JP2025114005A - Processing solution and processing method for resist stripping and seed etching - Google Patents

Abstract

To provide, in one aspect, a processing solution capable of efficiently and simultaneously performing peeling of a negative type dry film resist and etching a metal seed layer.SOLUTION: This disclosure relates to, in one aspect, a processing solution for simultaneously performing the peeling of a negative-type dry film resist layer and the etching of a metal seed layer in the manufacture of an electronic substrate using a substrate that has the negative-type dry film resist layer and the metal seed layer, that is, a processing solution for resist peeling and seed etching comprising an organic alkali (Component A), a primary ammonium source (Component B), and an oxidizing agent (Component C).SELECTED DRAWING: None

Description

This disclosure relates to processing solutions and processing methods for resist stripping and seed etching.

In recent years, personal computers and various electronic devices have become increasingly power-efficient, faster, and more compact, and the wiring on the packaging substrates and other components used in these devices has become increasingly finer with each passing year. Until now, metal masking has primarily been 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 increasingly fine wiring, new methods are being adopted.

One new method is to use a dry film resist as a thick resin mask instead of a metal mask. This resin mask is eventually peeled off and removed, using an alkaline stripping cleaner.

For example, Patent Document 1 proposes a stock composition for removing post-etching residues in semiconductor manufacturing, the stock composition comprising a tetraalkylammonium hydroxide base or a quaternary trialkylalkanolamine base, a corrosion inhibitor, and at least two or more polybasic acids or combinations thereof, wherein at least one of the polybasic acids or salts thereof contains phosphorus.
Patent Document 2 proposes a cleaning liquid for semiconductor devices, which contains an oxidizing agent, a metal etchant, and a surfactant and has a pH of 10 to 14, as a cleaning liquid for removing photoresist, etching residues, anti-reflective coatings, ashing residues, and the like present on substrates in the manufacture of semiconductor devices.
Patent Document 3 proposes a stripping solution for semiconductor devices, which is composed of an aqueous solution containing a quaternary ammonium hydroxide, an oxidizing agent, an alkanolamine, and an alkali metal hydroxide, as a stripping solution for removing photoresist, an anti-reflective film, etching residues, and the like present on a substrate in a manufacturing process of a semiconductor device.
Patent Document 4 proposes a cleaning solution for copper wiring semiconductor devices, which contains water, urea and/or ethylene urea, an organic acid and/or a salt thereof, and an alkaline component.
Patent Document 5 proposes a resist stripping composition containing a water-soluble amine and/or ammonium compound, an oxidizing agent, a radical scavenger, and water as a resist stripping agent used in a method for manufacturing an electronic substrate.
Patent Document 6 proposes a method for producing an electronic substrate, which includes a copper wiring formation step, a resist disintegration step, and a resist stripping step, in which a disintegrant composition containing an oxidizing agent and having a pH of 2 to 8 is used in the resist disintegration step, and a stripper composition containing a quaternary ammonium compound and/or a water-soluble amine compound, an oxidizing agent, and water and having a pH of 9 to 14 is used in the resist stripping step.
Patent Document 7 proposes an alkaline cleaning solution for microelectronic substrates, which contains a metal ion-free aqueous base solution, a nonionic surfactant, and a component for adjusting the pH of the cleaning solution to a range of about 8 to 10.

Special Publication No. 2020-513440 Japanese Patent Application Laid-Open No. 2009-231354 JP 2009-75285 A Japanese Patent Application Laid-Open No. 2004-292792 Japanese Patent Application Laid-Open No. 2004-354649 Japanese Patent Application Laid-Open No. 2004-317584 Japanese Patent Application Publication No. 7-297158

Semi-additive processes are generally used to form wiring substrates for electrically connecting semiconductor chips together, particularly fine wiring. For example, Japanese Patent Application Laid-Open No. 2009-120870 proposes a method for manufacturing a wiring substrate using the semi-additive process.
The manufacturing process for a wiring board using the semi-additive method typically includes the steps of forming a metal seed layer on a substrate by electroless plating (this metal sheet layer will become an electrode or metal wiring by subsequent electrolytic plating), forming a dry film resist layer (resist pattern) for forming a circuit pattern on the surface of the metal seed layer and forming a mask for the circuit pattern by exposure and development, forming a metal layer (circuit pattern, electrode or metal wiring) by electrolytic plating on the exposed parts of the metal seed layer (parts not covered by the resist pattern) using the dry film resist layer as a mask, peeling off the dry film resist layer (resist peeling step), and etching the metal seed layer (parts covered by the resist pattern) exposed by peeling off the dry film resist layer (seed etching step).
However, in order to improve production efficiency and reduce capital investment, there is a demand for simplification of the manufacturing process for wiring boards using the semi-additive method.

The present disclosure therefore provides a processing solution and processing method that can efficiently strip negative dry film resist and etch a metal seed layer simultaneously.

In one aspect, the present disclosure relates to a treatment liquid for simultaneously stripping a negative dry film resist layer and etching a metal seed layer in the manufacture of electronic substrates using a substrate having a negative dry film resist layer and a metal seed layer, the treatment liquid comprising an organic alkali (component A), a primary ammonium source (component B), and an oxidizing agent (component C).

In one aspect, the present disclosure relates to a processing method for stripping a negative dry film resist layer and etching a metal seed layer from a substrate having a negative dry film resist layer and a metal seed layer, the processing method comprising contacting a processing solution of the present disclosure with the substrate having a negative dry film resist layer and a metal seed layer.

In one or more embodiments, the present disclosure provides a processing solution that can efficiently strip a negative dry film resist and etch a metal seed layer simultaneously.

As described above, in the manufacturing process of a wiring board using a semi-additive method, the resist stripping step and the seed etching step are usually performed separately. Generally, an alkaline stripping agent is used for resist stripping, and an acidic etching agent is used for seed etching.
As a result of extensive research, the inventors have found that by using a treatment liquid containing an organic alkali (component A), a primary ammonium source (component B), and an oxidizing agent (component C), it is possible to efficiently strip a negative dry film resist and etch a metal seed layer simultaneously, thereby simplifying the manufacturing process of electronic substrates using a semi-additive method.

In one aspect, the present disclosure relates to a treatment liquid for simultaneously stripping a negative dry film resist layer and etching a metal seed layer in the manufacture of electronic substrates using a substrate having a negative dry film resist layer and a metal seed layer, the treatment liquid for resist stripping and seed etching comprising an organic alkali (component A), a primary ammonium source (component B), and an oxidizing agent (component C) (hereinafter also referred to as the "treatment liquid of the present disclosure").

In one or more embodiments, the present disclosure provides a treatment solution that can efficiently remove a negative dry film resist and etch a metal seed layer simultaneously. Furthermore, by using the treatment solution of the present disclosure, high-quality electronic substrates can be obtained.

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.
In the semi-additive process, negative dry film resist is typically used as a mask. Alkaline strippers are used to strip negative dry film resists, with strippers using organic alkalis as the alkali source being particularly effective. While alkaline strippers are known to dissolve metals such as copper, their solubility is low. While oxidizing agents are used to dissolve oxidized copper and improve solubility when etching metals such as copper, oxidizing agents inhibit alkalinity, and therefore simply mixing an alkaline stripper with an oxidizing agent generally does not achieve both stripping and seed etching of negative dry film resists.
In the present disclosure, it is believed that by blending a primary ammonium source (component B) into a treatment solution containing an organic alkali (component A) and an oxidizing agent (component C), the alkalinity is maintained and the dissolution of metals such as copper is promoted by forming an ammonium complex. That is, in a method for manufacturing an electronic substrate using a substrate having a negative dry film resist layer and a metal seed layer, it is believed that peeling of the negative dry film resist layer and etching of the metal seed layer can be efficiently performed simultaneously.
However, the present disclosure need not be construed as being limited to this mechanism.

In the present disclosure, a negative dry film resist has a property that its solubility in a developer decreases when exposed to light, and after exposure and development, the exposed portion is used as a mask, which functions as a protective film to protect the surface of a material from processes such as etching, plating, and heating.
In the present disclosure, the manufacture of an electronic substrate using a substrate having a negative dry film resist layer and a metal seed layer is, in one or more embodiments, a method for manufacturing an electronic substrate in which metal wiring is formed by plating using the negative dry film resist as a mask.

In one or more embodiments, the processing solution of the present disclosure can be used to process a substrate having a negative dry film resist layer and a metal seed layer, where processing refers to efficiently simultaneously stripping the negative dry film resist layer and etching the metal seed layer.
In the present disclosure, "removing the negative dry film resist layer and etching the metal seed layer simultaneously" means that, in one or more embodiments, the negative dry film resist layer and the metal seed layer are removed and etched in a single step using a treatment liquid or a single treatment using a treatment liquid.

[Organic alkali (component A)]
The organic alkali contained in the treatment liquid of the present disclosure (hereinafter also referred to simply as "component A") may be one type or a combination of two or more types.
Examples of component A include at least one selected from a quaternary ammonium hydroxide (component A1) and an alkanolamine (component A2). From the viewpoint of improving the strippability of the negative dry film resist and improving the etching rate (etchability) of the metal seed layer, a combination of component A1 and component A2 is preferred.

(Component A1: Quaternary ammonium hydroxide)
Examples of the quaternary ammonium hydroxide (hereinafter also referred to as "component A1") include quaternary ammonium hydroxides represented by the following formula (I): Component A1 may be one type or a combination of two or more types.

In the above formula (I), R ¹ , R ² , R ³ and R ⁴ each independently represent at least one group selected from the group consisting of a methyl group, an ethyl group, a propyl group, a hydroxymethyl group, a hydroxyethyl group and a hydroxypropyl group.

The quaternary ammonium hydroxide represented by formula (I) is a salt composed 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, tetramethylammonium hydroxide (TMAH) is more preferred from the viewpoint of improving the strippability of the negative dry film resist and increasing the etching rate of the metal seed layer.

From the viewpoint of improving the strippability of negative dry film resist, the content of component A1 in the treatment solution 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. Similarly, from the viewpoint of improving the strippability of negative dry film resist, the content 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 component A1 in the treatment solution 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 10% by mass or less, and even more preferably 3% by mass or more and 7% by mass or less. When component A1 is a combination of two or more types, the content of component A1 refers to the total content thereof.

(Component A2: Alkanolamine)
Examples of alkanolamines (amino alcohols) (hereinafter also referred to as "component A2") include compounds represented by the following formula (II): Component A2 may be used alone or in combination of two or more types.

In the above formula (II), ^R5 represents a hydrogen atom, a methyl group, an ethyl group, or an aminoethyl group; ^R6 represents a hydrogen atom, a hydroxyethyl group, a hydroxypropyl group, a methyl group, or an ethyl group; and ^R7 represents a hydroxyethyl group or a hydroxypropyl group.

Examples of component A2 include at least one selected from 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 viewpoints of improving the strippability of negative dry film resists and increasing the etching rate of metal seed layers.

From the viewpoint of improving the strippability of negative dry film resists and improving the etching ability of metal seed layers, the content of component A2 in the treatment solution of the present disclosure is preferably 5% by mass or more, more preferably 8% by mass or more, and even more preferably 10% by mass or more. From the viewpoint of improving the strippability of negative dry film resists, the content is preferably 20% by mass or less, more preferably 18% by mass or less, and even more preferably 15% by mass or less. More specifically, the content of component A2 in the treatment solution of the present disclosure is preferably 5% by mass or more and 20% by mass or less, more preferably 8% by mass or more and 18% by mass or less, and even more preferably 10% by mass or more and 15% by mass or less. When component A2 is a combination of two or more types, the content of component A2 refers to the total content thereof.

From the viewpoint of improving the strippability of negative dry film resists and improving the etching ability of metal seed layers, the content of component A in the treatment solution of the present disclosure is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more. From the viewpoint of improving the strippability of negative dry film resists, the content is preferably 30% by mass or less, more preferably 25% by mass or less, and even more preferably 20% by mass or less. More specifically, the content of component A in the treatment solution of the present disclosure is preferably 5% by mass or more and 30% by mass or less, more preferably 10% by mass or more and 25% by mass or less, and even more preferably 15% by mass or more and 20% by mass or less. When component A is a combination of two or more types, the content of component A refers to the total content thereof.

The mass ratio A2/A1 of component A2 to component A1 in the treatment solution of the present disclosure [content of component A2 (mass%)/content of component A1 (mass%)] is preferably 0.01 or greater, more preferably 0.1 or greater, and even more preferably 1 or greater, from the viewpoint of improving the strippability of negative dry film resists and the etching ability of metal seed layers. From the same viewpoint, it is preferably 100 or less, preferably 50 or less, more preferably 10 or less, and even more preferably 5 or less. From the same viewpoint, the mass ratio A2/A1 in the treatment solution of the present disclosure is preferably 0.01 or greater and 50 or less, more preferably 0.1 or greater and 10 or less, and even more preferably 1 or greater and 5 or less.

In the present disclosure, the "content of each component in the processing liquid" refers to the content of each component in the processing liquid at the time of use, i.e., at the time when the processing liquid starts to be used for processing (resist stripping and seed etching).
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.

[Component B: Primary ammonium source]
The primary ammonium source (hereinafter also referred to as "component B") contained in the treatment liquid of the present disclosure may be one type or a combination of two or more types.
Component B may be ammonia or a primary ammonium salt from the viewpoint of improving the strippability of the negative dry film resist and improving the etching rate of the metal seed layer. Examples of the primary ammonium salt include inorganic ammonium salts and primary ammonium salts of organic acids. Examples of the inorganic ammonium salt include ammonium chloride, ammonium sulfide, ammonium sulfate, and ammonium nitrate. Examples of the primary ammonium salts of organic acids include ammonium salts of carboxylic acids having 1 to 5 carbon atoms, and more preferably ammonium formate or ammonium oxalate.

From the viewpoint of improving the etching ability of the metal seed layer, the content of component B in the treatment solution of the present disclosure is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 0.7% by mass or more, and even more preferably 1% by mass or more. From the viewpoint of improving the strippability of negative dry film resist, the content is preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 3% by mass or less, and even more preferably 2% by mass or less. More specifically, the content of component B in the treatment solution of the present disclosure is preferably 0.1% by mass or more and 10% by mass or less, more preferably 0.5% by mass or more and 5% by mass or less, even more preferably 0.7% by mass or more and 3% by mass or less, and even more preferably 1% by mass or more and 2% 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 of those components.

The mass ratio A/B of component A to component B in the treatment solution of the present disclosure [content of component A (mass%)/content of component B (mass%)] is preferably 0.01 or greater, more preferably 0.1 or greater, even more preferably 1 or greater, even more preferably 5 or greater, and even more preferably 8.5 or greater, from the viewpoint of improving the strippability of negative dry film resists and the etching ability of metal seed layers. From the same viewpoint, it is preferably 100 or less, more preferably 50 or less, even more preferably 25 or less, even more preferably 20 or less, and even more preferably 17 or less. From the same viewpoint, the mass ratio A/B in the treatment solution of the present disclosure is preferably 0.01 or greater and 100 or less, more preferably 0.1 or greater and 50 or less, even more preferably 1 or greater and 25 or less, even more preferably 5 or greater and 20 or less, and even more preferably 8.5 or greater and 17 or less.

The mass ratio A1/B of component A1 to component B in the treatment solution of the present disclosure [content of component A1 (mass%) / content of component B (mass%)] is preferably 0.01 or greater, more preferably 0.1 or greater, even more preferably 1 or greater, and even more preferably 2.5 or greater, from the viewpoint of improving the strippability of negative dry film resists and the etching ability of metal seed layers. From the same viewpoint, it is preferably 100 or less, more preferably 50 or less, even more preferably 15 or less, even more preferably 8 or less, and even more preferably 5 or less. From the same viewpoint, the mass ratio A1/B in the treatment solution of the present disclosure is preferably 0.01 or greater and 100 or less, more preferably 0.1 or greater and 50 or less, even more preferably 1 or greater and 15 or less, even more preferably 1 or greater and 8 or less, and even more preferably 2.5 or greater and 5 or less.

The mass ratio A2/B of component A2 to component B in the treatment solution of the present disclosure [content of component A2 (mass%) / content of component B (mass%)] is preferably 0.01 or greater, more preferably 0.1 or greater, even more preferably 1 or greater, even more preferably 5 or greater, even more preferably 6 or greater, and preferably 100 or less, more preferably 50 or less, even more preferably 25 or less, even more preferably 15 or less, and even more preferably 12 or less, from the viewpoint of improving the strippability of negative dry film resists and the etching ability of metal seed layers. From the same viewpoint, the mass ratio A2/B in the treatment solution of the present disclosure is preferably 0.01 or greater and 100 or less, more preferably 0.1 or greater and 50 or less, even more preferably 1 or greater and 25 or less, even more preferably 5 or greater and 15 or less, and even more preferably 6 or greater and 12 or less.

[Oxidizing agent (component C)]
The oxidizing agent (hereinafter also referred to as "component C") contained in the treatment liquid of the present disclosure may be one type or a combination of two or more types.
Examples of component C include peroxides, permanganic acid or a salt thereof, chromic acid or a salt thereof, peroxoacid or a salt thereof, oxyacid or a salt thereof, metal salts, nitric acids, and sulfuric acids, from the viewpoint of improving the strippability of the negative dry film resist and improving the etching rate of the metal seed layer. Among these, hydrogen peroxide is preferred.

From the viewpoint of improving the etching properties of the metal seed layer, the content of component C in the treatment solution of the present disclosure is preferably 1% by mass or more, more preferably 2% by mass or more, and even more preferably 3% by mass or more. From the viewpoint of improving the strippability of the negative dry film resist, the content 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 component C in the treatment solution 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 10% by mass or less, and even more preferably 3% by mass or more and 7% by mass or less. When component C is a combination of two or more types, the content of component C refers to the total content thereof.

The mass ratio A/C of component A to component C [content of component A (mass%) / content of component C (mass%)] in the treatment solution of the present disclosure is preferably 0.01 or more, more preferably 0.1 or more, even more preferably 1 or more, and even more preferably 2 or more, from the viewpoint of improving the strippability of negative dry film resists and the etching ability of metal seed layers. From the same viewpoint, it is preferably 100 or less, more preferably 50 or less, even more preferably 25 or less, even more preferably 10 or less, and even more preferably 5 or less. From the same viewpoint, the mass ratio A/C in the treatment solution of the present disclosure is preferably 0.01 or more and 100 or less, more preferably 0.1 or more and 50 or less, even more preferably 1 or more and 25 or less, even more preferably 2 or more and 10 or less, and even more preferably 2 or more and 5 or less.

The mass ratio B/C of component B to component C [content of component B (mass%) / content of component C (mass%)] in the treatment solution of the present disclosure is preferably 0.01 or greater, more preferably 0.5 or greater, and even more preferably 0.2 or greater, from the viewpoint of improving the strippability of negative dry film resists and the etching ability of metal seed layers. From the same viewpoint, it is preferably 100 or less, more preferably 50 or less, even more preferably 10 or less, even more preferably 2 or less, even more preferably 1 or less, and even more preferably 0.4 or less. From the same viewpoint, the mass ratio B/C in the treatment solution of the present disclosure is preferably 0.01 or greater and 100 or less, more preferably 0.5 or greater and 50 or less, even more preferably 0.2 or greater and 10 or less, even more preferably 0.2 or greater and 2 or less, even more preferably 0.2 or greater and 1 or less, and even more preferably 0.2 or greater and 0.4 or less.

The mass ratio A1/C of component A1 to component C [content of component A1 (mass%) / content of component C (mass%)] in the treatment solution of the present disclosure is preferably 0.01 or greater, more preferably 0.5 or greater, and even more preferably 0.2 or greater, from the viewpoint of improving the strippability of negative dry film resists and the etching ability of metal seed layers. From the same viewpoint, it is preferably 100 or less, more preferably 50 or less, even more preferably 10 or less, and even more preferably 2 or less. From the same viewpoint, the mass ratio A1/C in the treatment solution of the present disclosure is preferably 0.01 or greater and 100 or less, more preferably 0.5 or greater and 50 or less, even more preferably 0.2 or greater and 10 or less, and even more preferably 0.2 or greater and 2 or less.

The mass ratio A2/C of component A2 to component C [content of component A2 (mass%) / content of component C (mass%)] in the treatment solution of the present disclosure is preferably 0.01 or greater, more preferably 0.5 or greater, even more preferably 0.2 or greater, even more preferably 1 or greater, and preferably 100 or less, more preferably 50 or less, even more preferably 10 or less, and even more preferably 5 or less, from the viewpoint of improving the strippability of negative dry film resists and the etching ability of metal seed layers. From the same viewpoint, the mass ratio A2/C in the treatment solution of the present disclosure is preferably 0.01 or greater and 100 or less, more preferably 0.5 or greater and 50 or less, even more preferably 0.2 or greater and 10 or less, and even more preferably 1 or greater and 5 or less.

[Component D: Water]
In one or more embodiments, the treatment liquid of the present disclosure further contains water (hereinafter also referred to as “component D”). In one or more embodiments, examples of component D include ion-exchanged water, RO water, distilled water, pure water, and ultrapure water.

When the treatment solution of the present disclosure contains component D, the content of component D in the treatment solution of the present disclosure can be the remainder excluding components A, B, C, and the optional components described below. Specifically, from the viewpoints of improving the strippability of negative dry film resists, reducing the burden on wastewater treatment, and suppressing damage to the substrate resin, the content of component D in the treatment solution of the present disclosure is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 65% by mass or more. From the viewpoints of improving the strippability of negative dry film resists and improving the etching ability of metal seed layers, the content of component D is preferably 95% by mass or less, more preferably 80% by mass or less, and even more preferably 75% by mass or less. More specifically, the content of component D in the treatment solution of the present disclosure is preferably 50% by mass or more and 95% by mass or less, more preferably 60% by mass or more and 80% by mass or less, and even more preferably 65% by mass or more and 75% by mass or less.

From the viewpoint of improving the strippability of the negative dry film resist and improving the etching rate of the metal seed layer, the total amount of components A, B, C, and D in the treatment solution of the present disclosure is preferably 80% by mass or more, more preferably 85% by mass or more, even more preferably 90% by mass or more, and even more preferably 92% by mass or more.

[Glycol ether (component E)]
In one or more embodiments, the treatment liquid of the present disclosure may further contain a glycol ether (hereinafter also referred to as “Component E”) from the viewpoint of stability in stripping a negative dry film resist. Component E may be one type or a combination of two or more types.
From the viewpoint of stability in stripping of negative dry film resists, in one or more embodiments, Component E may be a compound having a structure in which 1 to 3 moles of ethylene glycol are added to an alcohol having 1 to 8 carbon atoms. Examples of Component E 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, and among these, diethylene glycol monobutyl ether (BDG) is preferred.

When the treatment solution of the present disclosure contains component E, the content of component E in the treatment solution of the present 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 viewpoint of stability in stripping of negative dry film resist. Also, from the viewpoint of improving the strippability of negative dry film resist and the etching ability of the metal seed layer, it is preferably 15% by mass or less, more preferably 10% by mass or less, and even more preferably 8% by mass or less. More specifically, the content of component E in the treatment solution of the present disclosure is preferably 2% by mass or more and 15% by mass or less, more preferably 3% by mass or more and 10% by mass or less, and even more preferably 5% by mass or more and 8% 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 of those components.

[Other ingredients]
The treatment liquid of the present disclosure may further contain other components as needed, in addition to the components A to E, to the extent that the effects of the present disclosure are not impaired. Examples of other components include alkalis other than component A, ammonium salts other than component B, organic solvents other than component E, surfactants, chelating agents, thickeners, dispersants, rust inhibitors, polymeric compounds, solubilizers, antioxidants, preservatives, antifoaming agents, and antibacterial agents.

The total content of organic matter derived from components A, B, C, and optional components (component E and other components) in the treatment solution 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 burden on wastewater treatment and reducing the impact on the substrate. Also, from the viewpoint of improving the strippability of negative dry film resist, it 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 components A, B, C, and optional components (component E and other components) in the treatment solution 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.

[Method of manufacturing the treatment liquid]
In one or more embodiments, the treatment liquid of the present disclosure can be produced by blending component A, component B, component C, and, if necessary, the above-mentioned optional components (component D, component E, other components) using a known method. For example, the treatment liquid of the present disclosure can be produced by blending at least component A, component B, and component C. Thus, the present disclosure relates to a method for producing a treatment liquid, which includes a step of blending at least component A, component B, and component C. In the present disclosure, "blending" includes mixing component A, component B, and component C, and, if necessary, the above-mentioned optional components (component D, component E, 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 can be the same as the preferred content of each component in the treatment liquid of the present disclosure described above.

The treatment solution of the present disclosure may be in a form that is used directly for treatment, or may be produced as a concentrate and diluted at the time of use, as long as separation, precipitation, or the like does not occur and storage stability is not impaired. In one or more embodiments, the present disclosure relates to a concentrate for obtaining the treatment solution of the present disclosure. In one or more embodiments, the treatment solution of the present disclosure may be prepared as a concentrate with a reduced amount of water (component D). From the standpoint of transportation and storage, the treatment solution concentrate of the present disclosure is preferably a concentrate diluted 3 times or more, and from the standpoint of storage stability, it is preferably a concentrate diluted 30 times or less. The treatment solution concentrate of the present disclosure can be used by diluting it with water (component D) so that each component (component A, component B, component C, component D, component E, and other components) reaches the above-mentioned content (i.e., the content at the time of treatment) at the time of use. Furthermore, the treatment solution concentrate of the present disclosure can also be used by adding each component separately at the time of use. In this disclosure, "at the time of use" or "at the time of treatment" of the treatment solution concentrate refers to the diluted state of the treatment solution concentrate.

[Processing object]
In one or more embodiments, the workpiece is a substrate having a metal seed layer and a negative dry film resist layer. In one or more embodiments, the workpiece is a substrate having a negative dry film resist and a metal layer on the metal seed layer.
(substrate)
The substrate may be, for example, an insulating plate or film.
In one or more embodiments, the substrate is an insulating substrate formed using an insulating material such as an epoxy resin, an epoxy acrylate resin, a polyimide resin, etc. Examples of insulating substrates include glass epoxy resin substrates.
The thickness of the substrate is, for example, 0.8 to 3.2 mm.
(Metal seed layer)
In one or more embodiments, the metal seed layer is a metal layer formed by electroless plating. In one or more embodiments, the metal seed layer is formed on the entire surface of the substrate.
In one or more embodiments, the metal seed layer is a copper-containing metal seed layer. In one or more embodiments, the copper-containing metal seed layer is a seed layer formed by electroless copper plating.
The thickness of the metal seed layer is, for example, 0.05 to 3 μm.
(negative dry film resist layer)
In one or more embodiments, the negative dry film resist layer is a negative resist layer obtained by laminating a negative dry film resist on a metal seed layer and then subjecting it to exposure and/or development treatment.
The negative dry film resist layer may have a thickness of, for example, 5 to 200 μm. A plurality of negative dry film resist layers (for example, five layers) may be stacked to form a layer having a thickness of 200 μm.
(metal layer)
The metal layer may be, for example, a copper-containing metal layer. In one or more embodiments, the copper-containing metal layer is a copper plating layer. The copper plating layer may be formed by, for example, an electroless copper plating method.
The thickness of the metal layer is, for example, 4 to 160 μm.
In one or more embodiments, the metal layer is used as metal wiring (for example, copper wiring).

Examples of the workpiece include electronic components that have wiring, connection terminals, etc. formed on the surface of a substrate by undergoing at least one of soldering and plating (copper plating, aluminum plating, nickel plating, tin plating, etc.) using a negative dry film resist as a mask. Examples of electronic components include at least one component selected from printed circuit boards, wafers, and metal plates such as copper plates and aluminum plates. The manufacturing intermediates are intermediate products in the manufacturing process of electronic components, and include intermediate products after resin mask treatment.
In the present disclosure, soldering refers to applying solder to the non-mask areas on the substrate and forming solder bumps by heating.
In the present disclosure, plating refers to performing at least one plating treatment selected from copper plating, aluminum plating, nickel plating, and tin plating on the mask-free areas of a substrate. The mask-free areas refer to areas where the mask has been removed by development in a resist pattern (a mask having a pattern shape) formed by developing a mask (negative type) laminated on the substrate.

[Processing method]
In one aspect, the present disclosure relates to a processing method for stripping a negative dry film resist layer from a substrate having a negative dry film resist layer and a metal seed layer and etching the metal seed layer, the processing method comprising contacting a processing solution of the present disclosure with a substrate (workpiece) having the negative dry film resist layer and the metal seed layer (hereinafter also referred to as the “processing method of the present disclosure”). Examples of the workpiece include the above-mentioned workpieces.
According to the processing method of the present disclosure, stripping of the negative dry film resist and etching of the metal seed layer can be efficiently performed simultaneously.

Examples of a method for simultaneously peeling off a negative dry film resist layer from a workpiece and etching a metal seed layer using the treatment liquid of the present disclosure, or a method for contacting a workpiece with the treatment liquid of the present disclosure, include a method for contacting the workpiece by immersing the workpiece in a bath containing the treatment liquid, and a method for contacting the workpiece by spraying the treatment liquid in a spray form (shower method).
As for the immersion conditions and spray irradiation conditions, for example, the temperature of the treatment agent during immersion or spray irradiation is preferably 40°C or higher, more preferably 45°C or higher, and even more preferably 50°C or higher, from the viewpoint of the time required for treatment. From the viewpoint of protecting the portions of the treatment object other than the mask (negative dry film resist) and seed (metal seed layer), it is preferably 70°C or lower, more preferably 65°C or lower, and even more preferably 60°C or lower. From the viewpoint of uniform treatment of the treatment object, the immersion time and spray irradiation time are preferably 15 seconds or higher, more preferably 20 seconds or higher, and even more preferably 30 seconds or higher, from the viewpoint of substrate productivity. From the viewpoint of suppressing consumption of the treatment solution, the spray pressure during spray irradiation can be, for example, 0.03 MPa or higher and 0.3 MPa or lower.

In one or more embodiments, the treatment method of the present disclosure may include a step of contacting an object to be treated with the treatment liquid of the present disclosure, rinsing the object with water, and drying the object.
In one or more embodiments, the treatment method of the present disclosure may include a step of rinsing the object to be treated with water after contacting the object with the treatment liquid of the present disclosure.

[Electronic component manufacturing method]
In one aspect, the present disclosure relates to a method for manufacturing an electronic component (hereinafter also referred to as the "electronic component manufacturing method of the present disclosure"), which includes a step (processing step) of processing a substrate (process object) having a negative dry film resist layer and a metal seed layer using the processing method of the present disclosure. Examples of the process object include the above-described process objects. The processing step refers to a process in which a stripping process of the negative dry film resist layer and an etching process of the metal seed layer are simultaneously performed. In one or more embodiments, the electronic component manufacturing method of the present disclosure may include a step of performing at least one of soldering and plating using a resin mask on at least one electronic component selected from a printed circuit board, a wafer, and a metal plate after the processing step.
The method for manufacturing electronic components disclosed herein can improve the manufacturing efficiency of electronic components by using the processing method disclosed herein to efficiently strip the negative dry film resist and etch the metal seed layer simultaneously.

[Method of manufacturing a wiring board]
In one aspect, the present disclosure relates to a method for manufacturing a wiring board using a semi-additive process (hereinafter also referred to as the "wiring board manufacturing method of the present disclosure").
In one or more embodiments, the wiring board manufacturing method of the present disclosure is a wiring board manufacturing method including a processing method (processing method of the present disclosure) of peeling off a negative dry film resist layer from a substrate having a negative dry film resist layer and a metal seed layer, and etching the metal seed layer,
A method for manufacturing a wiring substrate includes contacting a treatment liquid of the present disclosure with a substrate having a negative dry film resist layer and a metal seed layer.
In the wiring board manufacturing method of the present disclosure, the method of bringing the treatment solution of the present disclosure into contact with the treatment object may be the same as the treatment method of the present disclosure described above.
In one or more embodiments, the wiring board manufacturing method of the present disclosure can include a step of contacting an object to be treated with the treatment liquid of the present disclosure, rinsing the object with water, and drying the object.
In one or more embodiments, the wiring board manufacturing method of the present disclosure may include a step of rinsing the object to be treated with water after contacting the object with the treatment liquid of the present disclosure.

In one or more other embodiments, the wiring board manufacturing method of the present disclosure is a method for manufacturing a wiring board having metal wiring formed on a substrate using a semi-additive method,
a step of forming a metal seed layer on the substrate by electroless plating (seed layer formation step);
a step of forming a negative dry film resist layer (resist pattern) on the surface of the metal seed layer to form a mask for a circuit pattern (masking step);
a step of forming a metal layer (circuit pattern) by electrolytic plating on the exposed portion of the metal seed layer (portion not covered by the resist pattern) (circuit pattern forming step);
A method for manufacturing a wiring board includes a step (treatment step) of treating a negative dry film resist layer and a metal seed layer (portions covered by a resist pattern) using the treatment liquid or treatment method of the present disclosure.
In one or more other embodiments, the treatment step is a step of simultaneously stripping the negative dry film resist layer and etching the metal seed layer.
In the wiring board manufacturing method of the present disclosure described above, the steps up to the treatment step (i.e., the seed layer formation step, the masking step, and the circuit pattern formation step) can be performed using conventionally known methods used in the manufacture of printed circuit boards, semiconductor package substrates, etc. In addition, examples of the substrate, metal seed layer, negative dry film resist layer, and metal layer include those listed in the description of the workpiece.

The wiring board manufacturing method disclosed herein allows for efficient simultaneous removal of the negative dry film resist and etching of the metal seed layer.

[kit]
In one aspect, the present disclosure relates to a kit for use in the processing method of the present disclosure (hereinafter also referred to as the "kit of the present disclosure"). In one or more embodiments, the kit of the present disclosure is a kit for producing a processing solution of the present disclosure. The kit of the present disclosure can provide a processing solution that can efficiently strip a negative dry film resist and etch a metal seed layer simultaneously.
One embodiment of the kit of the present disclosure includes a kit (two-component treatment liquid) that includes a solution (first liquid) containing components A and B and a solution (second liquid) containing component C, which are not mixed with each other, and at least one of the first and second liquids further contains some or all of water (component D), and the first and second liquids are mixed at the time of use. After the first and second liquids are mixed, they may be diluted with water (component D) as needed. Each of the first and second liquids may contain the optional components described above as needed.

The present disclosure will be explained in detail below using examples, but the present disclosure is not limited to these examples in any way.

1. Preparation of Treatment Solutions for Examples 1 and 2 and Comparative Examples 1 and 2 The components shown in Table 1 were blended in the amounts (% by mass, active ingredient) shown in Table 1, and the blended mixture was stirred and mixed to prepare the treatment solutions for Examples 1 and 2 and Comparative Examples 1 and 2.
The amount of water (component D) included includes the amount of water contained in the TMAH aqueous solution, hydrogen peroxide solution, etc.

The treatment solutions of Examples 1 and 2 and Comparative Examples 1 and 2 were prepared using the following materials.
(Component A)
TMAH: tetramethylammonium hydroxide [manufactured by Resonac, 25% TMAH aqueous solution]
MEA: Monoethanolamine [manufactured by Nippon Shokubai]
(Component B)
Ammonium formate [Toyama Chemical]
Ammonium oxalate [manufactured by SIGMA-ALDRICH]
(Component C)
Hydrogen peroxide [30% by weight hydrogen peroxide solution, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.]
(Component D)
Water [pure water of 1 μS/cm or less produced using the Organo Corporation G-10DSTSET water purification system]
(Component E)
BDG: butyl diglycol [Nihon Nyukazai Co., Ltd., diethylene glycol monobutyl ether]

2. Evaluation of Treatment Liquid The treatment liquids prepared in Examples 1 and 2 and Comparative Examples 1 and 2 were evaluated as follows.

[Measurement of lifting point (evaluation of peelability)]
Test piece I was treated with the prepared treatment solution as described below to peel the dry film from the substrate. In the treatment method described below, the time (seconds) until the blue dry film resist was peeled off from the entire surface of test piece I by visual observation, exposing copper on the entire surface of test piece I, was measured, and the results are shown in Table 1.
(Test Piece I)
A photosensitive film for forming a negative resist (thickness: 45 μm) was laminated on the surface of a glass epoxy resin substrate (thickness: 0.9 mm) having a solid copper plating layer (thickness: 0.8 μm) formed by electroless plating, and then exposed to light to harden the film, thereby producing test piece I. Test piece I is a model of a substrate (thickness: 0.9 mm) having a metal seed layer (thickness: 0.8 μm) and a negative dry film resist layer (thickness: 45 μm).
(peeling treatment)
2.0 kg of the treatment liquid was added to a 3 L stainless steel beaker and heated to 60°C. Test piece I was sprayed (pressure: 0.03 MPa, spray distance: 8 cm) while circulating the liquid through a box-type spray washer equipped with a one-fluid nozzle (full cone shape) J020 (manufactured by Ikeuchi Co., Ltd.) as a spray nozzle.
The sample is then rinsed by immersing it in a rinsing tank containing 1.0 kg of water in a 1 L glass beaker, and then dried by nitrogen blowing.

[Measurement of Etching Rate (Evaluation of Etching Properties)]
Test piece II was treated with the prepared treatment solution as follows, and the etching rate was measured. The results are shown in Table 1.
(Test Piece II)
Test piece II (50 mm × 25 mm) was cut out from the substrate used in the measurement of the lifting point before laminating the negative resist-forming photosensitive film (i.e., a solid substrate having a copper plating layer (thickness: 0.8 μm) on the surface of a glass epoxy resin substrate).
(Etching process)
2.0 L of each treatment solution was prepared and heated to 60°C. The solution was circulated in a box-type spray washer equipped with a full-cone nozzle (J020, manufactured by Ikeuchi Co., Ltd.) and sprayed for 1 minute (pressure: 0.03 MPa, spray distance: 80 mm) onto test piece II, whose surface was copper-plated (area: 12.5 ^cm2 per side, 25.0 ^cm2 total). The amount of copper eluted was measured from the change in weight of test piece II before and after treatment, and the Cu etching rate (μm/min) was evaluated from the amount of elution using the following formula, assuming a copper density of 8.96 g/ ^cm3 .
Cu etching rate (μm/min) = copper elution amount (weight) ÷ copper density ÷ plating area ÷ treatment time

As shown in Table 1, the treatment solutions of Examples 1 and 2 exhibited improved Cu etching rates while stripping the negative dry film resist layer compared to Comparative Example 1, which did not contain Components B and C, and Comparative Example 2, which did not contain Component B. In other words, it was found that the treatment solutions of Examples 1 and 2 were capable of efficiently stripping the negative dry film resist and etching the metal seed layer simultaneously.

The present disclosure provides a treatment solution that can efficiently strip negative dry film resist and etch a metal seed layer simultaneously. Furthermore, use of the treatment solution of the present disclosure can improve the productivity of semiconductor devices.

Claims (8)

A treatment solution for simultaneously stripping a negative dry film resist layer and etching a metal seed layer in the manufacture of an electronic substrate using a substrate having a negative dry film resist layer and a metal seed layer, comprising:
A processing solution for resist stripping and seed etching, comprising an organic alkali (component A), a primary ammonium source (component B), and an oxidizing agent (component C). The treatment solution according to claim 1, wherein component A is at least one selected from a quaternary ammonium salt (component A1) and an alkanolamine (component A2). The treatment solution according to claim 1 or 2, wherein component A is a combination of a quaternary ammonium salt (component A1) and an alkanolamine (component A2). The treatment solution according to claim 1 or 2, further comprising water (component D). The treatment liquid according to claim 1 or 2, wherein the mass ratio A/C of component A to component C is 0.01 or more and 100 or less. The treatment liquid according to claim 1 or 2, wherein the mass ratio B/C of component B to component C is 0.01 or more and 100 or less. The treatment solution described in claim 1 or 2, wherein the metal seed layer is a copper-containing metal seed layer formed by electroless copper plating. A processing method for stripping a negative dry film resist layer from a substrate having a negative dry film resist layer and a metal seed layer and etching the metal seed layer, comprising:
A processing method comprising contacting the processing solution according to claim 1 or 2 with a substrate having a negative dry film resist layer and a metal seed layer.