Substrate processing method

Abstract

In one aspect, a method for treating a substrate is provided that can maintain the quality of the substrate after peeling off a resin mask even when a treatment liquid is recycled. In one aspect, the present disclosure relates to a method for processing a substrate, including the following steps 1, 2, and 3. Step 1: Treating a substrate having a resin mask with a treatment liquid containing an azole Step 2: Recovering the treatment liquid after step 1 Step 3: A step of converting the treatment liquid recovered in Step 2 into a recycled treatment liquid containing azoles to be used in Step 1.

Description

[Technical Field]

[0001] The present disclosure relates to a method for processing a substrate. [Background technology]

[0002] In recent years, personal computers and various electronic devices have become increasingly power-efficient, faster, and more compact, and the wiring on the package substrates and other components they are equipped with has been getting finer every year. Until now, metal masking has been the primary method used to form such fine wiring and connection terminals such as pillars and bumps, but due to its limited versatility and the difficulty of adapting to the miniaturization of wiring, new methods are being adopted.

[0003] One new method is the use of a resin mask, also known as a dry film resist. In this method, a metal seed layer is formed on an insulating substrate by electroless plating. The metal seed layer is then laminated with a resin mask, and a pattern is formed by exposure and development processes, after which copper wiring and tin bumps are formed by electrolytic plating. The resin mask remaining on the substrate is finally peeled off and removed using an alkaline stripping cleaner (processing liquid).

[0004] For example, Patent Document 1 discloses a composition for removing a photoresist for forming a copper-containing pattern after the pattern has been formed, which comprises an alkali agent containing at least one selected from alkanolamines, quaternary ammonium hydroxides, and inorganic alkalis, and a solubility parameter of 3.60 MPa with a radius of 3.60 MPa centered at coordinates δd=16.0, δp=8.7, and δh=15.5 in the Hansen solubility parameter. 0.5 A composition containing an organic solvent within the range of spheres and an azole compound has been proposed. Patent Document 2 proposes a composition for removing a photoresist for forming a copper-containing pattern after the pattern has been formed, the composition comprising an alkaline agent, an ammonium ion source, and an azole compound, wherein the alkaline agent comprises one or more selected from an alkanolamine, a quaternary ammonium hydroxide, and an inorganic alkali. Patent Document 3 proposes a composition for removing a photoresist for forming a copper-containing pattern after the pattern has been formed, the composition comprising an alkaline agent and an azole compound, wherein the alkaline agent is at least one selected from alkanolamines, quaternary ammonium hydroxides, and inorganic alkalis, the azole compound is at least one selected from compounds represented by specific formulas (1) to (3), and the composition has a pH of 10 or higher. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2024 / 128209 [Patent Document 2] International Publication No. 2024 / 128210 [Patent Document 3] International Publication No. 2024 / 128211 Summary of the Invention [Problem to be solved by the invention]

[0006] When forming fine wiring on printed circuit boards and the like, high cleaning performance (resin mask stripping ability, resin mask removability) is required for the processing solution (strip cleaner) used to treat substrates with resin masks, 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 solutions used in forming the fine wiring and bumps. Furthermore, because corrosion of copper, which is often used in wiring and connection terminals, can lead to a decrease in the quality and value of package substrates, processing solutions (strip cleaners) are required to have high corrosion prevention capabilities (etching inhibition performance). However, when processing solutions (strip cleaners) are recycled, changes in factors such as the component concentrations of the processing solution and processing conditions can affect the etching inhibition performance. If the etching inhibition performance is affected, for example, if the etching inhibition performance decreases, the quality of the substrate after resin mask removal (processing) cannot be maintained. Reducing the impact on etching inhibition performance requires significant management and operational costs and effort, so processing solutions are required to have the performance to consistently produce high-quality substrates after resin mask removal (processing), even when recycled.

[0007] Therefore, the present disclosure provides a substrate processing method that can maintain the quality of the substrate after removing the resin mask even when the processing liquid is recycled. [Means for solving the problem]

[0008] In one aspect, the present disclosure relates to a method for treating a substrate, including the following steps 1, 2, and 3. Step 1: Treating a substrate having a resin mask with a treatment liquid containing an azole Step 2: Recovering the treatment liquid after step 1 Step 3: A step of converting the treatment liquid recovered in Step 2 into a recycled treatment liquid containing azoles to be used in Step 1. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to provide a substrate processing method that can maintain the quality of the substrate after peeling off the resin mask even when the processing liquid is recycled. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present disclosure is based on the finding that by including an azole in the treatment liquid, the deterioration of etching suppression performance can be suppressed even when the treatment liquid is recycled, and the quality of the substrate can be maintained after the resin mask is removed.

[0011] In one aspect, the present disclosure relates to a substrate processing method (hereinafter also referred to as "the substrate processing method of the present disclosure") including the following steps 1, 2, and 3. Step 1: A step of treating a substrate having a resin mask with a treatment liquid containing an azole (hereinafter also referred to as the "treatment liquid of the present disclosure"). Step 2: Recovering the treatment liquid after step 1 Step 3: A step of converting the treatment liquid recovered in Step 2 into a recycled treatment liquid containing azoles to be used in Step 1.

[0012] According to the present disclosure, a substrate processing method can be provided that can maintain the quality of the substrate after removing the resin mask even when the processing solution is recycled. Furthermore, by using the substrate processing method of the present disclosure, high-quality electronic components can be obtained with a high yield.

[0013] Although the details of the mechanism of action by which the effects of the present disclosure are manifested are still unclear, it is presumed as follows. Adding an amine and a hydroxide to a processing solution is generally known to be an effective method for removing a resin mask. It is believed that the addition of the amine and hydroxide penetrates into the resin mask, promoting dissociation of the alkali-soluble resin contained in the resin mask, and further promoting peeling of the resin mask by causing repulsion of the charges generated by the dissociation. Amines are also believed to have the ability to etch copper. However, in the present disclosure, by using a treatment solution containing azoles, it is believed that a protective film is formed by the adsorption of the azoles to the copper surface, and copper etching due to coordination of the amine is suppressed. As a result, it is believed that a treatment solution containing amines and azoles exhibits good stripping performance while suppressing copper etching (corrosion). Furthermore, a treatment solution containing azoles with high adsorption properties is believed to promote the formation of a protective film and improve etching suppression performance, and to maintain the quality of the substrate after resin mask removal even when factors such as the component concentrations of the treatment solution and processing conditions change due to the cyclic use of the treatment solution. However, the present disclosure need not be construed as being limited to this mechanism.

[0014] In the present disclosure, a resin mask is a mask for protecting the surface of a material from treatments such as etching, plating, and heating, that is, a mask formed from a resin that functions as a protective film. In one or more embodiments, the resin mask may be a resist layer after exposure and development processes, a resist layer that has been subjected to at least one of exposure and development processes (hereinafter also referred to as "exposed and / or developed"), or a hardened resist layer. In one or more embodiments, the resin mask is formed using a resist whose physical properties, such as solubility in a developer, change when exposed to light, an electron beam, or the like. Resists are broadly classified into negative and positive types based on how they react with light or an electron beam. Negative resists have the property of decreasing their solubility in a developer when exposed to light, and the exposed portion of a layer containing negative resist (hereinafter also referred to as a "negative resist layer") is used as a resin mask after exposure and development. Positive resists have the property of increasing their solubility in a developer when exposed to light, and the exposed portion of a layer containing positive resist (hereinafter also referred to as a "positive resist layer") is removed after exposure and development, and the unexposed portion is used as a resin mask. By using a resin mask with such properties, fine connections on a circuit board, such as metal wiring, metal pillars, and solder bumps, can be formed. In one or more embodiments, the resin material for forming the resin mask may be a film-like photosensitive resin, a resist film, or a photoresist. A general-purpose resist film may be used. In one or more embodiments, the resin mask is a copper or tin plating mask for use in a copper or tin plating process.

[0015] In one or more embodiments, the substrate processing method of the present disclosure is used in a process before seed layer etching (a resin mask peeling process before a metal seed layer removal process). In one or more embodiments, the substrate processing method of the present disclosure is used in the manufacturing process of electronic components (electronic substrates such as printed circuit boards and package substrates).

[0016] [Process 1: Processing process] In one or more embodiments, step 1 in the substrate processing method of the present disclosure is a step (processing step) of processing a substrate having a resin mask (hereinafter also referred to as "object to be processed") using a processing liquid containing an azole (processing liquid of the present disclosure). In one or more embodiments, the processing includes cleaning the substrate having the resin mask, stripping the resin mask from the substrate having the resin mask, and removing the resin mask from the substrate having the resin mask. In one or more embodiments, the treatment step includes contacting the treatment liquid of the present disclosure with the object to be treated.

[0017] Examples of a method for peeling a resin mask from an object to be treated using the treatment liquid of the present disclosure, or a method for bringing the treatment liquid of the present disclosure into contact with the object to be treated, include a method in which the object to be treated is brought into contact by immersing the object to be treated in a cleaning bath containing the treatment liquid, a method in which the treatment liquid is sprayed out in a spray form and brought into contact with the object to be treated (shower method), and an ultrasonic cleaning method in which the object to be treated is irradiated with ultrasonic waves while immersed in the treatment liquid. The treatment solution of the present disclosure can be used for cleaning as is without dilution. Examples of the object to be treated include the objects to be treated described below. In one or more embodiments, step 1 includes spraying the treatment liquid of the present disclosure onto a substrate (object to be treated) having a resin mask. The time for which the treatment liquid of the present disclosure is brought into contact with or immersed in the treatment object (contact time or immersion time) may be, for example, from 1 minute to 10 minutes, or from 3 minutes to 6 minutes. When the treatment liquid of the present disclosure is sprayed and brought into contact, the spray time may be, for example, from 1 minute to 10 minutes, or from 3 minutes to 6 minutes.

[0018] In step 1, in order to facilitate the exertion of the peeling and cleaning power (resin mask peeling ability and resin mask removal ability) of the treatment liquid of the present disclosure, it is preferable to irradiate the treatment liquid with ultrasonic waves when the treatment liquid comes into contact with the treatment object, and it is more preferable that the ultrasonic waves have a relatively high frequency. From the same viewpoint, the ultrasonic irradiation conditions are, for example, preferably 26 to 72 kHz and 80 to 1500 W, and more preferably 36 to 72 kHz and 80 to 1500 W.

[0019] In Step I, the temperature of the treatment liquid during use is preferably 40°C or higher, more preferably 50°C or higher, so that the treatment liquid of the present disclosure can easily exhibit its peeling and cleaning power (resin mask peeling ability, resin mask removal ability), and from the viewpoint of reducing the impact on the substrate, it is preferably 70°C or lower, more preferably 60°C or lower.

[0020] In one or more embodiments, step 1 in the substrate processing method of the present disclosure may further include post-cleaning after contacting the object to be processed with the processing solution of the present disclosure. In one or more embodiments, the post-cleaning may be water washing, acid washing, or alkali washing, and can be appropriately selected depending on the components contained in the processing solution.

[0021] In one or more embodiments, step 1 of the substrate processing method of the present disclosure may further include rinsing with water and drying after contacting the object to be processed with the processing solution of the present disclosure or after post-cleaning. Examples of rinsing methods include rinsing with running water. Examples of drying methods include air blow drying. In one or more embodiments, the substrate processing method of the present disclosure may include rinsing with water after contacting the object to be processed with the processing solution of the present disclosure or after post-cleaning.

[0022] [Processing object] In one or more embodiments, the workpiece is a substrate having a resin mask. Examples of the substrate include a printed circuit board, a wafer, a copper plate, and an aluminum plate. The resin mask may be, for example, a negative resin mask or a positive resin mask, and a negative resin mask is preferred in terms of the ease with which the effects of the present disclosure can be exerted. Examples of negative resin masks include negative dry film resists that have been exposed and / or developed. In the present disclosure, a negative resin mask is formed using a negative resist, and examples thereof include a negative resist layer that has been subjected to exposure and / or development treatment. In the present disclosure, a positive resin mask is formed using a positive resist, and examples thereof include a positive resist layer that has been subjected to exposure and / or development treatment. The thickness of the resin mask is, for example, 5 μm to 35 μm or less.

[0023] In one or more embodiments, the substrate (workpiece) having a resin mask is a substrate having a copper-containing metal layer and a resin mask on its surface. In one or more embodiments, the substrate having a copper-containing metal layer and a resin mask on its surface has undergone at least one of soldering and plating using a resin mask. In one or more embodiments, the copper-containing metal layer is a copper plating layer. The copper plating layer can be formed, for example, by electroless copper plating. In one or more embodiments, the copper-containing metal layer is used as metal wiring. The thickness of the copper-containing metal layer is, for example, 3 μm to 30 μm. The substrate may be, for example, an insulating plate or film.

[0024] In one or more embodiments, the substrate (workpiece) having the resin mask includes an electronic component having a copper-containing metal portion and a resin mask on its surface, and a manufacturing intermediate thereof. Examples of the electronic component include at least one component selected from a printed circuit board, a wafer, and a metal plate such as a copper plate or an aluminum plate. The manufacturing intermediate is an intermediate product in the manufacturing process of the electronic component, and includes an intermediate product after resin mask treatment. Specific examples of the workpiece include electronic components in which wiring, connection terminals, etc. are formed on the surface of a substrate by undergoing at least one of soldering using a resin mask and plating (copper plating, aluminum plating, nickel plating, tin plating, etc.). In the present disclosure, soldering refers to applying solder to the resin mask-free areas of a substrate and then heating to form solder bumps. In the present disclosure, plating refers to performing at least one plating process selected from copper plating, aluminum plating, nickel plating, and tin plating on the resin mask-free areas of a substrate. The resin mask-free areas refer to areas in a resist pattern (a patterned resin mask) formed by developing a resin mask laminated on a substrate, where the resin mask has been removed by the development process. Thus, in one aspect, the present disclosure relates to the use of a treatment solution of the present disclosure as a cleaning agent in the manufacture of electronic components.

[0025] In one or more embodiments, the substrate (processed object) having the resin mask is a substrate having a resist pattern (a patterned resin mask) formed by developing a resin mask laminated on the substrate, and the substrate has undergone at least one of soldering and plating. For example, the processed object may be a substrate having a resin mask-present portion where a hardened resist layer is formed on the substrate, and a solder bump or a plating layer formed in a resin mask-free portion.

[0026] The resin mask may be, for example, a negative resin mask or a positive resin mask. In the present disclosure, a negative resin mask is formed using a negative resist, and examples thereof include a negative resist layer that has been subjected to exposure and / or development. In the present disclosure, a positive resin mask is formed using a positive resist, and examples thereof include a positive resist layer that has been subjected to exposure and / or development.

[0027] [Processing solution used in step 1] In one or more embodiments, the treatment liquid of the present disclosure is a treatment liquid for use in treating a substrate having a resin mask, a cleaning composition for stripping a resin mask for cleaning a substrate having a resin mask, or a stripper composition for stripping a resin mask from a substrate having a resin mask.

[0028] In one or more embodiments, the treatment liquid of the present disclosure can be used to clean a substrate (workpiece) having a copper-containing metal layer and a resin mask on its surface. In one or more embodiments, the treatment liquid of the present disclosure can be used to strip a resin mask from a substrate (workpiece) having a copper-containing metal layer and a resin mask on its surface. That is, in one aspect, the present disclosure relates to use of the treatment liquid of the present disclosure to strip a resin mask from a substrate (workpiece) having a copper-containing metal layer and a resin mask on its surface. By using the treatment liquid of the present disclosure for cleaning a substrate (workpiece) having a copper-containing metal layer and a resin mask on its surface, the resin mask can be removed while suppressing copper corrosion.Furthermore, by using the treatment liquid of the present disclosure for cleaning electronic components such as electronic circuit boards having a resin mask, high-quality electronic components can be obtained with a high yield.

[0029] In one or more embodiments, the treatment liquid of the present disclosure used in step 1 is a treatment liquid containing an azole, and in one or more embodiments, may be a treatment liquid further containing at least one selected from an amine, a hydroxide, and water, which will be described later. In one or more embodiments, the treatment liquid of the present disclosure may further contain at least one selected from an organic solvent and an ammonium salt of an organic acid. The components contained in the treatment liquid will be described in detail below.

[0030] (Component D: Azoles) The treatment liquid of the present disclosure may contain one type of azole (hereinafter referred to as "component D"), or two or more types in combination. In one or more embodiments, Component D includes at least one selected from azoles or derivatives thereof, such as at least one selected from pyrazole, thiazole, oxazole, triazole, benzotriazole, tolyltriazole, dimethylbenzotriazole, tetrazole, triazine, tetrazine, pentazole, imidazole, methylimidazole, phenylimidazole, dimethylbenzimidazole, 2-mercaptobenzothiazole (MBT), benzimidazole (BI), and 5,6-dimethylbenzimidazole (DMBI). Among these, from the viewpoint of improving substrate quality and inhibiting copper etching, at least one selected from triazole, benzotriazole, tolyltriazole, dimethylbenzotriazole, 2-mercaptobenzothiazole (MBT), benzimidazole (BI), and 5,6-dimethylbenzimidazole (DMBI) is preferred, and at least one selected from 2-mercaptobenzothiazole (MBT), benzimidazole (BI), and 5,6-dimethylbenzimidazole (DMBI) is more preferred. The azoles may be used alone or in combination of two or more. In one or more embodiments, the azoles (component D) are Cu inhibitors (copper corrosion inhibitors).

[0031] In one or more embodiments, from the viewpoints of improving substrate quality and inhibiting copper corrosion, Component D is preferably two or more azoles. From the same viewpoints, the two or more azoles are preferably a combination of two or more selected from azoles or derivatives thereof, more preferably two or more compounds having an imidazole skeleton, even more preferably two or more compounds having a benzimidazole skeleton, and even more preferably a combination of benzimidazole (BI) and 5,6-dimethylbenzimidazole (DMBI).

[0032] From the viewpoints of improving substrate quality and inhibiting copper corrosion, the content of component D in the treatment solution of the present disclosure is preferably 0.01% by mass or more, more preferably 0.03% by mass or more, and even more preferably 0.05% by mass or more. From the same viewpoints, the content is preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 1% by mass or less. More specifically, the content of component D in the treatment solution of the present disclosure is preferably 0.01% by mass or more and 5% by mass or less, more preferably 0.03% by mass or more and 3% by mass or less, and even more preferably 0.05% by mass or more and 1% by mass or less. When component D is a combination of two or more types, the content of component D refers to the total content thereof.

[0033] In the present disclosure, the "content of each component in the treatment liquid" refers to the content of each component at the time of use (cleaning), that is, at the time when the treatment liquid starts to be used for cleaning (resin mask removal treatment). In one or more embodiments, the content of each component in the treatment liquid of the present disclosure can be considered to be the blending amount of each component in the treatment liquid of the present disclosure.

[0034] (Component A: Amine) In one or more embodiments, the treatment liquid of the present disclosure may further contain an amine (hereinafter also referred to as "component A") from the viewpoint of improving the removability of the resin mask. In one or more embodiments, Component A includes an alkanolamine (amino alcohol), such as a compound represented by the following formula (I): Component A may be one type, or two or more types may be combined. [ka]

[0035] In the above formula (I), R 1 represents a hydrogen atom, a methyl group, an ethyl group, or an aminoethyl group, and R 2 represents a hydrogen atom, a hydroxyethyl group, a hydroxypropyl group, a methyl group, or an ethyl group, and R 3 represents a hydroxyethyl group or a hydroxypropyl group.

[0036] Examples of alkanolamines include 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, from the viewpoint of improving the removability of the resin mask, it is preferable that component A contains monoethanolamine (MEA).

[0037] From the viewpoints of improving resin mask removability and inhibiting copper corrosion, the content of component A in the treatment solution of the present disclosure is preferably 1% by mass or more, more preferably 6% by mass or more, even more preferably 8% by mass or more, and even more preferably 10% by mass or more. From the same viewpoint, the content of component A in the treatment solution of the present disclosure is preferably 1% by mass or more and 18% by mass or less, more preferably 6% by mass or more and 16% by mass or less, even more preferably 8% by mass or more and 14% by mass or less, and even more preferably 10% by mass or more and less than 14% by mass. When component A is a combination of two or more types, the content of component A refers to the total content thereof.

[0038] <Mass ratio A / D> The mass ratio A / D of component A to component D (content of component A / content of component D) in the treatment solution of the present disclosure is preferably 10 or more, preferably 30 or more, or preferably 50 or more from the viewpoint of improving resin mask removability, and is preferably 200 or less, and is preferably 150 or less from the viewpoint of copper corrosion inhibition.

[0039] (Component B: hydroxide) In one or more embodiments, the treatment liquid of the present disclosure may further contain a hydroxide (hereinafter also referred to as "component B"). Component B includes at least one selected from aliphatic quaternary ammonium hydroxides and inorganic metal hydroxides. Component B may be one type or a combination of two or more types.

[0040] <Aliphatic quaternary ammonium hydroxide> Examples of aliphatic quaternary ammonium hydroxides include quaternary ammonium hydroxides represented by the following formula (II): The aliphatic quaternary ammonium hydroxides may be one type or a combination of two or more types. [ka]

[0041] In the above formula (II), R 4 , R 5 , R 6 and R 7 are each 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.

[0042] The quaternary ammonium hydroxide represented by formula (II) is a salt consisting of a quaternary ammonium cation and a hydroxide, and examples thereof include 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, from the viewpoint of improving the removability of the resin mask, it is preferable that component B contains tetramethylammonium hydroxide (TMAH).

[0043] When component B contains an aliphatic quaternary ammonium hydroxide, the content of the aliphatic quaternary ammonium hydroxide in the treatment solution of the present disclosure is preferably 0.5% by mass or more, more preferably 1.5% by mass or more, and even more preferably 2.5% by mass or more, from the viewpoints of improving resin mask removability and inhibiting copper corrosion. From the same viewpoint, the content of component B in the treatment solution of the present 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 2.5% by mass or less. From the same viewpoint, the content of component B in the treatment solution of the present 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 2.5% by mass or more and 5% by mass or less. When two or more aliphatic quaternary ammonium hydroxides are used in combination, the content of the aliphatic quaternary ammonium hydroxides refers to the total content of the aliphatic quaternary ammonium hydroxides.

[0044] <Inorganic metal hydroxide> Examples of inorganic metal hydroxides include alkali metal hydroxides, and from the viewpoint of improving the removability (peelability) of the resin mask, examples include at least one selected from sodium hydroxide, potassium hydroxide, lithium hydroxide, and calcium hydroxide, and among these, potassium hydroxide is preferred. The inorganic metal hydroxides may be used alone or in combination of two or more. When the treatment liquid of the present disclosure contains an inorganic metal hydroxide, the content of the inorganic metal hydroxide in the treatment liquid of the present disclosure is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and even more preferably 0.5% by mass or more, from the viewpoints of improving resin mask removability (peelability) and inhibiting copper corrosion, and from the same viewpoints, is preferably 10% by mass or less, more preferably 8% by mass or less, and even more preferably 5% by mass or less. When two or more inorganic metal hydroxides are used in combination, the content of the inorganic metal hydroxides refers to the total content thereof.

[0045] From the viewpoint of improving the removability of the resin mask, Component B preferably contains an aliphatic quaternary ammonium hydroxide, more preferably tetramethylammonium hydroxide (TMAH). The content of the aliphatic quaternary ammonium hydroxide in Component B is preferably 0.5% by mass or more, more preferably 1.5% by mass or more, even more preferably 2.5% by mass or more, and even more preferably 3.5% by mass or more.

[0046] From the viewpoints of improving resin mask removability (peelability) and inhibiting copper corrosion, the content of Component B in the treatment liquid 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, and from the same viewpoints, it is preferably 15% by mass or less, more preferably 10% by mass or less, and even more preferably 8% by mass or less. When Component B is a combination of two or more types, the content of Component B refers to the total content thereof.

[0047] <Mass ratio B / D> The mass ratio B / D of component B to component D (content of component B / content of component D) in the treatment liquid of the present disclosure is preferably 10 or more, and more preferably 15 or more, from the viewpoint of improving resin mask removability and inhibiting copper corrosion, and is preferably 200 or less, and more preferably 100 or less, from the viewpoint of inhibiting copper corrosion.

[0048] (Component C: water) In one or more embodiments, the treatment liquid of the present disclosure may further contain water (hereinafter also referred to as "component C"). In one or more embodiments, examples of component C include ion-exchanged water, RO water, distilled water, pure water, and ultrapure water.

[0049] In one or more embodiments, the content of component C in the treatment solution of the present disclosure may be the remainder excluding components D, A, B, and the optional components described below. Specifically, from the viewpoints of improving resin mask removability and inhibiting copper corrosion, the content of component C in the treatment solution of the present disclosure is preferably 60% by mass or more, more preferably 65% ​​by mass or more, and even more preferably 70% by mass or more. From the viewpoint of improving resin mask removability, the content of component C in the treatment solution of the present disclosure is preferably 98% by mass or less, and more preferably 90% by mass or less. From the same viewpoint, the content of component C in the treatment solution of the present disclosure is preferably 60% by mass or more and 98% by mass or less, more preferably 65% ​​by mass or more and 98% by mass or less, and even more preferably 70% by mass or more and 90% by mass or less.

[0050] (Component E: organic solvent) In one or more embodiments, the treatment liquid of the present disclosure may further contain an organic solvent (hereinafter also referred to as "component E") from the viewpoint of improving the removability of the resin mask. Component E may be one type or a combination of two or more types. In one or more embodiments, Component E includes at least one solvent selected from glycol ethers and aromatic alcohols. From the same viewpoint, examples of glycol ethers include compounds having a structure in which 1 to 3 moles of ethylene glycol are added to an alcohol having 1 to 8 carbon atoms. Specific examples of glycol ethers include at least one selected from diethylene glycol monobutyl ether (BDG), ethylene glycol monobenzyl ether, diethylene glycol monohexyl ether, ethylene glycol monophenyl ether, and diethylene glycol diethyl ether. In one or more embodiments, the aromatic alcohol may be a compound having a substituted aromatic ring and a hydroxyl group bonded to at least one of the substituents. Examples of the substituent include an alkyl group having 1 to 3 carbon atoms. Examples of the aromatic ring include a benzene ring and a naphthalene ring. From the viewpoint of improving the removability (peelability) of the resin mask, the number of carbon atoms in the aromatic alcohol is preferably 7 or more and preferably 9 or less. Examples of the aromatic alcohol include benzyl alcohol (BA). The aromatic alcohol may be one type or a combination of two or more types.

[0051] When the treatment liquid of the present disclosure contains Component E, the content of Component E in the treatment liquid 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 resin mask removability, and from the same viewpoint, is preferably 15% by mass or less, more preferably 13% by mass or less, and even more preferably 10% by mass or less. More specifically, the content of Component E in the treatment liquid of the present disclosure is preferably 1% by mass or more and 15% by mass or less, more preferably 2% by mass or more and 13% by mass or less, and even more preferably 3% by mass or more and 10% by mass or less. When Component E is a combination of two or more types, the content of Component E refers to the total content thereof.

[0052] (Component F: Ammonium salt of organic acid) In one or more embodiments, the treatment liquid of the present disclosure may further contain at least one ammonium salt of an organic acid (hereinafter also referred to as "component F") from the viewpoint of improving the removability of the resin mask. From the same viewpoint, component F is preferably an ammonium salt of a carboxylic acid having 1 to 5 carbon atoms, and more preferably ammonium formate (AF). Component F may be one type or a combination of two or more types.

[0053] When the treatment liquid of the present disclosure contains component F, the content of component F in the treatment liquid of the present disclosure is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and even more preferably 0.3% by mass or more, from the viewpoint of improving resin mask removability, and from the same viewpoint, is preferably 2% by mass or less, more preferably 1.5% by mass or less, and even more preferably 1% by mass or less. More specifically, the content of component F in the treatment liquid of the present disclosure is preferably 0.1% by mass or more and 2% by mass or less, more preferably 0.2% by mass or more and 1.5% by mass or less, and even more preferably 0.3% by mass or more and 1% by mass or less. When component F is a combination of two or more types, the content of component F refers to the total content thereof.

[0054] (Other ingredients) The treatment liquid of the present disclosure may further contain other components as needed in addition to the above-described Components A to F. Examples of other components include components that can be used in ordinary cleaning agents, such as alkaline agents other than Components A and B, amines other than alkanolamines, solvents other than Component E, corrosion inhibitors other than Component D, surfactants, chelating agents, thickeners, dispersants, rust inhibitors, polymeric compounds, solubilizers, antioxidants, preservatives, antifoaming agents, and antibacterial agents.

[0055] The total content of organic matter derived from component D and optional components (component A, component B, component E, component F, and other components) during use of the treatment liquid of the present disclosure is preferably 30% by mass or less, more preferably 25% by mass or less, even more preferably 20% by mass or less, and even more preferably 16% by mass or less, from the viewpoint of reducing the wastewater treatment load and reducing the impact on the substrate, and from the viewpoint of improving the removability of the resin mask, is preferably 2% by mass or more, more preferably 3% by mass or more, even more preferably 4% by mass or more, and even more preferably 6% by mass or more. More specifically, the total content of organic matter derived from component D and optional components (component A, component B, component E, component F, and other components) during use of the treatment liquid of the present disclosure is preferably 2% by mass or more and 30% by mass or less, more preferably 3% by mass or more and 25% by mass or less, even more preferably 4% by mass or more and 20% by mass or less, and even more preferably 6% by mass or more and 16% by mass or less.

[0056] [Method of manufacturing the processing solution used in step 1] In one or more embodiments, the treatment liquid of the present disclosure can be produced by blending component D and, as needed, the above-mentioned optional components (component A, component B, component C, component E, component F, and other components) using a known method. For example, the treatment liquid of the present disclosure can be one that is blended with at least component D. Accordingly, the present disclosure relates to a method for producing a treatment liquid that includes a step of blending at least component D. In the present disclosure, "blending" includes mixing component D and, as needed, the above-mentioned optional components (component A, component B, component C, component E, component F, and other components) simultaneously or in any order. In the method for producing a treatment liquid of the present disclosure, the preferred amount of each component to be blended can be the same as the preferred content of each component in the treatment liquid of the present disclosure described above.

[0057] In one or more embodiments, the treatment liquid of the present disclosure may be prepared as a concentrate by reducing the amount of water (component C) to the extent that separation, precipitation, or the like does not occur and storage stability is not impaired. From the viewpoint of transportation and storage, the treatment liquid concentrate is preferably a concentrate diluted 3 times or more, and from the viewpoint of storage stability, it is preferably a concentrate diluted 30 times or less. The treatment liquid concentrate can be used by diluting it with water (component C) at the time of use so that component D and optional components (component A, component B, component C, component E, component F, and other components) reach the above-mentioned contents (i.e., contents at the time of cleaning). Furthermore, the treatment liquid concentrate can also be used by adding each component separately at the time of use. In the present disclosure, "at the time of use" or "at the time of cleaning" of a concentrated treatment liquid refers to the diluted state of the treatment liquid concentrate.

[0058] [Process 2: Recovery process] Step 2 in the substrate processing method of the present disclosure is a step of recovering the processing liquid after step 1.

[0059] [Step 3: Reuse] Step 3 in the substrate processing method of the present disclosure is a step of converting the processing liquid recovered in step 2 into a recycled processing liquid containing azoles to be used in step 1. In one or more embodiments, at least a portion of the treatment liquid recovered in step 2 can be used as the treatment liquid to be used in step 1 (recycled treatment liquid). In one or more embodiments, at least a portion of the treatment liquid recovered in step 2 can be mixed with treatment liquid components (at least one selected from the above-mentioned Component A, Component B, Component C, Component D, Component E, Component F, and other components) as needed to prepare a treatment liquid (recycled treatment liquid) to be used in step 1. Step 3 may include preparing a recycled treatment liquid containing an azole to be used in step 1 using the treatment liquid recovered in step 2. In one or more embodiments, the substrate processing method of the present disclosure includes circulating the processing liquid by repeating steps 1 to 3.

[0060] <Recycled processing liquid> In one or more embodiments, a method for preparing the reused treatment liquid includes mixing (replenishing) treatment liquid components (at least one selected from the above-mentioned components A, B, C, D, E, F, and other components) with (replenish) the treatment liquid recovered in step 2 as needed. The mixing (replenishment) conditions can be set appropriately, and can be set, for example, based on the concentrations of the components in the treatment liquid recovered in step 2. In one or more embodiments, the recycled treatment liquid is a mixed liquid obtained by mixing the treatment liquid recovered in step 2 with at least one selected from the above-mentioned component A, component B, component C, component D, component E, component F, and other components. Components contained in the recycled treatment liquid include the same components as those in the treatment liquid of the present disclosure described above. The preferred content of each component contained in the recycled treatment liquid is the same as the preferred content of each component contained in the treatment liquid of the present disclosure described above.

[0061] This includes a change in a factor that affects the etching rate in the treatment liquid in at least one of the above-described steps 1, 2, and 3. In one or more embodiments, the change in the factor that affects the etching rate in the treatment liquid may be a change in the amine concentration in the treatment liquid, a change in the treatment temperature, or a change in the treatment pressure. In one or more embodiments, the change in the amine concentration in the treatment solution is a change in the amine concentration due to the addition of an amine when preparing the reused treatment solution (e.g., an increase in the amine concentration), or a change in the amine concentration due to consumption during treatment, an error in a measuring instrument, or the like (e.g., an increase or decrease in the amine concentration).

[0062] [Electronic component manufacturing method] In one aspect, the present disclosure relates to a method for manufacturing an electronic component substrate (hereinafter also referred to as "the method for manufacturing an electronic component of the present disclosure") that includes the substrate processing method of the present disclosure. In one or more embodiments, the method for manufacturing an electronic component according to the present disclosure includes a step of treating a substrate (workpiece) having a copper-containing metal layer and a resin mask on its surface using the substrate treatment method according to the present disclosure (hereinafter also referred to as a "treatment step"). Examples of the treatment method in the treatment step include the same method as the substrate treatment method according to the present disclosure described above. Examples of the workpiece include the workpiece described above. In one or more embodiments, the method for manufacturing an electronic component of the present disclosure may include, before the processing step, a step of performing at least one of soldering using a resin mask and plating on at least one electronic component selected from a printed circuit board, a wafer, and a metal plate. In one or more embodiments, the method for manufacturing an electronic component according to the present disclosure may include, after the treatment step, a step of etching the copper-containing metal layer. The method for manufacturing electronic components according to the present disclosure uses the substrate processing method according to the present disclosure to perform cleaning, thereby suppressing copper corrosion while removing the resin mask attached to the substrate (electronic component), thereby enabling the manufacturing of highly reliable electronic components. Furthermore, the use of the substrate processing method according to the present disclosure makes it easy to remove the resin mask attached to the electronic component, thereby shortening the cleaning time and improving the manufacturing efficiency of electronic components. [Example]

[0063] The present disclosure will be specifically described below using examples, but the present disclosure is not limited to these examples in any way.

[0064] Test 1: Effect of amine concentration on etching inhibition performance 1-1. Preparation of Treatment Solutions A and B in Examples 1 and 2 and Comparative Example 1 Treatment liquid A for Examples 1 and 2 and Comparative Example 1 was prepared by blending the components shown in Table 1 in the amounts (mass %, active ingredient) shown in Table 1 and mixing them with stirring. The treatment liquids A prepared in Examples 1 and 2 and Comparative Example 1 were evaluated as follows. After the following evaluations were performed, the used treatment liquid was recovered. 1% by mass of MEA was added to the recovered treatment liquid and mixed by stirring to prepare treatment liquid B for Examples 1 and 2 and Comparative Example 1. Here, the processing liquid A is assumed to be the processing liquid used in step 1. The processing liquid B is assumed to be the recycled processing liquid in step 3.

[0065] The following materials were used to prepare treatment solutions A and B in Examples 1 and 2 and Comparative Example 1. (Component D: Azoles) MBT: 2-mercaptobenzothiazole [Tokyo Chemical Industry Co., Ltd.] BI: Benzimidazole [Tokyo Chemical Industry Co., Ltd.] DMBI: 5,6-dimethylbenzimidazole [Tokyo Chemical Industry Co., Ltd.] (Non-component D: Non-azoles) HOPO: 2-hydroxypyridine-N-oxide [Suzhou Haofan Biotechnology Co., Ltd.] (Component A: Amine) MEA: Monoethanolamine [manufactured by Nippon Shokubai Co., Ltd.] (Component B: hydroxide) TMAH: Tetramethylammonium hydroxide [Showa Denko K.K., concentration 25% by mass] (Component C: water) Water [Pure water of 1 μS / cm or less produced using the Organo Corporation G-10DSTSET water purification system] (Component E: organic solvent) BDG: Butyl diglycol [Nihon Nyukazai Co., Ltd., diethylene glycol monobutyl ether] BA: Benzyl alcohol [manufactured by LANXESS] (Component F: Ammonium salt of organic acid) AF: Ammonium formate [Fujifilm Wako Pure Chemical Industries, Ltd.] (Other ingredients) HEDP: Etidronic acid [Italmatch Japan Co., Ltd., Dequest 2010, concentration 60% by mass]

[0066] 1-2. Evaluation of Treatment Solutions A and B in Examples 1 and 2 and Comparative Example 1 The prepared treatment solutions A and B of Examples 1 and 2 and Comparative Example 1 were evaluated as follows.

[0067] [Test piece] A test piece (50 mm x 50 mm) consisting of a solid substrate having a copper plating layer (thickness: 3 μm) on its surface was obtained by electroless plating on an insulating substrate.

[0068] [Evaluation of etching inhibition performance (copper corrosion), variation and rate of change in etching rate due to changes in amine concentration] 2.5 L of each treatment solution was prepared and heated to 60°C. The solution was circulated through a box-type spray washer equipped with a full-cone nozzle (J020, manufactured by Ikeuchi Co., Ltd.) and copper plated onto the surface (area: 25 cm per side). 2 , 50cm on both sides 2The test piece was then sprayed (treatment temperature: 60°C, treatment pressure: 0.03 MPa, treatment time: 4 minutes, spray distance: 80 mm). The test piece was then rinsed for 30 seconds in a cleaning bottle filled with pure water, and finally dried with nitrogen blow. The treatment liquid circulating in the washer was sampled and diluted with water, after which the amount of copper eluted was measured using ICP analysis (Agilent Technologies, Agilent 5110 ICP-OES). The copper density was calculated to be 8.96 g / cm using the following formula: 3 The Cu etching rate (μm / min) was calculated from the amount of elution. Cu etching rate (μm / min) = amount of copper dissolved (weight) ÷ copper density ÷ plating area ÷ processing time Furthermore, the difference (change in etching rate (μm / min)) between the Cu etching rate when treatment solution A was used as a reference and the Cu etching rate when treatment solution B was used and the change in etching rate (%) were calculated using the following formula. The effect of changes in amine concentration was then evaluated using the following evaluation criteria. The lower the change in Cu etching rate and the change rate, the smaller the effect of changes in amine concentration on the Cu etching rate (copper corrosivity). The results are shown in Table 1. Change rate of Cu etching rate (%) = (Cu etching rate when using treatment solution B - Cu etching rate when using treatment solution A) / (Cu etching rate when using treatment solution A) × 100% <Evaluation criteria> A: Change rate is less than 20% B: Change rate is 20% or more but less than 30% C: Change rate is 30% or more

[0069] [Table 1]

[0070] As shown in Table 1, in Examples 1 and 2, which used a treatment liquid containing azoles, the effect of changes in amine concentration on the Cu etching rate (etching inhibition performance) was smaller than in Comparative Example 1, which used a treatment liquid containing no azoles but non-azoles. Therefore, it is believed that the quality of the substrate after peeling off the resin mask can be maintained even if the treatment liquid is recycled. The peelability of the resin masks of the treatment solutions A and B in Examples 1 and 2 and Comparative Example 1 was good (data not shown).

[0071] Test 2: Effect of process conditions (process pressure) on etching suppression performance 2-1. Preparation of treatment solutions for Example 3 and Comparative Example 2 The components shown in Table 2 were blended in the amounts (mass %, active ingredient) shown in Table 2 and then stirred to mix, thereby preparing the treatment solutions of Example 3 and Comparative Example 2. The same components used in the preparation of Examples 1 and 2 and Comparative Example 1 were used to prepare the treatment solutions.

[0072] 2-2. Evaluation of the treatment solutions of Example 3 and Comparative Example 2 The prepared treatment solutions of Example 3 and Comparative Example 2 were evaluated as follows.

[0073] [Test piece] A test piece (50 mm x 50 mm) consisting of a solid substrate having a copper plating layer (thickness: 3 μm) on its surface was obtained by electroless plating on an insulating substrate.

[0074] [Evaluation of etching suppression performance (copper corrosion), rate of change in etching rate due to changes in processing pressure] (Example 3-1 and Comparative Example 2-1: Before Change in Treatment Pressure) 2.5 L of each treatment solution was prepared and heated to 60°C. The solution was circulated through a box-type spray washer equipped with a full-cone nozzle (J020, manufactured by Ikeuchi Co., Ltd.) and sprayed onto copper-plated test pieces (treatment temperature: 60°C, treatment pressure: 0.03 MPa, treatment time: 4 minutes, spray distance: 80 mm). The test pieces were then rinsed for 30 seconds in a wash bottle filled with pure water and finally dried with nitrogen. The treatment solution circulating through the washer was sampled and diluted with water. The amount of copper elution was measured using ICP analysis (Agilent Technologies, Agilent 5110 ICP-OES). The copper density was calculated to be 8.96 g / cm using the following formula: 3 The Cu etching rate (μm / min) was calculated from the amount of elution. After the evaluation, the used treatment liquid was collected. (Example 3-2 and Comparative Examples 2-2 to 2-4: After Change in Treatment Pressure) Except for using the recovered treatment liquid and changing the treatment conditions (treatment pressure) as shown in Table 2, the same evaluations as in Example 3-1 and Comparative Example 2-2 were performed, and the Cu etching rates (μm / min) of Example 3-2 and Comparative Examples 2-2 to 2-4 were calculated. Cu etching rate (μm / min) = amount of copper dissolved (weight) ÷ copper density ÷ plating area ÷ processing time Furthermore, the etching rate change rate (%) was calculated using the difference in etching rate before and after the change in processing conditions (processing pressure) (difference in etching rate between Example 3-2 and Example 3-1, difference in etching rate between Comparative Example 2-2 and Comparative Example 2-1, difference in etching rate between Comparative Example 2-3 and Comparative Example 2-1, difference in etching rate between Comparative Example 2-4 and Comparative Example 2-1) according to the following formula. It can be determined that the lower the numerical value of the change rate in Cu etching rate, the smaller the effect of the change in processing conditions (processing pressure) on the Cu etching rate (copper corrosivity). The results are shown in Table 2. Change rate of Cu etching rate (%) = (Cu etching rate after change in processing conditions - Cu etching rate before change in processing conditions) / (Cu etching rate before change in processing conditions) × 100%

[0075] [Table 2]

[0076] As shown in Table 2, Example 3, which used a treatment liquid containing azoles, had a smaller effect on the Cu etching rate (etching inhibition performance) due to changes in treatment conditions than Comparative Example 2, which used a treatment liquid containing no azoles but non-azoles. Therefore, it is believed that the quality of the substrate after peeling off the resin mask can be maintained even if the treatment liquid is recycled. The peelability of the resin masks of the treatment solutions of Example 3 and Comparative Example 2 was good (data not shown). [Industrial Applicability]

[0077] According to the present disclosure, a substrate processing method can be provided that can maintain the quality of the substrate after removing the resin mask even when the processing solution is recycled. Furthermore, by using the substrate processing method of the present disclosure, it is possible to improve the performance and reliability of the manufactured electronic components, and to improve the productivity of semiconductor devices.

Claims

1. A method for processing a substrate, comprising the following steps 1, 2, and 3: Step 1: A step of treating a substrate having a resin mask with a treatment liquid containing an azole. Step 2: Recovering the treatment liquid after step 1 Step 3: A step of converting the treatment liquid recovered in Step 2 into a recycled treatment liquid containing azoles to be used in Step 1. Here, the treatment liquid in step 1 contains an amine (component A), a hydroxide (component B), and an azole (component D), and the mass ratio B / D of component B to component D (content of component B / content of component D) is 15 or more and 60 or less.

2. 2. The processing method according to claim 1, wherein a factor affecting the etching rate of the processing liquid is changed in at least one of steps 1, 2, and 3.

3. 3. The processing method according to claim 2, wherein the change in the factor that affects the etching rate of the processing solution is a change in the amine concentration in the processing solution.

4. 3. The processing method according to claim 2, wherein the change in the factor that affects the etching rate of the processing solution is a change in processing temperature.

5. 3. The processing method according to claim 2, wherein the change in the factor that affects the etching rate of the processing liquid is a change in processing pressure.

6. 2. The processing method according to claim 1, wherein the processing solution contains two or more kinds of azoles.

7. 2. The processing method according to claim 1, wherein the mass ratio A / D (content of component A / content of component D) of component A to component D in the processing solution in step 1 is 10 or more and 200 or less.

8. The processing method of claim 1 , wherein the processing solution further comprises water.

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