Aqueous composition and cleaning method using the same

Abstract

According to the present invention, there can be provided an aqueous composition comprising: (A) 0.001 to 20% by mass of one or more fluorine-containing compounds selected from tetrafluoroboric acid, hexafluorosilicic acid, hexafluoroaluminic acid, hexafluorotitanic acid and salts thereof, based on the total amount of the composition; and (B) 0.0001 to 10% by mass of a fluorine-containing compound 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.

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 point of view, various cleaning agents have been developed. For example, Japanese Patent Publication No. 2013-533631 (Patent Document 1), Japanese Patent Publication No. 2016-171294 (Patent Document 2), Japanese Patent Publication No. 2006-83376 (Patent Document 3), etc. disclose cleaning compositions for removing dry etching residues generated after dry etching, cleaning methods using the same, etc.

[0004] A hard mask is sometimes used in the process of forming a semiconductor integrated circuit. Silicon and titanium based materials have been used as hard mask materials, but zirconium oxide based hard masks have been proposed in recent years (Non-Patent Document 1: M Padmanaban et al, J. Photopolym. Sci. Technol., 27 (2014) 503).

[0005] In addition, when forming a via hole by dry etching, a fluorine-based gas can be selected. If aluminum oxide is selected as an etching stop layer, aluminum oxide has high resistance to fluorine-based gases, and therefore has the advantage of functioning as an etching stop layer even in a thin film. In recent years, an aluminum oxide-based etching stop layer has been proposed (Non-patent document 2: 16th MME workshop, Goeteborg, Sweden, 2005 "Etch stop materials for release by vapor HF etching").

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application No. 2013-533631

[0009] Patent Document 2: Japanese Patent Application Publication No. 2016-171294

[0010] Patent Document 3: Japanese Patent Application Publication No. 2006-83376

[0011] Non-patent literature

[0012] Non-patent document 1: M Padmanaban et al, J. Photopolym. Sci. Technol., 27 (2014) 503

[0013] Non-patent literature 2: 16th MME workshop, Goeteborg, Sweden, 2005 “Etch stop materials for release by vapor HF etching” Summary of the invention

[0014] Problem that the invention aims to solve

[0015] 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.

[0016] Solutions for solving problems

[0017] The present invention provides the following aqueous composition, a cleaning method using the same, and the like.

[0018] [1] An aqueous composition comprising: (A) 0.001 to 20% by mass of one or more fluorine-containing compounds selected from tetrafluoroboric acid, hexafluorosilicic acid, hexafluoroaluminic acid, hexafluorotitanic acid and salts thereof, based on the total amount of the composition; and

[0019] 0.0001 to 10% by mass of (B) 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.

[0020] [2] The composition according to [1] above, wherein the pH thereof is in the range of 0 to 7 (eg, 0 to 6, 0 to 5, 0 to 4, or 0 to 3).

[0021] [3] The composition according to [1] or [2] above, further comprising hydrogen fluoride (HF).

[0022] [4] The composition according to [3] above, wherein the component (A) is hexafluorosilicic acid or a salt thereof (eg, ammonium salt).

[0023] [5] The composition according to any one of [1] to [4] above, wherein the aqueous composition contains at least one selected from the following substances:

[0024] 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;

[0025] 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,

[0026] The aforementioned alkylphosphonic acids and salts of the aforementioned alkylphosphonic acid esters.

[0027] [5a] The composition according to any one of [1] to [5] above, wherein the alkylphosphonic acid is C 4-13 Alkylphosphonic acid (preferably C 5-11 Alkylphosphonic acid, more preferably C 5-9 Alkylphosphonic acid, more preferably C 6-8 alkylphosphonic acid).

[0028] [6] The composition according to any one of [1] to [4] 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] [6a] The composition according to any one of [1] to [6] 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] [6b] The composition according to any one of [1] to [6a] 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] [6c] The composition according to any one of [1] to [6b] above, which is a composition for corrosion protection of wiring materials (such as cobalt or cobalt alloy) of electronic devices to be cleaned.

[0034] [6d] The composition according to any one of [1] to [6c] above, wherein dodecylphosphonic acid is excluded from the alkylphosphonic acid.

[0035] [7] The composition according to any one of [1] to [6] above, wherein the number of alkyl chains in the alkylphosphonic acid, the alkylphosphonic acid ester and the alkylphosphonic acid is 2 or less.

[0036] [8] The composition according to any one of [1] to [7] above, wherein the number of alkyl chains in the alkylphosphonic acid, the alkylphosphonic acid ester and the alkylphosphonic acid is 1.

[0037] [9] A method for cleaning an electronic device, comprising the step of bringing the composition according to any one of [1] to [8] above into contact with the electronic device.

[0038]

[10] A method for producing an electronic device, comprising the step of bringing the composition according to any one of [1] to [8] above into contact with an electronic device.

[0039]

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

[0040]

[12] A cleaning solution comprising the composition according to any one of [1] to [8] above.

[0041] Effects of the Invention

[0042] The aqueous composition of the preferred embodiment of the present invention can provide corrosion protection for wiring metal materials such as cobalt or cobalt alloys, silicon nitride, interlayer insulating films, etc., and can efficiently remove dry etching residues (such as zirconium-based dry etching residues, titanium-based dry etching residues, polymer-based dry etching residues, etc.).

[0043] According to the cleaning method of the preferred embodiment of the present invention, the anti-corrosion effect and dry etching residue removal performance on wiring metal materials such as cobalt or cobalt alloys, silicon nitride, interlayer insulating films, 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

[0044] Figure 1It is a schematic diagram of a cross-sectional view of one embodiment of a semiconductor element having a structure including a zirconium oxide-based hard mask 2, cobalt or a 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.

[0045] Figure 2 The present invention is a schematic diagram of a cross-sectional view of a semiconductor element in which the bottom of a via hole is cobalt or a cobalt alloy, the semiconductor element has a structure of a zirconium oxide hard mask 2, cobalt or a cobalt alloy 3, aluminum oxide 4, a low dielectric constant interlayer insulating film 5, and silicon nitride 6 before removing a dry etching residue 1.

[0046] Figure 3 The schematic diagram of a cross-sectional view of a semiconductor element in one mode is a structure in which the bottom of the via hole is aluminum oxide, the semiconductor element before the dry etching residue 1 is removed, and the semiconductor element has a zirconium oxide hard mask 2, cobalt or cobalt alloy 3, aluminum oxide 4, a low dielectric constant interlayer insulating film 5, and silicon nitride 6. DETAILED DESCRIPTION

[0047] The aqueous composition of the present invention comprises: (A) one or more fluorine-containing compounds selected from tetrafluoroboric acid, hexafluorosilicic acid, hexafluoroaluminic acid, hexafluorotitanic acid and salts thereof in an amount of 0.001 to 20% by mass based on the total amount of the composition; and (B) 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.

[0048] In addition, in this specification, the range of the content of each component includes an upper limit and a lower limit. For example, the range of the content of the above-mentioned (A) component includes 0.001 mass % and 20 mass %.

[0049] Hereinafter, the aqueous composition according to the present invention will be described in detail.

[0050] [(A) Component: Fluorine-containing compound]

[0051] The fluorine-containing compound used in the present invention is selected from tetrafluoroboric acid, hexafluorosilicic acid, hexafluoroaluminic acid, hexafluorotitanic acid, and their salts. As the salts of these compounds, for example, ammonium salts, tetramethylammonium salts, tetraethylammonium salts, tetrapropylammonium salts, tetrabutylammonium salts, lithium salts, sodium salts, potassium salts, rubidium salts, cesium salts, beryllium salts, magnesium salts, strontium salts, barium salts, etc. can be cited. Among these compounds, hexafluorosilicic acid or its salts (for example, ammonium salts) are particularly preferred.

[0052] The content of the fluorine-containing compound in the composition is 0.001 to 20% by mass, preferably 0.005 to 10% by mass, more preferably 0.01 to 5% by mass, particularly preferably 0.03 to 2% by mass, based on the total amount of the composition.

[0053] It should be noted that in the present invention, in addition to the above-mentioned fluorine-containing compound, hydrogen fluoride, ammonium fluoride, etc. can also be appropriately blended. The blending amount can be appropriately determined in consideration of the blending amounts of other components, for example, 0.001 to 10% by mass, preferably 0.005 to 1% by mass, more preferably 0.01 to 0.1% by mass based on the total amount of the composition.

[0054] [Component (B): alkylphosphonic acid, alkylphosphonic acid or salts thereof, etc.]

[0055] (B1) Alkylphosphonic acid, alkylphosphonic acid ester, or salt thereof

[0056] 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, it can be obtained 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 6-8 Alkylphosphonic 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.

[0057] In the aqueous composition, 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).

[0058] 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 hydrogen, wherein at least one of the two R2 groups is an alkyl group) can also be used in aqueous compositions.

[0059] 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.

[0060] 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.

[0061] R1P(=O)(OR2)2···(A)

[0062] (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.)

[0063] The alkylphosphonate used in the present invention is a C 4-13 Alkylphosphonate (alkylphosphonate having a total of 4 to 13 carbon atoms). Alkylphosphonate is 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.

[0064] The alkyl group of the alkylphosphonate, that is, R1 and R2 in the above general formula may be linear or branched, and preferably includes a linear alkyl group.

[0065] 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, 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.

[0066] 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.

[0067] Examples of the alkylphosphonic acid or its salt used in the present invention include 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, salts thereof or mixtures thereof.

[0068] 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, a salt thereof or a mixture thereof.

[0069] In addition, the salt of the above-mentioned alkylphosphonic acid ester may also be used in the aqueous composition. For example, examples of the salt of the alkylphosphonic acid ester include those corresponding to the above-mentioned salt of the alkylphosphonic acid.

[0070] 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 0.0002 to 2% by mass, more preferably 0.0003 to 0.5% by mass, and particularly preferably 0.0003 to 0.1% by mass based on the total amount of the composition.

[0071] (B2) Alkyl phosphoric acid or its salt

[0072] 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 5-9 Alkyl 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. In the branched alkyl portion of the alkyl phosphoric acid, the number of branches is preferably 5 or less, more preferably 3 or less, and particularly preferably 1.

[0073] 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 in which only one of R3 of phosphoric acid represented by the general formula P(=O)(OR3)3 (R3 are all hydrogen atoms) is substituted with an alkyl group, but also dialkyl esters in which two of R3 are substituted with an alkyl group and trialkyl esters in which both of R3 are substituted with an alkyl group 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 of the above general formula P(=O)(OR3)3 are alkyl groups) and monoalkyl esters (only one of R3 of the above 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 (alkyl group represented by the above R3).

[0074] 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 phosphate, preferably C 6-8 Alkyl phosphates.

[0075] 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.

[0076] 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.

[0077] Examples of the alkyl phosphoric acid or its salt used in the present invention include 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.

[0078] The alkylphosphoric acid or its salt preferably used 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.

[0079] 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 0.0002 to 2% by mass, more preferably 0.0003 to 0.5% by mass, and particularly preferably 0.0003 to 0.1% by mass based on the total amount of the composition.

[0080] [(C) ingredient: water]

[0081] The composition of the present invention is aqueous and contains water as a diluent. The water of 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 is particularly preferably pure water or ultrapure water.

[0082] The content of water in the present composition is usually 40 to 99.9999% by mass, preferably 97.95 to 99.9697% by mass.

[0083] [Other ingredients]

[0084] The aqueous composition of the present invention may contain additives that have been conventionally used in aqueous compositions for semiconductors within a range that does not impair the purpose of the present invention.

[0085] The aqueous composition of the present invention may contain additives conventionally used in aqueous compositions for semiconductors as desired within a range not impairing the purpose of the present invention.

[0086] For example, as additives, there may be added acids, bases, chelating agents, surfactants, defoaming agents, oxidizing agents, reducing agents, metal preservatives, water-soluble organic solvents, etc. These additives are well known and described in, for example, JP-2013-533631A.

[0087] [Method for preparing aqueous composition (liquid composition)]

[0088] The aqueous composition (liquid composition) of the present invention can be prepared by adding the above-mentioned (A) component, the above-mentioned (B) component, water, and other components as required, and stirring until the mixture becomes uniform.

[0089] The pH range of the aqueous composition is not particularly limited, but is usually 0 to 7, preferably 0 to 6, more preferably 0 to 5, and further preferably 0 to 4.

[0090] According to the preferred embodiment of the present invention, the aqueous composition can provide corrosion protection for wiring metal materials such as cobalt or cobalt alloys, silicon nitride, interlayer insulating films, etc., and efficiently remove dry etching residues (such as zirconium-based dry etching residues, titanium-based dry etching residues, polymer-based dry etching residues, etc.).

[0091] [Usage of aqueous composition: Cleaning / manufacturing method of electronic devices]

[0092] The aqueous composition of the present invention is used as an aqueous 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. 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 as a dry etching residue removing liquid (cleaning liquid), the aqueous cleaning composition 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.

[0093] 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.

[0094] 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., particularly preferably 20 to 60° C. The temperature can be appropriately selected depending on the cleaning conditions and the electronic device (eg, semiconductor element) used.

[0095] 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.

[0096] [Electronic devices to be cleaned / manufactured]

[0097] 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, silicon nitride (SiN), and low dielectric constant interlayer insulating films (such as tetraethoxysilicate films).

[0098] 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 the above case, the target dry etching residues contain zirconium.

[0099] Example

[0100] 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.

[0101] It should be noted that, unless otherwise specified, % means mass %.

[0102] [Evaluation wafer]

[0103] <Evaluation Wafer A>: Evaluation of the removal status of dry etching residue

[0104] Silicon nitride, an interlayer insulating film, silicon nitride, zirconium oxide, and a photoresist are formed from the bottom layer, and then the photoresist is patterned.

[0105] Using the photoresist as a mask, the predetermined portion of the hard mask is 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.

[0106] <Wafer with film>: For damage evaluation of silicon nitride, low-k interlayer insulating film, and cobalt

[0107] A wafer with films formed of silicon nitride, a low dielectric constant interlayer insulating film, and cobalt was used. As the low dielectric constant interlayer insulating film, TEOS (tetraethoxysilicate), which is one type of low dielectric constant interlayer insulating film, was formed.

[0108] The films were respectively formed as follows.

[0109] (1) Silicon nitride (SiN): using plasma chemical vapor deposition method to A film of thickness is formed on Si.

[0110] (2) TEOS: Using chemical vapor deposition method, A film of thickness is formed on Si.

[0111] (3) Cobalt: Films are made using physical vapor deposition. A film of thickness is formed on Si.

[0112] [Evaluation method]

[0113] <Dry etching residue removal status>

[0114] SEM observation was performed on the evaluation wafer A treated with various aqueous compositions (cleaning solutions).

[0115] Measurement equipment: Hitachi Hightech Co., Ltd., ultra-high resolution field emission scanning electron microscope SU9000 (magnification 100,000 times)

[0116] Determination method:

[0117] E: Dry etching residue is completely removed.

[0118] G: The dry etching residue is almost completely removed.

[0119] N: Removal of dry etching residue is slightly insufficient.

[0120] P: Removal of dry etching residue is insufficient.

[0121] E and G were judged as passing.

[0122] <Film thickness>

[0123] 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 cobalt film was measured using the film thickness measuring device A, and the film thickness of the wafer with silicon nitride film and the wafer with TEOS film was measured using the film thickness measuring device B.

[0124] <ER(etching rate)>

[0125] Each wafer with a film is treated with a cleaning solution, and the difference in film thickness before and after the treatment is divided by the treatment time to calculate the ER.

[0126] The ER of silicon nitride is / min or less, TEOS ER is / min or less, and the ER of cobalt is / min or less is considered acceptable.

[0127] <Measurement of pH value>

[0128] 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.).

[0129] [Examples 1 to 14 and Comparative Examples 1 to 11]

[0130] The test used evaluation wafer A, a wafer with a silicon nitride film, a wafer with a TEOS film, and a wafer with a cobalt film. The wafers were immersed in the aqueous composition (cleaning liquid) described in Table 1 at the treatment temperature described in Table 1, and then rinsed with ultrapure water and dried by spraying dry nitrogen gas.

[0131] Regarding the evaluation wafer A, all the wafers were subjected to the immersion treatment for 3 minutes, and the wafers after the treatment were observed with a SEM.

[0132] The wafer with a silicon nitride film, the wafer with a TEOS film, and the wafer with a cobalt film were immersed for 30 minutes, and the ER was calculated from the film thickness before and after the treatment.

[0133] It is found that in Examples 1 to 14, the dry etching residue is completely removed while preventing damage to silicon nitride (SiN), TEOS, and cobalt.

[0134] On the other hand, it is found that in Comparative Examples 1 to 11 in Table 2, the damage to cobalt cannot be suppressed, the dry etching residue cannot be removed, and the dry etching residue cannot be removed while sufficiently preventing damage to silicon nitride and TEOS.

[0135] [Table 1]

[0136]

[0137] [Table 2]

[0138]

[0139] Industrial Applicability

[0140] The aqueous composition of a preferred embodiment of the present invention can prevent the corrosion of wiring metal materials such as cobalt or cobalt alloys, silicon nitride, interlayer insulating films, etc., and can efficiently remove dry etching residues.

[0141] The etching solution, cleaning solution and cleaning method according to the preferred embodiment of the present invention have good anti-corrosion effect and dry etching residue removal performance for wiring metal materials such as cobalt or cobalt alloys, silicon nitride, interlayer insulating films, 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.

[0142] Description of Reference Numerals

[0143] 1. Zirconia-based dry etching residue

[0144] 2. Zirconia hard mask

[0145] 3. Cobalt or cobalt alloy

[0146] 4. Alumina

[0147] 5. Low dielectric constant interlayer insulation film

[0148] 6. Silicon Nitride (SiN)

Claims

1. An aqueous composition comprising: (A) at least one fluorine-containing compound selected from tetrafluoroboric acid, hexafluorosilicic acid, hexafluoroaluminic acid, hexafluorotitanic acid and salts thereof in an amount of 0.03 to 2% by mass based on the total amount of the composition; and 0.0003 to 0.1% by mass of (B) 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 their salts, The C 4-13 The alkylphosphonic acid is selected from at least any one of the following: 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, and n-tridecylphosphonic acid; The C 4-13 The alkylphosphonate is selected from at least any one of the following: n-butylphosphonate, n-pentylphosphonate, n-hexylphosphonate, n-heptylphosphonate, n-octylphosphonate, n-nonylphosphonate, n-decylphosphonate, n-undecylphosphonate, n-dodecylphosphonate, and n-tridecylphosphonate; The C 4-13 The alkyl phosphoric acid is selected from the group consisting of 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, and isodecyl phosphate; The pH of the aqueous composition is in the range of 0-7.

2. The aqueous composition according to claim 1, wherein Also contains hydrogen fluoride (HF).

3. The aqueous composition according to claim 1 or 2, wherein The component (A) is hexafluorosilicic acid or a salt thereof.

4. The aqueous composition according to claim 1 or 2, wherein In the alkylphosphonic acid, the alkylphosphonic acid ester and the alkylphosphonic acid, the number of alkyl chains is 2 or less.

5. The aqueous composition according to claim 1 or 2, wherein In the alkylphosphonic acid, the alkylphosphonic acid ester and the alkylphosphonic acid, the number of alkyl chains is 1. 6 . 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. 7 . A method for producing an electronic device, comprising the step of bringing the aqueous composition according to claim 1 into contact with an electronic device. 8 . An etching solution comprising the aqueous composition according to claim 1 . 9 . A cleaning solution comprising the aqueous composition according to claim 1 .

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