Composition and cleaning method for semiconductor substrates

Abstract

This composition for cleaning a semiconductor substrate contains an alkaline compound (A), a corrosion prevention agent (B), and water. The alkaline compound (A) is at least one selected from the group consisting of a quaternary ammonium hydroxide (A1) and potassium hydroxide (A2). The corrosion prevention agent (B) is at least one selected from the group consisting of position 4 substituted pyrazoles, potassium tris(1-pyrazolyl)borohydride, 2-(4-thiazolyl)benzimidazole, and halogenated-8-hydroxyquinolines.

Description

Technical Field

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

Background Art

[0002] In the manufacture of a semiconductor substrate with highly integrated semiconductor elements, usually, on a substrate such as a silicon wafer, a conductive thin film such as a metal film serving as a wiring material for conduction, an interlayer insulating film for insulating between the conductive thin films, a hard mask, a sacrificial layer, etc. are formed. Then, a photoresist is uniformly applied to the surface thereof to provide a photosensitive layer, and selective exposure and development processes are performed thereon to create a desired photoresist pattern. Next, using this photoresist pattern as a mask, a dry etching process is applied to the substrate on which the interlayer insulating film, hard mask, etc. are laminated to form a desired pattern on the substrate. And then, a series of steps of removing the photoresist pattern and residues generated by the dry etching process (hereinafter referred to as "dry etching residues") by ashing with oxygen plasma or a cleaning liquid, etc. are generally taken.

[0003] In the treatment with a cleaning liquid, it is known that the photoresist can be removed by using an alkaline cleaning liquid. However, there are cases where the alkaline cleaning liquid may damage the metal layer. Therefore, studies have been made to improve the cleaning performance while preventing deterioration and corrosion of the metal layer and the like. For example, Patent Document 1 discloses a treatment liquid for a semiconductor device containing an organic alkali compound, a corrosion inhibitor, an organic solvent, Ca, Fe, and Na for the purpose of improving the corrosion prevention property of the metal layer and the resist removal property. Also, Patent Document 2 discloses a stripping cleaning liquid containing a quaternary ammonium hydroxide, a water-soluble organic solvent, water, a corrosion inhibitor, and potassium hydroxide of 1 mass% or less with respect to the total amount for the purpose of preventing deterioration of a Low-k material or Cu and removing metal residues and the like.

Prior Art Documents

[0004] [Patent Document 1] International Publication No. 2017 / 208767 [Patent Document 2] Special Publication No. 2006-527783 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] In recent years, the miniaturization of design rules has led to an increase in the current density of metal wiring, creating a stronger need for countermeasures against electromigration, which occurs when current flows through metal wiring materials, causing atoms constituting the wiring to move and creating holes (failures) in the wiring. Countermeasures include forming a layer of cobalt or cobalt alloy as a cap metal around copper wiring, or using cobalt or cobalt alloy as the metal wiring material itself. However, conventional cleaning agents and methods have made it difficult to remove photoresist patterns and dry etching residues while suppressing the corrosion of cobalt or cobalt alloys. Therefore, there has been a need for a cleaning agent that can remove photoresist patterns and dry etching residues while suppressing cobalt corrosion. Therefore, the problem that the present invention aims to solve is to provide a semiconductor substrate cleaning composition that can suppress the corrosion of cobalt when cleaning a semiconductor substrate containing cobalt. [Means for solving the problem]

[0006] The present invention provides the following semiconductor substrate cleaning compositions. <1> A semiconductor substrate cleaning composition comprising an alkali compound (A), a corrosion inhibitor (B), and water, wherein the alkali compound (A) is at least one selected from the group consisting of quaternary ammonium hydroxide (A1) and potassium hydroxide (A2), and the corrosion inhibitor (B) is at least one selected from the group consisting of 4-substituted pyrazoles, potassium tris(1-pyrazolyl)borohydride, 2-(4-thiazolyl)benzimidazole, and halogenated-8-hydroxyquinolines. <2> The corrosion inhibitor (B) is at least one selected from the group consisting of 4-bromo-1H-pyrazole, 2-(4-thiazolyl)benzimidazole, 4-chloro-1H-pyrazole, 4-methylpyrazole, 8-hydroxy-7-iodoquinoline-5-sulfonic acid, 5-chloro-8-hydroxy-7-iodoquinoline, 5-chloro-8-hydroxyquinoline, 7-bromo-5-chloro-8-hydroxyquinoline, potassium tris(1-pyrazolyl)borohydride, and 5,7-diiodo-8-hydroxyquinoline. <1> The semiconductor substrate cleaning composition described above. <3> The content of the alkali compound (A) is 0.005 to 35% by mass in the semiconductor substrate cleaning composition. <1> or <2> The semiconductor substrate cleaning composition described above. <4> The content of the aforementioned corrosion inhibitor (B) is 0.05 to 3% by mass in the semiconductor substrate cleaning composition, <1> ~ <3> A semiconductor substrate cleaning composition as described in any of the following. <5> The water content in the semiconductor substrate cleaning composition is 7 to 99.945% by mass. <1> ~ <4> A semiconductor substrate cleaning composition as described in any of the following. <6> The composition further contains an organic solvent (C), wherein the content of the organic solvent (C) is 0.0001 to 40% by mass in the semiconductor substrate cleaning composition. <1> ~ <5> A semiconductor substrate cleaning composition as described in any of the following. <7> The organic solvent (C) is at least one selected from the group consisting of alkylene glycol alkyl ethers and alcohols. <6> The semiconductor substrate cleaning composition described above. <8> The above, where the pH is 7 or higher. <1> ~ <7> A semiconductor substrate cleaning composition as described in any of the following. <9> The quaternary ammonium hydroxide (A1) is at least one selected from the group consisting of tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, and benzyltrimethylammonium hydroxide. <1> ~ <8> A semiconductor substrate cleaning composition as described in any of the following. <10> The above is for cleaning semiconductor substrates containing cobalt. <1> ~ <9> A semiconductor substrate cleaning composition as described in any of the following. <11> The aforementioned <1> ~ <10> A method for cleaning a semiconductor substrate, comprising cleaning a cobalt-containing semiconductor substrate using a semiconductor substrate cleaning composition described in any of the above. <12> The aforementioned <1> ~ <10> A method for cleaning a semiconductor substrate, comprising using a semiconductor substrate cleaning composition described in any of the above, to remove at least one selected from the group consisting of dry etching residue and photoresist from the semiconductor substrate. <13> The aforementioned <1> ~ <10> A method for manufacturing a semiconductor substrate, comprising the step of removing at least one selected from the group consisting of dry etching residue and photoresist from a semiconductor substrate using a semiconductor substrate cleaning composition described in any of the above. <14> A method for inhibiting cobalt corrosion, comprising using a composition containing water and an alkali compound (A) selected from the group consisting of quaternary ammonium hydroxide (A1) and potassium hydroxide (A2) to clean a semiconductor substrate containing cobalt, and inhibiting the corrosion of cobalt with a corrosion inhibitor (B) selected from the group consisting of 4-substituted pyrazoles, potassium tris(1-pyrazolyl)borohydride, 2-(4-thiazolyl)benzimidazole, and halogenated-8-hydroxyquinolines. [Effects of the Invention]

[0007] The semiconductor substrate cleaning composition of the present invention can suppress cobalt corrosion when cleaning a semiconductor substrate containing cobalt. [Modes for carrying out the invention]

[0008] The present invention relates to a semiconductor substrate cleaning composition containing an alkali compound (A), a corrosion inhibitor (B), and water, wherein the alkali compound (A) is at least one selected from the group consisting of quaternary ammonium hydroxide (A1) and potassium hydroxide (A2), and the corrosion inhibitor (B) is at least one selected from the group consisting of 4-substituted pyrazoles, potassium tris(1-pyrazolyl)borohydride, 2-(4-thiazolyl)benzimidazole, and halogenated-8-hydroxyquinolines, and a cleaning method using the semiconductor substrate cleaning composition.

[0009] [Composition for cleaning semiconductor substrates] The semiconductor substrate cleaning composition of the present invention is a semiconductor substrate cleaning composition containing an alkaline compound (A), a corrosion inhibitor (B), and water, wherein the alkaline compound (A) is at least one selected from the group consisting of quaternary ammonium hydroxide (A1) and potassium hydroxide (A2), and the corrosion inhibitor (B) is at least one selected from the group consisting of 4-substituted pyrazoles, potassium tris(1-pyrazolyl)borohydride, 2-(4-thiazolyl)benzimidazole, and halogenated-8-hydroxyquinolines. The semiconductor substrate cleaning composition of the present invention preferably contains an alkaline compound (A), a corrosion inhibitor (B), and water, wherein the alkaline compound (A) is at least one selected from the group consisting of quaternary ammonium hydroxide (A1) and potassium hydroxide (A2), and the corrosion inhibitor (B) is at least one selected from the group consisting of 4-bromo-1H-pyrazole, 2-(4-thiazolyl)benzimidazole, 4-chloro-1H-pyrazole, 4-methylpyrazole, 8-hydroxy-7-iodoquinoline-5-sulfonic acid, 5-chloro-8-hydroxy-7-iodoquinoline, 5-chloro-8-hydroxyquinoline, 7-bromo-5-chloro-8-hydroxyquinoline, potassium tris(1-pyrazolyl)borohydride, and 5,7-diiodo-8-hydroxyquinoline.

[0010] <Alkaline compound (A)> The semiconductor substrate cleaning composition of the present invention contains an alkaline compound (A). The alkali compound (A) is at least one selected from the group consisting of quaternary ammonium hydroxide (A1) and potassium hydroxide (A2). The semiconductor substrate cleaning composition of the present invention, by containing an alkaline compound (A), effectively removes photoresist and dry etching residue, and suppresses damage to low dielectric constant interlayer insulating films and metal wiring. Quaternary ammonium hydroxide (A1) and potassium hydroxide (A2) may be used individually or in combination. In particular, including both quaternary ammonium hydroxide (A1) and potassium hydroxide (A2) as the alkali compound (A) is preferable because it reduces corrosion of the metal constituting the semiconductor substrate.

[0011] The quaternary ammonium hydroxide (A1) 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, with tetramethylammonium hydroxide being more preferred.

[0012] The content of alkali compound (A) in the semiconductor substrate cleaning composition is preferably 0.005 to 35% by mass, more preferably 0.3 to 30% by mass, even more preferably 3 to 25% by mass, and even more preferably 5 to 20% by mass. The content of quaternary ammonium hydroxide (A1) in the semiconductor substrate cleaning composition is preferably 1 to 30% by mass, more preferably 2 to 25% by mass, and even more preferably 3 to 20% by mass. The content of potassium hydroxide (A2) is preferably 0.005 to 5% by mass, more preferably 0.01 to 4.5% by mass, still more preferably 0.05 to 4% by mass, and even more preferably 0.1 to 4% by mass in the semiconductor substrate cleaning composition. When the content of the alkali compound (A) is within the above range, the solubility of the corrosion inhibitor (B) becomes good, which is preferable. When the content of the quaternary ammonium hydroxide (A1) is within the above range, the solubility of the corrosion inhibitor (B) becomes good, which is preferable. When the content of potassium hydroxide (A2) is within the above range, the solubility of the corrosion inhibitor (B) becomes good, and furthermore, the removal performance of the sacrificial layer is enhanced, so it is preferable.

[0013] <Corrosion inhibitor (B)> The semiconductor substrate cleaning composition of the present invention contains a corrosion inhibitor (B), and the corrosion inhibitor (B) is at least one selected from the group consisting of 4-substituted pyrazoles, potassium tris(1-pyrazolyl)borohydride, 2-(4-thiazolyl)benzimidazole, and halogenated-8-hydroxyquinolines. Among these, preferred corrosion inhibitors (B) are at least one selected from the group consisting of 4-bromo-1H-pyrazole, 2-(4-thiazolyl)benzimidazole, 4-chloro-1H-pyrazole, 4-methylpyrazole, 8-hydroxy-7-iodoquinoline-5-sulfonic acid, 5-chloro-8-hydroxy-7-iodoquinoline, 5-chloro-8-hydroxyquinoline, 7-bromo-5-chloro-8-hydroxyquinoline, potassium tris(1-pyrazolyl)borohydride, and 5,7-diiodo-8-hydroxyquinoline. By containing the corrosion inhibitor (B), the semiconductor substrate cleaning composition of the present invention can suppress the corrosion of cobalt particularly when cleaning a semiconductor substrate containing cobalt. The reason why the semiconductor substrate cleaning composition of the present invention can particularly suppress the corrosion of cobalt is not clear, but it is thought that the corrosion inhibitor (B) is adsorbed onto the cobalt surface and forms a protective film (passivation layer), thereby suppressing the elution of cobalt into the semiconductor substrate cleaning composition.

[0014] The corrosion inhibitor (B) is at least one selected from the group consisting of 4-substituted pyrazoles, potassium tris(1-pyrazolyl)borohydride, 2-(4-thiazolyl)benzimidazole, and halogenated-8-hydroxyquinolines. Preferred corrosion inhibitor (B) is at least one selected from the group consisting of 4-bromo-1H-pyrazole, 2-(4-thiazolyl)benzimidazole, 4-chloro-1H-pyrazole, 4-methylpyrazole, 8-hydroxy-7-iodoquinoline-5-sulfonic acid, 5-chloro-8-hydroxy-7-iodoquinoline, 5-chloro-8-hydroxyquinoline, 7-bromo-5-chloro-8-hydroxyquinoline, potassium tris(1-pyrazolyl)borohydride, and 5,7-diiodo-8-hydroxyquinoline. Among these, from the viewpoint of suppressing the corrosion of cobalt constituting the semiconductor substrate, it is preferable to have at least one selected from the group consisting of 4-bromo-1H-pyrazole, 2-(4-thiazolyl)benzimidazole, 4-chloro-1H-pyrazole, 4-methylpyrazole, 5-chloro-8-hydroxy-7-iodoquinoline, 5-chloro-8-hydroxyquinoline, 7-bromo-5-chloro-8-hydroxyquinoline, potassium tris(1-pyrazol)borohydride, and 5,7-diiodo-8-hydroxyquinoline, and more preferably 4-bromo-1H-pyrazole, 2-(4-thiazolyl)benzimidazole, 4-chloro-1H-pyrazole, 4-methylpyrazole, 5-chloro-8-hydroxy-7-iodoquinoline, 7-bromo-5-chloro-8-hydroxyquinoline, potassium tris(1-pyrazol)borohydride, and 5,It is at least one selected from the group consisting of 7-iodo-8-hydroxyquinoline. From the viewpoint of suppressing the corrosion of cobalt in the semiconductor substrate cleaning composition having a wide composition range, more preferably, it is at least one selected from the group consisting of 4-bromo-1H-pyrazole, 2-(4-thiazolyl)benzimidazole, 4-chloro-1H-pyrazole, 4-methylpyrazole, 5-chloro-8-hydroxy-7-iodoquinoline, 7-bromo-5-chloro-8-hydroxyquinoline, and potassium tris(1-pyrazolyl)borohydride. From the viewpoint of suppressing the corrosion of cobalt even with a small addition amount, even more preferably, it is at least one selected from the group consisting of 4-bromo-1H-pyrazole, 4-chloro-1H-pyrazole, 4-methylpyrazole, 5-chloro-8-hydroxy-7-iodoquinoline, 7-bromo-5-chloro-8-hydroxyquinoline, and potassium tris(1-pyrazolyl)borohydride. Even more preferably, it is at least one selected from the group consisting of 4-bromo-1H-pyrazole, 4-chloro-1H-pyrazole, 4-methylpyrazole, 7-bromo-5-chloro-8-hydroxyquinoline, and potassium tris(1-pyrazolyl)borohydride. Even more preferably, it is at least one selected from the group consisting of 4-chloro-1H-pyrazole, 7-bromo-5-chloro-8-hydroxyquinoline, and potassium tris(1-pyrazolyl)borohydride.,

[0015] When the semiconductor substrate cleaning composition of the present invention contains both a quaternary ammonium hydroxide (A1) and potassium hydroxide (A2) as the alkali compound (A), the corrosion prevention properties of each compound of the corrosion inhibitor (B) change depending on the mass ratio [(A1) / (A2)] of the quaternary ammonium hydroxide (A1) and potassium hydroxide (A2). The reason is not clear, but it is considered that potassium ions and tetramethylammonium ions affect the coordination to the corrosion inhibitor or the adsorption on the surface of cobalt., When the mass ratio of quaternary ammonium hydroxide (A1) and potassium hydroxide (A2) [(A1) / (A2)] is 10 or more, the corrosion inhibitor (B) is preferably at least one selected from the group consisting of 4-bromo-1H-pyrazole, 2-(4-thiazolyl)benzimidazole, 4-chloro-1H-pyrazole, 4-methylpyrazole, 5-chloro-8-hydroxy-7-iodoquinoline, 7-bromo-5-chloro-8-hydroxyquinoline, potassium tris(1-pyrazolyl)borohydride, and 5,7-diiodo-8-hydroxyquinoline, more preferably 4-bromo-1H- At least one selected from the group consisting of pyrazole, 4-chloro-1H-pyrazole, 4-methylpyrazole, 5-chloro-8-hydroxy-7-iodoquinoline, 7-bromo-5-chloro-8-hydroxyquinoline, potassium tris(1-pyrazolyl)borohydride, and 5,7-diiodo-8-hydroxyquinoline, more preferably at least one selected from the group consisting of 4-chloro-1H-pyrazole, 5-chloro-8-hydroxy-7-iodoquinoline, 7-bromo-5-chloro-8-hydroxyquinoline, and 5,7-diiodo-8-hydroxyquinoline.

[0016] If the mass ratio [(A1) / (A2)] of quaternary ammonium hydroxide (A1) and potassium hydroxide (A2) is less than 10, the corrosion inhibitor (B) is preferably at least one selected from the group consisting of 4-bromo-1H-pyrazole, 2-(4-thiazolyl)benzimidazole, 4-chloro-1H-pyrazole, 4-methylpyrazole, 5-chloro-8-hydroxyquinoline, and potassium tris(1-pyrazol)borohydride, more preferably at least one selected from the group consisting of 4-bromo-1H-pyrazole, 2-(4-thiazolyl)benzimidazole, 4-chloro-1H-pyrazole, and 4-methylpyrazole, and even more preferably at least one selected from the group consisting of 4-bromo-1H-pyrazole and 4-chloro-1H-pyrazole.

[0017] As described above, the corrosion inhibitor (B) used in the semiconductor substrate cleaning composition of the present invention is at least one selected from the group consisting of 4-substituted pyrazoles, potassium tris(1-pyrazolyl)borohydride, 2-(4-thiazolyl)benzimidazole, and halogenated-8-hydroxyquinolines. Among the 4-substituted pyrazoles, 4-halogenated pyrazoles in which the 4th position is substituted with a halogen are preferred, and 4-chloropyrazoles in which the 4th position is substituted with a chlorine atom are more preferred. Among the halogenated-8-hydroxyquinolines, 7-halogenated-8-hydroxyquinolines in which the 7th position is substituted with a halogen are preferred, and 5-chloro-7-halogenated-8-hydroxyquinolines in which the 5th position is substituted with chlorine are more preferred.

[0018] The content of the corrosion inhibitor (B) in the semiconductor substrate cleaning composition is preferably 0.0001 to 10% by mass, more preferably 0.001 to 5% by mass, even more preferably 0.005 to 5% by mass, even more preferably 0.01 to 5% by mass, even more preferably 0.01 to 3% by mass, even more preferably 0.05 to 3% by mass, even more preferably 0.1 to 2.5% by mass, and even more preferably 0.2 to 2.0% by mass.

[0019] To give specific examples of compounds, for example, 7-bromo-5-chloro-8-hydroxyquinoline is preferably present in the semiconductor substrate cleaning composition at a concentration of 0.01 to 2% by mass, more preferably 0.05 to 1% by mass, even more preferably 0.1 to 0.5% by mass, and even more preferably 0.15 to 0.3% by mass. 4-chloro-1H-pyrazole is preferably present in the semiconductor substrate cleaning composition at a concentration of 0.1 to 5% by mass, more preferably 0.3 to 4% by mass, even more preferably 0.5 to 3% by mass, and even more preferably 1.0 to 2.5% by mass. Potassium tris(1-pyrazolyl)borohydride is preferably present in the semiconductor substrate cleaning composition at a concentration of 0.01 to 2% by mass, more preferably 0.05 to 1% by mass, even more preferably 0.1 to 0.5% by mass, and even more preferably 0.15 to 0.3% by mass.

[0020] 5-Chloro-8-hydroxy-7-iodoquinoline is preferably present in the semiconductor substrate cleaning composition at a concentration of 0.01 to 2% by mass, more preferably at 0.05 to 1% by mass, even more preferably at 0.1 to 0.5% by mass, and even more preferably at 0.15 to 0.3% by mass. 5,7-Diiodo-8-hydroxyquinoline is preferably present in the semiconductor substrate cleaning composition at a concentration of 0.01 to 2% by mass, more preferably at 0.05 to 1% by mass, even more preferably at 0.1 to 0.5% by mass, and even more preferably at 0.15 to 0.3% by mass. 4-bromo-1H-pyrazole is preferably present in the semiconductor substrate cleaning composition at a concentration of 0.1 to 5% by mass, more preferably 0.3 to 4% by mass, even more preferably 0.5 to 3% by mass, and even more preferably 1.0 to 2.5% by mass.

[0021] The content of the corrosion inhibitor (B) being within the above-mentioned range allows for the inhibition of cobalt corrosion, and is also economically advantageous.

[0022] <Water> The semiconductor substrate cleaning composition of the present invention contains water. While the water is not particularly limited, it is preferable to use water from which metal ions, organic impurities, and particles have been removed by distillation, ion exchange treatment, filtering, or various adsorption treatments. Pure water is more preferable, and ultrapure water is especially preferable. The water content in the semiconductor substrate cleaning composition is preferably 7 to 99.99% by mass, more preferably 7 to 99.945% by mass, and the remainder after removing the alkali compound (A) and corrosion inhibitor (B) may be water. Furthermore, when using the organic solvent (C) described later, the remainder after removing the alkali compound (A), corrosion inhibitor (B), and organic solvent (C) may be water. The water content in the semiconductor substrate cleaning composition is more preferably 10 to 99% by mass, even more preferably 20 to 90% by mass, even more preferably 30 to 80% by mass, and even more preferably 40 to 70% by mass. When the water content is within the above range, the effects of the present invention can be achieved, and it is also more economical.

[0023] <Organic solvent (C)> The semiconductor substrate cleaning composition of the present invention preferably further contains an organic solvent (C), and the content of the organic solvent (C) is preferably 0.0001 to 40% by mass in the semiconductor substrate cleaning composition.

[0024] The organic solvent (C) is preferably at least one selected from the group consisting of alkylene glycol alkyl ethers and alcohols, and more preferably alcohols. Examples of alcohols include monohydric alcohols and polyhydric alcohols, with polyhydric alcohols being preferred. Examples of polyhydric alcohols include ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, and glycerin. Examples of alkylene glycol alkyl ethers include polyalkylene glycol monoalkyl ethers, monoalkylene glycol monoalkyl ethers, polyalkylene glycol polyalkyl ethers, and monoalkylene glycol polyalkyl ethers, with polyalkylene glycol monoalkyl ethers being preferred. Examples of polyalkylene glycol monoalkyl ethers include diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, and dipropylene glycol monomethyl ether. The content of organic solvent (C) in the semiconductor substrate cleaning composition is preferably 0.0001 to 40% by mass, more preferably 1 to 40% by mass, even more preferably 10 to 37% by mass, and even more preferably 20 to 35% by mass. A content of organic solvent (C) within the above range is preferable because it suppresses damage to the metal wiring material.

[0025] <Characteristics of compositions for cleaning semiconductor substrates> The pH of the semiconductor substrate cleaning composition of the present invention is preferably 7 or higher, more preferably 10 to 14, even more preferably 12 to 14, even more preferably 13 to 14, and even more preferably 13.5 to 14. By maintaining the pH within the aforementioned range, it is possible to prevent cobalt corrosion while improving the cleanability of the photoresist. Furthermore, it is also possible to improve the cleanability of the sacrificial layer.

[0026] The semiconductor substrate cleaning composition of the present invention is preferably for cleaning semiconductor substrates containing cobalt. The semiconductor substrate cleaning composition of the present invention can suppress the corrosion of cobalt when cleaning a semiconductor substrate containing cobalt. Cobalt is used as a metal wiring in the semiconductor substrate. Examples of cobalt include metallic cobalt and cobalt alloys.

[0027] In addition to the components described above, the semiconductor substrate cleaning composition of the present invention may contain other components as long as they do not impair the purpose of the present invention. For example, surfactants, defoamers, dissolved oxygen removers, etc., may be added.

[0028] Although they have a similar structure to the corrosion inhibitor (B), it is preferable that the following compounds are substantially excluded from the semiconductor substrate cleaning composition of the present invention. Compounds that are preferably substantially excluded from the semiconductor substrate cleaning composition of the present invention include 1-amino-2-naphthol-4-sulfonic acid, sodium m-nitrobenzenesulfonate, disodium 3-hydroxy-4-nitroso-2,7-naphthalenedisulfonate, 2-pyridinecarboxylic acid, dimethyl acetylenedicarboxylic acid, 5-chlorobenzotriazole, sodium 1-(m-sulfophenyl)-5-mercapto-1H-tetrazole, 3-nitropyrazole, and N,N'-carbonyldiimidazole. By excluding these compounds, the corrosion of cobalt can be effectively suppressed.

[0029] Furthermore, it is preferable that the semiconductor substrate cleaning composition of the present invention substantially does not contain sodium hydroxide. By not including sodium hydroxide, the influence of the cleaning composition on the electrical properties of the semiconductor can be suppressed, and the yield can be improved.

[0030] [Method for cleaning semiconductor substrates] The present invention relates to a method for cleaning a semiconductor substrate, which involves cleaning the semiconductor substrate using the semiconductor substrate cleaning composition. In particular, it is preferable to use the semiconductor substrate cleaning composition to clean a semiconductor substrate containing cobalt. According to the present invention's cleaning method, even when cleaning a semiconductor substrate containing cobalt, the corrosion of the cobalt can be suppressed. Cobalt is used in semiconductor substrates as metal wiring, barrier metal, plating seed layers, etc. Examples of cobalt include metallic cobalt and cobalt alloys. Furthermore, the semiconductor substrate cleaning method of the present invention 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 residue and photoresist in the semiconductor substrate. In particular, in order to maximize the effects of the present invention, the semiconductor substrate cleaning method of the present invention is more preferably a cleaning method that uses the semiconductor substrate cleaning composition to clean a semiconductor substrate containing cobalt and remove at least one selected from the group consisting of dry etching residue and photoresist in the semiconductor substrate.

[0031] The cleaning temperature in the cleaning method of the present invention is not particularly limited, but is preferably 10 to 85°C, and more preferably 30 to 70°C. Ultrasound may also be used during cleaning. The cleaning time in the cleaning method of the present invention is not particularly limited, but is preferably 0.1 to 120 minutes, and more preferably 1 to 60 minutes. Furthermore, it is preferable to rinse with a rinsing solution containing water or alcohol after cleaning.

[0032] In the cleaning method of the present invention, the method of bringing the semiconductor substrate cleaning composition of the present invention into contact with the semiconductor substrate is not particularly limited. For example, the semiconductor substrate cleaning composition of the present invention may be brought into contact with the semiconductor substrate by dropping (single-wafer spin treatment) or spraying (aerosol treatment), or the semiconductor substrate may be immersed in the semiconductor substrate cleaning composition of the present invention. Any of these methods may be used in the present invention.

[0033] [Methods for inhibiting cobalt corrosion] The aforementioned corrosion inhibitor (B) can effectively suppress cobalt corrosion during the cleaning of semiconductor substrates. In other words, the method for suppressing cobalt corrosion of the present invention is a method for suppressing cobalt corrosion by using a corrosion inhibitor (B) selected from the group consisting of 4-substituted pyrazoles, potassium tris(1-pyrazolyl)borohydride, 2-(4-thiazolyl)benzimidazole, and halogenated-8-hydroxyquinolines during the cleaning of a semiconductor substrate containing cobalt using a composition containing an alkali compound (A) selected from the group consisting of quaternary ammonium hydroxide (A1) and potassium hydroxide (A2), and water.

[0034] The corrosion inhibitor (B) and alkali compound (A) used in this method are the same as those described in the section on [Compositions for cleaning semiconductor substrates] above, and the preferred compounds and preferred ranges are also the same.

[0035] Furthermore, by using corrosion inhibitor (B), the corrosion of cobalt during the cleaning of semiconductor substrates can be suppressed to at least half (less than 50%).

[0036] [Manufacturing method for semiconductor substrates] The present invention provides a method for manufacturing a semiconductor substrate, comprising the step of removing at least one selected from the group consisting of dry etching residue and photoresist from the semiconductor substrate using the semiconductor substrate cleaning composition. In other words, the present invention provides a semiconductor substrate manufacturing method which includes a step of removing at least one selected from the group consisting of dry etching residue and photoresist from a semiconductor substrate using a semiconductor substrate cleaning composition containing an alkali compound (A) selected from the group consisting of quaternary ammonium hydroxide (A1) and potassium hydroxide (A2), a corrosion inhibitor (B) selected from the group consisting of 4-substituted pyrazoles, potassium tris(1-pyrazolyl)borohydride, 2-(4-thiazolyl)benzimidazole, and halogenated-8-hydroxyquinolines, and water. The specific method for manufacturing semiconductor substrates is shown below.

[0037] First, a barrier insulating film, a low dielectric constant interlayer insulating film, a hard mask, and a photoresist are laminated onto a substrate such as silicon having a barrier metal, metal wiring, a low dielectric constant interlayer insulating film, and optionally a cap metal. Alternatively, a barrier insulating film, a low dielectric constant interlayer insulating film, a hard mask, a sacrificial layer, and a photoresist are laminated onto the substrate. Then, the photoresist is subjected to selective exposure and development to form a photoresist pattern. Next, the hard mask, the low dielectric constant interlayer insulating film, and the barrier insulating film are subjected to dry etching using the photoresist pattern as an etching mask. Subsequently, the above-mentioned step of removing at least one selected from the group consisting of dry etching residue and photoresist from the semiconductor substrate using the semiconductor substrate cleaning composition is performed to obtain a semiconductor substrate having the desired metal wiring pattern.

[0038] Here, silicon, amorphous silicon, polysilicon, glass, etc. are used as substrate materials. Tantalum, tantalum nitride, ruthenium, manganese, magnesium, cobalt, and their oxides are used as barrier metals. Copper or copper alloys, cobalt or cobalt alloys formed as cap metals on copper or copper alloys, cobalt or cobalt alloys are used as metal wiring. 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 as low dielectric constant interlayer insulating films. As barrier insulating films, silicon nitride, silicon carbide, silicon carbide nitride, etc., are used. As hard masks, titanium, titanium nitride, etc., are used. Organosiloxane-based materials are used as the sacrificial layer.

[0039] The semiconductor substrate manufacturing method of the present invention includes a step of removing unwanted components using the semiconductor substrate cleaning composition, thereby enabling the production of high-precision, high-quality semiconductor substrates with a high yield. [Examples]

[0040] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0041] <Analysis Methods and Evaluation Methods> (1) pH The pH of the semiconductor substrate cleaning composition was measured using the glass electrode method (HORIBA F-55S benchtop pH meter, HORIBA Standard ToupH electrode 9165S-10D, temperature: 25°C).

[0042] (2) Evaluation of cobalt (Co) corrosion The Etching Rate (ER) (Å / min) when a Co blanket wafer was immersed in the semiconductor substrate cleaning composition obtained in the examples and comparative examples was calculated by the following method. A PVD-Co blanket wafer manufactured by a domestic manufacturer was cut into 2cm squares and immersed in 10g of a semiconductor substrate cleaning composition weighed into a polypropylene (PP) container at 45°C for 1 minute. After immersion, the cut Co blanket wafer was removed from the semiconductor substrate cleaning composition, and the Co ion concentration contained in the semiconductor substrate cleaning composition was measured using ICP-AES. The film thickness of dissolved Co was calculated from the measured value, and the etching rate was calculated by dividing this value by the processing time. A lower etching rate indicates better control over cobalt corrosion. Furthermore, the corrosion-inhibiting effect (corrosion protection) of corrosion inhibitor (B), etc. (corrosion inhibitor (B) and the comparative example compounds) can be determined as follows: If the Etching Rate value when corrosion inhibitor (B), etc. is added (for example, Examples 1 to 10, Comparative Examples 2 to 9) is less than half (50%) of the Etching Rate value when corrosion inhibitor (B), etc. is not added (for example, Comparative Example 1), then corrosion inhibitor (B), etc. (corrosion inhibitor (B) and the comparative example compounds) have a corrosion-inhibiting effect (corrosion protection).

[0043] (3) Evaluation of organosiloxane-based sacrificial layer removal capability In the semiconductor substrate cleaning compositions obtained in the examples and comparative examples, organosiloxane-based thin film blanket wafers with a film thickness of 2000 Å were immersed in the compositions for cleaning semiconductor substrates at 45°C for 10 seconds, and the film thickness was measured using an N&K Analyzer 1280 from N&K Technology. If the film thickness was 0 Å, the organosiloxane-based sacrificial layer was removed, indicating that the semiconductor substrate cleaning compositions have excellent sacrificial layer removal properties.

[0044] <Composition for cleaning semiconductor substrates> Example 1 A semiconductor substrate cleaning composition was prepared by blending 16 parts by mass of tetramethylammonium hydroxide, 0.15 parts by mass of potassium hydroxide, 25 parts by mass of glycerin, and 2.0 parts by mass of 4-bromo-1H-pyrazole as a corrosion inhibitor (B). This mixture was then diluted with ultrapure water to a total volume of 100 parts by mass. Table 1 shows the percentage amounts of each component. The cobalt corrosiveness of the obtained semiconductor substrate cleaning composition was evaluated. The results are shown in Table 1. Furthermore, when the obtained semiconductor substrate cleaning composition was used to evaluate its ability to remove organosiloxane-based sacrificial layers, it was found that the sacrificial layer could be removed. The content of corrosion inhibitor (B) used in the examples and the content of compounds used in the comparative examples, as shown in the "Corrosion Inhibitor (B), etc." column of Tables 1 and 2, are expressed as mass percentages (mass%) relative to the semiconductor substrate cleaning composition. Similarly, the content of each component, as shown in the "Composition of Cleaning Composition" column of Tables 1 and 2, are also expressed as mass percentages (mass%) relative to the semiconductor substrate cleaning composition.

[0045] Examples 2-10 A semiconductor substrate cleaning composition was obtained in the same manner as in Example 1, except that 2.0 parts by mass of 4-bromo-1H-pyrazole was replaced with the compounds shown in the "Corrosion Inhibitor (B), etc." column of Table 1 in the amounts shown in Table 1. The cobalt corrosiveness of the obtained semiconductor substrate cleaning composition was evaluated. The results are shown in Table 1. Furthermore, when the organosiloxane-based sacrificial layer removal capabilities were evaluated using the semiconductor substrate cleaning compositions obtained in Examples 2 to 10, the sacrificial layer was successfully removed in all cases.

[0046] Comparative Example 1 A semiconductor substrate cleaning composition was obtained in the same manner as in Example 1, except that 4-bromo-1H-pyrazole was not included. The cobalt corrosiveness of the obtained semiconductor substrate cleaning composition was evaluated. The results are shown in Table 1.

[0047] Comparative Examples 2-9 A semiconductor substrate cleaning composition was obtained in the same manner as in Example 1, except that 2.0 parts by mass of 4-bromo-1H-pyrazole was replaced with the compounds shown in the "Corrosion Inhibitor (B), etc." column of Table 1, in the amounts shown in Table 1. The cobalt corrosiveness of the obtained semiconductor substrate cleaning composition was evaluated. The results are shown in Table 1.

[0048] [Table 1]

[0049] Example 11 A semiconductor substrate cleaning composition was prepared by blending 12 parts by mass of tetramethylammonium hydroxide, 4 parts by mass of potassium hydroxide, 25 parts by mass of glycerin, and 2.0 parts by mass of 4-bromo-1H-pyrazole as a corrosion inhibitor (B). The mixture was then diluted with ultrapure water to a total volume of 100 parts by mass. Table 2 shows the percentage amounts of each component. The cobalt corrosiveness of the obtained semiconductor substrate cleaning composition was evaluated. The results are shown in Table 2.

[0050] Examples 12-20 A semiconductor substrate cleaning composition was obtained in the same manner as in Example 11, except that 2.0 parts by mass of 4-bromo-1H-pyrazole was replaced with the compounds shown in the "Corrosion Inhibitor (B), etc." column of Table 2, in the amounts shown in Table 2, as the corrosion inhibitor (B). The obtained semiconductor substrate cleaning composition was used to evaluate its cobalt corrosivity. The results are shown in Table 2.

[0051] Comparative Example 10 A semiconductor substrate cleaning composition was obtained in the same manner as in Example 11, except that 4-bromo-1H-pyrazole was not included. The cobalt corrosiveness of the obtained semiconductor substrate cleaning composition was evaluated. The results are shown in Table 2.

[0052] Comparative Examples 11-18 A semiconductor substrate cleaning composition was obtained in the same manner as in Example 11, except that 2.0 parts by mass of 4-bromo-1H-pyrazole was replaced with the compounds shown in the "Corrosion Inhibitor (B), etc." column of Table 2, in the amounts shown in Table 2. The cobalt corrosiveness of the obtained semiconductor substrate cleaning composition was evaluated. The results are shown in Table 2.

[0053] [Table 2]

[0054] As can be seen from the results of the examples shown in Tables 1 and 2, the semiconductor substrate cleaning composition of the present invention can suppress cobalt corrosion even when cleaning semiconductor substrates containing cobalt. From this, it can be seen that the semiconductor substrate cleaning composition of the present invention is useful as a cleaning agent that can remove photoresist patterns and dry etching residues while suppressing the corrosion of cobalt and cobalt alloys. The cleaning composition used in the example in Table 1 and the cleaning composition used in the example in Table 2 have different alkali compound contents, but both show an excellent cobalt corrosion suppression effect. From this, it can be seen that cleaning is possible while suppressing cobalt corrosion under a wide range of cleaning conditions and on various objects. Furthermore, although the compound used in the comparative example was similar to the compound used as the corrosion inhibitor (B) in the semiconductor substrate cleaning composition of the example, it was unable to sufficiently suppress the corrosion of cobalt.

Claims

1. A composition for cleaning semiconductor substrates, comprising an alkaline compound (A), a corrosion inhibitor (B), and water, The alkali compound (A) is at least one selected from the group consisting of quaternary ammonium hydroxide (A1) and potassium hydroxide (A2). A semiconductor substrate cleaning composition wherein the corrosion inhibitor (B) is at least one selected from the group consisting of 4-bromo-1H-pyrazole, 2-(4-thiazolyl)benzimidazole, 4-chloro-1H-pyrazole, 4-methylpyrazole, 8-hydroxy-7-iodoquinoline-5-sulfonic acid, 5-chloro-8-hydroxy-7-iodoquinoline, 5-chloro-8-hydroxyquinoline, 7-bromo-5-chloro-8-hydroxyquinoline, potassium tris(1-pyrazolyl)borohydride, and 5,7-diiodo-8-hydroxyquinoline.

2. The semiconductor substrate cleaning composition according to claim 1, wherein the alkali compound (A) comprises both quaternary ammonium hydroxide (A1) and potassium hydroxide (A2).

3. The semiconductor substrate cleaning composition according to claim 1 or 2, wherein the content of the alkali compound (A) in the semiconductor substrate cleaning composition is 0.005 to 35% by mass.

4. The semiconductor substrate cleaning composition according to any one of claims 1 to 3, wherein the content of the corrosion inhibitor (B) is 0.05 to 3% by mass in the semiconductor substrate cleaning composition.

5. The semiconductor substrate cleaning composition according to any one of claims 1 to 4, wherein the water content is 7 to 99.945% by mass in the semiconductor substrate cleaning composition.

6. The semiconductor substrate cleaning composition according to any one of claims 1 to 5, further containing an organic solvent (C), wherein the content of the organic solvent (C) is 0.0001 to 40% by mass in the semiconductor substrate cleaning composition.

7. The semiconductor substrate cleaning composition according to claim 6, wherein the organic solvent (C) is at least one selected from the group consisting of alkylene glycol alkyl ethers and alcohols.

8. A semiconductor substrate cleaning composition according to any one of claims 1 to 7, wherein the pH is 7 or higher.

9. The semiconductor substrate cleaning composition according to any one of claims 1 to 8, wherein the quaternary ammonium hydroxide (A1) is at least one selected from the group consisting of tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, and benzyltrimethylammonium hydroxide.

10. A semiconductor substrate cleaning composition according to any one of claims 1 to 9, for cleaning semiconductor substrates containing cobalt.

11. A method for cleaning a semiconductor substrate, comprising cleaning a semiconductor substrate containing cobalt using the semiconductor substrate cleaning composition described in any one of claims 1 to 10.

12. A method for cleaning a semiconductor substrate, comprising using a semiconductor substrate cleaning composition according to any one of claims 1 to 10 to remove at least one selected from the group consisting of dry etching residue and photoresist from the semiconductor substrate.

13. A method for manufacturing a semiconductor substrate, comprising the step of removing at least one selected from the group consisting of dry etching residue and photoresist from a semiconductor substrate using a semiconductor substrate cleaning composition according to any one of claims 1 to 10.

14. A method for inhibiting cobalt corrosion, wherein when cleaning a semiconductor substrate containing cobalt using a composition containing water and an alkali compound (A) selected from the group consisting of quaternary ammonium hydroxide (A1) and potassium hydroxide (A2), the corrosion of cobalt is inhibited by an anticorrosive agent (B) selected from the group consisting of 4-bromo-1H-pyrazole, 2-(4-thiazolyl)benzimidazole, 4-chloro-1H-pyrazole, 4-methylpyrazole, 8-hydroxy-7-iodoquinoline-5-sulfonic acid, 5-chloro-8-hydroxy-7-iodoquinoline, 5-chloro-8-hydroxyquinoline, 7-bromo-5-chloro-8-hydroxyquinoline, potassium tris(1-pyrazolyl)borohydride, and 5,7-diiodo-8-hydroxyquinoline.

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