Etching liquid for titanium and / or titanium alloy, etching method for titanium and / or titanium alloy using the etching liquid, and manufacturing method for substrate using the etching liquid

Abstract

Provided is an etching method for continuously and stably performing processing, which is capable of quickly removing a seed layer formed of titanium and / or a titanium alloy while suppressing elution of other metals such as copper wiring, and a composition used in the etching method. More specifically, provided is a composition for etching titanium and / or a titanium alloy, and an etching method using the same, the composition comprising hydrogen peroxide (A), a fluoride (B), a halide ion other than a fluoride ion (C), and water (D), wherein the content of the hydrogen peroxide (A) is 0.01 to 0.23 mass% based on the total amount of the composition; the content of the fluoride (B) is 0.2 to 3 mass% based on the total amount of the composition; and the content of the halide ion other than the fluoride ion (C) is 0.0005 to 0.025 mass% based on the total amount of the composition.

Description

Technical Field

[0001] This invention relates to an etching composition for titanium and / or titanium alloys. More specifically, this invention relates to an etching composition for titanium and / or titanium alloys, an etching method for titanium and / or titanium alloys using the composition, and a method for manufacturing substrates such as printed circuit boards and semiconductor wafers using the etching composition. Background Technology

[0002] To form fine circuits in printed circuit boards, a semi-additive method is typically used. For example, a thin metal film is formed on an insulating layer, serving as a seed layer for electrolytic copper plating. After forming a resist pattern on the seed layer, copper wiring is formed through electrolytic copper plating. Then, the unwanted resist pattern is removed, and the unplated portions of the seed layer are removed, completing the copper wiring. For the seed layer, electroless copper plating or sputtering can be used; however, titanium sputtering is often chosen for forming finer wiring.

[0003] Typically, electroless copper plating used to form printed circuit boards can be removed by an etching solution containing hydrogen peroxide-sulfuric acid. For etching sputtered titanium films, methods such as those described in Patent Documents 1-4 can be employed. However, hydrogen peroxide lacks sufficient stability in these methods. Therefore, there is a need for an etching method that can rapidly remove seed layers formed from titanium and / or titanium alloys and suppress the dissolution of other metals such as copper or copper alloys and cobalt wiring, to be practically applied as soon as possible.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 8-13166

[0007] Patent Document 2: Japanese Patent Application Publication No. 8-53781

[0008] Patent Document 3: U.S. Patent No. 4,554,050

[0009] Patent Document 4: Japanese Patent Application Publication No. 2005-146358 Summary of the Invention

[0010] The problem the invention aims to solve

[0011] The present invention provides an etching composition and an etching method using the composition, which can rapidly remove titanium and / or titanium alloys, and / or titanium-containing compounds with metallic properties, and inhibit the leaching of other metals such as copper or copper alloys, cobalt, etc.

[0012] Solution for solving the problem

[0013] The inventors conducted repeated and in-depth research and found that by using an aqueous solution containing halide ions other than hydrogen peroxide, fluoride, and fluoride ions, titanium and / or titanium alloys, and / or titanium-containing compounds with metallic properties can be rapidly removed, and the leaching of other metals such as copper or copper alloys and cobalt wiring can be inhibited, thus completing the present invention.

[0014] That is, the present invention includes the following technical solutions:

[0015] <1>

[0016] A composition for etching titanium and / or titanium alloys, the composition comprising hydrogen peroxide (A), fluoride (B), halide ions other than fluoride ions (C), and water (D), wherein,

[0017] Based on the total amount of the composition, the content of hydrogen peroxide (A) is 0.01 to 0.23% by mass;

[0018] Based on the total amount of the composition, the content of fluoride (B) is 0.2 to 3% by mass;

[0019] Based on the total amount of the composition, the content of halide ions (C) other than fluoride ions is 0.0005 to 0.025% by mass.

[0020] <2>

[0021] According to the composition described in <1> above, the fluoride (B) comprises one or more selected from the group consisting of hydrogen fluoride, acidic ammonium fluoride, acidic sodium fluoride and acidic potassium fluoride.

[0022] <3>

[0023] According to the composition described in <1> or <2> above, the halide ion (C) comprises at least one of chloride ions and bromide ions.

[0024] <4>

[0025] The composition according to any one of <1> to <3> above further comprises a phosphonic acid chelating agent (E).

[0026] <5>

[0027] According to the composition described in <4> above, the phosphonic acid chelating agent (E) comprises at least one of 1,2-propylidene diaminetetra(methylenephosphonic acid) and diethylenetriaminepenta(methylenephosphonic acid).

[0028] <6>

[0029] According to the composition described in <4> or <5> above, the content of the phosphonic acid chelating agent (E) is 0.005 to 0.1% by mass, based on the total amount of the composition.

[0030] <7>

[0031] The composition according to any one of <1> to <6> above, wherein the composition is a composition for inhibiting the etching of copper or copper alloys and etching titanium and / or titanium alloys.

[0032] <8>

[0033] The composition according to any one of <1> to <7> above, wherein the copper etching rate at 30°C is less than 100 nm / min.

[0034] <9>

[0035] The composition according to any one of <1> to <8> above, wherein the ratio of titanium etching rate to copper etching rate at 30°C is 2 or more.

[0036] <10>

[0037] An etching method that uses the composition described in any one of <1> to <9> above to etch titanium and / or titanium alloys.

[0038] <11>

[0039] A method for forming a circuit, wherein the composition described in any one of <1> to <9> above is used to etch titanium and / or titanium alloy to form a circuit formed by laminating titanium and / or titanium alloy with copper or copper alloy.

[0040] <12>

[0041] A method for manufacturing a substrate, comprising the step of etching titanium and / or titanium alloys using the composition described in any one of <1> to <9> above.

[0042] The effects of the invention

[0043] This invention is effectively applicable to the removal of layers formed by etching, for example, titanium and / or titanium alloys used for electroplating, and / or titanium-containing compounds with metallic properties. This invention can suppress the leaching of other metals such as copper or copper alloys, cobalt, etc., in wiring, and is therefore useful in the manufacture of electronic components with fine copper or copper alloy, cobalt, etc. wiring. Attached Figure Description

[0044] Figure 1 This is a diagram illustrating an example of a printed circuit board manufacturing method process provided by an embodiment of the present invention. Detailed Implementation

[0045] The present invention will now be described in detail. It should be noted that the present invention is not limited to the description herein, and various changes or modifications can be made without departing from the spirit of the present invention.

[0046] 1. A composition for etching

[0047] The composition of the present invention for etching titanium and / or titanium alloys (hereinafter also referred to as "the composition of the present invention") comprises hydrogen peroxide (A), fluoride (B), halide ions other than fluoride ions (C), and water (D), wherein,

[0048] Based on the total amount of the composition, the content of hydrogen peroxide (A) is 0.01 to 0.23% by mass;

[0049] Based on the total amount of the composition, the content of fluoride (B) is 0.2 to 3% by mass;

[0050] Based on the total amount of the composition, the content of halide ions (C) other than fluoride ions is 0.0005 to 0.025% by mass.

[0051] Based on the composition of the present invention, a seed layer of titanium and / or titanium alloys, preferably formed of titanium and / or titanium alloys, can be rapidly removed, and the leaching of other metals such as copper or copper alloys, cobalt, etc., can be suppressed. More preferably, based on the composition of the present invention, a seed layer of titanium and / or titanium alloys, preferably formed of titanium and / or titanium alloys, can be rapidly removed, and the leaching of copper or copper alloys can be at least suppressed. That is, the composition of the present invention is preferably a composition for suppressing the etching of copper or copper alloys and etching titanium and / or titanium alloys. The composition of the present invention can also be used to remove layers formed of titanium-containing compounds having metallic properties.

[0052] It should be noted that the term "copper alloy" in this specification refers to any substance containing copper with the addition of one or more metallic or non-metallic elements other than copper, and which possess metallic properties; there is no particular limitation on this term. The content of metallic or non-metallic elements other than copper in the copper alloy is not particularly limited, but preferably it contains 50% by mass or more of copper, more preferably 80% by mass or more, further preferably 90% by mass or more, and particularly preferably 98% by mass or more. Examples of metallic or non-metallic elements other than copper include, for instance, aluminum (Al).

[0053] Furthermore, the term "titanium alloy" in this specification is not particularly limited to any substance containing one or more metallic or non-metallic elements other than titanium that possess metallic properties. The content of metallic or non-metallic elements other than titanium in the titanium alloy is not particularly limited, but preferably it contains 50% by mass or more of titanium, more preferably 80% by mass or more, further preferably 90% by mass or more, and particularly preferably 98% by mass or more. Examples of metallic or non-metallic elements other than titanium include nitrogen. Examples of nitrogen-containing substances with metallic properties include titanium nitride (TiN) and titanium oxynitride (TiN2). x O y ).

[0054] In addition, in this specification, "other metals" such as copper or copper alloys and cobalt refer to metals other than titanium and titanium alloys that can be used for circuit wiring, but copper, copper alloys, cobalt, and cobalt alloys are preferred.

[0055] In one embodiment of the present invention, the composition of the present invention may contain a phosphonic acid chelating agent (E) as an arbitrary component.

[0056] The components contained in the composition of the present invention will be described below.

[0057] <Hydrogen peroxide (A)>

[0058] The hydrogen peroxide (A) contained in the compositions of the present invention is typically mixed with other components as an aqueous solution of moderate concentration. The concentration of hydrogen peroxide (A) in the aqueous hydrogen peroxide solution used to manufacture the compositions of the present invention is not particularly limited and can be, for example, 10–90% by mass, preferably 35–60% by mass conforming to industrial standards.

[0059] In addition, hydrogen peroxide (A) may contain stabilizers that are unavoidable during manufacturing. There are no limitations on the manufacturing process or the route of acquisition of hydrogen peroxide; for example, products manufactured using the anthraquinone process can be used. Furthermore, hydrogen peroxide (A) can be a product purified by methods such as passing a liquid through an ion exchange resin.

[0060] Based on the total amount of the composition, the content of hydrogen peroxide (A) in the composition of the present invention is 0.01 to 0.23% by mass, preferably 0.03 to 0.2% by mass, and more preferably 0.05 to 0.15% by mass. When the content of hydrogen peroxide (A) is within the above range, the oxidizing power of titanium and / or titanium alloys is sufficient, thus obtaining sufficient dissolution power of titanium and / or titanium alloys. In addition, the dissolution of copper or copper alloys, cobalt, and other metals can be suppressed. Furthermore, based on the total amount of the composition, when the content of hydrogen peroxide (A) is less than 0.01% by mass, Ti will peel off in a film-like manner. Therefore, based on the total amount of the composition, the content of hydrogen peroxide (A) is preferably 0.01% by mass or more. When Ti peels off in a film-like manner, the peeled Ti will re-adhere to the substrate, becoming a cause of problems in subsequent processes; in addition, when Ti peels off, the Cu wiring on Ti will also peel off together. Therefore, it is preferable that Ti does not peel off in a film-like manner.

[0061] <Fluoride (B)>

[0062] Fluoride (B) is not particularly limited to any compound containing fluoride ions (i.e., in which fluorine atoms exist as anions), and examples include: hydrogen fluoride (hydrofluoric acid), lithium fluoride, sodium fluoride, potassium fluoride, rubidium fluoride, cesium fluoride, magnesium fluoride, calcium fluoride, strontium fluoride, barium fluoride, manganese fluoride, iron fluoride, copper fluoride, tin fluoride, aluminum fluoride, titanium fluoride, tantalum fluoride, antimony fluoride, ammonium fluoride, tetrafluoroborate, sodium fluoroborate, potassium fluoroborate, ammonium fluoroborate, hexafluorosilicic acid, sodium fluorosilicate, potassium fluorosilicate, ammonium fluorosilicate, acidic sodium fluoride, acidic potassium fluoride, acidic ammonium fluoride, tetramethylammonium fluoride, and tetraethylammonium fluoride. In one embodiment of the present invention, fluoride (B) may be one of the above-mentioned fluorides that, when dissolved in water, makes the liquid acidic. In a preferred embodiment of the present invention, the fluoride (B) contained in the composition of the present invention is more preferably hydrogen fluoride, fluoroboric acid, acidic sodium fluoride, acidic potassium fluoride, or acidic ammonium fluoride, and even more preferably hydrogen fluoride, acidic sodium fluoride, acidic potassium fluoride, or acidic ammonium fluoride. These fluorides may be used alone or in combination of two or more.

[0063] Based on the total amount of the composition, the fluoride (B) content in the composition of the present invention is 0.2 to 3% by mass, preferably 0.3 to 2% by mass, more preferably 0.5 to 1.8% by mass, and even more preferably 0.8 to 1.5% by mass. When the fluoride (B) content is within the above range, sufficient dissolving power for titanium and / or titanium alloys can be obtained, and a dissolution rate that is not too fast for the removal of titanium and / or titanium alloys can be obtained.

[0064] Furthermore, in order to remove titanium and titanium alloys and suppress the leaching of copper or copper alloys, cobalt, and other metals, the ratio of [hydrogen peroxide (A) content] to [fluorine content from fluoride (B) source] is preferably 0.01 to 0.5 by mass. When the above mass ratio is within the above range, situations such as film-like peeling of the titanium and / or titanium alloy layer, or even peeling off of the wiring of copper or copper alloys, cobalt, and other metals on the titanium and / or titanium alloy layer, will not occur. In addition, the leaching of copper or copper alloys, cobalt, and other metals can be prevented.

[0065] In this invention, by containing the aforementioned fluoride (B), the composition used for etching titanium and / or titanium alloys is acidic. In one embodiment of this invention, the pH of the composition used for etching titanium and / or titanium alloys is preferably 3 to 6, more preferably 3.5 to 6, and even more preferably 4 to 5.5. When the pH of the composition used for etching titanium and / or titanium alloys is within the above range, the etching rate of copper or copper alloys, cobalt, etc., used for wiring can be suitably controlled. The pH value can be measured by conventional methods, for example, by the method described in the examples.

[0066] <Halide ions other than fluoride ions (C)>

[0067] As a halide ion (C) other than fluoride ions, chloride ions (Cl) can be used. - ), bromide ions (Br) - ), iodide ions (I - Preferably, the ions are chloride ions or bromide ions, more preferably chloride ions. In a preferred embodiment of the present invention, the halide ion (C) may include at least one of chloride ions and bromide ions.

[0068] The source of halide ions (C) other than fluoride ions is not particularly limited, as long as it is a compound capable of providing halide ions other than fluoride ions. Examples of such compounds include lithium chloride, sodium chloride, potassium chloride, ammonium chloride, lithium bromide, sodium bromide, potassium bromide, ammonium bromide, lithium iodide, sodium iodide, potassium iodide, and ammonium iodide. Preferably, one or more of the following are selected from the group consisting of sodium chloride, potassium chloride, ammonium chloride, sodium bromide, potassium bromide, and ammonium bromide, and more preferably one or more of the following are selected from the group consisting of sodium chloride, potassium chloride, and ammonium chloride. In a preferred embodiment of the present invention, the source of halide ions (C) other than fluoride ions is preferably sodium chloride, potassium bromide, or potassium iodide.

[0069] Based on the total amount of the composition, the content of halide ions (C) other than fluoride ions in the composition of the present invention is 0.0005 to 0.025% by mass, preferably 0.001 to 0.01% by mass. When the content of halide ions (C) other than fluoride ions is within the above range, sufficient leaching inhibition effect of copper or copper alloys and cobalt can be obtained, and it is also economically preferred.

[0070] <Water (D)>

[0071] The composition of the present invention contains water (D). The water (D) is not particularly limited, but is preferably water in which metal ions or organic impurities, particles, etc., have been removed by distillation, ion exchange treatment, filtration treatment, various adsorption treatments, etc., and is more preferably pure water, especially ultrapure water.

[0072] The water (D) content is the balance of the composition of the present invention, based on the total amount of the composition, preferably 60% by mass or more, more preferably 70% to 99.7% by mass, further preferably 80% to 99.5% by mass, particularly preferably 90% to 99.2% by mass, and especially preferably 95% to 99% by mass. A water (D) content within the above range is more economical.

[0073] <Phosonic acid chelating agents (E)>

[0074] Phosphonic acid chelating agents (E) are not particularly limited to any compound that generates phosphonic acid chelate ions in aqueous solution, and may also be salts or hydrates of phosphonic acids in addition to phosphonic acids. Examples of phosphonic acid salts include, but are not limited to, sodium salts, potassium salts, and ammonium salts. Examples of phosphonic acid chelating agents (E) that can be used in this invention include, but are not limited to, aminotris(methylenephosphonic acid), ethylenediaminetetra(methylenephosphonic acid) (EDTMP), ethylenediaminetetra(methylenephosphonic acid) hydrate, 1,2-propylidenediaminetetra(methylenephosphonic acid) (PDTP), diethylenetriaminepenta(methylenephosphonic acid) (DTPP), 1-hydroxyethane-1,1-diphosphonic acid (HEDP), etc. In a preferred embodiment of the present invention, the phosphonic acid chelating agent (E) is preferably at least one of 1,2-propylidenediaminetetra(methylenephosphonic acid) (PDTP), ethylenediaminetetra(methylenephosphonic acid) (EDTMP) and its hydrate, diethylenetriaminepenta(methylenephosphonic acid) (DTPP), and 1-hydroxyethane-1,1-diphosphonic acid (HEDP). In a more preferred embodiment of the present invention, the phosphonic acid chelating agent (E) is preferably at least one of diethylenetriaminepenta(methylenephosphonic acid) (DTPP) and 1-hydroxyethane-1,1-diphosphonic acid (HEDP).

[0075] When the composition of the present invention contains a phosphonic acid chelating agent (E), the content of the phosphonic acid chelating agent (E) is 0.005 to 0.1% by mass, preferably 0.01 to 0.05% by mass, based on the total amount of the composition. When the content of the phosphonic acid chelating agent (E) is within the above range, the precipitation of dissolved copper ions on titanium and / or titanium alloys can be suppressed, and it is also economically preferable.

[0076] <Other Ingredients>

[0077] Without impairing the effects of the present invention, the compositions of the present invention may contain other ingredients as needed. Examples of other ingredients that may be included in the compositions of the present invention include surfactants, defoamers, hydrogen peroxide stabilizers, pH adjusters, etc.

[0078] The composition of the present invention is preferably substantially free of sulfuric acid. By being substantially free of sulfuric acid, the etching rate of copper or copper alloys, cobalt, etc., can be appropriately controlled, thereby enabling rapid removal of the seed layer of titanium and / or titanium alloys, preferably formed of titanium and / or titanium alloys, and inhibiting the dissolution of other metals such as copper or copper alloys, cobalt, etc.

[0079] <Preparation of the Composition>

[0080] The compositions of the present invention can be prepared by uniformly stirring hydrogen peroxide (A), fluoride (B), halide ions other than fluoride ions (C), water (D), and optionally a phosphonic acid chelating agent (E), and other components added as needed. The stirring method for these components is not particularly limited and can be any commonly used stirring method.

[0081] <Uses of the Composition>

[0082] The object to be etched using the composition of the present invention is not particularly limited as long as it includes a substrate of titanium and / or titanium alloy as the object to be etched, but is preferably a substrate constituting a printed circuit board, a packaging substrate for mounting semiconductor components, a semiconductor wafer (e.g., a semiconductor substrate on which semiconductor components are formed), a semiconductor component (e.g., a semiconductor chip), etc. More preferably, it is a substrate constituting a circuit (electronic component) having at least a layer of titanium and / or titanium alloy and copper or copper alloy.

[0083] The composition of the present invention can be well used in the following scenarios: forming a circuit pattern constituting a connection terminal portion of a wiring of copper or copper alloy, cobalt, etc. on an insulating layer having at least partially copper or copper alloy, cobalt, etc., the circuit pattern comprising at least one selected from the group consisting of copper or copper alloy, cobalt, etc. and tin and tin alloy; after forming the circuit pattern, removing the photoresist used to form the circuit pattern; further removing the copper seed layer used to form the circuit pattern of copper or copper alloy, cobalt, etc. as needed; and quickly removing the portion of the seed layer formed of titanium and / or titanium alloy exposed with the removal of the photoresist and copper seed layer, while suppressing the dissolution of other metals used in the connection terminal portion, etc., formed by at least one selected from the group consisting of copper or copper alloy, cobalt, etc. and tin and tin alloy.

[0084] Furthermore, the composition of the present invention can be well used not only for forming the connection terminal portion, but also for forming more wiring circuits.

[0085] Here, "an insulating layer having at least partially copper or copper alloy, cobalt, or the like" is not particularly limited as long as it is an insulating layer with copper or copper alloy, cobalt, or the like embedded on or inside the surface. Examples include, for instance, resin insulating layers in printed circuit boards or packaging substrates for mounting semiconductor components, and silicon insulating layers in semiconductor wafers or semiconductor components.

[0086] Furthermore, "the circuit pattern constituting the connection terminal portion of the wiring of the copper or copper alloy, cobalt, etc., wherein the circuit pattern includes at least one selected from the group consisting of copper or copper alloy, cobalt and tin and tin alloy" refers to a component that electrically connects the connection terminal portion of the wiring of the copper or copper alloy, cobalt, etc., present in the insulating layer to other components. In one embodiment of the present invention, the connection terminal portion is the connection terminal portion of the wiring of the copper or copper alloy, cobalt, etc., in a printed circuit board. In another embodiment of the present invention, the connection terminal portion is the connection terminal portion of the wiring of the copper or copper alloy, cobalt, etc., in a semiconductor device mounting package substrate. In yet another embodiment of the present invention, the connection terminal portion is the connection terminal portion of the wiring of the copper or copper alloy, cobalt, etc., in a semiconductor wafer or semiconductor device.

[0087] In addition, when more wiring circuits are formed instead of the connection terminal portion, a circuit pattern constituting a wiring circuit connected to the copper or copper alloy, cobalt, etc. is formed on an insulating layer that at least partially has wiring of copper or copper alloy, cobalt, etc. The circuit pattern includes at least one selected from the group consisting of copper or copper alloy, cobalt, etc. and tin and tin alloy. After forming the circuit pattern, the photoresist used to form the circuit pattern is removed, and the copper seed layer used to form the circuit pattern of copper or copper alloy, cobalt, etc. is further removed as needed. Then, the portion of the seed layer formed by titanium and / or titanium alloy that is exposed with the removal of the photoresist and copper seed layer is quickly removed. At the same time, the dissolution of other metals used in wiring circuits formed by at least one selected from the group consisting of copper or copper alloy, cobalt, etc. and tin and tin alloy is suppressed. Thus, a wiring circuit connected to the copper or copper alloy, cobalt, etc. can be formed on an insulating layer that at least partially has wiring of copper or copper alloy, cobalt, etc. In one embodiment of the present invention, the wiring circuit is a circuit formed on an insulating layer having wiring of copper or copper alloy, cobalt, etc., at least partially on a printed circuit board or a semiconductor package mounting substrate. In another embodiment of the present invention, the wiring circuit is a circuit formed on an insulating layer having wiring of copper or copper alloy, cobalt, etc., at least partially on a semiconductor wafer or semiconductor element.

[0088] For example, the composition of the present invention can be well used in the following scenario: in the manufacturing process of a printed circuit board (e.g., a packaging substrate for mounting semiconductor components), a circuit pattern constituting a connection terminal portion or wiring circuit of the wiring of the copper or copper alloy, cobalt, etc. is formed on an insulating layer that at least partially has wiring of the copper or copper alloy, cobalt, etc., the circuit pattern comprising at least one selected from the group consisting of copper or copper alloy, cobalt, etc. and tin and tin alloy, after the circuit pattern is formed, the photoresist used to form the circuit pattern is removed, and the copper seed layer used to form the circuit pattern of the copper or copper alloy, cobalt, etc. is further removed as needed, and the portion of the seed layer formed of titanium and / or titanium alloy exposed with the removal of the photoresist and the copper seed layer is quickly removed, while suppressing the dissolution of other metals used in the wiring of the copper or copper alloy, cobalt, etc.

[0089] Furthermore, the composition of the present invention can be well used in the following scenarios: in the manufacturing process of a semiconductor wafer or semiconductor device, on an insulating layer having at least partially copper or copper alloy, cobalt, or the like wiring, a circuit pattern constituting the connection terminal portion or wiring circuit of the copper or copper alloy, cobalt, or the like wiring is formed, the circuit pattern comprising at least one selected from the group consisting of copper, tin, and tin alloys; after forming the circuit pattern, the photoresist used to form the circuit pattern is removed; after further removing the copper seed layer used to form the copper or copper alloy, cobalt, or the like circuit pattern as needed, the portion of the seed layer formed by titanium and / or titanium alloy exposed with the removal of the photoresist and the copper seed layer is quickly removed, while suppressing the dissolution of other metals used in the wiring of copper or copper alloy, cobalt, or the like.

[0090] Here, as a photoresist used in the manufacture of printed circuit boards, examples include compositions comprising, for instance, binder polymers, photopolymerizable monomers, photopolymerization initiators, and other additives.

[0091] As a binder polymer, examples include products obtained by copolymerizing various vinyl monomers such as methacrylates, acrylates, and styrene with at least one of methacrylic acid and acrylic acid as essential components.

[0092] As photopolymerizable monomers, at least one of methacrylates and acrylates is preferably listed.

[0093] Examples of photopolymerization initiators include at least one from the group consisting of benzophenone, 4,4'-diaminobenzophenone, 4,4'-bis(dimethylamino)benzophenone, 2-ethylanthraquinone, benzoin, benzoin methyl ether, 9-phenylacridine, benzoyldimethyl ketal, and benzoyldiethyl ketal. Alternatively, a bimolecular system consisting of hexaaryl biimidazole and a hydrogen donor (2-mercaptobenzoxazole, N-phenylglycine) can also be used.

[0094] Other additives include thermal polymerization initiators and dyes.

[0095] As photoresist for manufacturing semiconductor wafers or semiconductor devices, combinations of phenol-formaldehyde resin (collectively referred to as "phenolic varnish resin") and naphthoquinone diazide compounds as photosensitive components are preferred examples.

[0096] 2. Etching method

[0097] The etching method of the present invention is a method for etching titanium and / or titanium alloys, including using the composition of the present invention described above to bring the composition of the present invention into contact with the object described above. By using the etching method of the composition of the present invention, the seed layer formed by titanium and / or titanium alloys can be quickly removed, and the leaching of other metals such as wiring, copper or copper alloys, cobalt, etc., can be suppressed.

[0098] In the etching method of the present invention, the etching temperature using the composition of the present invention is not particularly limited, but is preferably 10–70°C, more preferably 20–65°C, further preferably 25–60°C, and particularly preferably 20–50°C. When the etching temperature is within the above range, there is a tendency to suppress changes in the composition of the composition of the present invention, maintain stable etching conditions, and achieve good removal of titanium and titanium alloys as the etching targets, thus resulting in excellent production efficiency for substrates such as printed circuit boards. Furthermore, within the above range, there is a tendency to suppress the dissolution of copper or copper alloys, cobalt, and other metals. Generally, the higher the etching temperature, the higher the etching rate of titanium and titanium alloys; the optimal temperature can be appropriately determined based on factors such as minimizing changes in the composition of the composition.

[0099] In the etching method of the present invention, the etching time using the composition of the present invention is not particularly limited, but is preferably 20 to 600 seconds, more preferably 30 to 300 seconds, and can be 30 to 240 seconds. The etching time can be appropriately determined by considering various conditions such as the surface condition of the titanium and / or titanium alloy to be etched, the concentration of the composition, and the etching temperature.

[0100] In the etching method of the present invention, there are no particular limitations on the method of contacting the composition of the present invention with the titanium and / or titanium alloy to be etched. For example, methods such as dripping (single-leaf spin coating) or spraying (spraying) can be used to contact the composition of the present invention with the titanium and / or titanium alloy to be etched, or methods such as immersing a substrate including the titanium and / or titanium alloy to be etched in the composition of the present invention can be used. In the present invention, any method can be used.

[0101] In the etching method of the present invention, in order to maintain a stable concentration of dissolved metal, a certain amount of liquid can be extracted from the composition bath of the present invention and the missing components can be replenished to achieve continuous and stable etching processing. In the etching method of the present invention, the concentration of metal in the composition of the present invention is preferably 0.5% by mass or less, more preferably 0.1% by mass or less. In the etching method of the present invention, when the metal concentration is within the above range, the amount of liquid extracted to maintain the metal concentration is not excessive, which is more economical; in addition, the etching speed is not too slow, and the production efficiency of the substrate can be maintained appropriately.

[0102] In the etching method of the present invention, in order to suppress the decomposition of hydrogen peroxide and make the etching effect continuous, a hydrogen peroxide stabilizer may be added or supplemented.

[0103] In one embodiment of the present invention, the etching rate of copper or copper alloys, cobalt, etc., at 30°C is preferably 100 nm / min or less. When the etching rate of copper or copper alloys, cobalt, etc., at 30°C is within the above range, the production efficiency of the substrate can be adequately maintained, and the dissolution of other metals such as wiring of copper or copper alloys, cobalt, etc., can be suppressed. In one embodiment of the present invention, the etching rate of copper or copper alloys, cobalt, etc., at 30°C is preferably 70 nm / min or less, more preferably 50 nm / min or less, and even more preferably 30 nm / min or less. The etching rate of copper or copper alloys, cobalt, etc., at 30°C can be measured using the method described in the examples.

[0104] In one embodiment of the present invention, the titanium etching rate at 30°C is preferably 100 nm / min or higher. When the titanium etching rate at 30°C is within the above range, layers formed of titanium and / or titanium alloys can be removed quickly. In one embodiment of the present invention, the titanium etching rate at 30°C is more preferably 150 nm / min or higher, and even more preferably 200 nm / min or higher. Furthermore, when the titanium etching rate at 30°C is 1000 nm / min or higher, the conveyor belt speed cannot keep up, therefore it is preferably less than 1000 nm / min. The titanium etching rate at 30°C can be measured using the method described in the examples.

[0105] In one embodiment of the present invention, the ratio of titanium etching rate to copper etching rate at 30°C is preferably 2 or more and 50 or less. When the ratio of titanium etching rate to copper etching rate at 30°C is within the above range, layers formed of titanium and / or titanium alloys can be removed quickly, and the dissolution of other metals such as copper or copper alloys and cobalt wiring can be suppressed. In one embodiment of the present invention, the ratio of titanium etching rate to copper etching rate at 30°C is more preferably 2.5 or more and 30 or less, and even more preferably 3 or more and 10 or less. The ratio of titanium etching rate to copper etching rate at 30°C can be measured using the method described in the examples.

[0106] 3. Circuit Formation Methods

[0107] The circuit formation method of the present invention is a method of forming a circuit of titanium and / or titanium alloy laminated with copper or copper alloy, cobalt, or other metals by etching titanium and / or titanium alloys. The etching method of titanium and / or titanium alloys includes using the composition of the present invention described above to bring the composition of the present invention into contact with the object. By using the composition of the present invention for etching, the seed layer formed by titanium and / or titanium alloys can be quickly removed, and the dissolution of other metals such as copper or copper alloys, cobalt, etc., wiring can be suppressed. Thus, on an insulating layer at least partially containing copper or copper alloys, cobalt, etc., wiring, a circuit pattern constituting the connection terminal portion or wiring circuit of the copper or copper alloys, etc., wiring, can be formed with good yield. The circuit pattern includes at least one selected from the group consisting of copper, tin, and tin alloys. The formed circuit pattern constitutes a circuit. The preferred method of forming the circuit of the present invention is a method of etching titanium and / or titanium alloys to at least form a circuit of titanium and / or titanium alloy laminated with copper or copper alloy.

[0108] 4. Substrate manufacturing method

[0109] The method for manufacturing the substrate of the present invention includes a step of etching titanium and / or titanium alloys by contacting the composition of the present invention with the object described above. By using the composition of the present invention for etching, the seed layer formed of titanium and / or titanium alloys can be quickly removed, and the dissolution of other metals such as wirings of copper or copper alloys, cobalt, etc., can be suppressed. Thus, a substrate can be manufactured in which a circuit pattern constituting the connection terminal portion of the wirings of copper or copper alloys, cobalt, etc., is formed with good yield on an insulating layer at least partially having wirings of copper or copper alloys, cobalt, etc., wherein the circuit pattern includes at least one selected from the group consisting of copper or copper alloys, cobalt, etc., and tin and tin alloys. In this specification, substrates include, but are not limited to, printed circuit boards, semiconductor device mounting packaging substrates, semiconductor wafers, and semiconductor devices.

[0110] The substrate obtained by the substrate manufacturing method of the present invention is preferably a substrate having at least a circuit having a titanium and / or titanium alloy laminated with copper or copper alloy.

[0111] The following is an example of a method for manufacturing a printed circuit board, which is an example of a method for manufacturing a substrate. Figure 1 A figure illustrating an example of a printed circuit board manufacturing method process provided in one embodiment of the present invention.

[0112] like Figure 1 As shown in (a), firstly, a resin substrate 1 is prepared as an insulating layer, on which copper wiring 10 is partially provided, the copper wiring 10 being embedded between interlayer insulating resins 12.

[0113] Next, as Figure 1As shown in (b), a titanium / titanium alloy layer 8 is formed on the surface of the resin substrate 1 as a barrier metal layer, and a copper layer 2 is formed on the surface of the titanium / titanium alloy layer 8. The copper layer 2 can be formed by chemically plating copper onto the surface of the titanium / titanium alloy layer 8, or by sputtering copper to form a film. In the method for manufacturing the printed circuit board of the present invention, it is preferable to form the copper layer 2 by sputtering copper to form a film. Although not shown, other layers can be further formed between the copper layer 2 and the titanium / titanium alloy layer 8 (barrier metal layer). Barrier metal layers such as titanium layers can be formed, for example, by sputtering.

[0114] Next, as Figure 1 As shown in (c), a dry film resist layer 3 is formed on the surface of copper layer 2, a circuit mask pattern (not shown) is applied on it, and then exposed and developed, as shown in (c). Figure 1 As shown in (d), a photoresist pattern formed by photoresist 3b is formed with an opening 3a, the opening 3a exposing a portion of the surface of the copper layer 2.

[0115] Next, as Figure 1 As shown in (e), copper plating is applied at the opening 3a of the resist pattern to form a copper layer (copper plating) 4. Alternatively, although not shown, tin plating or a tin alloy plating (e.g., tin-silver alloy plating) can be applied to the surface of the copper layer 4 to form a tin layer or tin alloy layer, thereby forming a circuit pattern comprising at least one of the groups selected from copper, tin, and tin alloys that constitutes the connection terminal portion of the copper wiring 10. Alternatively, although not shown, tin plating and tin alloy plating can be sequentially applied to the surface of the copper layer 4 to form a tin layer and a tin alloy layer, thereby forming a circuit pattern comprising copper, tin, and tin alloys that constitutes the connection terminal portion of the copper wiring 10. In this case, the order of tin plating and tin alloy plating is not particularly limited and can be determined appropriately.

[0116] After the circuit pattern is formed, the photoresist removal composition is brought into contact with photoresist 3b, such as... Figure 1 As shown in (f), photoresist 3b is removed.

[0117] Next, the copper etching composition is brought into contact with the exposed portion 2a of the exposed copper layer 2, such as... Figure 1 As shown in (g), the exposed portion 2a of the exposed copper layer 2 is removed.

[0118] Then, the titanium / titanium alloy layer 8 (barrier metal layer) exposed due to the removal of exposed portion 2a can be removed using the composition of the present invention, such as Figure 1 As shown in (h), a connection terminal portion of copper wiring 10 is formed on the resin substrate 1.

[0119] As described above, a printed circuit board can be manufactured having copper wiring and a circuit pattern comprising connection terminals of the copper wiring, wherein the circuit pattern comprises at least one selected from the group consisting of copper, tin, and tin alloys. The connection terminals can be used when mounting semiconductor components on the resulting printed circuit board (a packaging substrate for mounting semiconductor components).

[0120] The same applies when the substrate is a semiconductor wafer. In one example of the printed circuit board manufacturing method process described above, by replacing the interlayer insulating resin 12 with a silicon insulating layer 12 and the resin substrate 1 with a silicon substrate 1, a semiconductor wafer with copper wiring 10 connection terminals formed on the silicon substrate 1 can be manufactured. Then, the semiconductor wafer can be cut to a specified size for use as a semiconductor device.

[0121] In this way, a semiconductor device can be manufactured having a circuit pattern comprising copper wiring and a connection terminal portion constituting the copper wiring, wherein the circuit pattern comprises at least one selected from the group consisting of copper, tin, and tin alloys. The connection terminal portion can be used when the obtained semiconductor device is mounted on a printed circuit board (a packaging substrate for mounting semiconductor devices).

[0122] Example

[0123] The present invention will be specifically described below through embodiments, but the implementation method can be appropriately changed as long as the effects of the present invention can be obtained.

[0124] <Substrate Fabrication>

[0125] A titanium film with a thickness of 500 nm was formed on a glass substrate with a thickness of 1 mm by sputtering, and a titanium film sample was obtained for measuring the etching rate.

[0126] A copper film with a thickness of 20 μm was formed on both sides of a copper-clad laminate (manufactured by Mitsubishi Gas Chemical Co., Ltd. HL-832HS) with 12 μm copper foil on both sides by electrolytic copper plating, and a copper film sample for measuring the etching rate was obtained.

[0127] <Preparation of the drug solution>

[0128] In a 100 mL resin beaker, add components (A), (B), (C), (D), and any other components as needed, as described in Table 1, and stir to prepare a homogeneous aqueous composition.

[0129] <Determination of Etching Rate>

[0130] The substrate sample was immersed in the aqueous composition at 30°C and etched by stirring (300 rpm) to bring the substrate sample into contact with the aqueous composition. For the determination of the etching rate, the copper etching rate was first measured, and then the titanium etching rate was measured using the same aqueous composition used in the copper etching rate determination.

[0131] The copper etching rate was determined as follows: the mass of the copper film samples before and after treatment was measured, and the difference in mass and the density of copper (8.92 g / cm³) were used to determine the etching rate. 3 The thickness etched away is calculated by taking the copper film area of ​​the copper film sample and the amount of etching per minute (copper etching rate).

[0132] The titanium etching rate was determined as follows: the titanium film sample was brought into contact with an aqueous composition, and the time required for the titanium on the glass substrate to disappear as can be visually confirmed was recorded. For the etched glass substrate, the time required for further confirmation of the absence of titanium using SEM-EDX (Hitachi High Technology Co., Ltd. S-3700 / Oxford Company INCA x-act) was visually confirmed, and the etching amount per minute (titanium etching rate) was calculated.

[0133] <Determination of Copper Deposits on Titanium>

[0134] After determining the copper etching rate, the titanium etching rate was then measured. When measuring the titanium etching rate, the titanium surface was first visually inspected, with the color turning brown as an indicator to confirm the presence of copper precipitation. Subsequently, SEM-EDX (Hitachi High-Tech S-3700 / Oxford INCA x-act) was used to further confirm the presence of copper precipitation. If copper precipitation was confirmed during the titanium etching rate measurement, the titanium etching rate was measured using a separately prepared etching solution without performing the copper etching rate measurement.

[0135] <pH Measurement>

[0136] The pH values ​​of the compositions in the examples and comparative examples were measured at 25°C using a pH meter (pH meter F-52 manufactured by Horiba Corporation). The pH values ​​were measured before the etching rate was measured.

[0137] The results are shown in Table 1.

[0138] [Table 1]

[0139]

[0140] ※As a source of halide ions (C), chloride ions (Cl) - The source uses sodium chloride, bromide ions (Br) - Potassium bromide was used as the source for iodide ions (I₂). -The source is potassium iodide.

[0141] ※PDTP: 1,2-Propyldiaminetetra(methylenephosphonic acid)

[0142] DTPP: Diethylenetriaminepenta (methylenephosphonic acid)

[0143] HEDP: 1-Hydroxyethane-1,1-Diphosphonic acid

[0144] EDTMP: Ethylenediaminetetra(methylenephosphonic acid)

[0145] ※In the table, H2O2 represents hydrogen peroxide and NH4HF2 represents acidic ammonium fluoride.

[0146] [Table 2]

[0147]

[0148] ※As a source of halide ions (C), chloride ions (Cl) - The source uses sodium chloride.

[0149] ※PDTP: 1,2-Propyldiaminetetra(methylenephosphonic acid)

[0150] ※In the table, H2O2 represents hydrogen peroxide and NH4HF2 represents acidic ammonium fluoride.

[0151] As shown above, by using the composition of the present invention for etching, the seed layer formed of titanium and / or titanium alloy can be quickly removed, and the leaching of other metals such as copper or copper alloys, cobalt and other wiring can be suppressed.

[0152] Explanation of symbols

[0153] 1: Resin substrate or silicon substrate

[0154] 2: Copper layer

[0155] 2a: Exposed area

[0156] 3: Dry film resist

[0157] 3a: Opening

[0158] 3b: Photoresist

[0159] 4: Copper layer (copper plating)

[0160] 8: Titanium / Titanium Alloy Layer (Barrier Metal Layer)

[0161] 10: Copper wiring

[0162] 12: Interlayer insulating resin or silicon insulating layer

Claims

1. A composition which is a composition for etching titanium and / or a titanium alloy, the composition comprising hydrogen peroxide (A), a fluoride (B), a halide ion other than a fluoride ion (C), and water (D), wherein, the content of the hydrogen peroxide (A) is 0.01 to 0.23 mass% based on the total amount of the composition; the content of the fluoride (B) is 0.2 to 3 mass% based on the total amount of the composition; the content of the halide ion other than a fluoride ion (C) is 0.0005 to 0.025 mass% based on the total amount of the composition, the pH of the composition is 3.5 to 6.

2. The composition of claim 1, wherein, the fluoride (B) comprises one or more selected from the group consisting of hydrogen fluoride, an acidic ammonium fluoride, an acidic sodium fluoride, and an acidic potassium fluoride.

3. The composition according to claim 1 or 2, wherein, the halide ion (C) comprises at least any one of a chloride ion and a bromide ion.

4. The composition according to claim 1 or 2, further comprising a phosphonic acid-based chelating agent (E).

5. The composition of claim 4, wherein, the phosphonic acid-based chelating agent (E) comprises at least any one of 1,2- propylenediaminetetrakis(methylene phosphonic acid) and diethylenetriaminepenta(methylene phosphonic acid).

6. The composition of claim 4, wherein, the content of the phosphonic acid-based chelating agent (E) is 0.005 to 0.1 mass% based on the total amount of the composition.

7. The composition of claim 1 or 2, wherein, the composition is a composition for inhibiting etching of copper or a copper alloy and etching of titanium and / or a titanium alloy.

8. The composition of claim 1 or 2, wherein, the copper etching rate at 30°C is 100 nm / min or less.

9. The composition of claim 1 or 2, wherein, the ratio of the titanium etching rate / copper etching rate at 30°C is 2 or more.

10. An etching method for etching titanium and / or a titanium alloy using the composition according to any one of claims 1 to 9.

11. A method for forming a circuit by etching titanium and / or a titanium alloy using the composition according to any one of claims 1 to 9 to form a circuit in which titanium and / or a titanium alloy is laminated with copper or a copper alloy.

12. A method for manufacturing a substrate, comprising a step of etching titanium and / or a titanium alloy using the composition according to any one of claims 1 to 9.

Images