TWI855138B - Semiconductor processing composition and processing method - Google Patents

Abstract

The subject of the present invention is to provide a semiconductor processing composition and a processing method using the same, wherein the semiconductor processing composition has excellent storage stability, can suppress corrosion of metal wiring and the like of a processed object, and can effectively remove contamination from the surface of the processed object. The semiconductor processing composition of the present invention contains (A) at least one selected from the group consisting of cyclodextrin and cyclodextrin derivatives, (B) a compound having an amphoteric ionic structure, and (C) a liquid medium, and when the content of the component (A) is _MA [mass %] and the content of the component (B) is _MB [mass %], _MA / _MB = 3 to 15.

Description

Semiconductor processing composition and processing method

The present invention relates to a semiconductor processing composition and a processing method using the same.

Chemical Mechanical Polishing (CMP) slurry used in the CMP process, which is effective for manufacturing semiconductor devices, contains not only abrasive particles (abrasive grains) but also an etchant and the like. When the abrasive particles aggregate to form coarse particles, this causes polishing damage. Therefore, a method has been proposed to effectively utilize an inclusion compound such as cyclodextrin to improve the stability of the CMP slurry (for example, refer to Patent Document 1).

In addition, in the manufacture of semiconductor devices, after the CMP step or the like, a cleaning step is required to remove contamination such as grinding debris or organic residues from the surface of the semiconductor substrate. Metal wiring materials such as tungsten and cobalt are exposed on the surface of the semiconductor substrate, so in the cleaning step, it is necessary to suppress corrosion of the polished surface where the metal wiring materials are exposed. As a technology for suppressing corrosion of the surface of the semiconductor substrate, a method of effectively using an inclusion compound such as cyclodextrin has been proposed (for example, refer to Patent Document 2). [Prior Art Document] [Patent Document]

[Patent document 1] Japanese Patent Publication No. 2009-302255 [Patent document 2] Japanese Patent Publication No. 2019-507207

[Problems to be solved by the invention] However, with the further miniaturization of circuit structures in recent years, there is a demand for processing technology that can further suppress corrosion of metal wiring and the like of the processed object and effectively remove contamination from the surface of the processed object. In addition, in order to further improve the production stability of semiconductor devices, it is also necessary to improve the storage stability of the processing agent.

Therefore, some aspects of the present invention provide a semiconductor processing composition and a processing method using the same by solving at least a part of the above-mentioned problems. The semiconductor processing composition has excellent storage stability, can inhibit corrosion of metal wiring of the processed object, etc., and effectively remove contamination from the surface of the processed object.

[Means for solving the problem] The present invention is made to solve at least part of the above-mentioned problem and can be implemented in any of the following aspects.

One embodiment of the semiconductor processing composition of the present invention comprises: (A) at least one selected from the group consisting of cyclodextrin and cyclodextrin derivatives, (B) a compound having an amphoteric ionic structure, and (C) a liquid medium, wherein when the content of the component (A) is _MA [mass %] and the content of the component (B) is _MB [mass %], _MA / _MB = 3 to 15.

The semiconductor processing composition of the above aspect can be used by diluting 1 to 100 times.

In any of the above-mentioned semiconductor processing compositions, the component (B) may be a compound having at least one functional group selected from the group consisting of a carboxyl group and a sulfonic acid group and an alkyl group having 12 or more and 18 or less carbon atoms.

In any of the above-mentioned semiconductor processing compositions, the cyclodextrin derivative may be at least one selected from 2-hydroxypropyl-β-cyclodextrin and 2-hydroxyethyl-β-cyclodextrin.

In any of the above-mentioned semiconductor processing compositions, an organic acid may also be contained.

In any of the above-mentioned semiconductor processing compositions, a water-soluble polymer may also be contained.

One aspect of the processing method of the present invention includes the following steps: Using any of the above-mentioned aspects of the semiconductor processing composition, a wiring substrate containing tungsten as a wiring material is processed.

One aspect of the processing method of the present invention includes the following steps: After chemical mechanical polishing of the wiring substrate containing tungsten as the wiring material of the wiring substrate, processing is performed using any of the above-mentioned semiconductor processing compositions.

[Effect of the invention] According to the semiconductor processing composition of the present invention, even if stored for a long time, the polishing characteristics and cleaning characteristics are less deteriorated, and semiconductor manufacturing can be performed stably. In addition, according to the semiconductor processing composition of the present invention, corrosion of metal wiring of the object to be processed can be suppressed and contamination can be effectively removed from the surface of the object to be processed. The semiconductor processing composition of the present invention is particularly effective for processing a wiring substrate containing tungsten or cobalt as a wiring material.

The following describes in detail suitable embodiments of the present invention. The present invention is not limited to the following embodiments, but includes various modifications that can be implemented without changing the gist of the present invention.

1. Semiconductor Processing Composition A semiconductor processing composition according to an embodiment of the present invention comprises (A) at least one selected from the group consisting of cyclodextrin and cyclodextrin derivatives (also referred to as "(A) component" in this specification), (B) a compound having an amphoteric ionic structure (also referred to as "(B) component" in this specification), and (C) a liquid medium, wherein when the content of the (A) component is _MA [mass %] and the content of the (B) component is _MB [mass %], _MA / _MB = 3 to 15. The semiconductor processing composition according to this embodiment may be a concentrated type for use after dilution with a liquid medium such as pure water or an organic solvent, or may be an undiluted type for use without dilution. In this specification, unless it is specified as a concentrated type or an undiluted type, the term "semiconductor processing composition" can be interpreted as including the concepts of both concentrated type and undiluted type.

In addition, the semiconductor processing composition of this embodiment can be used as a CMP slurry for chemical mechanical polishing, a cleaning agent for removing particles or metal impurities on the surface of the processed object after the completion of CMP, an anti-etchant stripping agent for stripping the anti-etchant from a semiconductor substrate treated with an anti-etchant, an etchant for shallowly etching the surface of metal wiring to remove surface contamination, and other processing agents.

That is, the so-called "treatment agent" in the present invention refers to a treatment agent prepared by diluting the concentrated semiconductor treatment composition by adding a liquid medium or the non-diluted semiconductor treatment composition itself, and is a liquid used when actually treating the surface to be treated. The concentrated semiconductor treatment composition usually exists in a state where each component is concentrated. Therefore, each user dilutes the concentrated semiconductor processing composition with a liquid medium to prepare a processing agent, or uses the undiluted semiconductor processing composition directly as a processing agent, and can use the processing agent as a CMP slurry for chemical mechanical polishing, a cleaning agent for cleaning semiconductor surfaces, an anti-etching agent stripping agent, and an etching agent. The following is a detailed description of each component contained in the semiconductor processing composition of this embodiment.

1.1. (A) Cyclodextrin and cyclodextrin derivatives The semiconductor treatment composition of this embodiment contains (A) at least one selected from the group consisting of cyclodextrin and cyclodextrin derivatives. Here, cyclodextrin is a type of cyclic oligosaccharide in which several molecules of D-glucose are bonded by glucoside bonds to obtain a cyclic structure. Cyclodextrins with 5 or more glucoses bonded are known, and common cyclodextrins are cyclodextrins with 6 to 8 glucoses bonded. As cyclodextrins, α-cyclodextrins with 6 glucoses bonded, β-cyclodextrins with 7 glucoses bonded, and γ-cyclodextrins with 8 glucoses bonded can be preferably used.

Cyclodextrin derivatives are obtained by modifying the hydroxyl groups of the above-mentioned cyclodextrins. As cyclodextrin derivatives, for example, 2-hydroxypropyl-β-cyclodextrin and 2-hydroxyethyl-β-cyclodextrin can be preferably used.

In a concentrated CMP slurry, when the total mass of the semiconductor processing composition is set to 100 mass %, the lower limit of the content of component (A) is preferably 0.01 mass %, more preferably 0.03 mass %, and particularly preferably 0.05 mass %. On the other hand, when the total mass of the semiconductor processing composition is set to 100 mass %, the upper limit of the content of component (A) is preferably 0.5 mass %, more preferably 0.3 mass %, and particularly preferably 0.2 mass %. In an undiluted CMP slurry, when the total mass of the semiconductor processing composition is set to 100 mass %, the lower limit of the content of component (A) is preferably 0.005 mass %, more preferably 0.01 mass %, and particularly preferably 0.02 mass %. On the other hand, when the total mass of the semiconductor processing composition is set to 100 mass%, the upper limit of the content of the component (A) is preferably 1 mass%, more preferably 0.5 mass%, and particularly preferably 0.1 mass%. When the content of the component (A) is within the above range, the component (B) can be effectively contained in the hydrophobic cavity inside the ring structure of the component (A), thereby improving the storage stability without causing precipitation.

In concentrated other treatment agents (e.g., cleaning agents), when the total mass of the semiconductor treatment composition is set to 100 mass%, the lower limit of the content of component (A) is preferably 0.1 mass%, more preferably 0.2 mass%, and particularly preferably 0.3 mass%. On the other hand, when the total mass of the semiconductor treatment composition is set to 100 mass%, the upper limit of the content of component (A) is preferably 10 mass%, more preferably 7 mass%, and particularly preferably 5 mass%. In non-diluted other treatment agents (e.g., cleaning agents), when the total mass of the semiconductor treatment composition is set to 100 mass%, the lower limit of the content of component (A) is preferably 0.005 mass%, more preferably 0.01 mass%, and particularly preferably 0.02 mass%. On the other hand, when the total mass of the semiconductor processing composition is set to 100 mass%, the upper limit of the content of the component (A) is preferably 1 mass%, more preferably 0.5 mass%, and particularly preferably 0.1 mass%. If the content of the component (A) is within the above range, particles or metal impurities on the surface of the object to be processed after the completion of CMP can be removed by being contained in the hydrophobic cavity inside the ring structure of the component (A), thereby reducing the slag contamination on the object to be processed and suppressing the generation of slag contamination from the semiconductor processing composition.

1.2. (B) Compounds with amphoteric ionic structures The semiconductor processing composition of this embodiment contains (B) compounds with amphoteric ionic structures. Here, the compound with amphoteric ionic structures refers to a compound having one or more functional groups that can have a positive charge in the composition and one or more functional groups that can have a negative charge in the composition in the same molecule. Examples of such compounds with amphoteric ionic structures include intramolecular salt compounds having a functional group that generates a positive charge such as an ammonium cation in the composition and a functional group that generates a negative charge such as a carboxylate anion in the same molecule.

The component (B) is not particularly limited as long as it is a compound having such an amphoteric ionic structure, but is preferably a compound having an amphoteric ionic structure having at least one functional group selected from the group consisting of a carboxyl group and a sulfonic acid group and an alkyl group having 12 to 18 carbon atoms, and more preferably a compound represented by the following general formula (1).

[Chemistry 1]

In the formula (1), ^R1 and ^R2 each independently represent a substituted or unsubstituted alkanediyl group having 1 to 6 carbon atoms, preferably an alkanediyl group having 1 to 4 carbon atoms, and more preferably an alkanediyl group having 1 to 2 carbon atoms. In the formula (1), ^R3 represents an alkyl group having 12 or more and 18 or less carbon atoms.

In particular, the compound represented by the general formula (1) has carboxyl groups at both ends of the molecule. Component (B) having such a structure has a high coordination ability for metal ions, and thus can effectively suppress corrosion of metal wiring materials and the like.

Specific examples of component (B) include amino acids such as alanine, arginine, asparagine, aspartic acid, cysteine, glutamine, glutamine, glycine, isoleucine, leucine, lysine, methionine, phenylalanine, serine, threonine, tyrosine, valine, tryptophan, histidine, 2-amino-3-aminopropionic acid, and N-[2-[(2-aminoethyl)dodecylamino]ethyl]glycine; lysine betaine, ornithine betaine, homarine, trigonelline, and propylamine. Betaine, taurobetin, phenylpropylamino betaine carnitine, homoserine betaine, valeric betaine, trimethylglycine (glycine betaine), stachydrine, γ-butyrobetaine, lauryl dimethylaminoacetic acid betaine, lauryl hydroxysulfobetaine, stearyl dimethylaminoacetic acid betaine, lauryl amidopropyl betaine, cocoamidopropyl betaine, glutamine betaine, sodium laurylaminodiacetate, sodium laurylaminodipropionate, and the like, and one or more selected from these can be used.

In concentrated CMP slurry, when the total mass of the semiconductor processing composition is set to 100 mass%, the lower limit of the content of component (B) is preferably 0.002 mass%, more preferably 0.005 mass%, and particularly preferably 0.01 mass%. On the other hand, when the total mass of the semiconductor processing composition is set to 100 mass%, the upper limit of the content of component (B) is preferably 0.2 mass%, more preferably 0.1 mass%, and particularly preferably 0.05 mass%. In non-diluted CMP slurry, when the total mass of the semiconductor processing composition is set to 100 mass%, the lower limit of the content of component (B) is preferably 0.001 mass%, more preferably 0.002 mass%, and particularly preferably 0.005 mass%. On the other hand, when the total mass of the semiconductor processing composition is set to 100 mass%, the upper limit of the content of the component (B) is preferably 0.2 mass%, more preferably 0.1 mass%, and particularly preferably 0.05 mass%. When the content of the component (B) is within the above range, the component (B) can be effectively contained in the hydrophobic cavity inside the ring structure of the component (A), thereby improving the storage stability without causing precipitation.

In concentrated other treatment agents (e.g., cleaning agents), when the total mass of the semiconductor treatment composition is set to 100 mass%, the lower limit of the content of the component (B) is preferably 0.01 mass%, more preferably 0.03 mass%, and particularly preferably 0.06 mass%. On the other hand, when the total mass of the semiconductor treatment composition is set to 100 mass%, the upper limit of the content of the component (B) is preferably 5 mass%, more preferably 3 mass%, and particularly preferably 1 mass%. In non-diluted other treatment agents (e.g., cleaning agents), when the total mass of the semiconductor treatment composition is set to 100 mass%, the lower limit of the content of the component (B) is preferably 0.005 mass%, more preferably 0.01 mass%, and particularly preferably 0.02 mass%. On the other hand, when the total mass of the semiconductor processing composition is set to 100 mass%, the upper limit of the content of the component (B) is preferably 0.2 mass%, more preferably 0.1 mass%, and particularly preferably 0.05 mass%. If the content of the component (B) is within the above range, particles or metal impurities on the surface of the object to be processed after the completion of CMP can be effectively reduced or removed, and metals such as metal wiring materials can be less likely to be corroded.

1.3. Content ratio of component (A) to component (B) Regarding the content ratio of component (A) to component (B) in the semiconductor processing composition of the present embodiment, when the content of component (A) is _MA [mass %] and the content of component (B) is _MB [mass %], the lower limit of the value of _MA / _MB is preferably 3.0, and more preferably 3.5. The upper limit of the value of _MA / _MB is preferably 15.0, and more preferably 14.5.

In the semiconductor processing composition of the present embodiment, it is presumed that the inclusion compound is formed by taking the (B) component into the hydrophobic cavity inside the ring structure of the (A) component. If the value of _MA / _MB , which is the content ratio of the (A) component to the (B) component, is within the above range, the content of the (A) component or the (B) component that does not form the inclusion compound can be suppressed, and therefore it is presumed that even if the (B) component is present in the semiconductor processing composition at a high concentration, the precipitation of the (B) component is suppressed, and the characteristics of the concentrated semiconductor processing composition are not deteriorated, and long-term storage can be achieved. In addition, when the value of _MA / _MB is within the above range, the content of the component (B) that does not form an inclusion compound can be suppressed, so it is considered that in the semiconductor processing step, the generation of slag derived from the agglomeration product of the metal material such as copper or tungsten exposed on the processed surface with the component (B) as the nucleus can be suppressed.

On the other hand, when the value of _MA / _MB exceeds the above range, the component (A) adheres to and remains on the processed object after processing to become a defect, inducing the degradation of the electrical characteristics of the semiconductor circuit as the processed object, resulting in a decrease in yield, etc., which is unfavorable. On the other hand, when the value of _MA / _MB is less than the above range, the component (B) adheres to and remains on the metal material such as copper or tungsten exposed on the processed surface to become a defect due to the presence of the component (B) in the semiconductor processing composition that does not form an inclusion compound, and it is considered that the flatness or electrical characteristics of the processed surface are deteriorated. In addition, since the content of the component (A) is too small relative to the content of the component (B), the component (B) may become excessive, thereby causing precipitation and impairing storage stability.

Furthermore, in CMP of a workpiece having tungsten as a wiring material, there is a case where a CMP slurry containing iron ions and peroxides (hydrogen peroxide, potassium iodate, etc.) is used. The iron ions contained in the CMP slurry are easily adsorbed on the surface of the workpiece, so the polished surface is easily contaminated by iron. In this case, by cleaning the polished surface using the semiconductor processing composition of this embodiment, the generation of a soluble salt such as potassium tungstate or sodium tungstate is promoted in the cleaning step. It is believed that this can reduce metal contamination on the wiring substrate, reduce corrosion of the workpiece, and efficiently remove polishing residues.

1.4. Liquid medium (C) The semiconductor processing composition of this embodiment contains a liquid medium (C) as a main component. The type of liquid medium (C) can be appropriately selected according to the purpose of use of the processing agent for polishing, cleaning, etching, resist stripping, etc. of the processed object.

When the semiconductor processing composition of the present embodiment is used as a CMP slurry or a cleaning agent, the liquid medium (C) is preferably an aqueous medium containing water as a main component. Examples of such aqueous mediums include water, a mixed medium of water and alcohol, and a mixed medium containing water and an organic solvent that is compatible with water. Among these aqueous media, water, a mixed medium of water and alcohol, and water is more preferably used.

When the semiconductor processing composition of the present embodiment is used as an etchant or resist stripper, the liquid medium (C) is preferably a non-aqueous medium containing an organic solvent as a main component. Examples of such non-aqueous medium include polar solvents such as ketone solvents, ester solvents, ether solvents, and amide solvents, and known organic solvents that can be used in semiconductor processing steps such as hydrocarbon solvents.

Examples of the ketone solvent include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 2-heptanone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, phenylacetone, methyl ethyl ketone, methyl isobutyl ketone, acetylacetone, acetonylacetone, ionone, diacetonyl alcohol, acetylmethanol, acetophenone, methylnaphthyl ketone, isophorone, propyl carbonate, and γ-butyrolactone.

Examples of the ester solvent include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, methoxyethyl acetate, ethoxyethyl acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, 2-ethoxybutyl acetate, 4-methoxypentyl acetate, 2-methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3-methoxypentyl acetate, 3-methyl-3-methoxypentyl acetate, 3-methyl-4-methoxypentyl acetate, 4-methyl-4-methoxypentyl acetate, propylene glycol diacetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl carbonate, propyl carbonate, butyl carbonate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetylacetate, ethyl acetylacetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, methyl-3-methoxypropionate, ethyl-3-methoxypropionate, ethyl-3-ethoxypropionate, propyl-3-methoxypropionate, and the like. Examples of cyclic ester solvents include lactones such as γ-butyrolactone.

Examples of the ether solvent include glycol ether solvents such as ethylene glycol dibutyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, and diethylene glycol dibutyl ether; diisoamyl ether, diisobutyl ether, dioxane, tetrahydrofuran, anisole, perfluoro-2-butyltetrahydrofuran, perfluorotetrahydrofuran, and 1,4-dioxane.

Examples of the amide solvent include N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, hexamethylphosphoric triamide, and 1,3-dimethyl-2-imidazolidinone. Examples of the other polar solvent include dimethyl sulfoxide.

Examples of hydrocarbon solvents include aliphatic hydrocarbon solvents such as pentane, hexane, octane, decane, 2,2,4-trimethylpentane, 2,2,3-trimethylhexane, perfluorohexane, perfluoroheptane, limonene and pinene; and aromatic hydrocarbon solvents such as toluene, xylene, ethylbenzene, propylbenzene, 1-methylpropylbenzene, 2-methylpropylbenzene, dimethylbenzene, diethylbenzene, ethylmethylbenzene, trimethylbenzene, ethyldimethylbenzene and dipropylbenzene.

1.5. Other components The semiconductor processing composition of this embodiment may contain other components as required depending on the purpose of use of the processing agent such as polishing, cleaning, etching, and resist stripping in addition to the above components. Examples of such components include abrasive particles, water-soluble polymers, organic acids, amines, pH adjusters, surfactants, and the like.

1.5.1. Abrasive grains When the semiconductor processing composition of this embodiment is used as a CMP slurry, it is preferred to contain abrasive grains. Examples of abrasive grains include inorganic particles such as silicon dioxide, zirconium oxide, aluminum oxide, zirconium oxide, and titanium oxide. Among these, silicon dioxide particles are preferred.

As silica particles, colloidal silica, fumed silica, etc. can be listed. Among them, colloidal silica is preferred. From the perspective of reducing polishing defects such as scratches, colloidal silica can be preferably used. As colloidal silica, for example, those produced by the method described in Japanese Patent Laid-Open No. 2003-109921 can be used. Alternatively, colloidal silica surface-modified by a method described in Japanese Patent Application Publication No. 2010-269985 or Journal of Industrial and Engineering Chemistry (J. Ind. Eng. Chem.), Vol. 12, No. 6, (2006) 911-917 may be used.

When the total mass of the CMP slurry used relative to the processed object is set to 100 mass%, the content ratio of the abrasive grains is preferably 0.01 mass% to 4 mass%, more preferably 0.1 mass% to 1.5 mass%, and particularly preferably 0.5 mass% to 1 mass%. When the content ratio of the abrasive grains is within the above range, a practical polishing rate for the processed object can be obtained.

1.5.2. Water-soluble polymer The semiconductor processing composition of this embodiment may contain a water-soluble polymer even if it is a processing agent for any purpose. By containing a water-soluble polymer, it is adsorbed on the surface of the treated object to form a film, thereby further reducing the corrosion of the treated object. In the present invention, "water-soluble" means that the mass dissolved in 100 g of water at 20°C is 0.1 g or more.

Examples of water-soluble polymers include polyacrylic acid, polymethacrylic acid, polymaleic acid, polyvinyl sulfonic acid, polyallyl sulfonic acid, polystyrene sulfonic acid, and salts thereof; copolymers of monomers such as styrene, α-methylstyrene, 4-methylstyrene, and acid monomers such as (meth)acrylic acid and maleic acid, or polymers containing repeating units having aromatic hydrocarbons obtained by condensing benzenesulfonic acid, naphthalenesulfonic acid, etc. with formalin, and salts thereof; vinyl synthetic polymers such as polyvinyl alcohol, polyethylene oxide, polyvinyl pyrrolidone, polyvinyl pyridine, polyacrylamide, polyvinyl formamide, polyethylene imine, polyvinyl oxazoline, polyvinyl imidazole, polyallylamine, etc.; modified products of natural polysaccharides such as hydroxyethyl cellulose, carboxymethyl cellulose, and processed starch, etc., but are not limited to these. These water-soluble polymers may be used alone or in combination of two or more.

The weight average molecular weight (Mw) of the water-soluble polymer that can be used in this embodiment is preferably 1,000 to 1,500,000, and more preferably 3,000 to 1,200,000. In addition, the "weight average molecular weight" in this specification refers to the weight average molecular weight calculated by polyethylene glycol measured by gel permeation chromatography (GPC).

The content ratio of the water-soluble polymer can be adjusted so that the viscosity of the semiconductor processing composition at room temperature is 2 mPa·s or less. If the viscosity of the semiconductor processing composition at room temperature exceeds 2 mPa·s, the viscosity becomes too high, and the semiconductor processing composition cannot be stably supplied to the object to be processed. The viscosity of the semiconductor processing composition is affected by the weight average molecular weight or content of the added water-soluble polymer, so it can be adjusted while considering the balance.

When the semiconductor processing composition of this embodiment is used as a cleaning agent, the content ratio of the water-soluble polymer can be appropriately changed according to the materials of metal wiring materials such as copper or tungsten, insulating materials such as silicon oxide, barrier metal materials such as tantalum nitride or titanium nitride, etc. exposed on the surface of the processed object after CMP, or the composition of the CMP slurry used.

In addition, when the semiconductor processing composition of the present embodiment is used as a cleaning agent, the content ratio of the water-soluble polymer can be appropriately changed according to the dilution degree of the concentrated semiconductor processing composition. When the total mass of the processing agent prepared by diluting the concentrated semiconductor processing composition or the non-diluted semiconductor processing composition (processing agent) is set to 100 mass%, the content ratio of the water-soluble polymer is preferably 0.001 mass% or more and 1 mass% or less, and more preferably 0.01 mass% or more and 0.1 mass% or less. When the content ratio of the water-soluble polymer is within the above range, both the suppression of corrosion and the effect of removing particles or metal impurities contained in the CMP slurry from the wiring substrate are promoted, so that a better processed object is easily obtained.

1.5.3. Organic acid The semiconductor processing composition of this embodiment may contain an organic acid other than component (B) even if it is a processing agent for any purpose. In addition, the "organic acid" in this specification is a concept that does not include the water-soluble polymer.

The organic acid preferably has one or more acidic functional groups such as carboxyl group and sulfonic group. Specific examples of the organic acid include citric acid, maleic acid, apple acid, tartaric acid, oxalic acid, malonic acid, succinic acid, ethylenediaminetetraacetic acid, acrylic acid, methacrylic acid, benzoic acid, phenyllactic acid, hydroxyphenyllactic acid, hydroxymalonic acid, phenylsuccinic acid, naphthalenesulfonic acid, and salts thereof. These organic acids may be used alone or in combination of two or more.

Among the organic acids, the compounds represented by the following general formula (2) can be preferably used.

[Chemistry 2] (In the general formula (2), ^R4 represents an organic group having 1 to 20 carbon atoms)

Examples of the organic group having 1 to 20 carbon atoms for ^R4 in the general formula (2) include a saturated aliphatic alkyl group having 1 to 20 carbon atoms, an unsaturated aliphatic alkyl group having 1 to 20 carbon atoms, an organic group having 6 to 20 carbon atoms having a cyclic saturated alkyl group, an organic group having 6 to 20 carbon atoms having an unsaturated cyclic alkyl group, a alkyl group having 1 to 20 carbon atoms having a carboxyl group, a alkyl group having 1 to 20 carbon atoms having a hydroxyl group, a alkyl group having 1 to 20 carbon atoms having both a carboxyl group and a hydroxyl group, and an organic group having 1 to 20 carbon atoms having a saturated cyclic alkyl group. A alkyl group having 1 to 20 carbon atoms having an amine group, a alkyl group having 1 to 20 carbon atoms having both an amine group and a carboxyl group, an organic group having 1 to 20 carbon atoms having a heterocyclic group, etc. Among these, an organic group having 1 to 20 carbon atoms having a saturated aliphatic alkyl group, an organic group having 1 to 20 carbon atoms having an unsaturated aliphatic alkyl group, or a alkyl group having 1 to 20 carbon atoms having a carboxyl group is preferred, and an organic group having 6 to 20 carbon atoms having an aromatic group or a carboxymethyl group is particularly preferred.

Specific examples of the compound represented by the general formula (2) include: citric acid, malonic acid, maleic acid, tartaric acid, apple acid, succinic acid, phthalic acid, glutamine, aspartic acid, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, iminodiacetic acid, etc. Among them, at least one selected from the group consisting of citric acid, malonic acid, maleic acid, tartaric acid, apple acid and succinic acid is preferred, and at least one selected from the group consisting of citric acid, malonic acid and apple acid is more preferred, and citric acid and malonic acid are particularly preferred. If it is such a component (B), there is a situation where pollution can be particularly reduced or removed. The compounds exemplified above can be used alone or in combination of two or more.

When the semiconductor processing composition of this embodiment is used as a cleaning agent, the content ratio of the organic acid can be appropriately changed according to the materials of metal wiring materials such as copper or tungsten, insulating materials such as silicon oxide, barrier metal materials such as tantalum nitride or titanium nitride, etc. exposed on the surface of the processed object after CMP, or the composition of the CMP slurry used.

Furthermore, the content ratio of the organic acid can also be appropriately changed according to the dilution degree of the concentrated semiconductor processing composition of this embodiment. When the total mass of the treatment agent prepared by diluting the concentrated semiconductor processing composition or the non-diluted semiconductor processing composition (treatment agent) is set to 100 mass%, the content ratio of the organic acid is preferably 0.0001 mass% or more and 1 mass% or less, and more preferably 0.0005 mass% or more and 0.5 mass% or less. If the content ratio of the organic acid is within the above range, there is a situation where impurities attached to the surface of the wiring material can be more effectively removed. In addition, there is a situation where the over-etching is more effectively suppressed and a good processed object is obtained.

1.5.4. Amines When the semiconductor processing composition of this embodiment is used as a cleaning agent, it is preferred to contain amines. Amines have the function of an etchant. Therefore, it is considered that by adding amines, metal oxide films (e.g., CuO, _Cu2O , and Cu(OH) ₂ layers) or organic residues (e.g., benzotriazole (BTA) layer) on the wiring substrate can be etched away in the cleaning step after CMP.

The amine used in the cleaning agent is preferably a water-soluble amine. As described above, the definition of "water-soluble" means that the mass dissolved in 100 g of water at 20°C is 0.1 g or more. Examples of amines include alkanolamines, primary amines, secondary amines, and tertiary amines.

Examples of alkanolamines include monoethanolamine, diethanolamine, triethanolamine, N-methylethanolamine, N-methyl-N,N-diethanolamine, N,N-dimethylethanolamine, N,N-diethylethanolamine, N,N-dibutylethanolamine, N-(β-aminoethyl)ethanolamine, N-ethylethanolamine, monopropanolamine, dipropanolamine, tripropanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, etc. Examples of primary amines include methylamine, ethylamine, propylamine, butylamine, pentylamine, 1,3-propylenediamine, etc. Examples of secondary amines include piperidine, piperazine, etc. Examples of tertiary amines include trimethylamine, triethylamine, etc. These amines may be used alone or in combination of two or more.

Among these amines, monoethanolamine and monoisopropanolamine are preferred, and monoethanolamine is more preferred, since they are highly effective in etching a metal oxide film or organic residue on a wiring board.

When the semiconductor processing composition of this embodiment is used as a cleaning agent, the amine content ratio can be appropriately changed according to the materials of metal wiring materials such as copper or tungsten, insulating materials such as silicon oxide, barrier metal materials such as tantalum nitride or titanium nitride, etc. exposed on the surface of the processed object after CMP, or the composition of the CMP slurry used.

Furthermore, the content ratio of the amine can be appropriately changed according to the dilution degree of the concentrated semiconductor processing composition of the present embodiment. When the total mass of the treatment agent prepared by diluting the concentrated semiconductor processing composition or the non-diluted semiconductor processing composition (treatment agent) is set to 100 mass%, the content ratio of the amine is preferably 0.0001 mass% or more and 1 mass% or less, and more preferably 0.0005 mass% or more and 0.5 mass% or less. If the content ratio of the amine is within the above range, the metal oxide film or organic residue on the wiring substrate can be more effectively etched and removed in the cleaning step after the CMP is completed.

1.5.5. pH adjuster In the case of a semiconductor processing composition for treating a surface to be treated containing copper as a wiring material, the lower limit of the pH value is preferably 9, more preferably 10, and the upper limit of the pH value is preferably 14. In the case of a semiconductor processing composition for treating a surface to be treated containing tungsten as a wiring material, the lower limit of the pH value is preferably 2, and the upper limit of the pH value is preferably 7, more preferably 6.

In the semiconductor processing composition of the present embodiment, if the desired pH value cannot be obtained by adding the above-mentioned components, a pH adjuster may be added to adjust the pH value to the above range. Examples of the pH adjuster include: inorganic acids such as hydrochloric acid, nitric acid, sulfuric acid, and phosphoric acid; alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, tin hydroxide, and cesium hydroxide; organic ammonium salts such as tetramethylammonium hydroxide; and alkaline compounds such as ammonia. These pH adjusters may be used alone or in combination of two or more.

In the present invention, the pH value refers to the hydrogen ion index, which can be measured at 25°C and 1 atmosphere using a commercially available pH meter (e.g., desktop pH meter manufactured by Horiba, Ltd.).

1.5.6. Surfactant The semiconductor processing composition of this embodiment may contain a surfactant (excluding component (A) and component (B)) even if it is a processing agent for any purpose. As the surfactant, a nonionic surfactant or anionic surfactant can be preferably used. By adding a surfactant, the effect of removing particles or metal impurities contained in the CMP slurry from the wiring substrate is improved, and a better treated surface can be obtained.

Examples of nonionic surfactants include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, and polyoxyethylene oleyl ether; polyoxyethylene aryl ethers such as polyoxyethylene octylphenyl ether and polyoxyethylene nonylphenyl ether; sorbitan fatty acid esters such as sorbitan monolaurate, sorbitan monopalmitate, and sorbitan monostearate; polyoxyethylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, and polyoxyethylene sorbitan monostearate, etc. The nonionic surfactants exemplified above may be used alone or in combination of two or more.

Examples of anionic surfactants include alkylbenzenesulfonic acids such as dodecylbenzenesulfonic acid; alkylnaphthalenesulfonic acids; alkylsulfates such as laurylsulfuric acid; sulfates of polyoxyethylene alkyl ethers such as polyoxyethylene laurylsulfuric acid; naphthalenesulfonic acid condensates; alkyliminodicarboxylic acids; ligninsulfonic acid, etc. These anionic surfactants may also be used in the form of salts. In this case, examples of counteracting cations include sodium ions, potassium ions, and ammonium ions. From the viewpoint of preventing excessive inclusion of potassium or sodium, ammonium ions are preferred.

In CMP of a workpiece having tungsten as a wiring material, a CMP slurry containing iron ions and peroxides (hydrogen peroxide, potassium iodate, etc.) is sometimes used. The iron ions contained in the CMP slurry are easily adsorbed on the surface of the workpiece, so the surface of the workpiece is easily contaminated by iron. In this case, iron ions are positively charged, so there is a case where iron contamination on the surface of the workpiece can be effectively removed by adding anionic surfactants to the semiconductor processing composition.

The content ratio of the surfactant can be appropriately changed according to the materials of metal wiring materials such as copper or tungsten, insulating materials such as silicon oxide, barrier metal materials such as tantalum nitride or titanium nitride, etc. exposed on the surface of the processed object after CMP, or the composition of the CMP slurry used.

Furthermore, the content of the surfactant may be appropriately changed according to the dilution degree of the concentrated semiconductor processing composition of the present embodiment. When the total mass of the processing agent prepared by diluting the concentrated semiconductor processing composition or the non-diluted semiconductor processing composition (processing agent) is set to 100 mass%, the content of the surfactant is preferably 0.001 mass% or more and 1 mass% or less, and more preferably 0.005 mass% or more and 0.5 mass% or less. If the content of the surfactant is within the above range, the effect of removing particles or metal impurities contained in the CMP slurry from the wiring substrate is improved, and a better treated surface can be obtained.

1.6. Preparation method of semiconductor processing composition The semiconductor processing composition of this embodiment is not particularly limited and can be prepared by using a known method. Specifically, it can be prepared by dissolving the above-mentioned components in a liquid medium such as water or an organic solvent and filtering. There is no particular limitation on the mixing order or mixing method of the above-mentioned components.

In the method for preparing a semiconductor processing composition of the present embodiment, it is preferred to filter using a depth filter or a pleated filter to control the amount of particles as needed. Here, the depth filter is a high-precision filter also called a deep filter or a volume filter. Such a depth filter has a multilayer structure in which filter membranes having a plurality of holes are layered, or a filter in which a fiber bundle is wound. Specifically, deep filters include: Profile II, Nexis NXA, Nexis NXT, Polyfine XLD, Ultipleat Profile, etc. (all manufactured by Pall Japan); depth cartridge filter, wynd cartridge filter, etc. (all manufactured by Advantec); CP filter, BM filter, etc. (all manufactured by Chisso); Slope-Pure, Dia, Microsyria, etc. (all manufactured by Roki Techno), etc.

As pleated filters, there are: a high-precision filter in a cylindrical shape obtained by pleating a microfiltration membrane sheet made of non-woven fabric, filter paper, wire mesh, etc., and then forming it into a cylindrical shape, and then sealing the pleated seams of the sheet liquid-tightly, and sealing both ends of the tube liquid-tightly. Specifically, there are: HDCII, Polyfine II, etc. (all manufactured by Pall Japan); PP pleated cartridge filter (manufactured by Advantec); Porous Fine (manufactured by Chisso); Sarton Pore, Micropure, etc. (all manufactured by Roki Techno), etc.

2. Treatment agent As described above, each user may prepare the treatment agent by diluting the concentrated semiconductor treatment composition with a liquid medium, or may directly use the undiluted semiconductor treatment composition as the treatment agent. Furthermore, the treatment agent may be used as a CMP slurry for chemical mechanical polishing, a cleaning agent for cleaning the semiconductor surface, an anti-etching agent stripping agent, or an etching agent.

Here, the liquid medium used for dilution has the same meaning as the liquid medium contained in the semiconductor processing composition, and can be appropriately selected from the liquid media exemplified above according to the type of the processing agent.

As a method of adding a liquid medium to a concentrated semiconductor processing composition for dilution, there are the following methods: a pipe for supplying a concentrated semiconductor processing composition and a pipe for supplying a liquid medium are merged in the middle to mix them, and the mixed processing agent is supplied to the surface to be processed. The mixing can be carried out by the following methods: a method of passing liquids through a narrow passage under pressure to cause collision and mixing; a method of repeatedly dividing, separating, and merging the flow of the liquid by filling the pipe with a filler such as a glass tube; a method of providing a blade that rotates by power in the pipe, and other commonly used methods.

In addition, as another method of adding a liquid medium to a concentrated semiconductor processing composition for dilution, there is a method in which a pipe for supplying a concentrated semiconductor processing composition and a pipe for supplying a liquid medium are independently provided, a predetermined amount of liquid is supplied to a processing surface from each pipe, and the two are mixed on the processing surface. Further, as another method of adding a liquid medium to a concentrated semiconductor processing composition for dilution, there is a method in which a predetermined amount of a concentrated semiconductor processing composition and a predetermined amount of a liquid medium are placed in a container, mixed, and the mixed processing agent is supplied to the processing surface.

Regarding the dilution ratio when adding a liquid medium to the concentrated semiconductor processing composition for dilution, it is preferred that 1 part by mass of the concentrated semiconductor processing composition be diluted to 1 part by mass to 500 parts by mass (1 time to 500 times), more preferably to 20 parts by mass to 500 parts by mass (20 times to 500 times), and particularly preferably to 30 parts by mass to 300 parts by mass (30 times to 300 times). Furthermore, it is preferred that the dilution be performed using the same liquid medium as the liquid medium contained in the concentrated semiconductor processing composition. By making the semiconductor processing composition concentrated in this way, it can be transported or stored in a smaller container than when the processing agent is directly transported and stored. As a result, the cost of transport or storage can be reduced. In addition, compared with the case where the processing agent is directly purified by filtering or the like, a smaller amount of processing agent is purified, so the purification time can be shortened, thereby enabling mass production.

3. Treatment method The treatment method of one embodiment of the present invention includes the following steps: using the semiconductor treatment composition (treatment agent) to treat a wiring substrate containing copper or tungsten as a wiring material. More specifically, as an aspect of the treatment method of this embodiment, there can be listed an aspect including the following steps: using the semiconductor treatment composition (CMP slurry) to polish a wiring substrate containing copper or tungsten as a wiring material. In addition, as an aspect of the treatment method of this embodiment, there can be listed an aspect including the following steps: after chemically mechanically polishing the wiring substrate containing tungsten as a wiring material of the wiring substrate, cleaning it using the semiconductor treatment composition (cleaning agent). An example of the processing method of this embodiment is described below in detail using drawings.

3.1. Fabrication of a wiring substrate Figure 1 is a cross-sectional view schematically showing a process for fabricating a wiring substrate used in the processing method of the present embodiment. The wiring substrate is formed by the following process.

Fig. 1 is a schematic cross-sectional view of a workpiece before CMP treatment. As shown in Fig. 1, the workpiece 100 has a substrate 10. The substrate 10 may include, for example, a silicon substrate and a silicon oxide film formed thereon. Furthermore, although not shown, functional elements such as transistors may also be formed on the substrate 10.

The object to be processed 100 is composed of an insulating film 12 having a wiring recess 20, a barrier metal film 14 provided to cover the surface of the insulating film 12 and the bottom and inner wall of the wiring recess 20, and a metal film 16 filled in the wiring recess 20 and formed on the barrier metal film 14, which are sequentially stacked on a substrate 10.

Examples of the insulating film 12 include: a silicon oxide film formed by a vacuum process (e.g., a plasma enhanced-tetraethoxysilane film (PETEOS film), a high density plasma enhanced-TEOS film (HDP film), a silicon oxide film obtained by thermal chemical vapor deposition, etc.), an insulating film called fluorine-doped silicate glass (FSG), a borophosphosilicic acid film (BPSG film), an insulating film called SiON (silicon oxynitride), silicon nitride (Si ₃ N ₄ ), etc.

Examples of the barrier metal film 14 include tantalum, titanium, cobalt, ruthenium, manganese, and compounds thereof. The barrier metal film 14 is often formed of one of these, but two or more of them, such as tantalum and tantalum nitride, may be used in combination.

The metal film 16 needs to completely fill the wiring recess 20 as shown in FIG1 . Therefore, a metal film of 10,000 Å to 15,000 Å is usually deposited by chemical evaporation or electroplating. Copper or tungsten can be listed as the material of the metal film 16. In the case of copper, not only high-purity copper but also an alloy containing copper can be used. The copper content in the alloy containing copper is preferably 95 mass % or more.

3.2. Polishing step Next, the metal film 16 other than the portion buried in the wiring recess 20 in the object 100 of FIG. 1 is polished at high speed by CMP until the barrier metal film 14 is exposed (first polishing step). Furthermore, the barrier metal film 14 exposed on the surface is polished by CMP (second polishing step). In this way, the wiring substrate 200 shown in FIG. 2 is obtained.

The semiconductor processing composition (CMP slurry for chemical mechanical polishing) can be used in any of the first polishing step and the second polishing step. By using the semiconductor processing composition as CMP slurry, it is possible to suppress corrosion of wiring materials or barrier metal materials after CMP, and effectively remove contamination from the surface of the object to be processed. The semiconductor processing composition is particularly effective for processing a wiring substrate containing tungsten or cobalt as a wiring material.

3.3. Cleaning step Next, the surface (processed surface) of the wiring substrate 200 shown in FIG. 2 is processed using the semiconductor processing composition (cleaning agent). By using the semiconductor processing composition as a cleaning agent, corrosion of the wiring material or barrier metal material after CMP can be suppressed, and contamination can be effectively removed from the surface of the processed object.

It is very effective to use the composition containing iron ions and peroxides (Fenton's reagent) described in Japanese Patent Laid-Open No. 10-265766 etc. to perform chemical mechanical polishing on a wiring substrate containing tungsten as a wiring material of the wiring substrate, and then use the semiconductor processing composition (cleaning agent) to perform a cleaning step. In CMP of a workpiece having tungsten as a wiring material, there is a case where a CMP slurry containing iron ions and peroxides (hydrogen peroxide, potassium iodate, etc.) is used as an oxidant with high oxidizing power. The iron ions contained in the CMP slurry are easily adsorbed on the surface of the workpiece, so the surface of the workpiece is easily contaminated by iron. In this case, the iron contamination can be removed by treating the surface of the object to be processed with dilute hydrofluoric acid, but the surface of the object to be polished is etched and easily corroded. However, by using the semiconductor processing composition to perform the cleaning step, iron ions and the like existing on the surface of the object to be processed after CMP are contained in the hydrophobic cavities inside the ring structure of the (A) component and removed, and the metal such as the metal wiring material is difficult to corrode due to the action of the (B) component.

There is no particular limitation on the cleaning method, and the cleaning method can be performed by bringing the semiconductor processing composition (cleaning agent) into direct contact with the wiring substrate 200. Examples of methods for bringing the cleaning agent into direct contact with the wiring substrate 200 include: an immersion method in which the cleaning agent is filled in a cleaning tank and the wiring substrate is immersed; a spin coating method in which the cleaning agent is made to flow down onto the wiring substrate from a nozzle while the wiring substrate is rotated at high speed; and a spray method in which the cleaning agent is sprayed onto the wiring substrate for cleaning. In addition, examples of devices for performing such methods include: a batch processing device that simultaneously processes a plurality of wiring substrates housed in a cassette, and a single-chip processing device that mounts a wiring substrate on a holder and processes the same.

During the cleaning step, the temperature of the cleaning agent is usually set to room temperature, but can also be heated within a range that does not damage the performance, for example, it can be heated to about 40°C to 70°C.

In addition to the above-mentioned method of bringing the cleaning agent into direct contact with the wiring substrate 200, it is also preferable to use a treatment method using physical force. In this way, the removal of contamination caused by particles attached to the wiring substrate 200 is improved, and the treatment time can be shortened. As a treatment method using physical force, wiping cleaning using a cleaning brush or ultrasonic cleaning can be listed.

Furthermore, ultrapure water or pure water may be used for cleaning before and/or after the cleaning step.

4. Examples The present invention is described below by using examples, but the present invention is not limited to these examples. In addition, unless otherwise specified, the "parts" and "%" in this example are based on mass.

4.1. Examples 1 to 10, Comparative Examples 1 to 4 4.1.1. Preparation of semiconductor processing composition (concentrated CMP slurry) In a polyethylene container, the (A) component and ion exchange water shown in Table 1 were added, and then the (B) component shown in Table 1 was added, and stirred for 15 minutes. Thereafter, the water-soluble polymer and organic acid shown in Table 1 were added, and then the abrasive particles and pH adjuster were added in sequence, and stirred for 15 minutes, thereby obtaining semiconductor processing compositions (concentrated CMP slurries) of Examples 1 to 10 and Comparative Examples 1 to 4.

4.1.2. Evaluation method <Stability evaluation> 50 g of the obtained semiconductor processing composition was added to a colorless transparent glass container, and the state was observed visually immediately after preparation and after being stored in a constant temperature storage room at 20°C for one month. The evaluation criteria are as follows. (Evaluation criteria) ·A (good): No accumulation of precipitate was observed, indicating a good state. ·B (bad): Agglomerates or precipitate accumulated at the bottom of the container, and the composition could not be used for practical purposes, indicating a bad state.

<Corrosion characteristics evaluation> An 8-inch silicon wafer (8-inch silicon substrate with a thermal oxide film on which a 2,000 Å thick tungsten film is deposited) with tungsten (W) deposited on the surface by sputtering was cut into 1 cm × 3 cm pieces and used as metal wafer test pieces. The sheet resistance of the test piece was measured using a metal film thickness meter "Σ-5" manufactured by NPS Co., Ltd. The film thickness was calculated in advance from the sheet resistance and the volume resistivity of the metal film using the following formula. Film thickness (Å) = [Volume resistivity of metal film (Ω·m) ÷ Sheet resistance (Ω)] × 10 ¹⁰

Next, the semiconductor processing composition just prepared and the semiconductor processing composition after standing in a constant temperature storage at 20°C for one month were diluted with ultrapure water to the dilution ratios listed in Table 1, and 100 g was added to a polyethylene container. Thereafter, 35% by mass hydrogen peroxide was converted to hydrogen peroxide and added to 1% by mass and stirred for 15 minutes. Furthermore, the metal wafer test piece with tungsten film formed was immersed in the obtained composition for 60 minutes while maintaining at 40°C. Thereafter, it was washed with running water for 10 seconds and dried. The film thickness of the metal wafer test piece after immersion treatment was measured again, and the reduced film thickness was divided by the immersion time of 60 minutes to calculate the etching rate (unit: Å/min). The evaluation criteria are as follows. The evaluation results are shown in Table 1. (Evaluation criteria) ·A: The etching rate is less than 5 Å/min, and the corrosion of tungsten in the polishing step can be effectively suppressed. Very good. ·B: The etching rate is 5 Å/min or more and 10 Å/min or less, and the corrosion of tungsten in the polishing step can be suppressed to a practical level. Good. ·C: The etching rate is 10 Å/min or more, and the corrosion of tungsten in the polishing step is large and cannot be used for practical purposes. Poor. ·D: Evaluation was not possible due to the formation of sediment. Very bad.

<Defect evaluation> Ultrapure water was used to dilute the semiconductor processing composition just prepared and the semiconductor processing composition after standing in a constant temperature storage at 20°C for one month at the dilution ratio listed in Table 1, and then 500 g was added to a polyethylene container, and 35% by mass of hydrogen peroxide was converted into hydrogen peroxide, and added to make 1% by mass, and stirred for 15 minutes to obtain a chemical mechanical polishing composition. An 8-inch silicon substrate with a thermal oxide film on which a 2,000 Å thick tungsten film was layered was cut into 3 cm × 3 cm and used as a wafer test piece. The wafer test piece was used as the polished object and subjected to chemical mechanical polishing for 60 seconds under the following polishing conditions. (Polishing conditions) ·Polishing device: "LM-15C" manufactured by Lapmaster SFT ·Polishing pad: "IC1000/K-Groove" manufactured by Rodel Nitta Co., Ltd. ·Platen speed: 90 rpm ·Polishing head speed: 90 rpm ·Polishing head push pressure: 3 psi ·Supply rate of chemical mechanical polishing composition: 100 mL/min

Next, a water cleaning treatment on the polishing pad was performed for 10 seconds under the cleaning condition of a supply rate of 500 mL/min of ion exchange water. For the metal wafer test piece subjected to chemical mechanical polishing using the above method, a scanning atomic force microscope (AFM) manufactured by Bruker Corporation, namely Dimension FastScan, was used to observe 5 locations with an outer frame size of 10 μm. The images of the 5 locations obtained were analyzed using image analysis software, and the total number of attachments with a height of more than 10 nm was taken as the number of defects. The evaluation criteria are as follows. The evaluation results are shown in Table 1. (Evaluation Criteria) ·A: The number of defects is less than 30. Very good polishing results. ·B: The number of defects is 30 or more and less than 50. Good polishing results that can be used practically. ·C: The number of defects is 50 or more. Poor polishing results that cannot be used practically. ·D: Evaluation cannot be performed due to the generation of sediment. Very poor.

4.1.3. Evaluation results The composition and evaluation results of the semiconductor processing composition (concentrated CMP slurry) are shown in Table 1 below.

[Table 1] Embodiment Comparison Example 1 2 3 4 5 6 7 8 9 10 1 2 3 4 Semiconductor processing composition (concentrated type) (A) Cyclodextrin and cyclodextrin derivatives Type β-Cyclodextrin β-Cyclodextrin β-Cyclodextrin β-Cyclodextrin β-Cyclodextrin β-Cyclodextrin β-Cyclodextrin α-Cyclodextrin 2-Hydroxypropyl-β-cyclodextrin 2-Hydroxyethyl-β-cyclodextrin β-Cyclodextrin β-Cyclodextrin - β-Cyclodextrin _MA (mass %) 0.28 0.056 0.1 0.2 0.1 0.1 0.1 0.1 0.1 0.1 1.8 0.12 - 0.08 (B) Compounds with zwitterionic structures Type Sodium Lauryl Amine Diacetate Sodium Lauryl Amine Diacetate Sodium Lauryl Amine Diacetate Sodium Lauryl Amine Diacetate Laurylamidopropyl betaine Dodecylaminoethylaminoethylglycine Lauryl Hydroxyl Sulfobetaine Sodium Lauryl Amine Diacetate Sodium Lauryl Amine Diacetate Sodium Lauryl Amine Diacetate Sodium Lauryl Amine Diacetate Sodium Lauryl Amine Diacetate Sodium Lauryl Amine Diacetate - _MB (mass %) 0.02 0.015 0.02 0.04 0.02 0.02 0.02 0.02 0.02 0.02 0.04 0.06 0.02 - M _A /M _B 14 3.7 5 5 5 5 5 5 5 5 45 2 - - Abrasive particles Type PL-3 PL-3 PL-3 PL-3 PL-3 PL-3 PL-3 PL-3 PL-3 PL-3 PL-3 PL-3 PL-3 PL-3 Quality% 4 1.5 2 4 2 2 2 2 2 2 2 2 2 2 Water-soluble polymer Polyacrylic acid (Mw=50,000) (Mass %) 0.03 0.02 0.04 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 Polystyrene sulfonic acid (Mw=75,000) (Mass %) 0.02 0.02 Organic acid Malonic acid (Mass %) 0.20 0.15 0.20 0.40 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 Maleic acid (Mass %) 0.20 Apple acid (Mass %) 0.20 pH Adjuster KOH KOH KOH KOH KOH - KOH KOH KOH KOH KOH KOH KOH KOH Manufacturing conditions Dilution ratio 2 1.5 2 4 2 2 2 2 2 2 2 2 2 2 Treatment agent pH 3.3 2.8 2.8 2.8 2.8 2.0 3.5 2.8 2.8 2.8 2.8 2.8 2.8 2.8 Type CMP slurry CMP slurry CMP slurry CMP slurry CMP slurry CMP slurry CMP slurry CMP slurry CMP slurry CMP slurry CMP slurry CMP slurry CMP slurry CMP slurry Evaluation items Stability evaluation Just after preparation A A A A A A A A A A A A B A After storing at 20℃ for one month A A A A A A A A A A A B B A Corrosion characteristics evaluation Just after preparation A A A A A A A A A A B A A C After storing at 20℃ for one month A A A A A A A A A A B D D C Defect evaluation Just after preparation A A A A A A A A A A C C C A After storing at 20℃ for one month A A A A A A A A A A C D D A

In Table 1, the numerical value of each component represents mass %. In each Example and each Comparative Example, the total amount of each component is 100 mass %, and the remainder is ion-exchanged water.

As shown in Table 1, the semiconductor processing composition (concentrated CMP slurry) having a ratio _MA / _MB of 3 to 15 of the content _MA [mass %] of the component (A) to the content _MB [mass %] of the component (B) has good corrosion properties for tungsten films, and the defect evaluation after the CMP step using the composition is also good. In addition, the semiconductor processing compositions of Examples 1 to 10 have no precipitate formation even after being stored at 20°C for one month, and have excellent stability. The corrosion properties and defect evaluation of the semiconductor processing compositions of Examples 1 to 10 after being stored at 20°C for one month are also good results.

On the other hand, as in the semiconductor processing composition of Comparative Example 1, when _MA / _MB exceeded 15, defects were found to be prone to occur on the tungsten film. As in the semiconductor processing composition of Comparative Example 2, when _MA / _MB was less than 3, deposits were found to be generated after storage at 20°C for one month, and stability was easily impaired, and defects were found to be prone to occur on the tungsten film. As in the semiconductor processing composition of Comparative Example 3, when component (A) was not contained, deposits were found to be generated immediately after preparation, and stability was extremely poor, and defects were found to be prone to occur on the tungsten film. When the semiconductor processing composition of Comparative Example 4 does not contain the component (B), the corrosion suppression capability is poor.

4.2. Examples 11 to 20, Comparative Examples 5 to 8 4.2.1. Preparation of semiconductor processing compositions (concentrated cleaning agents) In a polyethylene container, the components (A) and ion exchange water shown in Table 2 were added, and then the components (B) shown in Table 2 were added, and stirred for 15 minutes. Thereafter, the water-soluble polymer, organic acid, and amine shown in Table 2 were added, and then the pH adjuster was added, and further stirred for 15 minutes, thereby obtaining semiconductor processing compositions (concentrated cleaning agents) of Examples 11 to 20 and Comparative Examples 5 to 8.

4.2.2. Evaluation method <Stability evaluation> Evaluation was conducted using the same method and evaluation criteria as <Stability evaluation> in "4.1.2. Evaluation method". The results are shown in Table 2.

<Corrosion characteristics evaluation> An 8-inch silicon wafer (8-inch silicon substrate with a thermal oxide film on which a 2,000 Å thick tungsten film is deposited) with tungsten (W) deposited on the surface by sputtering was cut into 1 cm × 3 cm pieces and used as metal wafer test pieces. The sheet resistance of the test piece was measured using a metal film thickness meter "Σ-5" manufactured by NPS Co., Ltd. The film thickness was calculated in advance from the sheet resistance and the volume resistivity of the metal film using the following formula. Film thickness (Å) = [Volume resistivity of metal film (Ω·m) ÷ Sheet resistance (Ω)] × 10 ¹⁰

Next, ultrapure water was used to dilute the semiconductor processing composition just prepared and the semiconductor processing composition after standing in a constant temperature storage room at 20°C for one month to the dilution ratios listed in Table 2, and 100 g was placed in a polyethylene container. After that, the temperature was kept at 25°C, and the metal wafer test piece with a tungsten film was immersed in each semiconductor processing composition for 60 minutes. After that, it was washed with running water for 10 seconds and dried. The film thickness of the metal wafer test piece after the immersion treatment was measured again, and the reduced film thickness was divided by the immersion time of 60 minutes to calculate the etching rate (ER (Etching Rate), unit: Å/min). The evaluation criteria are as follows. The evaluation results are shown in Table 2. (Evaluation criteria) ·A: The etching rate is less than 1.5 Å/min, and the corrosion of tungsten in the cleaning step can be effectively suppressed. Very good. ·B: The etching rate is 1.5 Å/min or more and less than 5 Å/min, and the corrosion of tungsten in the cleaning step is suppressed to a practical level. Good. ·C: The etching rate is 5 Å/min or more, and the corrosion rate of tungsten in the cleaning step is high and cannot be practically used. Poor. ·D: Evaluation cannot be performed due to the generation of precipitates. Very poor.

<Defect evaluation> Colloidal silica water dispersion PL-3 (manufactured by Fuso Chemical Industries, Ltd.) was added to a polyethylene container in an amount equivalent to 1% by mass in terms of silica, and ion-exchanged water and maleic acid as a pH adjuster were added so that the total of the components was 100% by mass, and the pH value was adjusted to 3. Furthermore, 35% by mass of hydrogen peroxide water as an oxidizing agent was added in terms of 1% by mass in terms of hydrogen peroxide, and stirred for 15 minutes to obtain a chemical mechanical polishing composition. An 8-inch silicon substrate with a thermal oxide film on which a 2,000 Å thick tungsten film was laminated was cut into 3 cm × 3 cm pieces and used as wafer test pieces. The wafer test piece was used as the polished object and chemical mechanical polishing was performed for 60 seconds under the following polishing conditions. (Polishing conditions) · Polishing device: "LM-15C" manufactured by Lapmaster SFT · Polishing pad: "IC1000/K-Groove" manufactured by Rodel Nitta Co., Ltd. · Platen speed: 90 rpm · Polishing head speed: 90 rpm · Polishing head push pressure: 3 psi · Chemical mechanical polishing composition supply rate: 100 mL/min

Next, a water cleaning treatment on the polishing pad was performed for 10 seconds under the cleaning condition of supplying ion exchange water at a rate of 500 mL/min. For the wafer test piece subjected to chemical mechanical polishing using the above method, five locations were observed with an outer frame size of 10 μm using a scanning atomic force microscope (AFM), namely Dimension FastScan, manufactured by Bruker Corporation. The wafer test piece with a flat surface whose average arithmetic mean roughness of the five locations obtained was confirmed to be less than 0.2 nm was selected and used in the following defect evaluation.

The semiconductor processing composition just prepared and the semiconductor processing composition after standing in a constant temperature storage room at 20°C for one month were diluted with ultrapure water to the dilution ratios listed in Table 2, and then 50 mL was added to a glass beaker and kept at 25°C. After that, the wafer test piece subjected to chemical mechanical polishing in the above was immersed for 15 minutes, washed with running water for 10 seconds and dried, and then observed at 5 locations with an outer frame size of 10 μm using AFM. The images of the 5 locations obtained were analyzed using image analysis software, and the total number of attachments with a height of 2 nm or more was taken as the number of defects. The evaluation criteria are as follows. The evaluation results are shown in Table 2. (Evaluation criteria) ·A: The number of defects is less than 100. Very good polishing results. ·B: The number of defects is more than 100 and less than 500. Good polishing results that can be used practically. ·C: The number of defects is more than 500. Poor polishing results that cannot be used practically. ·D: Evaluation cannot be performed due to the generation of sediment. Very poor.

4.2.3. Evaluation results The composition and evaluation results of the semiconductor processing composition (concentrated cleaning agent) are shown in Table 2 below.

[Table 2] Embodiment Comparison Example 11 12 13 14 15 16 17 18 19 20 5 6 7 8 Semiconductor processing composition (concentrated type) (A) Cyclodextrin and cyclodextrin derivatives Type β-Cyclodextrin β-Cyclodextrin β-Cyclodextrin β-Cyclodextrin β-Cyclodextrin β-Cyclodextrin β-Cyclodextrin α-Cyclodextrin 2-Hydroxypropyl-β-cyclodextrin 2-Hydroxyethyl-β-cyclodextrin β-Cyclodextrin β-Cyclodextrin - β-Cyclodextrin _MA (mass %) 1.40 0.37 0.5 1.5 0.5 0.30 1.60 5.00 5.00 5.00 1.8 0.10 - 0.4 (B) Compounds with zwitterionic structures Type Sodium Lauryl Amine Diacetate Sodium Lauryl Amine Diacetate Sodium Lauryl Amine Diacetate Sodium Lauryl Amine Diacetate Laurylamidopropyl betaine Dodecylaminoethylaminoethylglycine Lauryl Hydroxyl Sulfobetaine Sodium Lauryl Amine Diacetate Sodium Lauryl Amine Diacetate Sodium Lauryl Amine Diacetate Sodium Lauryl Amine Diacetate Sodium Lauryl Amine Diacetate Sodium Lauryl Amine Diacetate - _MB (mass %) 0.10 0.10 0.10 0.30 0.10 0.06 0.40 1.00 1.00 1.00 0.10 0.10 0.10 - M _A /M _B 14 3.7 5 5 5 5 4 5 5 5 18 1 - - Water-soluble polymer Polyacrylic acid (Mw=50,000) (Mass %) 0.10 0.10 Polystyrene sulfonic acid (Mw=75,000) (Mass %) 0.10 0.10 0.10 0.10 0.10 0.10 Organic acid Malonic acid (Mass %) Maleic acid (Mass %) 0.12 Apple acid (Mass %) Citric Acid (Mass %) 0.10 0.10 0.10 0.30 0.10 0.40 0.10 0.10 0.10 0.10 amine Piperazine (Mass %) 1.00 1.00 1.00 pH Adjuster KOH KOH KOH KOH KOH KOH KOH Phosphoric acid Phosphoric acid Phosphoric acid - - - - Manufacturing conditions Dilution ratio 10 10 10 30 10 6 40 100 100 100 10 10 10 10 Treatment agent pH 4.5 4.5 4.5 4.5 4.5 2.1 4.5 5.0 5.0 5.0 4.5 4.5 4.5 4.5 Type Cleaning agent Cleaning agent Cleaning agent Cleaning agent Cleaning agent Cleaning agent Cleaning agent Cleaning agent Cleaning agent Cleaning agent Cleaning agent Cleaning agent Cleaning agent Cleaning agent Evaluation items Stability evaluation Just after preparation A A A A A A A A A A A B B A After storing at 20℃ for one month A A A A A A A A A A A B B A Corrosion characteristics evaluation Just after preparation A A A A A A A A A A B A A C After storing at 20℃ for one month A A A A A A A A A A B D D C Defect evaluation Just after preparation B A A A A B A A A A C C C A After storing at 20℃ for one month B A A A A B A A A A C D D A

In Table 2, the numerical values of each component represent mass %. In each embodiment and each comparative example, the total amount of each component is 100 mass %, and the remainder is ion exchange water. Here, each component in Table 1 and Table 2 is supplemented.

<(A) Cyclodextrin and cyclodextrin derivatives> ·α-Cyclodextrin: manufactured by Fuji Film & Wako Pure Chemical Industries, Ltd., trade name ·β-Cyclodextrin: manufactured by Fuji Film & Wako Pure Chemical Industries, Ltd., trade name ·2-Hydroxypropyl-β-cyclodextrin: manufactured by Fuji Film & Wako Pure Chemical Industries, Ltd., trade name ·2-Hydroxyethyl-β-cyclodextrin: manufactured by Fuji Film & Wako Pure Chemical Industries, Ltd., trade name <(B) Compounds with a zwitterionic structure> ·Sodium laurylaminodiacetate: manufactured by NOF Corporation, trade name "Nissananon ) (R) LA" ·Laurylamidopropyl betaine: manufactured by Kao Corporation, trade name "Amphitol 20AB" ·Dodecylaminoethylaminoethylglycine: manufactured by Sanyo Chemical Industries, Ltd., trade name "Lebon S" ·Lauryl hydroxysulfobetaine: manufactured by Kao Corporation, trade name "Amphitol 20HD" <Abrasive particles> ·PL-3: manufactured by Fuso Chemical Industries, Ltd., trade name "PL-3", colloidal silica, average secondary particle size 70 nm ＜Water-soluble polymer＞ · Polyacrylic acid: manufactured by Toagosei Co., Ltd., trade name "AC-10L", Mw = 50,000 · Polystyrene sulfonic acid: manufactured by Akzo Nobel, trade name "Versa-TL 71", Mw = 75,000 ＜Organic acid＞ · Malonic acid: manufactured by Shizen Co., Ltd., trade name "Malonic acid" · Maleic acid: manufactured by Fuso Chemical Industry Co., Ltd., trade name "Hydrogenic maleic acid" · Apple acid: Showa Chemical Industry Co., Ltd., trade name "DL-apple acid" · Citric acid: manufactured by Hayashi Jun Chemical Industry Co., Ltd., trade name "Citric acid (crystallized)" ＜Amine＞ · Piperazine: manufactured by Tosoh Co., Ltd., trade name "Piperazine" ＜pH adjuster＞ · KOH: manufactured by Kanto Chemical Co., Ltd., trade name "KOH (aqueous potassium hydroxide solution) 48%" · Phosphoric acid: manufactured by RASA Industries Co., Ltd., trade name "Phosphoric acid"

As shown in Table 2, the semiconductor processing composition (concentrated cleaning agent) having a ratio _MA / _MB of 3 to 15 of the content _MA [mass %] of the component (A) to the content _MB [mass %] of the component (B) has good corrosion properties for tungsten films, and the defect evaluation after the cleaning step using the composition after the CMP step is also good. In addition, the semiconductor processing compositions of Examples 11 to 20 have no precipitate formation even after being stored at 20°C for one month, and have excellent stability. The corrosion properties and defect evaluation of the semiconductor processing compositions of Examples 11 to 20 after being stored at 20°C for one month are also good results.

On the other hand, as in the semiconductor processing composition of Comparative Example 5, when _MA / _MB exceeded 15, defects were found to be prone to occur on the tungsten film. As in the semiconductor processing composition of Comparative Example 6, when _MA / _MB was less than 3, deposits were found to be generated after storage at 20°C for one month, and stability was easily impaired, and defects were found to be prone to occur on the tungsten film. As in the semiconductor processing composition of Comparative Example 7, when component (A) was not contained, deposits were found to be generated immediately after preparation, and stability was extremely poor, and defects were found to be prone to occur on the tungsten film. When the semiconductor processing composition of Comparative Example 8 does not contain the component (B), the corrosion inhibition ability is poor.

The results in Table 1 and Table 2 show that, in the case of a semiconductor processing composition within the range of _MA / _MB of 3 to 15, storage stability in a concentrated form of 1.5 times or more and 100 times or less can be ensured, and by diluting the composition to a predetermined concentration during use, both good corrosion suppression capability and defect suppression capability for the tungsten film can be achieved.

The present invention is not limited to the embodiments described above, and various modifications are possible. For example, the present invention includes structures that are substantially the same as the structures described in the embodiments (for example, structures with the same functions, methods, and results, or structures with the same purposes and effects). In addition, the present invention includes structures in which the non-essential parts of the structures described in the embodiments are replaced. In addition, the present invention includes structures that exert the same effects as the structures described in the embodiments, or structures that can achieve the same purposes. In addition, the present invention includes structures obtained by adding known technologies to the structures described in the embodiments.

10: Base 12: Insulation film 14: Barrier metal film 16: Metal film 20: Wiring recess 100: Processing object 200: Wiring substrate

FIG1 is a cross-sectional view schematically showing a manufacturing process of a wiring substrate used in a processing method of the present embodiment. FIG2 is a cross-sectional view schematically showing a manufacturing process of a wiring substrate used in a processing method of the present embodiment.

10: Matrix

12: Insulation film

14: Barrier metal film

16:Metal film

20: Wiring recess

100: Processed body

Claims (7)

A semiconductor processing composition comprises: (A) at least one selected from the group consisting of cyclodextrin and cyclodextrin derivatives, (B) a compound having an amphoteric ionic structure, and (C) a liquid medium, wherein the component (B) is a compound having at least one functional group selected from the group consisting of a carboxyl group and a sulfonic acid group and an alkyl group having 12 to 18 carbon atoms, and when the content of the component (A) is _MA [mass %] and the content of the component (B) is _MB [mass %], _MA / _MB = 3 to 15. The semiconductor processing composition as described in claim 1 is used after being diluted to 1 to 100 times. The semiconductor processing composition as described in claim 1 or claim 2, wherein the cyclodextrin derivative is at least one selected from 2-hydroxypropyl-β-cyclodextrin and 2-hydroxyethyl-β-cyclodextrin. The semiconductor processing composition as described in claim 1 or claim 2 further contains an organic acid. The semiconductor processing composition as described in claim 1 or claim 2 further contains a water-soluble polymer. A processing method comprising the following steps: using a semiconductor processing composition as described in any one of claim 1 to claim 5 to chemically mechanically polish, clean, resist strip, or etch a wiring substrate containing tungsten as a wiring material. A processing method comprises the following steps: after chemical mechanical polishing of a wiring substrate containing tungsten as a wiring material of the wiring substrate, chemical mechanical polishing, cleaning, anti-etching agent stripping, or etching is performed using a semiconductor processing composition as described in any one of claim 1 to claim 5.