.

4. The processing method according to claim 1, further comprising step III below. Step III: A step to recover the processed liquid after Step II.

5. The processing method according to claim 1, wherein the carbon dioxide concentration in solution A in step I is 0.2 mol / L or more and 10 mol / L or less.

6. The processing method according to claim 1, wherein the carbon dioxide concentration in solution B in step I is less than 0.2 mol / L.

7. The processing method according to claim 1, wherein step I further comprises mixing a composition (solution C) containing an alkanolamine, an inhibitor, and water.

8. A method for manufacturing an electronic component, comprising a method for processing a substrate according to any one of claims 1 to 7.

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