Aqueous composition and cleaning method using the same

Abstract

According to the present invention, there can be provided an aqueous composition comprising: (A) a fluoride ion supply source in an amount such that the fluoride ion concentration in the composition reaches 0.05 to 30 mmol / L; (B) a cation supply source in an amount such that the molar ratio of cations to fluoride ions in the composition reaches 0.3 to 20; and (C) selected from C in an amount of 0.0001 to 10% by mass based on the total amount of the composition. 4‑13 Alkylphosphonic acid, C 4‑13 Alkyl phosphonates, C 4‑13 One or more compounds of alkylphosphoric acids and salts thereof, wherein the pH of the aqueous composition is in the range of 2 to 6.

Description

Technical Field

[0001] The present invention relates to an aqueous composition and a cleaning method using the same, and for example, to a cleaning composition used in a manufacturing process of an electronic device (for example, a semiconductor element), and a cleaning method using the same. Background Art

[0002] In the process of manufacturing electronic devices such as semiconductor elements, a dry etching process is usually used to form a semiconductor integrated circuit. In this dry etching process, dry etching residues (zirconium-based residues, titanium-based residues, polymer residues, etc.) are generated and need to be removed. The cleaning agent used to remove the dry etching residue is preferably one that does not cause adverse effects (such as corrosion) on the wiring metal materials (such as copper, titanium, cobalt, tungsten, etc.) used in the semiconductor integrated circuit that is the cleaning object.

[0003] From this viewpoint, various cleaning agents have been developed. For example, Patent Document 1, Patent Document 2, Patent Document 3, etc. disclose cleaning compositions for removing dry etching residues generated after dry etching, cleaning methods using the same, and the like.

[0004] In addition, a hard mask is sometimes used in the process of forming a semiconductor integrated circuit. As a material of the hard mask, silicon-based and titanium-based materials have been used in the past, but in recent years, a zirconium oxide-based hard mask has been proposed (Non-Patent Document 1).

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application No. 2013-533631

[0008] Patent Document 2: Japanese Patent Application Publication No. 2016-171294

[0009] Patent Document 3: Japanese Patent Application Publication No. 2006-83376

[0010] Non-patent literature

[0011] Non-patent document 1: M Padmanaban et al, J. Photopolym. Sci. Technol., 27 (2014), 503 Summary of the invention

[0012] Problem that the invention aims to solve

[0013] There are many kinds of metal materials for wiring used in electronic devices and masking materials used in dry etching, and there are also many combinations thereof. Therefore, from the viewpoints of the removal efficiency of dry etching residues and the anticorrosion effect on metal materials for wiring, it is required to develop a new cleaning composition.

[0014] Solutions for solving problems

[0015] The present invention provides: the following aqueous composition, a cleaning method using the same, etc.

[0016] [1] An aqueous composition comprising:

[0017] (A) Fluoride ions (e.g., F) in the composition - A fluoride ion supply source having a concentration of 0.05 to 30 mmol / L;

[0018] (B) a cation supply source in an amount such that the molar ratio of cations in the composition to fluoride ions is 0.3 to 20; and

[0019] 0.0001 to 10% by mass of (C) based on the total amount of the composition is selected from C 4-13 Alkylphosphonic acid, C 4-13 Alkyl phosphonates, C 4-13 One or more compounds of alkylphosphoric acids and salts thereof, wherein the pH of the aqueous composition is in the range of 2 to 6 (eg, 2 to 5, 2 to 4, or 2 to 3).

[0020] [2] The aqueous composition according to [1] above, wherein the fluoride ion supply source of the component (A) is hydrogen fluoride, ammonium fluoride, acidic ammonium fluoride, tetramethylammonium fluoride, tetraethylammonium fluoride, tetrapropylammonium fluoride, tetrabutylammonium fluoride, lithium fluoride, sodium fluoride, potassium fluoride, acidic potassium fluoride, rubidium fluoride, cesium fluoride, beryllium fluoride, magnesium fluoride, strontium fluoride, barium fluoride or a mixture thereof.

[0021] [3] The aqueous composition according to [1] or [2], wherein the cation supply source of the component (B) is a lithium compound, a sodium compound, a potassium compound, a rubidium compound, a cesium compound, a beryllium compound, a magnesium compound, a strontium compound, a barium compound, an ammonium compound, a tetramethylammonium compound, a tetraethylammonium compound, a tetrapropylammonium compound, a tetrabutylammonium compound, or a mixture thereof (excluding fluorine-containing compounds).

[0022] [4] The aqueous composition according to any one of [1] to [3] above, wherein the aqueous composition is at least one selected from the following:

[0023] As the aforementioned alkylphosphonic acid, n-butylphosphonic acid, n-pentylphosphonic acid, n-hexylphosphonic acid, n-heptylphosphonic acid, n-octylphosphonic acid, n-nonylphosphonic acid, n-decylphosphonic acid, n-undecylphosphonic acid, n-dodecylphosphonic acid, n-tridecylphosphonic acid, or a mixture thereof;

[0024] As the aforementioned alkylphosphonate, n-butylphosphonate, n-pentylphosphonate, n-hexylphosphonate, n-heptylphosphonate, n-octylphosphonate, n-nonylphosphonate, n-decylphosphonate, n-undecylphosphonate, n-dodecylphosphonate, n-tridecylphosphonate, or a mixture thereof, and

[0025] The aforementioned alkylphosphonic acids and salts of the aforementioned alkylphosphonic acid esters.

[0026] [4a] The aqueous composition according to any one of [1] to [4] above, wherein the alkylphosphonic acid is C 5-12 Alkylphosphonic acid (preferably C 5-11 Alkylphosphonic acid, more preferably C 5-9 Alkylphosphonic acid, more preferably C 6-8 Alkylphosphonic acid),

[0027] The aforementioned alkylphosphonic acid esters are esters of these alkylphosphonic acids.

[0028] [5] The aqueous composition according to any one of [1] to [3] above, wherein the aqueous composition contains at least one selected from the following substances:

[0029] As the aforementioned alkyl phosphoric acid, n-butyl phosphoric acid, n-pentyl phosphoric acid, n-hexyl phosphoric acid, n-heptyl phosphoric acid, n-octyl phosphoric acid, n-nonyl phosphoric acid, n-decyl phosphoric acid, n-undecyl phosphoric acid, n-dodecyl phosphoric acid, n-tridecyl phosphoric acid, 2-ethylhexyl phosphate, isodecyl phosphate, or a mixture thereof; and

[0030] Salts of the foregoing alkylphosphoric acids.

[0031] [5a] The aqueous composition according to any one of [1] to [5] above, wherein the alkylphosphoric acid is C 4-13 Alkyl phosphate (preferably C 5-11 Alkyl phosphate, more preferably C 5-9 Alkyl phosphate, more preferably C 6-8 alkyl phosphate).

[0032] [5b] The aqueous composition according to any one of [1] to [5a] above, which is a composition for removing dry etching residue for removing residue after dry etching (for example, zirconium oxide-based dry etching residue).

[0033] [5c] The aqueous composition according to any one of [1] to [5b] above, which is a composition for preventing corrosion of wiring materials (e.g., cobalt or cobalt alloy) of electronic devices to be cleaned.

[0034] [5d] The aqueous composition according to any one of [1] to [5c] above, wherein dodecylphosphonic acid is excluded from the alkylphosphonic acid.

[0035] [5e] A composition according to any one of [1] to [5d] above, wherein the concentration of fluoride ions supplied from the fluoride ion supply source in the composition is 0.05 to 30 mmol / L (preferably 0.25 to 20 mmol / L, more preferably 0.5 to 5 mmol / L), and the cations supplied from the cation supply source are contained in an amount of 0.3 to 20 in terms of a molar ratio of cations to fluoride ions.

[0036] [6] A method for cleaning an electronic device, comprising the step of bringing the aqueous composition according to any one of [1] to [5e] above into contact with the electronic device.

[0037] [7] A method for producing an electronic device, comprising the step of bringing the composition according to any one of [1] to [5e] above into contact with an electronic device.

[0038] [8] An etching solution comprising the composition according to any one of [1] to [5e] above.

[0039] [9] A cleaning solution comprising the composition according to any one of [1] to [5e] above.

[0040] Effects of the Invention

[0041] The aqueous composition described in the preferred embodiment of the present invention can protect etching barrier films such as silicon nitride, interlayer insulating films, wiring metal materials such as cobalt or cobalt alloys, etc. from corrosion, and efficiently remove dry etching residues (for example, zirconium-based etching residues, titanium-based etching residues, polymer-based etching residues, etc.).

[0042] According to the cleaning method described in the preferred embodiment of the present invention, the anti-corrosion effect and etching residue removal performance of etching barrier films such as silicon nitride, interlayer insulating films, wiring metal materials such as cobalt or cobalt alloys, etc. are excellent. Therefore, in the manufacturing process of electronic devices such as semiconductor elements, high-precision and high-quality electronic devices can be manufactured with a good yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 The schematic diagram is a cross-sectional view of one embodiment of a semiconductor element having a structure of a zirconium oxide-based hard mask 2, cobalt or cobalt alloy 3, a low dielectric constant interlayer insulating film 5, and silicon nitride 6 in the semiconductor element before the dry etching residue 1 is removed. DETAILED DESCRIPTION

[0044] The aqueous composition of the present invention comprises: (A) a fluoride ion supply source in an amount such that the fluoride ion concentration in the composition reaches 0.05 to 30 mmol / L; (B) a cation supply source in an amount such that the molar ratio of cations to fluoride ions in the composition reaches 0.3 to 20; and, based on the total amount of the composition, 0.0001 to 10% by mass of (C) selected from C 4-13 Alkylphosphonic acid, C 4-13 Alkyl phosphonates, C 4-13 One or more compounds of alkylphosphoric acids and salts thereof, wherein the pH of the aqueous composition is in the range of 2 to 6.

[0045] Hereinafter, the aqueous composition according to the present invention will be described in detail.

[0046] [Component (A): Fluoride ion supply source]

[0047] The fluoride ion supply source used in the present invention is not particularly limited as long as it can supply fluoride ions. As the fluoride ion supply source used herein, for example, hydrogen fluoride, ammonium fluoride, acidic ammonium fluoride, tetramethylammonium fluoride, tetraethylammonium fluoride, tetrapropylammonium fluoride, tetrabutylammonium fluoride, lithium fluoride, sodium fluoride, potassium fluoride, acidic potassium fluoride, rubidium fluoride, cesium fluoride, beryllium fluoride, magnesium fluoride, strontium fluoride, barium fluoride or a mixture thereof can be cited. Among these, hydrogen fluoride, ammonium fluoride, acidic ammonium fluoride, tetramethylammonium fluoride, potassium fluoride and acidic potassium fluoride are particularly preferred.

[0048] When the fluoride ion supply source is used as a cleaning liquid, etc., it is mixed so that the fluoride ion concentration in the aqueous composition reaches 0.05 to 30 mmol / L. The preferred fluoride ion concentration in the composition is 0.25 to 20 mmol / L, more preferably 0.5 to 5 mmol / L, and further preferably 1.0 to 2.5 mmol / L. For example, the amount of the fluoride ion supply source is usually 0.001 to 0.6 mass %, preferably 0.005 to 0.5 mass %, and more preferably 0.02 to 0.4 mass % in terms of hydrogen fluoride in the composition.

[0049] [Component (B): cation supply source]

[0050] The cation supply source used in the present invention is not particularly limited, and examples thereof include lithium compounds, sodium compounds, potassium compounds, rubidium compounds, cesium compounds, beryllium compounds, magnesium compounds, strontium compounds, barium compounds, ammonium compounds, tetramethylammonium compounds, tetraethylammonium compounds, tetrapropylammonium compounds, tetrabutylammonium compounds, or mixtures thereof.

[0051] Preferred lithium compounds include, for example, lithium hydroxide, lithium nitrate, lithium sulfate, lithium chloride, lithium tetrafluorophosphate, lithium phosphate, and lithium acetate.

[0052] Preferred sodium compounds include, for example, sodium hydroxide, sodium nitrate, sodium sulfate, sodium chloride, sodium tetrafluorophosphate, sodium phosphate, sodium acetate, and the like.

[0053] Preferred examples of the potassium compound include potassium hydroxide, potassium nitrate, potassium sulfate, potassium chloride, potassium tetrafluorophosphate, potassium hexafluorophosphate, potassium phosphate, and potassium acetate.

[0054] Preferred examples of the rubidium compound include rubidium hydroxide, rubidium nitrate, rubidium sulfate, rubidium chloride, rubidium tetrafluorophosphate, rubidium phosphate, and rubidium acetate.

[0055] Preferred examples of the cesium compound include cesium hydroxide, cesium nitrate, cesium sulfate, cesium chloride, cesium tetrafluorophosphate, cesium phosphate, and cesium acetate.

[0056] Preferred beryllium compounds include, for example, beryllium hydroxide, beryllium nitrate, beryllium sulfate, beryllium chloride, beryllium tetrafluorophosphate, beryllium phosphate, beryllium acetate, and the like.

[0057] Preferred examples of the magnesium compound include magnesium hydroxide, magnesium nitrate, magnesium sulfate, magnesium chloride, magnesium tetrafluorophosphate, magnesium phosphate, and magnesium acetate.

[0058] Preferred examples of the strontium compound include strontium hydroxide, strontium nitrate, strontium sulfate, strontium chloride, strontium tetrafluorophosphate, strontium phosphate, and strontium acetate.

[0059] Preferred barium compounds include, for example, barium hydroxide, barium nitrate, barium sulfate, barium chloride, barium tetrafluorophosphate, barium phosphate, and barium acetate.

[0060] Preferred examples of the ammonium compound include ammonia, ammonium nitrate, ammonium sulfate, ammonium chloride, ammonium tetrafluorophosphate, ammonium phosphate, and ammonium acetate.

[0061] Preferred examples of the tetramethylammonium compound include tetramethylammonium hydroxide, tetramethylammonium nitrate, tetramethylammonium sulfate, tetramethylammonium chloride, tetramethylammonium tetrafluorophosphate, tetramethylammonium phosphate, and tetramethylammonium acetate.

[0062] Preferred examples of the tetraethylammonium compound include tetraethylammonium hydroxide, tetraethylammonium nitrate, tetraethylammonium sulfate, tetraethylammonium chloride, tetraethylammonium tetrafluorophosphate, tetraethylammonium phosphate, and tetraethylammonium acetate.

[0063] Preferred examples of the tetrapropylammonium compound include tetrapropylammonium hydroxide, tetrapropylammonium nitrate, tetrapropylammonium sulfate, tetrapropylammonium chloride, tetrapropylammonium tetrafluorophosphate, tetrapropylammonium phosphate, and tetrapropylammonium acetate.

[0064] Preferred examples of the tetrabutylammonium compound include tetrabutylammonium hydroxide, tetrabutylammonium nitrate, tetrabutylammonium sulfate, tetrabutylammonium chloride, tetrabutylammonium tetrafluorophosphate, tetrabutylammonium phosphate, and tetrabutylammonium acetate.

[0065] Among these, ammonium nitrate, potassium nitrate, potassium sulfate, potassium hexafluorophosphate, tetramethylammonium nitrate, lithium sulfate, rubidium sulfate, and potassium hydroxide are particularly preferred.

[0066] When the cation supply source is used as a cleaning liquid, etc., the cation supply source is mixed in such a manner that the molar ratio of cations to fluoride ions in the aqueous composition (molar concentration of cations / molar concentration of fluoride ions) reaches 0.3 to 20, preferably 0.4 to 20, more preferably 0.5 to 10, and further preferably 0.6 to 8. In another embodiment of the present invention, the lower limit of the above molar ratio is 0.1 or 0.2. For example, the amount of the cation supply source is usually in the range of 0.020 to 2.00 mass %, preferably 0.025 to 1.50 mass %, and more preferably 0.05 to 1.0 mass %, based on the total amount of the composition.

[0067] Here, in the calculation of the molar ratio of cations to fluoride ions (molar concentration of cations / molar concentration of fluoride ions) described above, the "molar concentration of cations" does not include protons derived from the component (A). On the other hand, when a compound other than hydrogen fluoride (HF) is used as the component (A), the total molar concentration of cations derived from the component (A) and the molar concentration of cations derived from the component (B) are calculated as the "molar concentration of cations" described above.

[0068] [Component (C): alkylphosphonic acid, alkylphosphonic acid ester, alkylphosphonic acid or salts thereof]

[0069] (C1) alkylphosphonic acid, alkylphosphonic acid ester, or salt thereof

[0070] The alkylphosphonic acid used in the present invention is a C 4-13 Alkylphosphonic acid (alkylphosphonic acid having 4 to 13 carbon atoms). Such alkylphosphonic acid is well known and commercially available (for example, available from Tokyo Chemical Industry Co., Ltd.). The alkylphosphonic acid is preferably C 5-11 Alkylphosphonic acid, more preferably C 5-9 Alkylphosphonic acid, more preferably C 6-8Alkylphosphonic acid. The alkyl portion of the alkylphosphonic acid may be linear or branched, preferably linear. When the alkyl portion of the alkylphosphonic acid is branched, the number of branches is preferably 5 or less, more preferably 3 or less, and particularly preferably 1.

[0071] In the aqueous composition of the present invention, the esters of the above-mentioned alkylphosphonic acid may also be used. 4-13 Alkyl esters of alkylphosphonic acid (alkylphosphonic acid having 4 to 13 carbon atoms).

[0072] Alkylphosphonic acid is usually represented by the general formula R1P(=O)(OH)2 (R1 is an alkyl group). Alkylphosphonic acid esters represented by the general formula R1P(=O)(OR2)2 (R1 is an alkyl group, R2 is an alkyl group or a hydrogen atom: wherein at least one of the two R2s is an alkyl group) can also be used in aqueous compositions.

[0073] In addition, the alkylphosphonic acid esters described in this specification also include alkyl esters of phosphonic acid (phosphonic acid esters). That is, the phosphonic acid esters represented by the general formula R1P(=O)(OR2)2 (R1 is hydrogen, R2 is an alkyl group or a hydrogen atom: wherein at least one of the two R2 groups is an alkyl group) can also be used in the aqueous composition as alkylphosphonic acid esters in this specification.

[0074] As shown above, in the aqueous composition, as the alkylphosphonic acid or the alkylphosphonic acid ester, a compound represented by the following general formula (A) can be used.

[0075] R1P(=O)(OR2)2···(A)

[0076] (In the general formula (A), R1 and R2 are each independently an alkyl group or a hydrogen atom: wherein at least one of R1 and two R2s is an alkyl group.)

[0077] The alkylphosphonate used in the present invention is a C 4-13 Alkylphosphonates (alkylphosphonates having 4 to 13 carbon atoms in total). Alkylphosphonates are preferably C 5-11 Alkyl phosphonate, more preferably C 5-9 Alkylphosphonate, more preferably C 6-8 Alkylphosphonate. In the above general formula (A), the alkyl chains of R1 and R2 each independently have preferably 4 to 12 carbon atoms, more preferably 6 to 11 carbon atoms, and even more preferably 8 to 10 carbon atoms.

[0078] The alkyl group of the alkylphosphonate, that is, R1 and R2 in the above general formula (A) may be linear or branched, and preferably includes a linear alkyl group.

[0079] In addition, the number of alkyl chains in the general formula (A), that is, the total number of alkyl chains of R1 and R2 is preferably 2 or less. That is, as the alkylphosphonic acid ester, it is also possible to use a case where both R1 and R2 in R1P(=O)(OR2)2 in the general formula (A) are alkyl groups, or a case where R1 is an alkyl group and one or less of R2 are alkyl groups, or a case where R1 is hydrogen and two or less of R2 are alkyl groups. It is further preferred to use an alkylphosphonic acid having only a single alkyl chain, that is, a case where only one of R1 and two R2 in R1P(=O)(OR2)2 in the general formula (A) is an alkyl group. It is particularly preferred to use a case where only R1 in the general formula (A) is an alkyl group.

[0080] The salt of the alkylphosphonic acid used in the present invention is a salt of the above-mentioned alkylphosphonic acid, for example, ammonium salt, tetramethylammonium salt, tetraethylammonium salt, tetrapropylammonium salt, tetrabutylammonium salt, lithium salt, sodium salt, potassium salt, rubidium salt, cesium salt, beryllium salt, magnesium salt, calcium salt, strontium salt, barium salt and the like.

[0081] As the alkylphosphonic acid or its salt used in the present invention, preferably n-butylphosphonic acid, n-pentylphosphonic acid, n-hexylphosphonic acid, n-heptylphosphonic acid, n-octylphosphonic acid, n-nonylphosphonic acid, n-decylphosphonic acid, n-undecylphosphonic acid, n-dodecylphosphonic acid, n-tridecylphosphonic acid, their salts or their mixtures can be cited. More preferably used alkylphosphonic acid or its salt is: n-pentylphosphonic acid, n-hexylphosphonic acid, n-heptylphosphonic acid, n-octylphosphonic acid, n-nonylphosphonic acid, n-decylphosphonic acid, n-undecylphosphonic acid, their salts or their mixtures. In addition, in the aqueous composition of the present invention, the salts of the above-mentioned alkylphosphonic acid esters can also be used. For example, as the salts of the alkylphosphonic acid esters, those corresponding to the salts of the above-mentioned alkylphosphonic acid can be cited.

[0082] The concentration of the alkylphosphonic acid, alkylphosphonic acid ester, or salt thereof in the aqueous composition can be appropriately changed in consideration of the type of wiring material of the electronic device to be etched or cleaned, the type of masking material used in the etching process, etc. The concentration of the alkylphosphonic acid, alkylphosphonic acid ester, or salt thereof is preferably 0.0003 to 5% by mass, more preferably 0.0004 to 1% by mass, further preferably 0.0005 to 0.1% by mass, and particularly preferably 0.001 to 0.1% by mass based on the total amount of the composition.

[0083] (C2) alkylphosphoric acid or its salt

[0084] The alkylphosphoric acid used in the present invention is a C 4-13 Alkyl phosphoric acid (alkyl phosphoric acid having 4 to 13 carbon atoms). Such alkyl phosphoric acid is well known and commercially available (for example, it can be obtained from Tokyo Chemical Industry Co., Ltd.). Alkyl phosphoric acid is preferably C 5-11 Alkyl phosphate, more preferably C 5-9Alkyl phosphate, more preferably C 6-8 Alkyl phosphoric acid. The alkyl portion of the alkyl phosphoric acid may be straight chain or branched, preferably straight chain. When the alkyl portion of the alkyl phosphoric acid is branched, the number of branches is preferably 5 or less, more preferably 3 or less, and particularly preferably 1.

[0085] In the aqueous composition of the present invention, as alkylphosphoric acid, dialkyl esters and trialkyl esters can be used in addition to monoalkyl esters of phosphoric acid. That is, not only monoalkyl esters of phosphoric acid represented by the general formula P(=O)(OR3)3 (R3 are all hydrogen atoms) in which only one of R3 is substituted by an alkyl group, but also dialkyl esters in which two of R3 are substituted by alkyl groups, and trialkyl esters in which all of R3 are substituted by alkyl groups can be used in the aqueous composition of the present invention. Among them, as alkylphosphoric acid, dialkyl esters having an alkyl chain number of 2 or less (two of R3 in the general formula P(=O)(OR3)3 are alkyl groups) and monoalkyl esters (only one of R3 in the general formula P(=O)(OR3)3 is alkyl group) are preferred, and monoalkyl esters having an alkyl chain number of 1 are more preferred. That is, the alkylphosphoric acid preferably has a single alkyl chain (as the alkyl group represented by R3).

[0086] The alkylphosphoric acid has a total of 4 to 13 carbon atoms regardless of the number of ester bonds. 5-11 Alkyl phosphate, more preferably C 5-9 Alkyl phosphoric acid, preferably C 6-8 Alkyl phosphate.

[0087] In addition, the alkyl chain of R3 in the general formula P(=O)(OR3)3 preferably has 4 to 12 carbon atoms, more preferably has 6 to 11 carbon atoms, and further preferably has 8 to 10 carbon atoms. The alkyl group of the alkylphosphoric acid, that is, R3 in the general formula P(=O)(OR3)3, may be a linear or branched chain, and preferably includes a linear alkyl group.

[0088] The salt of the alkyl phosphoric acid used in the present invention is a salt of the monoalkyl ester or dialkyl ester of the above phosphoric acid, for example, ammonium salt, tetramethylammonium salt, tetraethylammonium salt, tetrapropylammonium salt, tetrabutylammonium salt, lithium salt, sodium salt, potassium salt, rubidium salt, cesium salt, beryllium salt, magnesium salt, calcium salt, strontium salt, barium salt and the like.

[0089] As the alkyl phosphoric acid or its salt used in the present invention, preferably n-butyl phosphoric acid, n-pentyl phosphoric acid, n-hexyl phosphoric acid, n-heptyl phosphoric acid, n-octyl phosphoric acid, n-nonyl phosphoric acid, n-decyl phosphoric acid, n-undecyl phosphoric acid, n-dodecyl phosphoric acid, n-tridecyl phosphoric acid, 2-ethylhexyl phosphate, isodecyl phosphate, salts thereof or mixtures thereof can be mentioned.

[0090] More preferably used alkylphosphoric acid or its salt is n-pentylphosphoric acid, n-hexylphosphoric acid, n-heptylphosphoric acid, n-octylphosphoric acid, n-nonylphosphoric acid, n-decylphosphoric acid, n-undecylphosphoric acid, 2-ethylhexyl phosphate, isodecyl phosphate, salts thereof or mixtures thereof.

[0091] The concentration of the alkylphosphoric acid or its salt in the aqueous composition can be appropriately changed in consideration of the type of wiring material of the electronic device to be etched or cleaned, the type of masking material used in the etching process, etc. The concentration of the alkylphosphoric acid or its salt is preferably 0.0003 to 5% by mass, more preferably 0.0004 to 1% by mass, further preferably 0.0005 to 0.1% by mass, and particularly preferably 0.001 to 0.1% by mass based on the total amount of the composition.

[0092] [(D) ingredient: water]

[0093] The composition of the present invention is aqueous and contains water as a diluent. The water used in the present invention is not particularly limited, but is preferably water from which metal ions, organic impurities, particulate particles, etc. have been removed by distillation, ion exchange treatment, filter treatment, various adsorption treatments, etc., and pure water or ultrapure water is particularly preferred.

[0094] The content of water in the present composition is usually 40 to 99.9998% by mass, preferably 89.5 to 99.998% by mass.

[0095] [Other ingredients]

[0096] The aqueous composition of the present invention may contain additives conventionally used in aqueous compositions for semiconductors as desired within a range that does not impair the purpose of the present invention.

[0097] For example, as additives, there may be added acids, bases, chelating agents, surfactants, defoaming agents, oxidizing agents, reducing agents, metal anticorrosive agents, water-soluble organic solvents, etc. These additives are well known and described in, for example, JP-2013-533631A.

[0098] [Method for preparing aqueous composition (liquid composition)]

[0099] The aqueous composition (liquid composition) of the present invention can be prepared by adding the above-mentioned component (A), the above-mentioned component (B), the above-mentioned component (C), water, and other necessary components, and stirring until the mixture becomes uniform.

[0100] The pH range of the aqueous composition is 2-6, preferably 2-5, more preferably 2-4, and further preferably 2-3.

[0101] According to the aqueous composition of the present invention described in the preferred embodiment, etching barrier layers such as silicon nitride, interlayer insulating films, wiring metal materials such as cobalt or cobalt alloys, etc. can be protected from corrosion, and dry etching residues (for example, zirconium-based etching residues, titanium-based etching residues, polymer-based etching residues, etc.) can be removed efficiently.

[0102] [Method of using aqueous composition: Cleaning / manufacturing method of electronic devices]

[0103] The aqueous composition described in the present invention is used as a water-based composition for cleaning (hereinafter also referred to as "cleaning liquid"), and is in contact with an electronic device (such as a semiconductor element) during a wet etching process (or a process before or after it), so that dry etching residues can be removed. As a contact method, for example, the cleaning liquid is contained in a cleaning container, and the electronic device to be cleaned is immersed in the cleaning liquid, so that dry etching residues can be removed and the electronic device is cleaned. Or, the electronic device is treated in a single cleaning method, so that dry etching residues can be removed and the electronic device is cleaned. In addition to being suitable for use as a dry etching residue removing liquid (cleaning liquid), the aqueous composition for cleaning can also be suitable for use as an etching liquid. In addition, the aqueous composition can also be used as a cleaning liquid for cleaning electronic devices after the chemical mechanical polishing (CMP) process.

[0104] Thus, the aqueous composition of the present invention can be suitably used in a cleaning method including a step of cleaning an electronic device, and a method for producing an electronic device including such a step.

[0105] The temperature at which the cleaning solution of the present invention is used is usually 10 to 80° C., preferably 15 to 70° C., more preferably 20 to 65° C., and particularly preferably 20 to 60° C. The temperature can be appropriately selected depending on the etching conditions and the electronic device (eg, semiconductor element) used.

[0106] The cleaning solution of the present invention is usually used for 0.2 to 60 minutes. The time can be appropriately selected according to the cleaning conditions and the electronic device (e.g., semiconductor element) used. As the rinse solution after using the cleaning solution of the present invention, organic solvents, water, carbonated water, and ammonia water can be used.

[0107] [Electronic devices to be cleaned / manufactured]

[0108] The cleaning objects and electronic devices that can be suitably used in the present invention are, for example, semiconductor elements and display elements. Usually, the intermediate products after the dry etching process become the objects of cleaning. Semiconductor elements and display elements are substrate materials such as silicon, amorphous silicon, polycrystalline silicon, glass, insulating materials such as silicon oxide, silicon nitride, silicon carbide and their derivatives, materials such as cobalt, cobalt alloys, tungsten, titanium-tungsten, compound semiconductors such as gallium-arsenic, gallium-phosphorus, indium-phosphorus, indium-gallium-arsenic, indium-aluminum-arsenic, and oxide semiconductors such as chromium oxide. As electronic devices that become the cleaning objects of the present invention, particularly preferably, there can be cited elements using cobalt or cobalt alloy wiring materials, zirconium oxide-based hard masks, and low dielectric constant interlayer insulating films.

[0109] The dry etching residues that are the target of the present invention are generated when, for example, a via hole or a trench is formed in a low dielectric constant interlayer insulating film by dry etching using a zirconium oxide hard mask as a mask. A portion of the dry etching residues is generated when the etching gas contacts the zirconium oxide hard mask. Therefore, in this case, the target dry etching residues contain zirconium.

[0110] Example

[0111] Hereinafter, the present invention will be specifically described based on examples, but the embodiments may be modified as appropriate as long as the effects of the present invention are exhibited.

[0112] It should be noted that, unless otherwise specified, % means mass %.

[0113] [Evaluation wafer]

[0114] <Evaluation Wafer A>: Evaluation of the removal status of dry etching residue

[0115] Silicon nitride, an interlayer insulating film, silicon nitride, zirconium oxide (hard mask), and a photoresist are formed from the bottom layer, and then the photoresist is patterned.

[0116] Using the photoresist as a mask, predetermined portions of the hard mask are removed by dry etching, and the photoresist is removed by ashing using oxygen plasma. Furthermore, using the hard mask as a mask, via holes are formed in the silicon nitride and interlayer insulating film by dry etching.

[0117] <Wafer with film>: Evaluation of residue removability using zirconium oxide, and evaluation of damage using silicon nitride and cobalt

[0118] Wafers with films formed of zirconium oxide, silicon nitride, and cobalt were produced under the following film forming conditions.

[0119] (1) Zirconia: Film is made by physical vapor deposition. A film of thickness is formed on Si.

[0120] (2) Silicon nitride (SiN): using plasma chemical vapor deposition method, A film of thickness is formed on Si.

[0121] (3) Cobalt: Films are made by physical vapor deposition. A film of thickness is formed on Si.

[0122] [Evaluation method]

[0123] <Film thickness>

[0124] The film thickness of the wafer with film was measured using a fluorescent X-ray device SEA1200VX (film thickness measuring device A) manufactured by SII NanoTechnology Inc. or an optical film thickness meter N&K1280 (film thickness measuring device B) manufactured by N&K Technology Company. The film thickness of the wafer with zirconium oxide film and the wafer with cobalt film was measured using the film thickness measuring device A, and the film thickness of the wafer with silicon nitride film was measured using the film thickness measuring device B.

[0125] <Residue removal evaluation>

[0126] The determination was made using the ER of zirconium oxide at a temperature 20° C. higher than the treatment temperature in Table 1.

[0127] Determination method:

[0128] A: / minute or more and less than / minute

[0129] B: / minute or more

[0130] C: Lower than / minute

[0131] A and B are judged as pass.

[0132] <Corrosion prevention evaluation of anti-corrosion materials>

[0133] The determination was made using the ER of zirconium oxide at a temperature 20° C. higher than the treatment temperature in Table 1.

[0134] Determination method:

[0135] will exceed / minute was considered unqualified. (This is because the zirconia hard mask was damaged)

[0136] SiN: Determined by a value obtained by dividing the ER of zirconium oxide at a temperature 20° C. higher than the treatment temperature in Table 1 by the ER of SiN at the treatment temperature in Table 1.

[0137] Determination method:

[0138] A: 2 or more

[0139] B: 1 or more and less than 2

[0140] B': 0.8 or more and less than 1

[0141] C: less than 0.8

[0142] A, B, and B' are judged as passing.

[0143] Co: Determined by a value obtained by dividing the ER of zirconium oxide at a temperature 20° C. higher than the treatment temperature in Table 1 by the ER of cobalt at the treatment temperature in Table 1.

[0144] Determination method:

[0145] A: 1 or more

[0146] B: 0.1 or more and less than 1

[0147] C: less than 0.1

[0148] A and B are judged as pass.

[0149] <Measurement of pH value>

[0150] The pH value of the aqueous composition of each Example and Comparative Example was measured at 25° C. using a pH meter (pH meter F-52 manufactured by Horiba, Ltd.).

[0151] [Examples 1 to 21 and Comparative Examples 1 to 7]

[0152] Wafers with zirconium oxide films, wafers with silicon nitride films, and wafers with cobalt films were used in the test. They were immersed in the aqueous composition described in Table 1 at the treatment temperature described in Table 1 or at a temperature 20°C higher than the treatment temperature described in Table 1, and then rinsed with ultrapure water and dried by spraying dry nitrogen gas.

[0153] The wafer with zirconium oxide film, the wafer with silicon nitride film, and the wafer with cobalt film were immersed for 30 minutes, and the ER was calculated from the film thickness before and after the treatment.

[0154] It is found that in Examples 1 to 21, the dry etching residue can be removed while preventing damage to silicon nitride and cobalt.

[0155] On the other hand, it is found that in Comparative Examples 1 to 7 in Table 2, damage to cobalt cannot be suppressed in some cases, and dry etching residue cannot be removed while sufficiently preventing damage to silicon nitride in some cases.

[0156] [Table 1]

[0157]

[0158] [Table 2]

[0159]

[0160] Industrial Applicability

[0161] The aqueous composition described in a preferred embodiment of the present invention can prevent corrosion of etching stoppers such as silicon nitride, interlayer insulating films, wiring metal materials such as cobalt or cobalt alloys, and efficiently remove dry etching residues.

[0162] The etching solution, cleaning solution and cleaning method described in the preferred embodiment of the present invention have good anti-corrosion effect and dry etching residue removal performance for etching barrier layers such as silicon nitride, interlayer insulating films, wiring metal materials such as cobalt or cobalt alloys, etc. Therefore, in the manufacturing process of electronic devices such as semiconductor elements, high-precision and high-quality electronic devices can be manufactured with a good yield.

[0163] Description of Reference Numerals

[0164] 1. Zirconia-based dry etching residue

[0165] 2. Zirconia hard mask

[0166] 3. Cobalt or cobalt alloy

[0167] 5. Low dielectric constant interlayer insulation film

[0168] 6. Silicon Nitride (SiN)

Claims

1. An aqueous composition comprising: (A) a fluoride ion supply source in an amount such that the fluoride ion concentration in the composition reaches 0.05 to 30 mmol / L; (B) a cation supply source in an amount such that the molar ratio of cations in the composition to fluoride ions is 0.3 to 20; and 0.0001 to 10% by mass of (C) based on the total amount of the composition is selected from C 4-13 Alkylphosphonic acid, C 4-13 Alkyl phosphonates, C 4-13 Alkylphosphoric acid and one or more compounds of their salts, The cation supply source is selected from the group consisting of ammonium nitrate, sodium sulfate, potassium nitrate, potassium sulfate, potassium hexafluorophosphate, tetramethylammonium nitrate, lithium sulfate, rubidium sulfate and potassium hydroxide, The pH of the aqueous composition is in the range of 2-6.

2. The aqueous composition according to claim 1, wherein The fluoride ion supply source of the component (A) is: hydrogen fluoride, ammonium fluoride, acidic ammonium fluoride, tetramethylammonium fluoride, tetraethylammonium fluoride, tetrapropylammonium fluoride, tetrabutylammonium fluoride, lithium fluoride, sodium fluoride, potassium fluoride, acidic potassium fluoride, rubidium fluoride, cesium fluoride, beryllium fluoride, magnesium fluoride, strontium fluoride, barium fluoride, or a mixture thereof.

3. The aqueous composition according to claim 1 or 2, wherein The aqueous composition comprises at least any one selected from the following substances: As the alkylphosphonic acid, n-butylphosphonic acid, n-pentylphosphonic acid, n-hexylphosphonic acid, n-heptylphosphonic acid, n-octylphosphonic acid, n-nonylphosphonic acid, n-decylphosphonic acid, n-undecylphosphonic acid, n-dodecylphosphonic acid, n-tridecylphosphonic acid, or a mixture thereof; As the alkylphosphonate, n-butylphosphonate, n-pentylphosphonate, n-hexylphosphonate, n-heptylphosphonate, n-octylphosphonate, n-nonylphosphonate, n-decylphosphonate, n-undecylphosphonate, n-dodecylphosphonate, n-tridecylphosphonate, or a mixture thereof; and, The alkylphosphonic acids and the salts of the alkylphosphonic acid esters.

4. The aqueous composition according to claim 1 or 2, wherein The aqueous composition comprises at least any one selected from the following substances: As the alkyl phosphoric acid, n-butyl phosphoric acid, n-pentyl phosphoric acid, n-hexyl phosphoric acid, n-heptyl phosphoric acid, n-octyl phosphoric acid, n-nonyl phosphoric acid, n-decyl phosphoric acid, n-undecyl phosphoric acid, n-dodecyl phosphoric acid, n-tridecyl phosphoric acid, 2-ethylhexyl phosphate, isodecyl phosphate, or a mixture thereof; and A salt of said alkylphosphoric acid. 5 . A method for cleaning an electronic device, comprising the step of bringing the aqueous composition according to claim 1 into contact with an electronic device. 6 . A method for producing an electronic device, comprising the step of bringing the composition according to claim 1 into contact with an electronic device. 7 . An etching solution comprising the composition according to claim 1 .

8. A cleaning solution comprising the composition according to any one of claims 1 to 4.

Images