Semiconductor substrate cleaning composition and cleaning method

Abstract

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

Description

Technical Field

[0001] This invention relates to a composition and a cleaning method for semiconductor substrates. Prior Technology

[0002] In the manufacturing of highly integrated semiconductor substrates, the process typically involves forming conductive films such as metal films (which serve as conductive wiring materials), interlayer insulating films (for insulating between conductive films), hard masks, and sacrificial layers on a substrate such as a silicon wafer. A photoresist is then uniformly coated onto the surface to form a photosensitive layer, and selective exposure and development processes are performed to create the desired photoresist pattern. This photoresist pattern is then used as a mask and dry-etched onto a substrate with stacked interlayer insulating films and hard masks to form the desired pattern. Furthermore, the residue generated from the photoresist pattern and dry etching process (hereinafter referred to as "dry etching residue") is typically removed using an ashing process with oxygen plasma and a cleaning solution.

[0003] In treatments using cleaning solutions, it is known that photoresist can be removed by using alkaline cleaning solutions. However, alkaline cleaning solutions can sometimes damage the metal layer. Therefore, research has been conducted to improve cleaning performance while preventing the deterioration and corrosion of the metal layer. For example, Patent Document 1 discloses a processing liquid for semiconductor devices, which aims to improve the corrosion prevention of metal layers and the removal of inhibitors, and contains organic base compounds, corrosion inhibitors, organic solvents, Ca, Fe, and Na. Furthermore, Patent Document 2 discloses a stripping cleaning solution intended to prevent the deterioration of Low-k materials and Cu, and to remove metal residues, etc., comprising grade IV ammonium hydroxide, water-soluble organic solvent, water, corrosion inhibitor, and potassium hydroxide at a concentration of less than 1% by mass relative to the total amount. [Previous Technical Documents] [Patent Literature]

[0004] [Patent Document 1] International Publication No. 2017 / 208767 [Patent Document 2] Japanese Patent Publication No. 2006-527783 Summary of the Invention

[0005] [The problem that the invention aims to solve]

[0006] In recent years, due to advancements in design miniaturization, the current density of metal wiring has increased, leading to a stronger demand for countermeasures against electromigration that causes atomic movement within the wiring material during current flow, resulting in vacancies (failures) in the wiring. Countermeasures include forming a cobalt or cobalt alloy layer around the copper wiring as a capping metal, and using cobalt or cobalt alloy as the wiring material itself. However, it is difficult to simultaneously inhibit the corrosion of cobalt or cobalt alloy while removing photoresist patterns and dry etching residues using conventional cleaning agents and methods. Therefore, a cleaning agent capable of simultaneously inhibiting cobalt corrosion and removing photoresist patterns and dry etching residues is sought. Therefore, the problem to be solved by the present invention is to provide a composition for cleaning semiconductor substrates that can suppress cobalt corrosion when cleaning cobalt-containing semiconductor substrates. [Methods for solving problems]

[0007] The present invention provides the following composition for cleaning semiconductor substrates. <1> A composition for cleaning a semiconductor substrate comprises an alkaline compound (A), a etching inhibitor (B), and water. The alkaline compound (A) is selected from at least one of the group consisting of ammonium hydroxide (A1) and potassium hydroxide (A2). The etching inhibitor (B) is selected from at least one of the group consisting of 4-substituted pyrazoles, potassium triphenyl(1-pyrazolyl)borohydride, 2-(4-thiazolyl)benzimidazole, and halogenated 8-hydroxyquinoline compounds. <2> like <1> The composition for cleaning semiconductor substrates, wherein the resist (B) is selected from at least one of 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 triphenyl(1-pyrazolyl)borohydride, and 5,7-diiodo-8-hydroxyquinoline. <3> like <1> or <2> A composition for cleaning semiconductor substrates, wherein the content of the alkaline compound (A) is 0.005 to 35% by mass of the composition for cleaning semiconductor substrates. <4> like <1> to <3> The semiconductor substrate cleaning composition of any one of the above, wherein the content of the resist (B) is 0.05 to 3% by mass of the semiconductor substrate cleaning composition. <5> like <1> to <4> The semiconductor substrate cleaning composition of any one of the above, wherein the water content is 7 to 99.945% by mass of the semiconductor substrate cleaning composition. <6> like <1> to <5> The semiconductor substrate cleaning composition of any one of the above contains an organic solvent (C), the content of which is 0.0001 to 40% by mass of the semiconductor substrate cleaning composition. <7> like <6> The composition for cleaning semiconductor substrates, wherein the organic solvent (C) is selected from at least one of the groups consisting of alkyl diols, alkyl ethers, and alcohols. <8> like <1> to <7> The semiconductor substrate cleaning composition of any one of the following, wherein the pH is 7 or higher. <9> like <1> to <8> The semiconductor substrate cleaning composition of any one of the following, wherein the ammonium hydroxide (Al) is selected from at least one of the group consisting of tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, and benzyltrimethylammonium hydroxide. <10> like <1> to <9> The semiconductor substrate cleaning composition of any one of the above is used for cleaning cobalt-containing semiconductor substrates. <11> A method for cleaning a semiconductor substrate, which uses, for example <1> to <10> The semiconductor substrate cleaning composition of any one of the above is used to clean cobalt-containing semiconductor substrates. <12> A method for cleaning a semiconductor substrate, which uses, for example <1> to <10> The semiconductor substrate cleaning composition of any one of the following is used to remove at least one of the group consisting of dry etching residue and photoresist in the semiconductor substrate. <13> A method for manufacturing a semiconductor substrate includes the following steps: using, for example... <1> to <10> The semiconductor substrate cleaning composition of any one of the following is used to remove at least one of the group consisting of dry etching residue and photoresist in the semiconductor substrate. <14> A method for inhibiting cobalt corrosion involves using an inhibitor (B) selected from the group consisting of at least one alkali compound (A) and potassium hydroxide (A2) and water to clean a cobalt-containing semiconductor substrate. [Effects of the Invention]

[0008] The composition for cleaning semiconductor substrates of the present invention can suppress cobalt corrosion when cleaning cobalt-containing semiconductor substrates. Implementation

[0009] The present invention comprises: a semiconductor substrate cleaning composition containing an alkaline compound (A), a corrosion inhibitor (B), and water, wherein the alkaline compound (A) is selected from at least one of the group consisting of ammonium hydroxide (A1) and potassium hydroxide (A2), and the corrosion inhibitor (B) is selected from at least one of the group consisting of 4-substituted pyrazoles, potassium triphenyl(1-pyrazolyl)borohydride, 2-(4-thiazolyl)benzimidazole, and halogenated-8-hydroxyquinoline compounds; and a cleaning method using the semiconductor substrate cleaning composition.

[0010] [Composition for cleaning semiconductor substrates] The composition for cleaning semiconductor substrates of the present invention contains an alkaline compound (A), a photoresist (B), and water. The alkaline compound (A) is selected from at least one of the group consisting of ammonium hydroxide (A1) and potassium hydroxide (A2). The photoresist (B) is selected from at least one of the group consisting of 4-substituted pyrazoles, potassium triphenyl(1-pyrazolyl)borohydride, 2-(4-thiazolyl)benzimidazole, and halogenated 8-hydroxyquinoline compounds. The semiconductor substrate cleaning composition of the present invention preferably contains an alkaline compound (A), a etching inhibitor (B), and water, wherein the alkaline compound (A) is selected from at least one of the group consisting of ammonium hydroxide (A1) and potassium hydroxide (A2), and the etching inhibitor (B) is selected from at least one of 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 triphenyl(1-pyrazolyl)borohydride, and 5,7-diiodo-8-hydroxyquinoline.

[0011] <Alkali compound (A)> The composition for cleaning semiconductor substrates of the present invention contains alkali compound (A). The alkali compound (A) is selected from at least one of the group consisting of ammonium hydroxide (A1) and potassium hydroxide (A2). The semiconductor substrate cleaning composition of the present invention can effectively remove photoresist and dry etching residue by containing an alkaline compound (A), and suppress damage to low dielectric constant interlayer insulating film and metal wiring. Ammonium hydroxide grade 4 (A1) and potassium hydroxide (A2) can be used individually or in combination. In particular, using both ammonium hydroxide grade 4 (A1) and potassium hydroxide (A2) as an alkali compound (A) is ideal because it reduces corrosion of the metals constituting the semiconductor substrate.

[0012] Ammonium hydroxide grade 4 (A1) is not particularly limited, but it is more ideal to select at least one from the group consisting of tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, and benzyltrimethylammonium hydroxide, with tetramethylammonium hydroxide being more ideal.

[0013] The content of alkali compound (A) in the composition for cleaning semiconductor substrates is ideally 0.005 to 35% by mass, even more ideally 0.3 to 30% by mass, even more ideally 3 to 25% by mass, and even more ideally 5 to 20% by mass. The content of grade 4 ammonium hydroxide (Al) in the composition for cleaning semiconductor substrates is ideally 1-30% by mass, more ideally 2-25% by mass, and even more ideally 3-20% by mass. The content of potassium hydroxide (A2) in the composition for cleaning semiconductor substrates is ideally 0.005 to 5% by mass, even more ideally 0.01 to 4.5% by mass, even more ideally 0.05 to 4% by mass, and even more ideally 0.1 to 4% by mass. If the content of alkali compound (A) falls within the above range, the solubility of corrosion inhibitor (B) will be better and more ideal. If the content of grade 4 ammonium hydroxide (A1) falls within the above range, the solubility of the corrosion inhibitor (B) will be better and more ideal. If the content of potassium hydroxide (A2) falls within the above range, the solubility of the corrosion inhibitor (B) will be better, and the removal performance of the sacrificial layer can also be improved, which is more ideal.

[0014] <Etching Inhibitor (B)> The semiconductor substrate cleaning composition of the present invention contains etching inhibitor (B), which is selected from at least one of the group consisting of 4-substituted pyrazoles, potassium triphenyl(1-pyrazolyl)borohydride, 2-(4-thiazolyl)benzimidazole, and halogenated 8-hydroxyquinoline compounds. The more desirable corrosion inhibitor (B) is selected from at least one of the following groups: 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 triphenyl(1-pyrazolyl)borohydride, and 5,7-diiodo-8-hydroxyquinoline. The semiconductor substrate cleaning composition of the present invention, by containing the above-mentioned corrosion inhibitor (B), can suppress cobalt corrosion, especially when cleaning cobalt-containing semiconductor substrates. The reason why the composition for cleaning semiconductor substrates of the present invention can suppress the corrosion of cobalt is not clear, but it is believed to be because the corrosion inhibitor (B) adsorbs on the surface of cobalt to form a protective film (passivation layer), thereby inhibiting the dissolution of cobalt into the composition for cleaning semiconductor substrates.

[0015] The corrosion inhibitor (B) is selected from at least one of the group consisting of 4-substituted pyrazoles, potassium trisodium (1-pyrazolyl)borohydride, 2-(4-thiazolyl)benzimidazole, and halogenated 8-hydroxyquinolines. More preferably, the corrosion inhibitor (B) is selected from at least one of 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 trisodium (1-pyrazolyl)borohydride, and 5,7-diiodo-8-hydroxyquinoline. Among them, considering the need to suppress corrosion of cobalt constituting the semiconductor substrate, it is ideal to select at least one 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 triphenyl(1-pyrazolyl)borohydride, and 5,7-diiodo-8-hydroxyquinoline. More ideally, it is 4-bromo-1H-pyrazole. Among the compositions for cleaning semiconductor substrates that comprise at least one of the following groups: 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-pyrazole)borohydride, and 5,7-diiodo-8-hydroxyquinoline, considering the broad range of compositions, it is even more ideal to select 4-bromo-1H-pyrazole or 2-(4-thiazolyl)benzimidazole from the group consisting of 1H-pyrazole, 2-(4-thiazolyl)benzimidazole, 4-chloro-1H-pyrazole, 4-methylpyrazole, 5-chloro-8-hydroxy-7-iodoquinoline, 7-bromo-5-chloro-8-hydroxy ... The preferred choice is at least one of the following groups: (1-)benzimidazole, 4-chloro-1H-pyrazole, 4-methylpyrazole, 5-chloro-8-hydroxy-7-iodoquinoline, 7-bromo-5-chloro-8-hydroxyquinoline, and potassium triphenyl(1-pyrazolyl)borohydride. Considering that even small amounts of these compounds inhibit cobalt corrosion, the preferred choice is ideally 4-bromo-1H-pyrazole, 4-chloro-1H-pyrazole, 4-methylpyrazole, 5-chloro-8-hydroxy-7-iodoquinoline, or 7-bromo-5-chloro-8-hydroxyquinoline. At least one of the group consisting of potassium triphenyl(1-pyrazolyl)borohydride, and even more preferably, at least one of the group consisting of 4-bromo-1H-pyrazole, 4-chloro-1H-pyrazole, 4-methylpyrazole, 7-bromo-5-chloro-8-hydroxyquinoline, and potassium triphenyl(1-pyrazolyl)borohydride, and even more preferably, at least one of the group consisting of 4-chloro-1H-pyrazole, 7-bromo-5-chloro-8-hydroxyquinoline, and potassium triphenyl(1-pyrazolyl)borohydride.

[0016] In the semiconductor substrate cleaning composition of the present invention, when ammonium hydroxide (A1) and potassium hydroxide (A2) are both included as alkali compounds (A), the corrosion resistance of each compound in the resist (B) varies with the mass ratio of ammonium hydroxide (A1) to potassium hydroxide (A2) [(A1) / (A2)]. The reason for this is not yet clear, but it is believed to be due to the presence of potassium ions and tetramethylammonium ions coordinated with or adsorbed on the surface of the resist. When the mass ratio of grade IV ammonium hydroxide (A1) to potassium hydroxide (A2) [(A1) / (A2)] is 10 or higher, the corrosion inhibitor (B) is preferably selected from at least one of the following groups: 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 triphenyl(1-pyrazolyl)borohydride, and 5,7-diiodo-8-hydroxyquinoline. More ideally, it should be selected from... At least one of 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, potassium tris(1-pyrazolyl)borohydride, and 5,7-diiodo-8-hydroxyquinoline, preferably at least one of 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.

[0017] When the mass ratio of grade IV ammonium hydroxide (A1) to potassium hydroxide (A2) [(A1) / (A2)] is less than 10, the corrosion inhibitor (B) is preferably selected from at least one of the group consisting of 4-bromo-1H-pyrazole, 2-(4-thiazolyl)benzimidazole, 4-chloro-1H-pyrazole, 4-methylpyrazole, 5-chloro-8-hydroxyquinoline, and potassium triphenyl(1-pyrazolyl)borohydride; more preferably selected from at least one of the group consisting of 4-bromo-1H-pyrazole, 2-(4-thiazolyl)benzimidazole, 4-chloro-1H-pyrazole, and 4-methylpyrazole; and even more preferably selected from at least one of the group consisting of 4-bromo-1H-pyrazole and 4-chloro-1H-pyrazole.

[0018] As described above, the etching inhibitor (B) used in the semiconductor substrate cleaning composition of the present invention is selected from at least one of the group consisting of 4-position substituted pyrazoles, potassium (1-pyrazolyl)borohydride, 2-(4-thiazolyl)benzimidazole, and halogenated-8-hydroxyquinolines. Among the 4-position substituted pyrazoles, 4-halogenated pyrazoles with halogen substitution at the 4-position are more desirable, and 4-chloropyrazoles with chlorine substitution at the 4-position are even more desirable. Furthermore, among the halogenated-8-hydroxyquinolines, 7-halogenated-8-hydroxyquinolines with halogen substitution at the 7-position are more desirable, and 5-chloro-7-halogenated-8-hydroxyquinolines with chlorine substitution at the 5-position are even more desirable.

[0019] The content of the etching inhibitor (B) in the composition for cleaning semiconductor substrates is ideally 0.0001 to 10% by mass, even more ideally 0.001 to 5% by mass, even more ideally 0.005 to 5% by mass, even more ideally 0.01 to 5% by mass, even more ideally 0.01 to 3% by mass, even more ideally 0.05 to 3% by mass, even more ideally 0.1 to 2.5% by mass, and even more ideally 0.2 to 2.0% by mass.

[0020] For specific examples of compounds, 7-bromo-5-chloro-8-hydroxyquinoline is ideally present at 0.01-2% by mass, more ideally at 0.05-1% by mass, even more ideally at 0.1-0.5% by mass, and even more ideally at 0.15-0.3% by mass. 4-chloro-1H-pyrazole is ideally present at 0.1-5% by mass, more ideally at 0.3-4% by mass, even more ideally at 0.5-3% by mass, and even more ideally at 1.0-2.5% by mass. Potassium tris(1-pyrazolyl)borohydride is ideally present at 0.01-2% by mass, more ideally at 0.05-1% by mass, even more ideally at 0.1-0.5% by mass, and even more ideally at 0.15-0.3% by mass.

[0021] The concentration of 5-chloro-8-hydroxy-7-iodoquinoline in the composition for cleaning semiconductor substrates is ideally 0.01-2% by mass, more ideally 0.05-1% by mass, even more ideally 0.1-0.5% by mass, and even more ideally 0.15-0.3% by mass. Similarly, the concentration of 5,7-diiodo-8-hydroxyquinoline in the composition for cleaning semiconductor substrates is ideally 0.01-2% by mass, more ideally 0.05-1% by mass, even more ideally 0.1-0.5% by mass, and even more ideally 0.15-0.3% by mass. The concentration of 4-bromo-1H-pyrazole in the composition for cleaning semiconductor substrates is ideally 0.1-5% by mass, even more ideally 0.3-4% by mass, even more ideally 0.5-3% by mass, and even more ideally 1.0-2.5% by mass.

[0022] By ensuring that the content of the corrosion inhibitor (B) falls within the above range, the corrosion resistance of cobalt will be exhibited, and it is also more economical.

[0023] <Water> The composition for cleaning semiconductor substrates of the present invention contains water. As for water, there are no particular limitations, but water that can remove metal ions, organic impurities, particles, etc. through distillation, ion exchange, filtration, and various adsorption processes is more ideal, pure water is even more ideal, and ultrapure water is especially ideal. The water content in the semiconductor substrate cleaning composition is ideally 7-99.99% by mass, and even more ideally 7-99.945% by mass. The residue after removing the above-mentioned alkaline compound (A) and etching inhibitor (B) is also water. Furthermore, when using the organic solvent (C) described later, it is also permissible to leave water as the residue after removing the alkali compound (A), corrosion inhibitor (B), and organic solvent (C). The water content in the composition for cleaning semiconductor substrates is preferably 10-99% by mass, even more preferably 20-90% by mass, even more preferably 30-80% by mass, and even more preferably 40-70% by mass. If the water content falls within the above range, the effect of the present invention can be maximized, and it is more economical.

[0024] <Organic Solvent (C)> It is preferable that the composition for cleaning semiconductor substrates of the present invention contains an organic solvent (C), and the content of the organic solvent (C) in the composition for cleaning semiconductor substrates is preferably 0.0001 to 40% by mass.

[0025] The organic solvent (C) is preferably selected from at least one of the groups consisting of alkyl diols, alkyl ethers, and alcohols, with alcohols being more preferred. In terms of alcohols, examples include monohydric alcohols and polyhydric alcohols, with polyhydric alcohols being more ideal. Examples of polyols include ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, and glycerol. Regarding polyalkylene glycol alkyl ethers, examples include polyalkylene glycol monoalkyl ethers, monoalkylene glycol monoalkyl ethers, polyalkylene glycol polyalkyl ethers, and monoalkylene glycol polyalkyl ethers, with polyalkylene glycol monoalkyl ethers being the most ideal. 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 composition for cleaning semiconductor substrates is ideally 0.0001~40% by mass, more ideally 1~40% by mass, even more ideally 10~37% by mass, and even more ideally 20~35% by mass. If the content of organic solvent (C) falls within the above range, it will suppress damage to the metal wiring material, and is therefore ideal.

[0026] <Characteristics of the composition for cleaning semiconductor substrates, etc.> The pH of the composition for cleaning semiconductor substrates of the present invention is preferably 7 or above, 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 keeping the pH within the aforementioned range, corrosion of cobalt can be prevented while improving the cleanability of the photoresist. Furthermore, the cleanability of the sacrificial layer can also be improved.

[0027] The composition system for cleaning semiconductor substrates of the present invention is ideal for cleaning cobalt-containing semiconductor substrates. The semiconductor substrate cleaning composition of the present invention can suppress cobalt corrosion when cleaning cobalt-containing semiconductor substrates. Furthermore, the cobalt is used as the metal wiring in the semiconductor substrate. Examples of cobalt include metallic cobalt and cobalt alloys.

[0028] In addition to the above-mentioned components, other components may be incorporated into the composition for cleaning semiconductor substrates of the present invention without compromising the purpose of the present invention. For example, surfactants, defoamers, dissolved oxygen removers, etc., may also be added.

[0029] Furthermore, although having a structure similar to that of the corrosion inhibitor (B), it is more desirable that the following compounds are substantially absent from the composition for cleaning semiconductor substrates of the present invention. Examples of compounds that would be more desirable if substantially absent from the composition for cleaning semiconductor substrates 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 ethynyl dicarboxylate, 5-chlorobenzotriazole, sodium 1-(m-sulfonylphenyl)-5-mercapto-1H-tetrazole, 3-nitropyrazole, and N,N'-carbonyldiimidazole. By omitting these compounds, cobalt corrosion can be effectively suppressed.

[0030] Furthermore, it is preferable that the composition for cleaning semiconductor substrates of the present invention is substantially free of sodium hydroxide. By eliminating sodium hydroxide, the influence of the cleaning composition on the electrical properties of the semiconductor can be suppressed, thereby improving the yield.

[0031] [Semiconductor Substrate Cleaning Method] The semiconductor substrate cleaning method of the present invention is a cleaning method for cleaning semiconductor substrates using the aforementioned semiconductor substrate cleaning composition, wherein the cleaning method for cleaning cobalt-containing semiconductor substrates using the aforementioned semiconductor substrate cleaning composition is more ideal. With the cleaning method of the present invention, cobalt corrosion can be suppressed even when cleaning cobalt-containing semiconductor substrates. Furthermore, cobalt is used as metal wiring, metal barrier layers, and plating seed layers of semiconductor substrates. 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 above-mentioned semiconductor substrate cleaning composition to remove at least one of the group consisting of dry etching residue and photoresist in the semiconductor substrate. In order to maximize the effect of the present invention, the semiconductor substrate cleaning method of the present invention is more preferably a cleaning method that uses the above-mentioned semiconductor substrate cleaning composition to clean a cobalt-containing semiconductor substrate to remove at least one of the group consisting of dry etching residue and photoresist in the semiconductor substrate.

[0032] The cleaning temperature in the cleaning method of this invention is not particularly limited, but 10~85℃ is more ideal, and 30~70℃ is even more ideal. Furthermore, ultrasound can also be used during cleaning. The cleaning time in the cleaning method of this invention is not particularly limited, but 0.1 to 120 minutes is more ideal, and 1 to 60 minutes is even more ideal. It is also more ideal to rinse with a rinsing solution containing water, alcohol, etc. after cleaning.

[0033] In the cleaning method of the present invention, the method of 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 means of dripping (single-wafer rotation processing) or spraying (spray processing), or the semiconductor substrate can be immersed in the semiconductor substrate cleaning composition of the present invention. In the present invention, any method can be used.

[0034] [Cobalt Corrosion Inhibition Method] The above-mentioned corrosion inhibitor (B) can effectively inhibit cobalt corrosion during the cleaning of semiconductor substrates. That is, the cobalt corrosion inhibition method of the present invention is a method of inhibiting cobalt corrosion by using a corrosion inhibitor (B) selected from at least one of the following groups: 4-substituted pyrazoles, potassium triborohydride (1-pyrazolyl), 2-(4-thiazolyl)benzimidazole, and halogenated-8-hydroxyquinoline compounds, when cleaning a cobalt-containing semiconductor substrate using an alkaline compound (A) containing at least one of the following groups: 4-substituted pyrazoles, potassium triborohydride (1-pyrazolyl), 2-(4-thiazolyl)benzimidazole, and halogenated-8-hydroxyquinoline compounds.

[0035] The resist (B) and alkali compound (A) used in this method are the same as those described in the above-mentioned [Composition for cleaning semiconductor substrates] item, and the ideal compounds and ideal ranges are also the same.

[0036] In addition, by using an anti-corrosion agent (B), the corrosion of cobalt on the semiconductor substrate during cleaning can be suppressed to at least 1 / 2 (50%).

[0037] [Method for manufacturing a semiconductor substrate] The method for manufacturing a semiconductor substrate of the present invention includes the following steps: using the above-mentioned semiconductor substrate cleaning composition to remove at least one of the group consisting of dry etching residue and photoresist in the semiconductor substrate. That is, the semiconductor substrate manufacturing method of the present invention includes the following steps: using a semiconductor substrate cleaning composition containing at least one of the following: an alkaline compound (A) selected from the group consisting of ammonium hydroxide (A1) and potassium hydroxide (A2), an anti-etchant (B) selected from the group consisting of 4-substituted pyrazoles, potassium borohydride (1-pyrazolyl), 2-(4-thiazolyl)benzimidazole and halogenated-8-hydroxyquinoline, and water, to remove dry etching residues and at least one of the following photoresists selected from the group consisting of the semiconductor substrate. The following describes a specific method for manufacturing a semiconductor substrate.

[0038] First, a barrier insulating film, a low-dielectric-constant interlayer insulating film, a hard mask, and a photoresist are stacked on a substrate having a metal barrier layer, metal wiring, a low-dielectric-constant interlayer insulating film, and silicon with a cap metal as needed. Alternatively, a barrier insulating film, a low-dielectric-constant interlayer insulating film, a hard mask, a sacrificial layer, and a photoresist are stacked on the aforementioned substrate. Then, the photoresist is selectively exposed and developed to form a photoresist pattern. Next, the photoresist pattern is used as an etching mask to perform dry etching on the hard mask, the low-dielectric-constant interlayer insulating film, and the barrier insulating film. Then, the step of using the aforementioned semiconductor substrate cleaning composition to remove at least one of the following groups of components: dry etching residue in the semiconductor substrate and photoresist, is performed to obtain a semiconductor substrate having the desired metal wiring pattern.

[0039] Regarding the substrate material, silicon, amorphous silicon, polycrystalline silicon, and glass are used. Regarding the metal barrier layer, tantalum, tantalum nitride, ruthenium, manganese, magnesium, cobalt, and their oxides are used. Regarding the metal wiring, copper or copper alloys, copper or copper alloys with cobalt or cobalt alloys formed as cap metal, and cobalt or cobalt alloys are used. Regarding the low-dielectric-constant interlayer insulating film, 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 Co., Ltd.) are used. For barrier insulating films, silicon nitride, silicon carbide, and silicon carbide nitride are used. For hard shielding, titanium and titanium nitride are used. As for the sacrificial layer, it uses organic silicate materials, etc.

[0040] The semiconductor substrate manufacturing method of the present invention has a step of removing unwanted components using the above-mentioned semiconductor substrate cleaning composition, thus enabling the production of high-precision, high-quality semiconductor substrates with good yield. [Example]

[0041] The present invention will now be described in more detail with reference to embodiments, but the present invention is not limited to these embodiments.

[0042] <Analytical and Evaluation Methods> (1) pH The pH of the components used for cleaning semiconductor substrates was determined using the glass electrode method (HORIBA F-55S benchtop pH meter, HORIBA standard ToupH electrode 9165S-10D, temperature: 25℃).

[0043] (2) Evaluation of cobalt (Co) corrosion In the semiconductor substrate cleaning composition obtained in the examples and comparative examples, the Etching Rate (ER) (Å / min) when impregnating Co-coated wafers was calculated by the following method. Domestically manufactured PVD-Co blanket-coated wafers were cut into 2cm square pieces 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-coated wafers were removed from the semiconductor substrate cleaning composition. The Co ion concentration in the semiconductor substrate cleaning composition was measured using ICP-AES. The thickness of the dissolved Co film was calculated from the measured value, and the etching rate was calculated by dividing this value by the processing time. The smaller the Etching Rate value, the more the corrosion of cobalt is suppressed, which is a good result. Furthermore, the corrosion inhibition effect (corrosion resistance) of the corrosion inhibitor (B) and the like (corrosion inhibitor (B) and the compounds of the comparative examples) can be judged as follows. If the value of the Etching Rate when the corrosion inhibitor (B) and the like are added (e.g., Examples 1-10, Comparative Examples 2-9) is less than half (50%) of the value of the Etching Rate when the corrosion inhibitor (B) and the like are not added (e.g., Comparative Example 1), then the corrosion inhibition effect (corrosion resistance) of the corrosion inhibitor (B) and the like (corrosion inhibitor (B) and the compounds of the comparative examples) is present.

[0044] (3) Evaluation of the removal performance of organosiloxane sacrificial layers In the semiconductor substrate cleaning compositions obtained in the examples and comparative examples, an organosiloxane-based thin-film blanket wafer with a film thickness of 2000 Å was immersed at 45°C for 10 seconds, and the film thickness was measured using an N&K Analyzer 1280 from N&K Technology. A film thickness of 0 Å indicates that the organosiloxane-based sacrificial layer can be removed, and the composition for semiconductor substrate cleaning exhibits excellent sacrificial layer removal properties.

[0045] <Composition for cleaning semiconductor substrates> Example 1 A semiconductor substrate cleaning composition was obtained by mixing 16 parts by weight of tetramethylammonium hydroxide, 0.15 parts by weight of potassium hydroxide, 25 parts by weight of glycerol, and 2.0 parts by weight of 4-bromo-1H-pyrazole as a corrosion inhibitor (B), and diluting with ultrapure water to bring the total composition to 100 parts by weight. Table 1 shows the doping amounts of each component as percentages. The cobalt corrosion resistance was evaluated using the obtained semiconductor substrate cleaning composition. The results are shown in Table 1. The removal performance of the organosiloxane sacrificial layer was evaluated using the obtained semiconductor substrate cleaning composition, and the results showed that the sacrificial layer could be removed. Furthermore, the content of the resist (B) used in the examples and the content of the compound used in the comparative examples, shown in the "Resistant (B) etc." column of Tables 1 and 2, are expressed as a mass percentage (mass %) relative to the composition for cleaning semiconductor substrates. Also, the content of each component shown in the "Composition of the Cleaning Composition" column of Tables 1 and 2 is also expressed as a mass percentage (mass %) relative to the composition for cleaning semiconductor substrates.

[0046] Examples 2-10 Replace 2.0 parts by weight of 4-bromo-1H-pyrazole as etchant (B), and incorporate the compounds shown in the "Etiquette Inhibitor (B) etc." column of Table 1 in the amounts shown in Table 1. Otherwise, proceed as in Example 1 to obtain a composition for cleaning semiconductor substrates. The cobalt corrosion resistance was evaluated using the obtained composition for cleaning semiconductor substrates. The results are shown in Table 1. In addition, the removal performance of organosiloxane sacrificial layers was evaluated using the semiconductor substrate cleaning compositions obtained in Examples 2-10, and the results showed that the sacrificial layers could be removed in all cases.

[0047] Comparative Example 1 Without the addition of 4-bromo-1H-pyrazole, the process was the same as in Example 1 to obtain a composition for cleaning semiconductor substrates. The cobalt corrosion resistance was evaluated using the obtained composition for cleaning semiconductor substrates. The results are shown in Table 1.

[0048] Comparative Examples 2-9 Replace 2.0 parts by weight of 4-bromo-1H-pyrazole, and incorporate the compounds shown in the "Inhibitor (B) etc." column of Table 1 in the amounts shown in Table 1. Otherwise, proceed as in Example 1 to obtain a composition for cleaning semiconductor substrates. The cobalt corrosion resistance was evaluated using the obtained composition for cleaning semiconductor substrates. The results are shown in Table 1.

[0049] [Table 1] Corrosion inhibitor (B), etc. Dosage (quality%) Co ER (Å / min) Example 1 4-Bromo-1H-pyrazole 2.0 1.6 Example 2 2-(4-Thiazolyl)benzimidazole 1.0 2.8 Example 3 4-Chloro-1H-pyrazole 2.0 0.9 Example 4 4-Methylpyrazole 2.0 1.1 Example 5 8-Hydroxy-7-iodoquinoline-5-sulfonic acid 2.0 4.3 Example 6 5-Chloro-8-hydroxy-7-iodoquinoline 0.2 0.4 Example 7 5-Chloro-8-hydroxyquinoline 0.5 4.6 Example 8 7-Bromo-5-chloro-8-hydroxyquinoline 0.2 0.4 Example 9 Potassium (1-pyrazolyl)borohydride 0.2 1.4 Example 10 5,7-Diiodo-8-hydroxyquinoline 0.2 0.4 Comparative Example 1 none - 21.4 Comparative Example 2 pyrazole 1.0 30.3 Comparative Example 3 3,4,5-Tribromopyrazole 1.0 20.7 Comparative Example 4 7-Bromoquinoline 0.2 20.3 Comparative Example 5 3-Amino-1,2,4-triazole 2.0 21.9 Comparative Example 6 5-Chlorobenzotriazole 2.0 14.5 Comparative Example 7 2-Mercaptobenzimidazole 2.0 16.0 Comparative Example 8 3-Bromo-1H-pyrazole 2.0 17.1 Comparative Example 9 3-Amino-1,2,4-triazole-5-carboxylic acid 2.0 22.4 *) Composition of the cleaning agent: Tetramethylammonium hydroxide 16% by mass, potassium hydroxide 0.15% by mass 25% by weight of glycerol and residual water *) pH (25℃): 14 (Examples 1-10 and Comparative Examples 1-9)

[0050] Example 11 A semiconductor substrate cleaning composition was obtained by mixing 12 parts by mass of tetramethylammonium hydroxide, 4 parts by mass of potassium hydroxide, 25 parts by mass of glycerol, and 2.0 parts by mass of 4-bromo-1H-pyrazole as a corrosion inhibitor (B), and diluting with ultrapure water to bring the total composition to 100 parts by mass. The doping amounts of each component are expressed as percentages in Table 2. The cobalt corrosion resistance of the obtained semiconductor substrate cleaning composition was evaluated. The results are shown in Table 2.

[0051] Examples 12-20 Replace 2.0 parts by weight of 4-bromo-1H-pyrazole as etchant (B), and incorporate the compounds shown in the "Etiquette Inhibitor (B) etc." column of Table 2 in the amounts shown in Table 2. Otherwise, proceed in the same manner as in Example 11 to obtain a composition for cleaning semiconductor substrates. The cobalt corrosion resistance was evaluated using the obtained composition for cleaning semiconductor substrates. The results are shown in Table 2.

[0052] Comparative Example 10 Without incorporating 4-bromo-1H-pyrazole, the process was the same as in Example 11 to obtain a composition for cleaning semiconductor substrates. The cobalt corrosion resistance was evaluated using the obtained composition for cleaning semiconductor substrates. The results are shown in Table 2.

[0053] Comparative Examples 11-18 Replace 2.0 parts by weight of 4-bromo-1H-pyrazole, and incorporate the compounds shown in the "Inhibitor (B) etc." column of Table 2 in the amounts shown in Table 2. Otherwise, proceed in the same manner as in Example 11 to obtain a composition for cleaning semiconductor substrates. The cobalt corrosion resistance was evaluated using the obtained composition for cleaning semiconductor substrates. The results are shown in Table 2.

[0054] [Table 2] Corrosion inhibitor (B), etc. Dosage (quality%) Co ER (Å / min) Example 11 4-Bromo-1H-pyrazole 2.0 0.5 Example 12 2-(4-Thiazolyl)benzimidazole 1.0 0.9 Example 13 4-Chloro-1H-pyrazole 2.0 0.3 Example 14 4-Methylpyrazole 2.0 0.9 Example 15 8-Hydroxy-7-iodoquinoline-5-sulfonic acid 2.0 4.5 Example 16 5-Chloro-8-hydroxy-7-iodoquinoline 0.2 5.0 Example 17 5-Chloro-8-hydroxyquinoline 0.5 1.9 Example 18 7-Bromo-5-chloro-8-hydroxyquinoline 0.2 4.1 Example 19 Potassium (1-pyrazolyl)borohydride 0.2 1.9 Example 20 5,7-Diiodo-8-hydroxyquinoline 0.2 9.5 Comparative Example 10 none - 20.0 Comparative Example 11 pyrazole 1.0 23.7 Comparative Example 12 3,4,5-Tribromopyrazole 1.0 15.7 Comparative Example 13 7-Bromoquinoline 0.2 18.8 Comparative Example 14 3-Amino-1,2,4-triazole 2.0 31.0 Comparative Example 15 5-Chlorobenzotriazole 2.0 17.7 Comparative Example 16 2-Mercaptobenzimidazole 2.0 18.3 Comparative Example 17 3-Bromo-1H-pyrazole 2.0 20.8 Comparative Example 18 3-Amino-1,2,4-triazole-5-carboxylic acid 2.0 23.0 *) Composition of the cleaning agent: Tetramethylammonium hydroxide 12% by mass, potassium hydroxide 4% by mass 25% by weight of glycerol and residual water *) pH (25℃): 14 (Examples 11-20 and Comparative Examples 10-18)

[0055] As can be understood from the results of the embodiments shown in Tables 1 and 2, the semiconductor substrate cleaning composition of the present invention can suppress cobalt corrosion even when cleaning cobalt-containing semiconductor substrates. Therefore, the semiconductor substrate cleaning composition of the present invention is useful as a cleaning agent that can simultaneously suppress the corrosion of cobalt and cobalt alloys and remove photoresist patterns and dry etching residues. The cleaning compositions used in the embodiments of Table 1 and Table 2 differ in their alkaline compound content, but both exhibit excellent cobalt corrosion suppression effects. Therefore, it can be understood that cleaning can be performed while suppressing cobalt corrosion, regardless of a wide range of cleaning conditions and various objects. Furthermore, although the compound used in the comparative example is similar to the compound used as a corrosion inhibitor (B) in the semiconductor substrate cleaning composition of the example, it cannot adequately suppress the corrosion of cobalt.

Claims

1. A composition for cleaning a semiconductor substrate, comprising an alkaline compound (A), a photoresist (B), and water, wherein the alkaline compound (A) comprises ammonium hydroxide (A1) and potassium hydroxide (A2), the content of the alkaline compound (A) is 3-35% by mass of the composition for cleaning a semiconductor substrate, the photoresist (B) is at least one selected from the group consisting of 4-substituted pyrazoles, potassium triphenyl(1-pyrazolyl)borohydride, 2-(4-thiazolyl)benzimidazole, and halogenated 8-hydroxyquinoline compounds, the content of the photoresist (B) is 0.05-3% by mass of the composition for cleaning a semiconductor substrate, the content of water is 7-90% by mass of the composition for cleaning a semiconductor substrate, and the ammonium hydroxide (A1) is at least one selected from the group consisting of tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, and benzyltrimethylammonium hydroxide.

2. The composition for cleaning semiconductor substrates as claimed in claim 1, wherein, The corrosion inhibitor (B) is selected from at least one of the following groups: 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 triphenyl(1-pyrazolyl)borohydride, and 5,7-diiodo-8-hydroxyquinoline.

3. The semiconductor substrate cleaning composition of claim 1 or 2 further contains an organic solvent (C), the content of which is 0.0001 to 40% by mass of the semiconductor substrate cleaning composition.

4. The composition for cleaning semiconductor substrates as described in claim 3, wherein, The organic solvent (C) is selected from at least one of the groups consisting of alkyl diols, alkyl ethers, and alcohols.

5. The composition for cleaning semiconductor substrates as claimed in claim 1 or 2, wherein, pH is above 7.

6. The semiconductor substrate cleaning composition as described in claim 1 or 2 is used for cleaning cobalt-containing semiconductor substrates.

7. A method for cleaning a semiconductor substrate, comprising cleaning a cobalt-containing semiconductor substrate using a semiconductor substrate cleaning composition as described in any one of claims 1 to 6.

8. A method for cleaning a semiconductor substrate, comprising using a semiconductor substrate cleaning composition as described in any one of claims 1 to 6 to remove at least one of the group consisting of dry etching residue and photoresist in the semiconductor substrate.

9. A method for manufacturing a semiconductor substrate, comprising the following steps: using a semiconductor substrate cleaning composition as described in any one of claims 1 to 6 to remove at least one of the group consisting of dry etching residue and photoresist in the semiconductor substrate.

10. A method for inhibiting cobalt corrosion, wherein when cleaning a cobalt-containing semiconductor substrate using a composition comprising an alkaline compound (A) containing ammonium hydroxide (A1) and potassium hydroxide (A2) and water, the corrosion of cobalt is inhibited by using an inhibitor (B) selected from at least one of the group consisting of 4-substituted pyrazoles, potassium triphenyl(1-pyrazolyl)borohydride, 2-(4-thiazolyl)benzimidazole, and halogenated 8-hydroxyquinolines, wherein the contents of the alkaline compound (A), the inhibitor (B), and the water in the semiconductor substrate cleaning composition are 3-35% by mass, 0.05-3% by mass, and 7-90% by mass, respectively, and the ammonium hydroxide (A1) is selected from at least one of the group consisting of tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, and benzyltrimethylammonium hydroxide.

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