Semiconductor substrate cleaning composition and cleaning method

Abstract

This composition for a semiconductor substrate cleaning composition contains hydrogen peroxide (A), a hydrogen peroxide stabilizer (B), an alkaline compound (C), and water, wherein the hydrogen peroxide stabilizer (B) is at least one item selected from the group consisting of oxalic acid, diethylenetriamine pentaacetic acid, hydroxyethyliminodiacetic acid, potassium oxalate, 5-phenyl-1H-tetrazole, triethylenetetramine hexaacetic acid, trans-1,2-cyclohexanediaminetetraacetic acid, 8-quinolinol, L(+)-isoleucine, DL-valine, L(-)-proline, hydroxyethylethylenediamine triacetic acid, N,N-di(2-hydroxyethyl) glycine, glycine, L-tryptophan, 2,6-pyridinedicarboxylic acid, benzothiazole and DL-alanine; and the alkaline compound (C) is at least one item selected from the group consisting of quaternary ammonium hydroxide (C1) and potassium hydroxide (C2).

Description

[Technical Field]

[0001] The present invention relates to a composition for cleaning semiconductor substrates and a cleaning method. [Background technology]

[0002] In the manufacture of semiconductor substrates with highly integrated semiconductor elements, a typical process involves forming a conductive thin film, such as a metal film serving as a conductive wiring material, an interlayer insulating film for insulating between the conductive thin films, a hard mask, and the like, on a substrate such as a silicon wafer. Then, a photoresist is uniformly applied to the surface to form a photosensitive layer, which is then selectively exposed to light and developed to form a desired photoresist pattern. Next, using this photoresist pattern as a mask, the substrate on which the interlayer insulating film, hard mask, and the like are layered is subjected to a dry etching process to form a desired pattern on the substrate. A series of steps is then generally performed, in which the photoresist pattern and residues generated by the dry etching process (hereinafter referred to as "dry etching residues") are removed by ashing with oxygen plasma, cleaning solutions, or the like.

[0003] In recent years, the current density of metal wiring has increased due to the advancement of miniaturization of design rules. Therefore, there is a strong demand for countermeasures against electromigration, a phenomenon in which atoms constituting metal wiring migrate when a current flows through the metal wiring material, causing holes in the metal wiring. Countermeasures include forming a layer of cobalt or a cobalt alloy as a cap metal around the copper wiring, and using cobalt or a cobalt alloy as the metal wiring material. Therefore, in the formation of semiconductor devices on substrates such as silicon wafers, methods have been proposed for removing hard masks in the presence of copper or copper alloys, and cobalt or a cobalt alloy.

[0004] For example, Patent Document 1 discloses a cleaning liquid composition that contains specific amounts of hydrogen peroxide, potassium hydroxide, aminopolymethylenephosphonic acid, and a zinc salt, as well as water, as a cleaning liquid composition that removes a titanium nitride hard mask while suppressing damage to copper or a copper alloy, or cobalt or a cobalt alloy.

[0005] Patent Documents 2 to 18 also disclose etching agents, cleaning agents, and stripping agents for semiconductor substrates, which contain an oxidizing agent mainly composed of hydrogen peroxide. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2017-076783 [Patent Document 2] Japanese Patent Publication No. 2020-017732 [Patent Document 3] Japanese Patent Application Publication No. 2018-093225 [Patent Document 4] Japanese Patent Application Laid-Open No. 2017-031502 [Patent Document 5] Japanese Patent Application Publication No. 2018-093225 [Patent Document 6] Japanese Patent Application Laid-Open No. 2015-156171 [Patent Document 7] Japanese Patent Application Laid-Open No. 2016-176126 [Patent Document 8] Special Publication No. 2015-506583 [Patent Document 9] Japanese Patent Application Laid-Open No. 2013-199702 [Patent Document 10] Japanese Patent Application Laid-Open No. 2011-228517 [Patent Document 11] Special Publication No. 2009-512194 [Patent Document 12] Special Publication No. 2009-505388 [Patent Document 13] Japanese Patent Application Laid-Open No. 2009-041112 [Patent Document 14] Japanese Patent Application Laid-Open No. 2009-120870 [Patent Document 15] Japanese Patent Application Laid-Open No. 2008-285508 [Patent Document 16] Japanese Patent Application Laid-Open No. 2004-317584 [Patent Document 17] Japanese Patent Application Laid-Open No. 2004-212818 [Patent Document 18] Japanese Patent Application Laid-Open No. 2005-201100 Summary of the Invention [Problem to be solved by the invention]

[0007] For example, the cleaning agents of prior art, such as those disclosed in Patent Document 1, are intended to prevent damage to copper or copper alloys, or cobalt or cobalt alloys, when cleaning semiconductor substrates. However, in the process of cleaning semiconductor substrates containing multiple metals, such as copper or copper alloys, cobalt or cobalt alloys, the hydrogen peroxide in the cleaning solution is easily decomposed, which creates problems such as the inability to clean for long periods of time or the inability to reuse the cleaning solution. Therefore, there has been a demand for a semiconductor substrate cleaning composition that has high stability of hydrogen peroxide even in the presence of multiple metals such as copper and cobalt, and that allows for long-term cleaning and repeated use of the cleaning solution.

[0008] The problem to be solved by the present invention is to provide a semiconductor substrate cleaning composition which has high stability of hydrogen peroxide even in the coexistence of multiple metals including cobalt, and which allows for long-term cleaning and repeated use of the cleaning solution. In particular, the first problem to be solved by the present invention is to provide a semiconductor substrate cleaning composition in which hydrogen peroxide is highly stable even in the presence of copper and cobalt, and which allows for long-term cleaning and repeated use of the cleaning solution. A second problem to be solved by the present invention is to provide a semiconductor substrate cleaning composition which contains hydrogen peroxide in a highly stable state even in the presence of cobalt and at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum, and which allows for long-term cleaning and repeated use of the cleaning solution. [Means for solving the problem]

[0009] The present invention provides the following composition for cleaning semiconductor substrates. <1> A semiconductor substrate cleaning composition containing hydrogen peroxide (A), a hydrogen peroxide stabilizer (B), an alkaline compound (C), and water, wherein the hydrogen peroxide stabilizer (B) is at least one selected from the group consisting of oxalic acid, diethylenetriaminepentaacetic acid, hydroxyethyliminodiacetic acid, potassium oxalate, 5-phenyl-1H-tetrazole, triethylenetetraminehexaacetic acid, trans-1,2-cyclohexanediaminetetraacetic acid, 8-quinolinol, L(+)-isoleucine, DL-valine, L(-)-proline, hydroxyethylethylenediaminetriacetic acid, N,N-di(2-hydroxyethyl)glycine, glycine, L-tryptophan, 2,6-pyridinedicarboxylic acid, benzothiazole, and DL-alanine, and the alkaline compound (C) is at least one selected from the group consisting of quaternary ammonium hydroxides (C1) and potassium hydroxide (C2). <2> The content of the hydrogen peroxide stabilizer (B) in the semiconductor substrate cleaning composition is 0.0001 to 5 mass %. <1> The semiconductor substrate cleaning composition according to claim 1. <3> The content of hydrogen peroxide (A) in the semiconductor substrate cleaning composition is 10 to 30 mass %. <1> or <2> The semiconductor substrate cleaning composition according to claim 1. <4> The pH is 7 to 12. <1> ~ <3> 10. The semiconductor substrate cleaning composition according to claim 9, wherein the cleaning agent is a fluororesin. <5> The above-mentioned composition further contains an aminopolymethylenephosphonic acid (D). <1> ~ <4> 10. The semiconductor substrate cleaning composition according to claim 9, wherein the cleaning agent is a fluororesin. <6> The content of the aminopolymethylenephosphonic acid (D) in the semiconductor substrate cleaning composition is 0.00005 to 0.005% by mass. <5> The semiconductor substrate cleaning composition according to claim 1. <7> The content of the quaternary ammonium hydroxide (C1) in the semiconductor substrate cleaning composition is 0.005 to 10 mass %. <1> ~ <6> 10. The semiconductor substrate cleaning composition according to claim 9, wherein the cleaning agent is a fluororesin. <8> The content of potassium hydroxide (C2) in the semiconductor substrate cleaning composition is 0.005 to 5 mass %. <1> ~ <7> 10. The semiconductor substrate cleaning composition according to claim 9, wherein the cleaning agent is a fluororesin. <9> The quaternary ammonium hydroxide (C1) is at least one selected from the group consisting of tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, and benzyltrimethylammonium hydroxide. <1> ~ <8> 10. The semiconductor substrate cleaning composition according to claim 9, wherein the cleaning agent is a fluororesin. <10> The aminopolymethylenephosphonic acid (D) is at least one selected from the group consisting of aminotri(methylenephosphonic acid), ethylenediaminetetra(methylenephosphonic acid), diethylenetriaminepenta(methylenephosphonic acid), and 1,2-propylenediaminetetra(methylenephosphonic acid). <5> ~ <9> 10. The semiconductor substrate cleaning composition according to claim 9, wherein the cleaning agent is a fluororesin. <11> The hydrogen peroxide stabilizer (B) is at least one selected from the group consisting of oxalic acid, diethylenetriaminepentaacetic acid, hydroxyethyliminodiacetic acid, potassium oxalate, triethylenetetraminehexaacetic acid, trans-1,2-cyclohexanediaminetetraacetic acid, 8-quinolinol, hydroxyethylethylenediaminetriacetic acid, 5-phenyl-1H-tetrazole, N,N-di(2-hydroxyethyl)glycine, and benzothiazole. <1> ~ <10> 10. The semiconductor substrate cleaning composition according to claim 9, wherein the cleaning agent is a fluororesin. <12> Ammonia and ammonium ions (NH4 + ) is substantially free of any of the above <1> ~ <11> 10. The semiconductor substrate cleaning composition according to claim 9, wherein the cleaning agent is a fluororesin. <13> The method is for cleaning a semiconductor substrate having a hard mask containing at least one selected from the group consisting of titanium and titanium nitride. <1> ~ <12> 10. The semiconductor substrate cleaning composition according to claim 9, wherein the cleaning agent is a fluororesin. <14> The above is for cleaning semiconductor substrates containing cobalt and copper. <1> ~ <13> 10. The semiconductor substrate cleaning composition according to claim 9, wherein the cleaning agent is a fluororesin. <15> the residual rate of hydrogen peroxide (A) after adding 400 ppb by mass of cobalt ions and 1000 ppb by mass of copper ions to the total amount of the semiconductor substrate cleaning composition and treating at 50°C for 6 hours is 50% or more based on the hydrogen peroxide content before the treatment; <1> ~ <14> 10. The semiconductor substrate cleaning composition according to claim 9, wherein the cleaning agent is a fluororesin. <16> The cleaning agent is for cleaning a semiconductor substrate containing at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum, and cobalt. <1> ~ <13> 10. The semiconductor substrate cleaning composition according to claim 9, wherein the cleaning agent is a fluororesin. <17> The at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum is at least one metal selected from the group consisting of titanium, zirconium, hafnium, tantalum, tungsten, manganese, ruthenium, magnesium, and aluminum. <16> The semiconductor substrate cleaning composition according to claim 1. <18> In the presence of cobalt ions and copper ions, <1> ~ <15> A cleaning method comprising cleaning a semiconductor substrate using the semiconductor substrate cleaning composition according to any one of the above items. <19> The aforementioned <1> ~ <15> 10. A cleaning method for cleaning a semiconductor substrate containing cobalt and copper, using the semiconductor substrate cleaning composition according to any one of the above items. <20> In the presence of ions of at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum, and cobalt ions, <1> ~ <13> , the above <16> and <17> A cleaning method comprising cleaning a semiconductor substrate using the semiconductor substrate cleaning composition according to any one of the above items. <21> The aforementioned <1> ~ <13> , the above <16> and <17> 1. A cleaning method for cleaning a semiconductor substrate containing at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum, and cobalt, using the semiconductor substrate cleaning composition according to any one of the above items. <22> cleaning a semiconductor substrate having a hard mask containing at least one selected from the group consisting of titanium and titanium nitride; <18> ~ <21> 10. The cleaning method according to claim 9, wherein the cleaning agent is a fluorine-containing compound. <23> The aforementioned <1> ~ <17> 1. A cleaning method for removing at least one selected from the group consisting of dry etching residues and hard masks in a semiconductor substrate, using the semiconductor substrate cleaning composition according to any one of 1 to 5. <24> A method for stabilizing hydrogen peroxide, comprising stabilizing hydrogen peroxide (A) in a liquid containing hydrogen peroxide (A), cobalt ions, copper ions, and water with a hydrogen peroxide stabilizer (B) selected from the group consisting of oxalic acid, diethylenetriaminepentaacetic acid, hydroxyethyliminodiacetic acid, potassium oxalate, 5-phenyl-1H-tetrazole, triethylenetetraminehexaacetic acid, trans-1,2-cyclohexanediaminetetraacetic acid, 8-quinolinol, L(+)-isoleucine, DL-valine, L(-)-proline, hydroxyethylethylenediaminetriacetic acid, N,N-di(2-hydroxyethyl)glycine, glycine, L-tryptophan, 2,6-pyridinedicarboxylic acid, benzothiazole, and DL-alanine. <25> The pH of the liquid containing hydrogen peroxide (A), cobalt ions, copper ions and water is 7 to 12. <24> 1. A method for stabilizing hydrogen peroxide according to claim 1. <26> A method for stabilizing hydrogen peroxide, comprising: stabilizing hydrogen peroxide (A) in a liquid containing hydrogen peroxide (A), ions of at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum, cobalt ions, and water, with hydrogen peroxide stabilizer (B) selected from the group consisting of oxalic acid, diethylenetriaminepentaacetic acid, hydroxyethyliminodiacetic acid, potassium oxalate, 5-phenyl-1H-tetrazole, triethylenetetraminehexaacetic acid, trans-1,2-cyclohexanediaminetetraacetic acid, 8-quinolinol, L(+)-isoleucine, DL-valine, L(-)-proline, hydroxyethylethylenediaminetriacetic acid, N,N-di(2-hydroxyethyl)glycine, glycine, L-tryptophan, 2,6-pyridinedicarboxylic acid, benzothiazole, and DL-alanine. <27> The pH of the liquid containing hydrogen peroxide (A), ions of at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum, cobalt ions, and water is 7 to 12. <26> 1. A method for stabilizing hydrogen peroxide according to claim 1. <28> The aforementioned <1> ~ <17> 1. A method for producing a semiconductor substrate, comprising a step of removing at least one selected from the group consisting of dry etching residues and hard masks in a semiconductor substrate by using the semiconductor substrate cleaning composition according to any one of the above items. [Effects of the Invention]

[0010] The semiconductor substrate cleaning composition of the present invention has high stability of hydrogen peroxide even in the presence of multiple metals including cobalt, allowing for long-term cleaning and repeated use of the cleaning solution. In particular, the semiconductor substrate cleaning composition of the present invention has high stability of hydrogen peroxide even in the presence of copper and cobalt, allowing for long-term cleaning and repeated use of the cleaning solution. Furthermore, in the semiconductor substrate cleaning composition of the present invention, the stability of hydrogen peroxide is high even in the presence of at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum, and cobalt, allowing for long-term cleaning and repeated use of the cleaning solution. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention relates to a composition for cleaning semiconductor substrates, which contains hydrogen peroxide (A), a hydrogen peroxide stabilizer (B), an alkaline compound (C), and water, wherein the hydrogen peroxide stabilizer (B) is selected from the group consisting of oxalic acid, diethylenetriaminepentaacetic acid, hydroxyethyliminodiacetic acid, potassium oxalate, 5-phenyl-1H-tetrazole, triethylenetetraminehexaacetic acid, trans-1,2-cyclohexanediaminetetraacetic acid, 8-quinolinol, L(+)-isoleucine, DL-valine, L(-)-proline, hydroxyethylethylenediaminetriacetic acid, N,N-di(2-hydrogen methyl acrylate), N,N-di(2-hydroxyethyl ... and the alkaline compound (C) is at least one selected from the group consisting of quaternary ammonium hydroxides (C1) and potassium hydroxide (C2); a cleaning method using the semiconductor substrate cleaning composition; and a method for producing a semiconductor substrate. The present invention also provides a method for stabilizing hydrogen peroxide (A) by using the hydrogen peroxide stabilizer (B).

[0012] [Semiconductor substrate cleaning composition] The semiconductor substrate cleaning composition of the present invention contains hydrogen peroxide (A), a hydrogen peroxide stabilizer (B), an alkaline compound (C), and water, wherein the hydrogen peroxide stabilizer (B) is at least one selected from the group consisting of oxalic acid, diethylenetriaminepentaacetic acid, hydroxyethyliminodiacetic acid, potassium oxalate, 5-phenyl-1H-tetrazole, triethylenetetraminehexaacetic acid, trans-1,2-cyclohexanediaminetetraacetic acid, 8-quinolinol, L(+)-isoleucine, DL-valine, L(-)-proline, hydroxyethylethylenediaminetriacetic acid, N,N-di(2-hydroxyethyl)glycine, glycine, L-tryptophan, 2,6-pyridinedicarboxylic acid, benzothiazole, and DL-alanine, and the alkaline compound (C) is at least one selected from the group consisting of quaternary ammonium hydroxides (C1) and potassium hydroxide (C2).

[0013] <Hydrogen peroxide (A)> The semiconductor substrate cleaning composition of the present invention contains hydrogen peroxide (A). Hydrogen peroxide (A) is usually mixed with other components as an aqueous solution of an appropriate concentration. The concentration of hydrogen peroxide (A) in the aqueous hydrogen peroxide solution used to produce the semiconductor substrate cleaning composition of the present invention is not particularly limited, but is preferably, for example, 10 to 90 mass %, and more preferably 30 to 60 mass % in accordance with industrial standards. The hydrogen peroxide (A) may contain a stabilizer used during its production. There is no limitation on the method for producing the hydrogen peroxide (A), and for example, hydrogen peroxide produced by the anthraquinone method is preferably used. The hydrogen peroxide (A) may also be purified by a method such as passing it through an ion exchange resin. From the viewpoint of cleaning properties, the content of hydrogen peroxide (A) in the composition for cleaning semiconductor substrates is preferably 10 to 30 mass %, more preferably 10 to 20 mass %.

[0014] <Hydrogen peroxide stabilizer (B)> The semiconductor substrate cleaning composition of the present invention contains a hydrogen peroxide stabilizer (B), which is at least one selected from the group consisting of oxalic acid, diethylenetriaminepentaacetic acid, hydroxyethyliminodiacetic acid, potassium oxalate, 5-phenyl-1H-tetrazole, triethylenetetraminehexaacetic acid, trans-1,2-cyclohexanediaminetetraacetic acid, 8-quinolinol, L(+)-isoleucine, DL-valine, L(-)-proline, hydroxyethylethylenediaminetriacetic acid, N,N-di(2-hydroxyethyl)glycine, glycine, L-tryptophan, 2,6-pyridinedicarboxylic acid, benzothiazole, and DL-alanine. The semiconductor substrate cleaning composition of the present invention contains the hydrogen peroxide stabilizer (B), which provides high hydrogen peroxide stability even in the presence of multiple metals including cobalt, allowing for long-term cleaning and repeated use. The semiconductor substrate cleaning composition of the present invention contains the hydrogen peroxide stabilizer (B), which provides high hydrogen peroxide stability, particularly in the presence of copper and cobalt, allowing for long-term cleaning and repeated use. Furthermore, the semiconductor substrate cleaning composition of the present invention contains the hydrogen peroxide stabilizer (B), which provides high hydrogen peroxide stability even in the presence of cobalt and at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum, allowing for long-term cleaning and repeated use.

[0015] As a result of investigations by the present inventors, it was found that when cleaning semiconductor substrates using a semiconductor substrate cleaning composition, decomposition of hydrogen peroxide is particularly likely to occur when multiple metals including cobalt are present, particularly when both copper and cobalt are present, i.e., when copper and cobalt coexist. Specifically, the prior art patent documents 2 to 18 describe stabilizers for hydrogen peroxide against metal ions such as copper ions or cobalt ions, but these are not capable of suppressing the decomposition of hydrogen peroxide when copper ions and cobalt ions coexist. Meanwhile, as a result of extensive research, the present inventors have discovered a semiconductor substrate cleaning composition that exhibits high hydrogen peroxide stability even in the presence of both copper ions and cobalt ions, as described above.Furthermore, as described above, the present inventors have discovered a semiconductor substrate cleaning composition that exhibits high hydrogen peroxide stability even in the presence of both cobalt ions and ions of at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum. The reason why the semiconductor substrate cleaning composition of the present invention enhances hydrogen peroxide stability, particularly in the presence of copper and cobalt, as described above, is unclear. However, the compounds exemplified herein are thought to exhibit strong chelating ability with either copper ions or cobalt ions, or both, even in the presence of two metals and in alkaline solutions, due to their structure, particularly the balance of amino and carboxyl groups. Furthermore, while copper and cobalt ions have a certain degree of hydrogen peroxide decomposition ability even when used alone, the simultaneous presence of copper and cobalt ions, as described above, has been problematic in that the decomposition rate increases. This mechanism is thought to involve not only the catalytic effect of copper and cobalt ions, but also the hydroxyl radicals generated by the Fenton-like reaction caused by the presence of copper ions. The hydrogen peroxide stabilizer (B) of the present invention is thought to further enhance hydrogen peroxide stability by possessing the ability to capture hydroxyl radicals in addition to its chelating ability.

[0016] The hydrogen peroxide stabilizer (B) is at least one selected from the group consisting of oxalic acid, diethylenetriaminepentaacetic acid, hydroxyethyliminodiacetic acid, potassium oxalate, 5-phenyl-1H-tetrazole, triethylenetetraminehexaacetic acid, trans-1,2-cyclohexanediaminetetraacetic acid, 8-quinolinol, L(+)-isoleucine, DL-valine, L(-)-proline, hydroxyethylethylenediaminetriacetic acid, N,N-di(2-hydroxyethyl)glycine, glycine, L-tryptophan, 2,6-pyridinedicarboxylic acid, benzothiazole, and DL-alanine.

[0017] Among the hydrogen peroxide stabilizers (B), from the viewpoint of inhibiting corrosion of metals constituting the semiconductor substrate, at least one selected from the group consisting of oxalic acid, diethylenetriaminepentaacetic acid, hydroxyethyliminodiacetic acid, potassium oxalate, triethylenetetraminehexaacetic acid, trans-1,2-cyclohexanediaminetetraacetic acid, 8-quinolinol, hydroxyethylethylenediaminetriacetic acid, 5-phenyl-1H-tetrazole, N,N-di(2-hydroxyethyl)glycine, and benzothiazole is preferred. From the viewpoint of further improving the stability of hydrogen peroxide while inhibiting metal corrosion, at least one selected from the group consisting of diethylenetriaminepentaacetic acid, hydroxyethyliminodiacetic acid, triethylenetetraminehexaacetic acid, 8-quinolinol, hydroxyethylethylenediaminetriacetic acid, and trans-1,2-cyclohexanediaminetetraacetic acid is more preferred, with trans-1,2-cyclohexanediaminetetraacetic acid being even more preferred. Semiconductor substrates contain metal parts such as metal wiring, and the hydrogen peroxide stabilizer (B) shown here has the unique property of capturing metal ions in solution without contributing to the ionization of the metal, and is thought to stabilize hydrogen peroxide and improve cleaning performance without corroding metal wiring, etc. It is also thought to have the ability to capture hydroxyl radicals.

[0018] Examples of hydrogen peroxide stabilizers (B) include the compounds listed above, but hydrates, salts, and derivatives that form these compounds in cleaning compositions can also be used. For example, trans-1,2-cyclohexanediaminetetraacetic acid is preferably used as a monohydrate in view of availability and ease of formulation.

[0019] The content of the hydrogen peroxide stabilizer (B) in the composition for cleaning semiconductor substrates is preferably 0.0001 to 5 mass %, more preferably 0.001 to 1 mass %. Examples of using specific compounds are given below. For example, the content of trans-1,2-cyclohexanediaminetetraacetic acid, as trans-1,2-cyclohexanediaminetetraacetic acid monohydrate, in the semiconductor substrate cleaning composition is preferably 0.0001 to 5 mass%, more preferably 0.001 to 1 mass%, even more preferably 0.001 to 0.5 mass%, still more preferably 0.002 to 0.3 mass%, even more preferably 0.003 to 0.2 mass%, and in consideration of the balance between cost and effect, it is even more preferably 0.003 to 0.1 mass%, even more preferably 0.005 to 0.05 mass%, even more preferably 0.005 to 0.01 mass%. The content of diethylenetriaminepentaacetic acid in the semiconductor substrate cleaning composition is preferably 0.0001 to 5% by mass, more preferably 0.001 to 1% by mass, even more preferably 0.01 to 1% by mass, even more preferably 0.02 to 0.8% by mass, and even more preferably 0.02 to 0.1% by mass. The content of hydroxyethyliminodiacetic acid in the semiconductor substrate cleaning composition is preferably 0.001 to 5% by mass, more preferably 0.01 to 3% by mass, even more preferably 0.05 to 1% by mass, and even more preferably 0.05 to 0.5% by mass. The content of triethylenetetraminehexaacetic acid in the semiconductor substrate cleaning composition is preferably 0.0001 to 5% by mass, more preferably 0.001 to 1% by mass, even more preferably 0.005 to 0.5% by mass, and even more preferably 0.01 to 0.1% by mass. The content of 8-quinolinol in the semiconductor substrate cleaning composition is preferably 0.0001 to 5 mass%, more preferably 0.0005 to 1 mass%, even more preferably 0.001 to 0.1 mass%, and even more preferably 0.001 to 0.01 mass%. The content of hydroxyethylethylenediaminetriacetic acid in the semiconductor substrate cleaning composition is preferably 0.001 to 5 mass%, more preferably 0.01 to 3 mass%, even more preferably 0.05 to 1 mass%, and even more preferably 0.05 to 0.5 mass%.

[0020] By setting the content of the hydrogen peroxide stabilizer (B) within the above range, the semiconductor substrate cleaning composition of the present invention exhibits high hydrogen peroxide stability in the presence of multiple metals including cobalt, particularly in the presence of copper and cobalt, allowing for long-term cleaning and repeated use. It also becomes possible to inhibit corrosion of metals constituting semiconductor substrates. Furthermore, the semiconductor substrate cleaning composition of the present invention exhibits high hydrogen peroxide stability even in the presence of cobalt and at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum, allowing for long-term cleaning and repeated use.

[0021] <Alkaline Compounds (C)> The composition for cleaning semiconductor substrates of the present invention contains an alkaline compound (C). The alkaline compound (C) is at least one selected from the group consisting of quaternary ammonium hydroxide (C1) and potassium hydroxide (C2). The alkaline compound (C) effectively removes hard masks and dry etching residues, and can suppress damage to low-k interlayer insulating films and metal wiring. The quaternary ammonium hydroxide (C1) and potassium hydroxide (C2) can be used alone or in combination of two or more. In particular, it is preferable that the alkali compound (C) contains both a quaternary ammonium hydroxide (C1) and potassium hydroxide (C2).

[0022] The quaternary ammonium hydroxide (C1) is not particularly limited, but is preferably at least one selected from the group consisting of tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, and benzyltrimethylammonium hydroxide. From the viewpoints of economy and ease of raw material availability, it is more preferably at least one selected from the group consisting of tetramethylammonium hydroxide, tetrapropylammonium hydroxide, and benzyltrimethylammonium hydroxide, and tetramethylammonium hydroxide is even more preferred. The content of the quaternary ammonium hydroxide (C1) in the composition for cleaning semiconductor substrates is preferably 0.005 to 10 mass %, more preferably 0.05 to 5 mass %, and even more preferably 0.1 to 3 mass %. The content of potassium hydroxide (C2) in the composition for cleaning semiconductor substrates is preferably 0.005 to 5 mass %, more preferably 0.01 to 5 mass %, and even more preferably 0.1 to 1 mass %. When the content of the alkali compound (C) is within the above range, the etching rate of titanium and titanium nitride in particular becomes good, which is preferable.

[0023] <Aminopolymethylenephosphonic acid (D)> The composition for cleaning semiconductor substrates of the present invention may contain an aminopolymethylene phosphonic acid (D). The inclusion of aminopolymethylenephosphonic acid (D) is preferred because it improves the stability of hydrogen peroxide by forming a chelate in the presence of copper ions.

[0024] The aminopolymethylene phosphonic acid (D) is preferably at least one selected from the group consisting of aminotri(methylene phosphonic acid), ethylenediaminetetra(methylene phosphonic acid), diethylenetriaminepenta(methylene phosphonic acid), and 1,2-propylenediaminetetra(methylene phosphonic acid). When the semiconductor substrate cleaning composition of the present invention contains aminopolymethylene phosphonic acid (D), the content of aminopolymethylene phosphonic acid (D) in the semiconductor substrate cleaning composition is preferably 0.00005 to 0.005 mass %, more preferably 0.0005 to 0.004 mass %, and further preferably 0.001 to 0.003 mass %. When the content of the aminopolymethylenephosphonic acid (D) is within the above range, the stability of hydrogen peroxide can be maintained while the cost can be reduced.

[0025] <Water> The semiconductor substrate cleaning composition of the present invention contains water. The water is not particularly limited, but is preferably water from which metal ions, organic impurities, particles, etc. have been removed by distillation, ion exchange treatment, filtration, various adsorption treatments, etc., and is more preferably pure water, and particularly preferably ultrapure water. The content of water is the remainder after excluding the components (A) to (D), any azoles, and other components from the semiconductor substrate cleaning composition of the present invention, and is preferably 50 mass % or more, more preferably 73 to 89.9385 mass %, even more preferably 75 to 89.798 mass %, even more preferably 75 to 85 mass %, and even more preferably 80 to 85 mass %. When the content of water is within the above range, the effects of the present invention can be exhibited and it is more economical.

[0026] <Characteristics of semiconductor substrate cleaning composition> The pH of the composition for cleaning semiconductor substrates of the present invention is preferably 7-12, more preferably 7.5-11, and even more preferably 8-10. By keeping the pH in the above range, the stability of hydrogen peroxide can be maintained at a high level, and the cleaning properties can also be improved. The pH can be measured by the method described in the Examples.

[0027] (Semiconductor substrate cleaning composition containing cobalt and copper for cleaning semiconductor substrates) The semiconductor substrate cleaning composition of the present invention is preferably used for cleaning a semiconductor substrate containing cobalt and copper. That is, the semiconductor substrate cleaning composition of the present invention is preferably used for cleaning a semiconductor substrate containing both cobalt and copper. Even when used to clean a semiconductor substrate containing both cobalt and copper, the semiconductor substrate cleaning composition of the present invention has high hydrogen peroxide stability. Cobalt and copper are used as metal wiring, etc., on semiconductor substrates. In the semiconductor substrate, cobalt and copper may be used as simple metals (pure metals) or as alloys. The semiconductor substrate cleaning composition of the present invention is prepared by adding 400 ppb by mass of cobalt ions and 1000 ppb by mass of copper ions to the total amount of the semiconductor substrate cleaning composition, and treating the composition at 50°C for 6 hours. After this, the residual rate of hydrogen peroxide (A) is preferably 50% or more, more preferably 60% or more, even more preferably 70% or more, and even more preferably 80% or more, based on the hydrogen peroxide content before the treatment. The residual rate of hydrogen peroxide (A) can be measured, for example, by the method described in the Examples. In the semiconductor substrate cleaning composition of the present invention, hydrogen peroxide remains stable for a long time even when cobalt ions and copper ions are coexisting in the cleaning solution, and the composition can be used for long-term cleaning of semiconductor substrates or repeated cleaning of semiconductor substrates. That is, in the semiconductor substrate cleaning composition of the present invention, hydrogen peroxide remains stable for a long time even in the presence of cobalt and copper, and the composition can be used for long-term cleaning of semiconductor substrates or repeated cleaning of semiconductor substrates.

[0028] (Semiconductor substrate cleaning composition for cleaning semiconductor substrates containing at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum, and cobalt) The semiconductor substrate cleaning composition of the present invention is also preferably used for cleaning a semiconductor substrate containing at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum, and cobalt. That is, the semiconductor substrate cleaning composition of the present invention is preferably used for cleaning a semiconductor substrate containing both at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum, and cobalt. Even when used to clean a semiconductor substrate containing both at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum, and cobalt, the semiconductor substrate cleaning composition of the present invention has high hydrogen peroxide stability. At least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum, and cobalt are used as materials for semiconductor substrates such as metal wiring. In the semiconductor substrate cleaning composition of the present invention, hydrogen peroxide remains stable for a long time even when ions of at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum, and cobalt ions are coexisting in the cleaning solution, and the composition can be used for long-term cleaning of semiconductor substrates or repeated cleaning of semiconductor substrates. That is, in the semiconductor substrate cleaning composition of the present invention, hydrogen peroxide remains stable for a long time even in the coexistence of at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum, and cobalt, and therefore the composition can be used for long-term cleaning of semiconductor substrates or repeated cleaning of semiconductor substrates.

[0029] The at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum may be used as a simple metal (pure metal) or as an alloy.

[0030] The at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum is preferably at least one metal selected from the group consisting of titanium, zirconium, hafnium, tantalum, tungsten, manganese, ruthenium, magnesium, and aluminum. The at least one metal selected from the group consisting of titanium, zirconium, hafnium, tantalum, tungsten, manganese, ruthenium, magnesium, and aluminum may be used as a simple metal (pure metal) or as an alloy.

[0031] (Semiconductor substrate cleaning composition for cleaning semiconductor substrates having hard masks containing titanium or titanium nitride) The semiconductor substrate cleaning composition of the present invention is preferably used for cleaning a semiconductor substrate having a hard mask containing at least one selected from the group consisting of titanium and titanium nitride, more preferably for cleaning a semiconductor substrate having a hard mask containing titanium nitride, and is preferably used for cleaning a semiconductor substrate having a hard mask consisting of at least one selected from the group consisting of titanium and titanium nitride, more preferably for cleaning a semiconductor substrate having a hard mask consisting of titanium nitride.

[0032] (Other ingredients) In addition to the above-mentioned components, the semiconductor substrate cleaning composition of the present invention may contain other components, such as surfactants and antifoaming agents, within the scope of the present invention.

[0033] The semiconductor substrate cleaning composition of the present invention may contain azoles other than 5-phenyl-1H-tetrazole and benzothiazole, provided that the object of the present invention is not impaired. The azoles are preferably at least one selected from the group consisting of imidazole compounds, pyrazole compounds, and triazole compounds, and more preferably triazole compounds. As the azoles, particularly, at least one azole selected from the group consisting of 1-methylimidazole, 1-vinylimidazole, 2-phenylimidazole, 2-ethyl-4-imidazole, N-benzyl-2-methylimidazole, 2-methylbenzimidazole, pyrazole, 4-methylpyrazole, 3,5-dimethylpyrazole, 1H-benzotriazole, 5-methyl-1H-benzotriazole, and 1H-tetrazole is preferred, at least one azole selected from the group consisting of 1-methylimidazole, pyrazole, 1H-benzotriazole, and 5-methyl-1H-benzotriazole is more preferred, and 5-methyl-1H-benzotriazole is even more preferred.

[0034] In the semiconductor substrate cleaning composition of the present invention, ammonia and ammonium ions (NH4 + ) have the effect of increasing the corrosion of copper and cobalt, so it is preferable that they are not substantially contained. Here, "substantially not contained" means that they are not contained or that they are contained within a range that does not impair the effects of the present invention. Specifically, ammonia and ammonium ions (NH + The total content of ammonia and ammonium ions (NH4) in the semiconductor substrate cleaning composition is preferably less than 0.01 mass %, more preferably less than 10 mass ppm. + ) is more preferably not included.

[0035] [Cleaning method] The cleaning method of the present invention is a cleaning method for cleaning a semiconductor substrate using the semiconductor substrate cleaning composition, and is preferably a cleaning method for cleaning a semiconductor substrate containing multiple metals including cobalt using the semiconductor substrate cleaning composition.

[0036] The cleaning method of the present invention is preferably a cleaning method for cleaning a semiconductor substrate having a hard mask containing at least one selected from the group consisting of titanium and titanium nitride, more preferably a cleaning method for cleaning a semiconductor substrate having a hard mask containing titanium nitride, and also is preferably a cleaning method for cleaning a semiconductor substrate having a hard mask containing at least one selected from the group consisting of titanium and titanium nitride, more preferably a cleaning method for cleaning a semiconductor substrate having a hard mask containing titanium nitride.

[0037] (Cleaning method for cleaning semiconductor substrates containing cobalt and copper) Among the above cleaning methods, a cleaning method using the semiconductor substrate cleaning composition to clean a semiconductor substrate containing both cobalt and copper is preferred. Even when cleaning a semiconductor substrate containing both cobalt and copper, the semiconductor substrate cleaning composition has high hydrogen peroxide stability. Cobalt and copper are used as metal wiring, etc., on the semiconductor substrate. Cobalt and copper may be used as simple metals (pure metals) or as alloys. The cleaning method of the present invention is preferably a cleaning method in which a semiconductor substrate is cleaned using the semiconductor substrate cleaning composition in the coexistence of cobalt ions and copper ions. Since hydrogen peroxide remains stable for a long period of time even in the presence of cobalt ions and copper ions, it is possible to clean semiconductor substrates for a long period of time or repeatedly clean semiconductor substrates. In the cleaning method of the present invention, cobalt and copper are present during cleaning as metal wiring on the semiconductor substrate, as ions dissolved in the cleaning solution, and as metal residues.

[0038] The cleaning method of the present invention can stably maintain the hydrogen peroxide content in the semiconductor substrate cleaning composition for a long period of time even in the coexistence of cobalt ions and copper ions, and therefore can efficiently remove dry etching residues and hard masks from semiconductor substrates. That is, the cleaning method is preferably a cleaning method that uses the semiconductor substrate cleaning composition to remove at least one selected from the group consisting of dry etching residues and hard masks from semiconductor substrates.

[0039] The temperature during cleaning in the cleaning method of the present invention is not particularly limited, but is preferably 20 to 80° C., more preferably 25 to 70° C. Ultrasonic waves may also be used during cleaning. The cleaning time in the cleaning method of the present invention is not particularly limited, but is preferably 0.3 to 20 minutes, more preferably 0.5 to 10 minutes. The pH of the cleaning solution in the cleaning method of the present invention is preferably 7-12, more preferably 7.5-11, and even more preferably 8-10. In the cleaning method of the present invention, it is preferable to further rinse with a rinse solution containing water, alcohol, or the like after cleaning.

[0040] In the cleaning method of the present invention, the method for contacting the semiconductor substrate cleaning composition of the present invention with the semiconductor substrate is not particularly limited. For example, the semiconductor substrate cleaning composition of the present invention can be contacted with the semiconductor substrate by dropping (single wafer spin treatment) or spraying (atomization treatment), or a method of immersing the semiconductor substrate in the semiconductor substrate cleaning composition of the present invention can be used. Either method can be used in the present invention.

[0041] (Cleaning method for cleaning a semiconductor substrate containing at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum, and cobalt) Furthermore, a preferred cleaning method is one in which the semiconductor substrate cleaning composition is used to clean a semiconductor substrate containing both cobalt and at least one metal selected from the group consisting of Group 4, Group 5, Group 6, Group 7, Group 8 elements, magnesium, and aluminum. The semiconductor substrate cleaning composition also has high hydrogen peroxide stability when used to clean a semiconductor substrate containing both cobalt and at least one metal selected from the group consisting of Group 4, Group 5, Group 6, Group 7, Group 8 elements, magnesium, and aluminum. The at least one metal selected from the group consisting of Group 4, Group 5, Group 6, Group 7, Group 8 elements, magnesium, and aluminum, and cobalt, are used as materials for semiconductor substrates, such as metal wiring.

[0042] The at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum may be used as a simple metal (pure metal) or as an alloy.

[0043] The cleaning method of the present invention is preferably a cleaning method in which a semiconductor substrate is cleaned using the semiconductor substrate cleaning composition in the coexistence of ions of at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum, and cobalt ions. Since hydrogen peroxide remains stable for a long period of time even in the coexistence of ions of at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum, and cobalt ions, it is possible to clean semiconductor substrates for a long period of time or repeatedly clean semiconductor substrates. In the cleaning method of the present invention, the at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum, and cobalt are present during cleaning as materials of the semiconductor substrate, such as metal wiring, as ions dissolved in the cleaning solution, and as metal residues.

[0044] The cleaning method of the present invention can stably maintain the hydrogen peroxide content in the semiconductor substrate cleaning composition for a long period of time even in the coexistence of ions of at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum, and cobalt ions, and therefore can efficiently remove dry etching residues and hard masks from semiconductor substrates. That is, the cleaning method is preferably a cleaning method that uses the semiconductor substrate cleaning composition to remove at least one selected from the group consisting of dry etching residues and hard masks from semiconductor substrates. In the cleaning method of the present invention, the at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum is preferably at least one metal selected from the group consisting of titanium, zirconium, hafnium, tantalum, tungsten, manganese, ruthenium, magnesium, and aluminum. The at least one metal selected from the group consisting of titanium, zirconium, hafnium, tantalum, tungsten, manganese, ruthenium, magnesium, and aluminum may be used as a simple metal (pure metal) or as an alloy.

[0045] The temperature during cleaning in the cleaning method of the present invention is not particularly limited, but is preferably 20 to 80° C., more preferably 25 to 70° C. Ultrasonic waves may also be used during cleaning. The cleaning time in the cleaning method of the present invention is not particularly limited, but is preferably 0.3 to 20 minutes, more preferably 0.5 to 10 minutes. The pH of the cleaning solution in the cleaning method of the present invention is preferably 7-12, more preferably 7.5-11, and even more preferably 8-10. In the cleaning method of the present invention, it is preferable to further rinse with a rinse solution containing water, alcohol, or the like after cleaning.

[0046] In the cleaning method of the present invention, the method for contacting the semiconductor substrate cleaning composition of the present invention with the semiconductor substrate is not particularly limited. For example, the semiconductor substrate cleaning composition of the present invention can be contacted with the semiconductor substrate by dropping (single wafer spin treatment) or spraying (atomization treatment), or a method of immersing the semiconductor substrate in the semiconductor substrate cleaning composition of the present invention can be used. Either method can be used in the present invention.

[0047] [Method of manufacturing semiconductor substrate] The method for producing a semiconductor substrate of the present invention includes a step of removing at least one selected from the group consisting of dry etching residues and hard masks from a semiconductor substrate using the semiconductor substrate cleaning composition. Specific examples of the method for producing a semiconductor substrate are shown below.

[0048] First, a barrier insulating film, a low-k interlayer insulating film, a hard mask, and a photoresist are laminated on a substrate such as silicon having a barrier metal, metal wiring, a low-k interlayer insulating film, and optionally a cap metal. The photoresist is then subjected to selective exposure and development to form a photoresist pattern. This photoresist pattern is then transferred onto the hard mask by dry etching. The photoresist pattern is then removed, and the low-k interlayer insulating film and the barrier insulating film are dry-etched using the hard mask as an etching mask. Next, the process of removing at least one selected from the group consisting of dry etching residues and the hard mask from the semiconductor substrate is carried out using the semiconductor substrate cleaning composition, resulting in a semiconductor substrate with a desired metal wiring pattern.

[0049] Here, silicon, amorphous silicon, polysilicon, glass, etc. are used as substrate materials. Tantalum, tantalum nitride, ruthenium, manganese, magnesium, cobalt, and oxides thereof, etc. are used as barrier metals. Copper or copper alloys, copper or copper alloys with cobalt or cobalt alloys formed as cap metals, cobalt or cobalt alloys, etc. are used as metal wiring. Low-dielectric constant interlayer insulating films, such as polysiloxane-based OCD (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) and carbon-doped silicon oxide (SiOC)-based Black Diamond (trade name, manufactured by Applied Materials, Inc.), are used. The barrier insulating film is made of silicon nitride, silicon carbide, silicon carbide nitride, etc. The hard mask is made of titanium, titanium nitride, etc.

[0050] According to the method for producing a semiconductor substrate of the present invention, since it includes a step of removing unnecessary components using the semiconductor substrate cleaning composition, it is possible to produce highly accurate, high quality semiconductor substrates with good yield.

[0051] [Method for stabilizing hydrogen peroxide] The semiconductor substrate cleaning composition of the present invention can suppress the decomposition of hydrogen peroxide (A) and stably maintain the content of hydrogen peroxide (A) for a long period of time even in the presence of multiple metals including cobalt during cleaning. In particular, the use of the hydrogen peroxide stabilizer (B) can exert this effect.

[0052] (Method for stabilizing hydrogen peroxide in a solution containing cobalt ions and copper ions) As described above, the semiconductor substrate cleaning composition of the present invention can suppress the decomposition of hydrogen peroxide (A) and stably maintain the content of hydrogen peroxide (A) for a long period of time even in the presence of cobalt and copper during cleaning. In particular, the use of the hydrogen peroxide stabilizer (B) can exert this effect. That is, the method for stabilizing hydrogen peroxide of the present invention is a method for stabilizing hydrogen peroxide, in which hydrogen peroxide (A) is stabilized in a liquid containing hydrogen peroxide (A), cobalt ions, copper ions, and water with a hydrogen peroxide stabilizer (B) that is at least one selected from the group consisting of oxalic acid, diethylenetriaminepentaacetic acid, hydroxyethyliminodiacetic acid, potassium oxalate, 5-phenyl-1H-tetrazole, triethylenetetraminehexaacetic acid, trans-1,2-cyclohexanediaminetetraacetic acid, 8-quinolinol, L(+)-isoleucine, DL-valine, L(-)-proline, hydroxyethylethylenediaminetriacetic acid, N,N-di(2-hydroxyethyl)glycine, glycine, L-tryptophan, 2,6-pyridinedicarboxylic acid, benzothiazole, and DL-alanine.

[0053] In the method for stabilizing hydrogen peroxide of the present invention, the hydrogen peroxide stabilizer (B) is at least one selected from the group consisting of oxalic acid, diethylenetriaminepentaacetic acid, hydroxyethyliminodiacetic acid, potassium oxalate, 5-phenyl-1H-tetrazole, triethylenetetraminehexaacetic acid, trans-1,2-cyclohexanediaminetetraacetic acid, 8-quinolinol, L(+)-isoleucine, DL-valine, L(-)-proline, hydroxyethylethylenediaminetriacetic acid, N,N-di(2-hydroxyethyl)glycine, glycine, L-tryptophan, 2,6-pyridinedicarboxylic acid, benzothiazole, and DL-alanine. The hydroxyethyl ethylenediaminetetraacetic acid is preferably at least one selected from the group consisting of diethylenetriaminepentaacetic acid, hydroxyethyliminodiacetic acid, potassium oxalate, triethylenetetraminehexaacetic acid, trans-1,2-cyclohexanediaminetetraacetic acid, 8-quinolinol, hydroxyethylethylenediaminetriacetic acid, 5-phenyl-1H-tetrazole, N,N-di(2-hydroxyethyl)glycine, and benzothiazole, more preferably at least one selected from the group consisting of diethylenetriaminepentaacetic acid, triethylenetetraminehexaacetic acid, and trans-1,2-cyclohexanediaminetetraacetic acid, and even more preferably trans-1,2-cyclohexanediaminetetraacetic acid.

[0054] The amount of the hydrogen peroxide stabilizer (B) used is preferably 0.0001 to 5 mass %, more preferably 0.001 to 1 mass %, in the liquid containing hydrogen peroxide (A), cobalt ions, copper ions, and water used in the method for stabilizing hydrogen peroxide of the present invention. Examples of specific compounds are given below. For example, the amount of trans-1,2-cyclohexanediaminetetraacetic acid used in the method for stabilizing hydrogen peroxide of the present invention, which contains hydrogen peroxide (A) as trans-1,2-cyclohexanediaminetetraacetic acid monohydrate, cobalt ions, copper ions, and water, is preferably 0.0001 to 5 mass%, more preferably 0.001 to 1 mass%, even more preferably 0.001 to 0.5 mass%, still more preferably 0.002 to 0.3 mass%, and even more preferably 0.003 to 0.2 mass%. In consideration of the balance between cost and effect, the amount is even more preferably 0.003 to 0.1 mass%, even more preferably 0.005 to 0.05 mass%, and even more preferably 0.005 to 0.01 mass%. The amount of diethylenetriaminepentaacetic acid used in the solution containing hydrogen peroxide (A), cobalt ions, copper ions, and water used in the method for stabilizing hydrogen peroxide of the present invention is preferably 0.0001 to 5% by mass, more preferably 0.001 to 1% by mass, even more preferably 0.01 to 1% by mass, still more preferably 0.02 to 0.8% by mass, and even more preferably 0.02 to 0.1% by mass. The amount of hydroxyethyliminodiacetic acid used in the solution containing hydrogen peroxide (A), cobalt ions, copper ions, and water used in the method for stabilizing hydrogen peroxide of the present invention is preferably 0.001 to 5% by mass, more preferably 0.01 to 3% by mass, even more preferably 0.05 to 1% by mass, and even more preferably 0.05 to 0.5% by mass. The amount of triethylenetetraminehexaacetic acid used in the liquid containing hydrogen peroxide (A), cobalt ions, copper ions, and water used in the method for stabilizing hydrogen peroxide of the present invention is preferably 0.0001 to 5 mass%, more preferably 0.001 to 1 mass%, even more preferably 0.005 to 0.5 mass%, and even more preferably 0.01 to 0.1 mass%.The amount of 8-quinolinol used in the solution containing hydrogen peroxide (A), cobalt ions, copper ions, and water used in the method for stabilizing hydrogen peroxide of the present invention is preferably 0.0001 to 5% by mass, more preferably 0.0005 to 1% by mass, even more preferably 0.001 to 0.1% by mass, and even more preferably 0.001 to 0.01% by mass. The amount of hydroxyethylethylenediaminetriacetic acid used in the solution containing hydrogen peroxide (A), cobalt ions, copper ions, and water used in the method for stabilizing hydrogen peroxide of the present invention is preferably 0.001 to 5% by mass, more preferably 0.01 to 3% by mass, even more preferably 0.05 to 1% by mass, and even more preferably 0.05 to 0.5% by mass.

[0055] In the method for stabilizing hydrogen peroxide of the present invention, the amount of hydrogen peroxide (A) used is not limited, but is preferably 10 to 30 mass %, and more preferably 10 to 20 mass %, in the liquid containing hydrogen peroxide (A), cobalt ions, copper ions, and water used in the method for stabilizing hydrogen peroxide of the present invention.

[0056] In the method for stabilizing hydrogen peroxide of the present invention, the pH of the liquid containing hydrogen peroxide (A), cobalt ions, copper ions, and water is preferably 7-12, more preferably 7.5-11, and even more preferably 8-10.

[0057] (Method for stabilizing hydrogen peroxide in a liquid containing hydrogen peroxide (A), ions of at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum, and cobalt ions) As described above, the semiconductor substrate cleaning composition of the present invention can suppress the decomposition of hydrogen peroxide (A) and stably maintain the content of hydrogen peroxide (A) for a long period of time even in the presence of at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum, and cobalt during cleaning. In particular, the use of the hydrogen peroxide stabilizer (B) can make this effect more pronounced. Specifically, the method for stabilizing hydrogen peroxide of the present invention involves stabilizing hydrogen peroxide (A) in a liquid containing hydrogen peroxide (A), ions of at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum, cobalt ions, and water, with hydrogen peroxide stabilizer (B) that is at least one selected from the group consisting of oxalic acid, diethylenetriaminepentaacetic acid, hydroxyethyliminodiacetic acid, potassium oxalate, 5-phenyl-1H-tetrazole, triethylenetetraminehexaacetic acid, trans-1,2-cyclohexanediaminetetraacetic acid, 8-quinolinol, L(+)-isoleucine, DL-valine, L(-)-proline, hydroxyethylethylenediaminetriacetic acid, N,N-di(2-hydroxyethyl)glycine, glycine, L-tryptophan, 2,6-pyridinedicarboxylic acid, benzothiazole, and DL-alanine.

[0058] In the method for stabilizing hydrogen peroxide of the present invention, the hydrogen peroxide stabilizer (B) is at least one selected from the group consisting of oxalic acid, diethylenetriaminepentaacetic acid, hydroxyethyliminodiacetic acid, potassium oxalate, 5-phenyl-1H-tetrazole, triethylenetetraminehexaacetic acid, trans-1,2-cyclohexanediaminetetraacetic acid, 8-quinolinol, L(+)-isoleucine, DL-valine, L(-)-proline, hydroxyethylethylenediaminetriacetic acid, N,N-di(2-hydroxyethyl)glycine, glycine, L-tryptophan, 2,6-pyridinedicarboxylic acid, benzothiazole, and DL-alanine. The hydroxyethyl ethylenediaminetetraacetic acid is preferably at least one selected from the group consisting of diethylenetriaminepentaacetic acid, hydroxyethyliminodiacetic acid, potassium oxalate, triethylenetetraminehexaacetic acid, trans-1,2-cyclohexanediaminetetraacetic acid, 8-quinolinol, hydroxyethylethylenediaminetriacetic acid, 5-phenyl-1H-tetrazole, N,N-di(2-hydroxyethyl)glycine, and benzothiazole, more preferably at least one selected from the group consisting of diethylenetriaminepentaacetic acid, triethylenetetraminehexaacetic acid, and trans-1,2-cyclohexanediaminetetraacetic acid, and even more preferably trans-1,2-cyclohexanediaminetetraacetic acid.

[0059] The amount of hydrogen peroxide stabilizer (B) used in the method for stabilizing hydrogen peroxide of the present invention is preferably 0.0001 to 5 mass %, and more preferably 0.001 to 1 mass %, in the liquid containing hydrogen peroxide (A), ions of at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum, cobalt ions, and water. Examples of specific compounds are given below. For example, the amount of trans-1,2-cyclohexanediaminetetraacetic acid used in the method for stabilizing hydrogen peroxide of the present invention, which contains trans-1,2-cyclohexanediaminetetraacetic acid monohydrate, hydrogen peroxide (A), ions of at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum, cobalt ions, and water, is preferably 0.0001 to 5 mass%, more preferably 0.001 to 1 mass%, even more preferably 0.001 to 0.5 mass%, still more preferably 0.002 to 0.3 mass%, and even more preferably 0.003 to 0.2 mass%. In consideration of the balance between cost and effect, the amount is preferably 0.003 to 0.1 mass%, even more preferably 0.005 to 0.05 mass%, and even more preferably 0.005 to 0.01 mass%. The amount of diethylenetriaminepentaacetic acid used in the method for stabilizing hydrogen peroxide of the present invention is preferably 0.0001 to 5 mass %, more preferably 0.001 to 1 mass %, even more preferably 0.01 to 1 mass %, still more preferably 0.02 to 0.8 mass %, and even more preferably 0.02 to 0.1 mass %, in a liquid containing hydrogen peroxide (A), ions of at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum, cobalt ions, and water. The amount of hydroxyethyliminodiacetic acid used in the method for stabilizing hydrogen peroxide of the present invention is preferably 0.001 to 5 mass %, more preferably 0.01 to 3 mass %, even more preferably 0.05 to 1 mass %, and even more preferably 0.05 to 0.5 mass %, in a liquid containing hydrogen peroxide (A), ions of at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum, cobalt ions, and water.The amount of triethylenetetraminehexaacetic acid used in the method for stabilizing hydrogen peroxide of the present invention is preferably 0.0001 to 5 mass %, more preferably 0.001 to 1 mass %, even more preferably 0.005 to 0.5 mass %, and even more preferably 0.01 to 0.1 mass %, in a liquid containing hydrogen peroxide (A), ions of at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum, cobalt ions, and water. The amount of 8-quinolinol used in the method for stabilizing hydrogen peroxide of the present invention is preferably 0.0001 to 5 mass %, more preferably 0.0005 to 1 mass %, even more preferably 0.001 to 0.1 mass %, and even more preferably 0.001 to 0.01 mass %, in a liquid containing hydrogen peroxide (A), ions of at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum, cobalt ions, and water. The amount of hydroxyethylethylenediaminetriacetic acid used in the method for stabilizing hydrogen peroxide of the present invention is preferably 0.001 to 5 mass %, more preferably 0.01 to 3 mass %, even more preferably 0.05 to 1 mass %, and even more preferably 0.05 to 0.5 mass %, in a liquid containing hydrogen peroxide (A), ions of at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum, cobalt ions, and water.

[0060] In the method for stabilizing hydrogen peroxide of the present invention, the amount of hydrogen peroxide (A) used is not limited, but is preferably 10 to 30 mass %, and more preferably 10 to 20 mass %, in a liquid used in the method for stabilizing hydrogen peroxide of the present invention, which liquid contains hydrogen peroxide (A), ions of at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum, cobalt ions, and water.

[0061] In the method for stabilizing hydrogen peroxide of the present invention, the pH of the liquid containing hydrogen peroxide (A), ions of at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum, cobalt ions, and water is preferably 7 to 12, more preferably 7.5 to 11, and even more preferably 8 to 10. [Example]

[0062] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0063] <Analysis and evaluation methods (1)> (1) pH The pH of the semiconductor substrate cleaning composition was measured by the glass electrode method (HORIBA: F-55S benchtop pH meter, HORIBA: Standard ToupH electrode 9165S-10D, temperature: 25°C).

[0064] (2) Evaluation of hydrogen peroxide stability As substitutes for metal residues contaminated after semiconductor substrate cleaning, standard solutions of copper ions and cobalt ions (ICP standard solutions Cu1000 (1000 ppm by mass) and Co1000 (1000 ppm by mass), manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were added to the semiconductor substrate cleaning compositions of the Examples and Comparative Examples in the amounts shown in Tables 1 to 5. The amount of hydrogen peroxide immediately after addition and after incubation at 50°C for 6 hours was measured using potassium permanganate according to the method described in JIS K1463:2007, and the residual hydrogen peroxide rate (unit: %) was calculated. The higher the residual hydrogen peroxide rate, the higher the stability of hydrogen peroxide.

[0065] (3) Metal corrosion evaluation A silicon wafer with a 600-angstrom-thick PVD seed layer on which a 6000-angstrom-thick electroplated copper film was formed and then annealed, and a silicon wafer (manufactured by Advantech) with a 2000-angstrom-thick cobalt film formed by PVD were measured for their film thickness by X-ray fluorescence analysis (SEA 1200VX, manufactured by Hitachi). After that, the wafers were immersed in a semiconductor substrate cleaning composition at 50°C for a predetermined time (copper: 60 minutes, cobalt: 5 minutes), rinsed with ultrapure water at room temperature, and the film thickness was measured again by X-ray fluorescence analysis, thereby measuring the reduction in the copper and cobalt film thickness per unit time. The measurement results were evaluated according to the following criteria. A: For copper, the film thickness reduction rate is 1 angstrom / min or less. For cobalt, the film thickness reduction rate is 3 angstroms / min or less. B: For copper, the film thickness reduction rate is greater than 1 angstrom / min and less than or equal to 2 angstroms / min. For cobalt, the film thickness reduction rate is greater than 3 angstroms / min and less than or equal to 10 angstroms / min. C: For copper, the film thickness loss is greater than 2 angstroms / minute. For cobalt, the film thickness loss is greater than 10 angstroms / minute.

[0066] <Semiconductor substrate cleaning composition> Example 1 A semiconductor substrate cleaning composition was obtained by blending 15 parts by mass of hydrogen peroxide (48.39 parts by mass of a 31% hydrogen peroxide aqueous solution was blended so that the amount of active ingredient was as described above), 0.15 parts by mass of potassium hydroxide, 0.5 parts by mass of tetramethylammonium hydroxide, and 0.005 parts by mass of trans-1,2-cyclohexanediaminetetraacetic acid monohydrate as a hydrogen peroxide stabilizer (B), and diluting the mixture with ultrapure water to a total of 100 parts by mass. The evaluations shown in Table 1 were carried out. In each table, the blending amount of each component is shown in "mass %."

[0067] Example 2 A semiconductor substrate cleaning composition was obtained by blending 20 parts by mass of hydrogen peroxide (64.52 parts by mass of 31% hydrogen peroxide aqueous solution to achieve the above-mentioned amount of active ingredient), 0.15 parts by mass of potassium hydroxide, 0.5 parts by mass of tetramethylammonium hydroxide, and 0.005 parts by mass of trans-1,2-cyclohexanediaminetetraacetic acid monohydrate as a hydrogen peroxide stabilizer (B), and diluting the mixture with ultrapure water to a total of 100 parts by mass. The evaluations shown in Table 1 were carried out.

[0068] Example 3 A semiconductor substrate cleaning composition was obtained by blending 25 parts by mass of hydrogen peroxide (80.65 parts by mass of 31% hydrogen peroxide aqueous solution so that the amount of active ingredient was as described above), 0.15 parts by mass of potassium hydroxide, 0.5 parts by mass of tetramethylammonium hydroxide, and 0.005 parts by mass of trans-1,2-cyclohexanediaminetetraacetic acid monohydrate as a hydrogen peroxide stabilizer (B), and diluting the mixture with ultrapure water to a total of 100 parts by mass. The evaluations shown in Table 1 were carried out.

[0069] Example 4 A semiconductor substrate cleaning composition was obtained by blending 15 parts by mass of hydrogen peroxide (48.39 parts by mass of 31% hydrogen peroxide aqueous solution to achieve the above-mentioned amount of active ingredient), 0.30 parts by mass of potassium hydroxide, 0.5 parts by mass of tetramethylammonium hydroxide, and 0.005 parts by mass of trans-1,2-cyclohexanediaminetetraacetic acid monohydrate as a hydrogen peroxide stabilizer (B), and diluting the mixture with ultrapure water to a total of 100 parts by mass. The evaluations shown in Table 1 were carried out.

[0070] Example 5 A semiconductor substrate cleaning composition was obtained by blending 15 parts by mass of hydrogen peroxide (48.39 parts by mass of 31% hydrogen peroxide aqueous solution to achieve the above-mentioned amount of active ingredient), 0.15 parts by mass of potassium hydroxide, 1.0 part by mass of tetramethylammonium hydroxide, and 0.005 parts by mass of trans-1,2-cyclohexanediaminetetraacetic acid monohydrate as a hydrogen peroxide stabilizer (B), and diluting the mixture with ultrapure water to a total of 100 parts by mass. The evaluations shown in Table 1 were carried out.

[0071] Example 6 A semiconductor substrate cleaning composition was obtained by blending 15 parts by mass of hydrogen peroxide (48.39 parts by mass of 31% hydrogen peroxide aqueous solution to achieve the above-mentioned amount of active ingredient), 0.15 parts by mass of potassium hydroxide, and 0.005 parts by mass of trans-1,2-cyclohexanediaminetetraacetic acid monohydrate as a hydrogen peroxide stabilizer (B), and diluting the mixture with ultrapure water to a total of 100 parts by mass. The evaluations shown in Table 1 were carried out.

[0072] Example 7 A semiconductor substrate cleaning composition was obtained by blending 15 parts by mass of hydrogen peroxide (48.39 parts by mass of 31% hydrogen peroxide aqueous solution so that the amount of active ingredient was as described above), 0.5 parts by mass of tetramethylammonium hydroxide, and 0.005 parts by mass of trans-1,2-cyclohexanediaminetetraacetic acid monohydrate as a hydrogen peroxide stabilizer (B), and diluting the mixture with ultrapure water to a total of 100 parts by mass. The evaluations shown in Table 1 were carried out.

[0073] Example 8 A semiconductor substrate cleaning composition was obtained by blending 15 parts by mass of hydrogen peroxide (48.39 parts by mass of 31% hydrogen peroxide aqueous solution to achieve the above-mentioned amount of active ingredient), 0.15 parts by mass of potassium hydroxide, 0.5 parts by mass of tetraethylammonium hydroxide, and 0.005 parts by mass of trans-1,2-cyclohexanediaminetetraacetic acid monohydrate as a hydrogen peroxide stabilizer (B), and diluting the mixture with ultrapure water to a total of 100 parts by mass. The evaluations shown in Table 1 were carried out.

[0074] Example 9 A semiconductor substrate cleaning composition was obtained by blending 15 parts by mass of hydrogen peroxide (48.39 parts by mass of 31% hydrogen peroxide aqueous solution to achieve the above-mentioned amount of active ingredient), 0.15 parts by mass of potassium hydroxide, 0.5 parts by mass of tetrapropylammonium hydroxide, and 0.005 parts by mass of trans-1,2-cyclohexanediaminetetraacetic acid monohydrate as a hydrogen peroxide stabilizer (B), and diluting the mixture with ultrapure water to a total of 100 parts by mass. The evaluations shown in Table 1 were carried out.

[0075] Example 10 A semiconductor substrate cleaning composition was obtained by blending 15 parts by mass of hydrogen peroxide (48.39 parts by mass of 31% hydrogen peroxide aqueous solution to achieve the above-mentioned amount of active ingredient), 0.15 parts by mass of potassium hydroxide, 0.5 parts by mass of tetrabutylammonium hydroxide, and 0.005 parts by mass of trans-1,2-cyclohexanediaminetetraacetic acid monohydrate as a hydrogen peroxide stabilizer (B), and diluting the mixture with ultrapure water to a total of 100 parts by mass. The evaluations shown in Table 1 were carried out.

[0076] Example 11 A semiconductor substrate cleaning composition was obtained by blending 15 parts by mass of hydrogen peroxide (48.39 parts by mass of 31% hydrogen peroxide aqueous solution to achieve the above-mentioned amount of active ingredient), 0.15 parts by mass of potassium hydroxide, 0.5 parts by mass of benzyltrimethylammonium hydroxide, and 0.005 parts by mass of trans-1,2-cyclohexanediaminetetraacetic acid monohydrate as a hydrogen peroxide stabilizer (B), and diluting the mixture with ultrapure water to a total of 100 parts by mass. The evaluations shown in Table 1 were carried out.

[0077] Example 12 A semiconductor substrate cleaning composition was obtained by blending 15 parts by weight of hydrogen peroxide (48.39 parts by weight of 31% hydrogen peroxide aqueous solution to achieve the above-mentioned amount of active ingredient), 0.15 parts by weight of potassium hydroxide, 0.5 parts by weight of tetramethylammonium hydroxide, 0.002 parts by weight of aminotri(methylenephosphonic acid), and 0.005 parts by weight of trans-1,2-cyclohexanediaminetetraacetic acid monohydrate as a hydrogen peroxide stabilizer (B), and diluting the mixture with ultrapure water to a total of 100 parts by weight. The evaluations shown in Table 1 were carried out.

[0078] Example 13 A semiconductor substrate cleaning composition was obtained by blending 15 parts by mass of hydrogen peroxide (48.39 parts by mass of 31% hydrogen peroxide aqueous solution was blended to achieve the above-mentioned amount of active ingredient), 0.15 parts by mass of potassium hydroxide, 0.5 parts by mass of tetramethylammonium hydroxide, 0.002 parts by mass of ethylenediaminetetra(methylenephosphonic acid), and 0.005 parts by mass of trans-1,2-cyclohexanediaminetetraacetic acid monohydrate as a hydrogen peroxide stabilizer (B), and diluting the mixture with ultrapure water to a total of 100 parts by mass. The evaluations shown in Table 1 were carried out.

[0079] Example 14 A semiconductor substrate cleaning composition was obtained by blending 15 parts by weight of hydrogen peroxide (48.39 parts by weight of 31% hydrogen peroxide aqueous solution to achieve the above-mentioned amount of active ingredient), 0.15 parts by weight of potassium hydroxide, 0.5 parts by weight of tetramethylammonium hydroxide, 0.002 parts by weight of diethylenetriaminepenta(methylenephosphonic acid), and 0.005 parts by weight of trans-1,2-cyclohexanediaminetetraacetic acid monohydrate as a hydrogen peroxide stabilizer (B), and diluting the mixture with ultrapure water to a total of 100 parts by weight. The evaluations shown in Table 1 were carried out.

[0080] Example 15 A semiconductor substrate cleaning composition was prepared by blending 15 parts by weight of hydrogen peroxide (48.39 parts by weight of 31% hydrogen peroxide aqueous solution was blended to achieve the above-mentioned amount of active ingredient), 0.15 parts by weight of potassium hydroxide, 0.5 parts by weight of tetramethylammonium hydroxide, 0.002 parts by weight of 1,2-propylenediaminetetra(methylenephosphonic acid), and 0.005 parts by weight of trans-1,2-cyclohexanediaminetetraacetic acid monohydrate as a hydrogen peroxide stabilizer (B), and diluting the mixture with ultrapure water to a total of 100 parts by weight. The evaluations shown in Table 1 were carried out.

[0081] Example 16 A semiconductor substrate cleaning composition was obtained by blending 15 parts by weight of hydrogen peroxide (48.39 parts by weight of 31% hydrogen peroxide aqueous solution was blended to achieve the above-mentioned amount of active ingredient), 0.15 parts by weight of potassium hydroxide, 0.5 parts by weight of tetramethylammonium hydroxide, 0.002 parts by weight of diethylenetriaminepenta(methylenephosphonic acid), and 0.1 parts by weight of trans-1,2-cyclohexanediaminetetraacetic acid monohydrate as a hydrogen peroxide stabilizer (B), and diluting the blend with ultrapure water to a total of 100 parts by weight. The evaluations shown in Table 1 were carried out.

[0082] Example 17 A semiconductor substrate cleaning composition was prepared by blending 15 parts by weight of hydrogen peroxide (48.39 parts by weight of 31% hydrogen peroxide aqueous solution to achieve the above-mentioned amount of active ingredient), 0.15 parts by weight of potassium hydroxide, 0.5 parts by weight of tetramethylammonium hydroxide, 0.002 parts by weight of diethylenetriaminepenta(methylenephosphonic acid), and 0.0001 parts by weight of trans-1,2-cyclohexanediaminetetraacetic acid monohydrate as a hydrogen peroxide stabilizer (B), and diluting the mixture with ultrapure water to a total of 100 parts by weight. The evaluations shown in Table 1 were carried out.

[0083] Example 18 A semiconductor substrate cleaning composition was obtained in the same manner as in Example 14, except that 0.50 parts by mass of tetramethylammonium hydroxide in Example 14 was changed to 0.50 parts by mass of ammonia and the amount of ultrapure water was adjusted so that the total amount was 100 parts by mass. The evaluations shown in Table 1 were carried out.

[0084] Example 19 A semiconductor substrate cleaning composition was obtained in the same manner as in Example 14, except that 0.50 parts by mass of tetramethylammonium hydroxide in Example 14 was changed to 0.50 parts by mass of ammonia, 0.002 parts by mass of 5-methyl-1H-tetrazole was added, and the amount of ultrapure water was adjusted so that the total amount was 100 parts by mass. The evaluations shown in Table 1 were carried out.

[0085] Comparative Example 1 A semiconductor substrate cleaning composition was obtained in the same manner as in Example 16, except that 0.10 parts by mass of trans-1,2-cyclohexanediaminetetraacetic acid monohydrate in Example 16 was not used and the amount of ultrapure water was adjusted to a total of 100 parts by mass. Table 1 shows the evaluation results.

[0086] Reference Examples 1 and 2 As a reference example, the stability of hydrogen peroxide was evaluated by adding only cobalt or copper to the semiconductor substrate cleaning composition of Comparative Example 1. The results are also shown in Table 1.

[0087] [Table 1]

[0088] Examples 20 to 35 A semiconductor substrate cleaning composition was obtained in the same manner as in Example 16, except that 0.10 parts by mass of trans-1,2-cyclohexanediaminetetraacetic acid monohydrate in Example 16 was changed to the compound amounts of each compound (compound of hydrogen peroxide stabilizer (B)) shown in Table 2 and the amount of ultrapure water was adjusted so that the total was 100 parts by mass. Table 2 shows the evaluation results.

[0089] Example 36 A semiconductor substrate cleaning composition was obtained in the same manner as in Example 16, except that 0.10 parts by mass of trans-1,2-cyclohexanediaminetetraacetic acid monohydrate in Example 16 was changed to 0.10 parts by mass of glycine, 0.02 parts by mass of 5-methyl-1H-benzotriazole was added, and the amount of ultrapure water was adjusted to make the total 100 parts by mass. Table 2 shows the evaluation results.

[0090] Example 37 A semiconductor substrate cleaning composition was obtained in the same manner as in Example 16, except that 0.02 parts by mass of 5-methyl-1H-benzotriazole in Example 36 was changed to 1.0 part by mass of pyrazole and the amount of ultrapure water was adjusted so that the total amount was 100 parts by mass. Table 2 shows the evaluation results.

[0091] Example 38 A semiconductor substrate cleaning composition was obtained in the same manner as in Example 16, except that 0.02 parts by mass of 5-methyl-1H-benzotriazole in Example 36 was changed to 1.0 part by mass of 1-methylimidazole and the amount of ultrapure water was adjusted so that the total amount was 100 parts by mass. Table 2 shows the evaluation results.

[0092] Example 39 A semiconductor substrate cleaning composition was obtained in the same manner as in Example 16, except that 0.02 parts by mass of 5-methyl-1H-benzotriazole in Example 36 was changed to 0.02 parts by mass of 1H-benzotriazole and the amount of ultrapure water was adjusted so that the total amount was 100 parts by mass. Table 2 shows the evaluation results.

[0093] [Table 2]

[0094] Comparative Examples 2 to 22 A semiconductor substrate cleaning composition was obtained in the same manner as in Example 16, except that 0.10 parts by mass of trans-1,2-cyclohexanediaminetetraacetic acid monohydrate in Example 16 was changed to each compound and amount shown in the compound column in Table 3. Table 3 shows the evaluation results.

[0095] [Table 3]

[0096] Example 40 1.0 part by mass of 5-methyl-1H-benzotriazole was blended into the semiconductor substrate cleaning composition of Example 14, and sulfuric acid was added to obtain a semiconductor substrate cleaning composition with a pH of 7. Table 4 shows the evaluation results.

[0097] Example 41 5.0 parts by mass of pyrazole was blended into the semiconductor substrate cleaning composition of Example 16, and sodium hydroxide was added to obtain a semiconductor substrate cleaning composition with a pH of 12. Table 4 shows the evaluation results.

[0098] Comparative Example 23 1.0 part by mass of 5-methyl-1H-benzotriazole was blended into the semiconductor substrate cleaning composition of Comparative Example 1, and sulfuric acid was added to obtain a semiconductor substrate cleaning composition with a pH of 7. Table 4 shows the evaluation results.

[0099] Comparative Example 24 5.0 parts by mass of pyrazole was blended into the semiconductor substrate cleaning composition of Comparative Example 1, and sodium hydroxide was added to obtain a semiconductor substrate cleaning composition with a pH of 12. Table 4 shows the evaluation results.

[0100] [Table 4]

[0101] Comparative Examples 25 to 40 A semiconductor substrate cleaning composition was obtained in the same manner as in Example 16, except that 0.10 parts by mass of trans-1,2-cyclohexanediaminetetraacetic acid monohydrate in Example 16 was changed to each compound and amount shown in Table 5 described in the above Patent Documents 2 to 17. Table 5 shows the evaluation results.

[0102] [Table 5]

[0103] As can be seen from Tables 1 to 5, the semiconductor substrate cleaning compositions of the examples have high stability of hydrogen peroxide even in the presence of two types of metal ions, copper and cobalt. Furthermore, it can be seen that the semiconductor substrate cleaning compositions using the hydrogen peroxide stabilizers shown in the examples cause less corrosion of the metals constituting the semiconductor substrate.

[0104] <Analysis and evaluation methods (2)> (1) Evaluation of hydrogen peroxide stability As substitutes for metal residues contaminated after semiconductor substrate cleaning, standard solutions of each metal ion and a standard solution of cobalt ions (ICP standard solution Co1000 (1000 mass ppm), manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were added to the semiconductor substrate cleaning compositions of the Examples and Comparative Examples in the amounts shown in Table 6. The amount of hydrogen peroxide immediately after addition and after incubation at 50°C for 6 hours was measured using potassium permanganate according to the method described in JIS K1463:2007, and the residual hydrogen peroxide rate (unit: %) was calculated. The higher the residual hydrogen peroxide rate, the higher the stability of hydrogen peroxide. The metal ions are ions of the following metals: tantalum (Group 5 element), ruthenium (Group 8 element), manganese (Group 7 element), magnesium, titanium (Group 4 element), aluminum, tungsten (Group 6 element), zirconium (Group 4 element), and hafnium (Group 4 element).

[0105] Example 42 A semiconductor substrate cleaning composition was obtained by blending 15 parts by mass of hydrogen peroxide (48.39 parts by mass of a 31% aqueous hydrogen peroxide solution was blended so that the amount of active ingredient was as described above), 0.2 parts by mass of potassium hydroxide, 0.5 parts by mass of tetramethylammonium hydroxide, 0.002 parts by mass of diethylenetriaminepenta(methylenephosphonic acid), and 0.05 parts by mass of diethylenetriaminepentaacetic acid as a hydrogen peroxide stabilizer (B), and diluting the blend with ultrapure water to a total of 100 parts by mass. The evaluations shown in Table 6 were carried out. In each of the following tables, the blending amount of each component is shown in "mass %."

[0106] Examples 43 to 45 A semiconductor substrate cleaning composition was obtained in the same manner as in Example 42, except that 0.05 parts by mass of diethylenetriaminepentaacetic acid in Example 42 was changed to each compound and amount shown in Table 6. Table 6 shows the evaluation results.

[0107] Examples 46 and 47 A semiconductor substrate cleaning composition was obtained in the same manner as in Example 42, except that 0.05 parts by mass of diethylenetriaminepentaacetic acid in Example 42 was changed to each compound and amount shown in Table 7. Table 7 shows the evaluation results.

[0108] Comparative Example 41 A semiconductor substrate cleaning composition was obtained in the same manner as in Example 42, except that 0.05 parts by mass of diethylenetriaminepentaacetic acid in Example 42 was not used and the amount of ultrapure water was adjusted so that the total amount was 100 parts by mass. Table 7 shows the evaluation results.

[0109] Reference example 3 As a reference example, the composition for cleaning semiconductor substrates of Comparative Example 41 was used to evaluate the stability of hydrogen peroxide by adding only cobalt ions. The results are shown in Table 7.

[0110] [Table 6]

[0111] [Table 7]

[0112] As can be seen from Tables 6 and 7, the semiconductor substrate cleaning compositions of the examples have high stability of hydrogen peroxide even in the presence of two types of metal ions: specific metals (Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum) and cobalt.

Claims

1. A semiconductor substrate cleaning composition comprising hydrogen peroxide (A), a hydrogen peroxide stabilizer (B), an alkaline compound (C), and water, the hydrogen peroxide stabilizer (B) is at least one selected from the group consisting of diethylenetriaminepentaacetic acid, hydroxyethyliminodiacetic acid, triethylenetetraminehexaacetic acid, trans-1,2-cyclohexanediaminetetraacetic acid, 8-quinolinol, and hydroxyethylethylenediaminetriacetic acid; The alkali compound (C) is a quaternary ammonium hydroxide (C1) and potassium hydroxide (C2), the quaternary ammonium hydroxide (C1) is at least one selected from the group consisting of tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, and benzyltrimethylammonium hydroxide; A composition for cleaning semiconductor substrates.

2. 2. The semiconductor substrate cleaning composition according to claim 1, wherein the content of the hydrogen peroxide stabilizer (B) in the semiconductor substrate cleaning composition is 0.0001 to 5% by mass.

3. 3. The semiconductor substrate cleaning composition according to claim 1, wherein the content of hydrogen peroxide (A) in the semiconductor substrate cleaning composition is 10 to 30 mass %.

4. 4. The semiconductor substrate cleaning composition according to claim 1, wherein the pH is 7 to 12.

5. The semiconductor substrate cleaning composition according to any one of claims 1 to 4, further comprising an aminopolymethylenephosphonic acid (D).

6. 6. The semiconductor substrate cleaning composition according to claim 5, wherein the content of the aminopolymethylenephosphonic acid (D) in the semiconductor substrate cleaning composition is 0.00005 to 0.005 mass %.

7. 7. The semiconductor substrate cleaning composition according to claim 1, wherein the content of the quaternary ammonium hydroxide (C1) in the semiconductor substrate cleaning composition is 0.005 to 10 mass %.

8. 8. The semiconductor substrate cleaning composition according to claim 1, wherein the content of potassium hydroxide (C2) in the semiconductor substrate cleaning composition is 0.005 to 5 mass %.

9. A composition for cleaning semiconductor substrates described in any one of claims 1 to 8, wherein the quaternary ammonium hydroxide (C1) is at least one selected from the group consisting of tetramethylammonium hydroxide, tetrapropylammonium hydroxide, and benzyltrimethylammonium hydroxide.

10. 10. The semiconductor substrate cleaning composition according to claim 5, wherein the aminopolymethylenephosphonic acid (D) is at least one selected from the group consisting of aminotri(methylenephosphonic acid), ethylenediaminetetra(methylenephosphonic acid), diethylenetriaminepenta(methylenephosphonic acid), and 1,2-propylenediaminetetra(methylenephosphonic acid).

11. A semiconductor substrate cleaning composition according to any one of claims 1 to 10, wherein the hydrogen peroxide stabilizer (B) is at least one selected from the group consisting of diethylenetriaminepentaacetic acid, hydroxyethyliminodiacetic acid, triethylenetetraminehexaacetic acid, trans-1,2-cyclohexanediaminetetraacetic acid, and hydroxyethylethylenediaminetriacetic acid.

12. Ammonia and ammonium ions (NH 4 ＋ 12. The semiconductor substrate cleaning composition according to claim 1, wherein the composition is substantially free of any of the following:

13. The semiconductor substrate cleaning composition according to any one of claims 1 to 12, which is used for cleaning a semiconductor substrate having a hard mask containing at least one selected from the group consisting of titanium and titanium nitride.

14. The semiconductor substrate cleaning composition according to any one of claims 1 to 13, which is used for cleaning a semiconductor substrate containing cobalt and copper.

15. 15. The semiconductor substrate cleaning composition according to claim 1, wherein after adding 400 ppb by mass of cobalt ions and 1000 ppb by mass of copper ions to the total amount of the semiconductor substrate cleaning composition and treating the composition at 50°C for 6 hours, the residual rate of hydrogen peroxide (A) is 50% or more based on the hydrogen peroxide content before the treatment.

16. The semiconductor substrate cleaning composition according to any one of claims 1 to 13, which is used for cleaning a semiconductor substrate containing at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum, and cobalt.

17. 17. The semiconductor substrate cleaning composition according to claim 16, wherein the at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum is at least one metal selected from the group consisting of titanium, zirconium, hafnium, tantalum, tungsten, manganese, ruthenium, magnesium, and aluminum.

18. A cleaning method comprising cleaning a semiconductor substrate using the semiconductor substrate cleaning composition according to any one of claims 1 to 15 in the coexistence of cobalt ions and copper ions.

19. A cleaning method for cleaning a semiconductor substrate containing cobalt and copper using the semiconductor substrate cleaning composition according to any one of claims 1 to 15.

20. A cleaning method for cleaning a semiconductor substrate using the semiconductor substrate cleaning composition according to any one of claims 1 to 13, 16 and 17 in the copresence of ions of at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium and aluminum, and cobalt ions.

21. A cleaning method for cleaning a semiconductor substrate containing at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum, and cobalt, by using the semiconductor substrate cleaning composition according to any one of claims 1 to 13, 16, and 17.

22. 22. The cleaning method according to claim 18, wherein a semiconductor substrate having a hard mask containing at least one selected from the group consisting of titanium and titanium nitride is cleaned.

23. A cleaning method for removing at least one selected from the group consisting of dry etching residues and hard masks in a semiconductor substrate, using the semiconductor substrate cleaning composition according to any one of claims 1 to 17.

24. A method for stabilizing hydrogen peroxide, comprising stabilizing hydrogen peroxide (A) in a liquid containing hydrogen peroxide (A), an alkali compound (C) which is cobalt ions, copper ions, a quaternary ammonium hydroxide (C1), and potassium hydroxide (C2), and water, with a hydrogen peroxide stabilizer (B) which is at least one selected from the group consisting of diethylenetriaminepentaacetic acid, hydroxyethyliminodiacetic acid, triethylenetetraminehexaacetic acid, trans-1,2-cyclohexanediaminetetraacetic acid, 8-quinolinol, and hydroxyethylethylenediaminetriacetic acid, wherein the quaternary ammonium hydroxide (C1) is at least one selected from the group consisting of tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, and benzyltrimethylammonium hydroxide.

25. 25. The method for stabilizing hydrogen peroxide according to claim 24, wherein the liquid containing hydrogen peroxide (A), cobalt ions, copper ions, and water has a pH of 7 to 12.

26. A method for stabilizing hydrogen peroxide, comprising: stabilizing hydrogen peroxide (A) in a liquid containing hydrogen peroxide (A), ions of at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum, cobalt ions, an alkali compound (C) which is a quaternary ammonium hydroxide (C1) and potassium hydroxide (C2), and water, with a hydrogen peroxide stabilizer (B) which is at least one selected from the group consisting of diethylenetriaminepentaacetic acid, hydroxyethyliminodiacetic acid, triethylenetetraminehexaacetic acid, trans-1,2-cyclohexanediaminetetraacetic acid, 8-quinolinol, and hydroxyethylethylenediaminetriacetic acid, wherein the quaternary ammonium hydroxide (C1) is at least one selected from the group consisting of tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, and benzyltrimethylammonium hydroxide.

27. The method for stabilizing hydrogen peroxide according to claim 26, wherein a solution containing hydrogen peroxide (A), ions of at least one metal selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, Group 7 elements, Group 8 elements, magnesium, and aluminum, cobalt ions, and water has a pH of 7 to 12.

28. A method for producing a semiconductor substrate, comprising a step of removing at least one selected from the group consisting of dry etching residues and hard masks in a semiconductor substrate by using the semiconductor substrate cleaning composition according to any one of claims 1 to 17.

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