Aqueous composition and cleaning method using same

Abstract

To provide a composition for cleaning use to be used in a manufacturing process of an electronic device (e.g. a semiconductor device), and a cleaning method by use thereof.SOLUTION: An aqueous composition, which is a composition for cleaning use comprises: one or more compounds selected from a group consisting of C4-13 alkyl phosphonic acid, and C4-13 alkyl phosphonic ester, C4-13 alkyl phosphoric acid, and their salts, which is 0.0001-10 mass% to total mass of the composition; and C4-13 alkyl phosphonic acid and C4-13 alkyl phosphonic ester, an acid other than C4-13 alkyl phosphoric acid or its salt, which is 0.0001-50 mass% to the total mass of the composition.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an aqueous composition and a cleaning method using the same, and more particularly to a cleaning composition used in the manufacturing process of electronic devices (e.g., semiconductor elements) and a cleaning method using the same. [Background technology]

[0002] In the process of manufacturing electronic devices such as semiconductor elements, a dry etching process is usually adopted when forming 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. It is preferable that the cleaning agent for removing the dry etching residues does not adversely affect (e.g., corrode) the metal wiring materials (e.g., copper, titanium, cobalt, tungsten, etc.) used in the semiconductor integrated circuit to be cleaned. From this viewpoint, various cleaning agents have been developed. For example, JP-T-2013-533631 (Patent Document 1), JP-A-2016-171294 (Patent Document 2), and JP-A-2006-83376 (Patent Document 3) disclose cleaning compositions for removing dry etching residues generated after dry etching, cleaning methods using the same, and the like. Hard masks are sometimes used in the process of forming semiconductor integrated circuits. Silicon-based and titanium-based materials have traditionally been used as hard mask materials, but zirconia-based hard masks have also been proposed in recent years (Non-Patent Document 1: M Padmanaban et al., J. Photopolym. Sci. Technol., 27 (2014) 503). In addition, when forming vias by dry etching, fluorine-based gases are selected. If alumina is selected as the etch stop layer, it has the advantage that even a thin film of alumina can function as an etch stop layer because alumina has high resistance to fluorine-based gases, and alumina-based etch stop layers have been proposed in recent years (Non-Patent Document 2: 16th MME workshop, Goeteborg, Sweden, 2005 "Etch stop materials for release by vapor HF etching"). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2013-533631 [Patent Document 2] JP 2016-171294 A [Patent Document 3] JP 2006-83376 A [Non-patent literature]

[0004] [Non-Patent Document 1] M Padmanaban et al, J. Photopolym.Sci.Technol.,27(2014)503 [Non-Patent Document 2] 16th MME workshop, Goeteborg, Sweden, 2005 “Etch stop materials for release by vapor HF etching” Summary of the Invention [Problem to be solved by the invention]

[0005] There are various metal materials for wiring used in electronic devices and masking materials for dry etching, and the combinations of these materials are also various. Therefore, there is a demand for the development of a new cleaning composition from the viewpoints of the efficiency of removing dry etching residues and the anticorrosive effect on the metal materials for wiring. [Means for solving the problem]

[0006] The present invention provides the following aqueous composition, cleaning method using the same, and the like. [1](A)C 4-13 Alkylphosphonic acid, C 4-13 Alkylphosphonates, C 4-13 One or more compounds selected from alkyl phosphoric acid and their salts are present in an amount of 0.0001 to 10 mass% based on the total mass of the composition, and (B)C 4-13 Alkylphosphonic acid and C 4-13 Alkylphosphonates and C 4-13 An aqueous composition comprising an acid other than an alkylphosphoric acid or a salt thereof in an amount of 0.0001 to 50 mass% based on the total mass of the composition. [2] The composition according to the above [1], having a pH in the range of 0 to 7 (e.g., 0 to 6, 0 to 5, 0 to 4, or 0 to 3). [3] The composition according to [1] or [2] above, wherein the acid or salt thereof of the component (B) is hydrofluoric acid, nitric acid, sulfuric acid, hydrochloric acid, phosphoric acid, acetic acid, or a salt thereof.

[0007] [4] The composition according to [3] above, wherein the acid is hydrofluoric acid. [5] The aqueous composition, 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 alkyl phosphonic acid ester, n-butyl phosphonic acid ester, n-pentyl phosphonic acid ester, n-hexyl phosphonic acid ester, n-heptyl phosphonic acid ester, n-octyl phosphonic acid ester, n-nonyl phosphonic acid ester, n-decyl phosphonic acid ester, n-undecyl phosphonic acid ester, n-dodecyl phosphonic acid ester, n-tridecyl phosphonic acid ester, or a mixture thereof; and Salts of said alkylphosphonic acids and said alkylphosphonic acid esters, The composition according to any one of the above [1] to [4], comprising at least one selected from the following: [5a] The alkylphosphonic acid is 5-12 Alkylphosphonic acid (preferably C 5-11 Alkylphosphonic acids, more preferably C 5-9 Alkylphosphonic acid, more preferably C 6-8 alkylphosphonic acid), The composition according to any one of the above [1] to [5], wherein the alkylphosphonic acid ester is an ester of these alkylphosphonic acids.

[0008] [6] The aqueous composition, 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 phosphoric acid, isodecyl phosphate, or a mixture thereof; a salt of said alkyl phosphate; The composition according to any one of the above [1] to [4], comprising at least one selected from the following: [6a] The alkyl phosphate is C 4-13 Alkyl phosphate (preferably C 5-11 Alkyl phosphate, more preferably C 5-9 Alkyl phosphate, more preferably C 6-8 The composition according to any one of the above [1] to [6], wherein the alkyl group is an alkyl phosphate.

[0009] [7] The composition according to any one of the above [1] to [6], wherein the alkyl phosphonic acid, the alkyl phosphonate ester, and the alkyl phosphoric acid each have 2 or less alkyl chains. [8] The composition described in [7] above, wherein the number of alkyl chains in the alkyl phosphonic acid, the alkyl phosphonic acid ester, and the alkyl phosphoric acid is 1. [9] The composition according to any one of the above [1] to [8], wherein the alkyl chain in the alkyl phosphonic acid, the alkyl phosphonate ester, and the alkyl phosphoric acid is linear.

[10] The composition according to any one of the above [1] to [9], further comprising a barium compound.

[11] The composition according to

[10] above, wherein the barium compound comprises at least one selected from the group consisting of barium nitrate, barium acetate, barium chloride and barium hydroxide. [11a] The composition according to any one of the above [1] to

[11] , which is a composition for removing dry etching residues (for example, zirconia-based dry etching residues) after dry etching. [11b] The composition according to any one of the above [1] to

[11] , which is a composition for preventing corrosion of a wiring material (such as cobalt or a cobalt alloy) of an electronic device to be cleaned. [11c] The composition according to any one of the above [1] to

[11] , wherein the alkylphosphonic acid does not include dodecylphosphonic acid.

[12] A method for cleaning an electronic device, comprising the step of contacting the composition according to any one of the above [1] to

[11] with the electronic device.

[13] A method for producing an electronic device, comprising the step of contacting the composition according to any one of the above [1] to

[11] with an electronic device.

[14] An etching solution comprising the composition according to any one of the above [1] to

[11] .

[15] A cleaning solution comprising the composition according to any one of [1] to

[11] above. Effect of the Invention

[0010] The aqueous composition according to a preferred embodiment of the present invention exhibits good anticorrosive effect on cobalt or cobalt alloys even in a low pH range (eg, 4 or less). Furthermore, an aqueous composition according to another preferred embodiment of the present invention (for example, a composition containing hydrogen fluoride) exhibits a good anticorrosive effect on cobalt or cobalt alloys, and also has good removability of etching residues. The cleaning method according to a preferred embodiment of the present invention has a good anticorrosive effect on wiring materials such as cobalt and a good ability to remove dry etching residues, and therefore can produce high-precision, high-quality electronic devices with good yields in the manufacturing process of electronic devices such as semiconductor elements. [Brief description of the drawings]

[0011] [Figure 1] This is a schematic cross-sectional view of one embodiment of a semiconductor element having a structure of a zirconia-based hard mask 2, cobalt or cobalt alloy 3, alumina 4, a low dielectric constant interlayer insulating film 5, and silicon nitride 6 in a semiconductor element in which the bottom of the via is made of alumina and before dry etching residue 1 is removed. [Diagram 2] This is a schematic cross-sectional view of one embodiment of a semiconductor element having a structure of a zirconia-based hard mask 2, cobalt or cobalt alloy 3, alumina 4, a low dielectric constant interlayer insulating film 5, and silicon nitride 6 in a semiconductor element in which the bottom of the via is cobalt or cobalt alloy and before the dry etching residue 1 is removed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The aqueous composition of the present invention is 4-13 Alkylphosphonic acid, C 4-13 Alkylphosphonates, C 4-13 One or more compounds selected from alkyl phosphoric acid and their salts are present in an amount of 0.0001 to 10 mass% based on the total amount of the composition, and (B) An acid other than component (A), i.e., C 4-13 Alkylphosphonic acid and C 4-13Alkylphosphonates and C 4-13 The composition contains an acid other than alkylphosphoric acid or a salt of such an acid in an amount of 0.0001 to 50% by mass based on the total mass of the composition. In this specification, the range of the content of each component includes the upper and lower limits; for example, the range of the content of the above component (A) includes 0.0001% by mass and 10% by mass. The aqueous composition according to the present invention will be described in detail below.

[0013] [Component (A): alkyl phosphonic acid or alkyl phosphoric acid, etc.] (A1) Alkylphosphonic acid and alkylphosphonic acid ester The alkylphosphonic acid used in the present invention is a C 4-13 Alkylphosphonic acids (alkylphosphonic acids having 4 to 13 carbon atoms). Such alkylphosphonic acids are known and commercially available (for example, from Tokyo Chemical Industry Co., Ltd.). The alkylphosphonic acids are preferably C 5-11 Alkylphosphonic acid, more preferably C 5-9 Alkylphosphonic acid, more preferably C 6-8 It is an alkylphosphonic acid. The alkyl portion of the alkylphosphonic acid may be linear or branched, but linear is preferred. 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.

[0014] In the aqueous composition of the present invention, esters of the above-mentioned alkylphosphonic acids can also be used. 4-13 Alkyl esters of alkylphosphonic acids (alkylphosphonic acids having 4 to 13 carbon atoms) can also be used. Alkylphosphonic acids are usually represented by the general formula R1P(=O)(OH)2 (R1 is an alkyl group), but 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; however, at least one of the two R2 is an alkyl group) may also be used in the aqueous composition. The alkyl phosphonate ester described herein also includes alkyl esters of phosphonic acid (phosphonate esters). That is, phosphonate esters represented by the general formula R1P(=O)(OR2)2 (R1 is hydrogen, R2 is an alkyl group or a hydrogen atom, provided that at least one of the two R2 is an alkyl group) may also be used in the aqueous composition as alkyl phosphonate esters herein. As is clear from the above, in the aqueous composition, a compound represented by the following general formula (A) is used as the alkylphosphonic acid or alkylphosphonic acid ester. R1P(=O)(OR2)2···(A) (In the general formula (A), R1 and R2 are each independently an alkyl group or a hydrogen atom; however, at least one of R1 and the two R2s is an alkyl group.) The alkylphosphonic acid ester used in the present invention is a C 4-13 The alkyl phosphonate is preferably an alkyl phosphonate having a total of 4 to 13 carbon atoms. 5-11 Alkyl phosphonates, more preferably C 5-9 Alkyl phosphonates, more preferably C 6-8 It is an alkylphosphonic acid ester. Furthermore, the alkyl chains of R1 and R2 in the above general formula (A) each independently preferably have 4 to 12 carbon atoms, more preferably have 6 to 11 carbon atoms, and further preferably have 8 to 10 carbon atoms.

[0015] The alkyl group of the alkylphosphonate ester, that is, R1 and R2 in the above general formula (A) may be linear or branched, but preferably contains a linear alkyl group. In addition, the number of alkyl chains in the above general formula (A), i.e., the total number of alkyl chains in R1 and R2, is preferably 2 or less. That is, as the alkylphosphonic acid ester, it is possible to use R1P(=O)(OR2)2 of the above general formula (A) in which R1 and R2 are both alkyl groups, but it is also possible to use R1 being an alkyl group and one or less of R2 being an alkyl group, or R1 being hydrogen and two or less of R2 being alkyl groups. More preferably, it is preferable to use an alkylphosphonic acid having only a single alkyl chain, i.e., it is preferable to use an alkylphosphonic acid having only one of R1 and two R2 of R1P(=O)(OR2)2 of the above general formula (A) in which only one is an alkyl group. It is particularly preferable to use an alkylphosphonic acid having only R1 of the above general formula (A) in which only R1 is an alkyl group.

[0016] The salt of alkylphosphonic acid used in the present invention is a salt of the above-mentioned alkylphosphonic acid, and examples thereof include 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, etc.

[0017] The alkylphosphonic acid or a salt thereof used in the present invention preferably includes 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. More preferably used alkylphosphonic acid or a salt thereof 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. In addition, in the aqueous composition of the present invention, a salt of the above-mentioned alkylphosphonic acid ester can also be used. For example, the salt of the alkylphosphonic acid ester may be one corresponding to the above-mentioned salt of the alkylphosphonic acid.

[0018] 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 step, etc. The concentration of the alkylphosphonic acid, alkylphosphonic acid ester, or salt thereof is preferably 0.0003 to 5 mass%, more preferably 0.0006 to 1 mass%, and particularly preferably 0.001 to 0.5 mass%, or 0.01 to 0.1 mass%, based on the total amount of the composition.

[0019] (A2) Alkyl phosphate The alkyl phosphate used in the present invention is a C 4-13 The alkyl phosphoric acid is preferably an alkyl phosphoric acid having 4 to 13 carbon atoms. Such alkyl phosphoric acids are known and commercially available (for example, from Tokyo Chemical Industry Co., Ltd.). The alkyl phosphoric acid is preferably C 5-11 Alkyl phosphate, more preferably C 5-9 Alkyl phosphate, more preferably C 6-8 It is an alkyl phosphoric acid. The alkyl portion of the alkyl phosphoric acid may be linear or branched, but linear is preferred. 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.

[0020] In the aqueous composition of the present invention, as the alkyl phosphoric acid, in addition to monoalkyl esters of phosphoric acid, dialkyl esters and trialkyl esters can also be used. That is, not only monoalkyl esters of phosphoric acid represented by the general formula P(=O)(OR3)3 (wherein R3 is a hydrogen atom) in which only one of R3 is substituted with an alkyl group, but also dialkyl esters in which two of R3 are substituted with alkyl groups, and trialkyl esters in which both R3 are substituted with alkyl groups can be used in the aqueous composition of the present invention. However, as the alkyl phosphoric acid, dialkyl esters (wherein two of R3 in the above general formula P(=O)(OR3)3 are alkyl groups) and monoalkyl esters (wherein only one of R3 in the above general formula P(=O)(OR3)3 is an alkyl group) in which the number of alkyl chains is 2 or less are preferred, and monoalkyl esters in which the number of alkyl chains is 1 are more preferred. That is, it is preferred that the alkyl phosphoric acid has a single alkyl chain (the alkyl group represented by R3 above).

[0021] Alkyl phosphates have a total of 4 to 13 carbon atoms, regardless of the number of ester bonds. 5-11 Alkyl phosphate is preferred, more preferably C 5-9 Alkyl phosphate, more preferably C 6-8 Alkyl phosphates are used. Furthermore, the alkyl chain of R3 in the above general formula P(=O)(OR3)3 preferably has 4 to 12 carbon atoms, more preferably has 6 to 11 carbon atoms, and even more preferably has 8 to 10 carbon atoms. The alkyl group of the alkyl phosphate, i.e., R3 in the above general formula P(=O)(OR3)3, may be linear or branched, but preferably contains a linear alkyl group.

[0022] The salt of alkyl phosphate used in the present invention is a salt of the monoalkyl ester or dialkyl ester of the above-mentioned phosphoric acid, and examples thereof include 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, etc.

[0023] The alkyl phosphoric acid or a salt thereof used in the present invention preferably includes 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. More preferably used alkyl phosphoric acid or its salt is 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, 2-ethylhexyl phosphate, isodecyl phosphate, salts thereof or mixtures thereof.

[0024] The concentration of alkyl phosphoric acid or its salt in the aqueous composition can be appropriately changed taking into consideration the type of wiring material of the electronic device to be etched or cleaned, the type of masking material used in the etching step, etc. The preferred concentration of alkyl phosphoric acid or its salt is in the range of 0.0003 to 5 mass%, more preferably 0.0006 to 1 mass%, particularly preferably 0.001 to 0.5 mass%, or 0.01 to 0.1 mass%, based on the total amount of the composition.

[0025] [Component (B): an acid other than component (A)] The acid used in the aqueous composition of the present invention may be any inorganic or organic acid other than the component (A). 4-13 Alkylphosphonic acid, partial ester, and acid C 4-13Alkylphosphonic acid esters and C 4-13 Acids other than alkylphosphoric acid may be used. Also, salts of acids other than component (A) may be used in the aqueous composition. Examples of inorganic acids that can be used in the present invention include hydrofluoric acid, nitric acid, sulfuric acid, hydrochloric acid, phosphoric acid, etc. Among these, hydrofluoric acid is preferred, and when hydrofluoric acid is used, the removability of dry etching residues is improved in the low pH range.

[0026] Examples of organic acids that can be used in the present invention include aliphatic carboxylic acids having 1 to 18 carbon atoms, aromatic carboxylic acids having 6 to 10 carbon atoms, and amino acids having 1 to 10 carbon atoms. Preferred examples of the aliphatic carboxylic acid having 1 to 18 carbon atoms include formic acid, acetic acid, propionic acid, lactic acid, glycolic acid, diglycolic acid, pyruvic acid, malonic acid, butyric acid, hydroxybutyric acid, tartaric acid, succinic acid, malic acid, maleic acid, fumaric acid, valeric acid, glutaric acid, itaconic acid, adipic acid, caproic acid, adipic acid, citric acid, propanetricarboxylic acid, trans-aconitic acid, enanthic acid, caprylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, and linolenic acid. Preferred examples of the aromatic carboxylic acid having 6 to 10 carbon atoms include benzoic acid, salicylic acid, mandelic acid, phthalic acid, isophthalic acid, and terephthalic acid. Preferred examples of the amino acid having 1 to 10 carbon atoms include carbamic acid, alanine, glycine, asparagine, aspartic acid, sarcosine, serine, glutamine, glutamic acid, 4-aminobutyric acid, iminodibutyric acid, arginine, leucine, isoleucine, and nitrilotriacetic acid.

[0027] The content of the acid in the present composition is 0.0001 to 50 mass%, preferably 0.0005 to 20 mass%, more preferably 0.001 to 10 mass%, still more preferably 0.01 to 1 mass%, and particularly preferably 0.02 to 1 mass%.

[0028] [(C) Ingredient: Water] 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, 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. The content of water in the present composition is usually 40 to 99.9998 mass %, and preferably 89.5 to 99.998 mass %.

[0029] [Component (D): Barium compound] The aqueous composition according to the present invention may contain a barium compound. The barium compound used in the present invention is an inorganic substance containing barium, and has the effect of preventing corrosion of alumina. Examples of barium compounds include barium nitrate, barium acetate, barium chloride, barium hydroxide, barium sulfite, barium chlorate, barium perchlorate, barium peroxide, barium chromate, barium oxide, barium cyanide, barium bromide, barium carbonate, barium metaborate, barium iodide, barium tetrafluoroborate, barium sulfate, barium sulfide, and salts obtained by reacting barium hydroxide with an acid, and these can be used alone or in combination of two or more types. Among these, barium nitrate, barium acetate, barium chloride and barium hydroxide are preferred because they are highly soluble in water and are easily available. The concentration of the barium compound in the composition is 0.00005 to 10 mass%, preferably 0.00025 to 5 mass%, more preferably 0.001 to 2 mass%, and particularly preferably 0.002 to 1 mass%. Within this range, damage to alumina can be effectively suppressed.

[0030] [Other ingredients] The aqueous composition of the present invention may contain additives that have been conventionally used in aqueous compositions for semiconductors, if desired, within the scope of not impairing the object of the present invention. For example, additives that can be added include alkali (e.g., ammonia), chelating agents, surfactants, antifoaming agents, oxidizing agents, reducing agents, metal corrosion inhibitors, water-soluble organic solvents, etc. These additives are known and are described in, for example, JP2013-533631A.

[0031] [Method for preparing aqueous composition (liquid composition)] The aqueous composition (liquid composition) of the present invention is prepared by adding the above-mentioned component (A), the above-mentioned component (B), and water, and, if necessary, the above-mentioned component (D) and other components, and stirring until the mixture is homogenous. The pH range of the aqueous composition of the present invention is not particularly limited, but is usually 0-7, preferably 0-6, more preferably 0-5, and further preferably 0-4. According to a preferred embodiment of the aqueous composition of the present invention, dry etching residues can be efficiently removed while protecting cobalt, alumina, etc. from corrosion.

[0032] [Method of using the aqueous composition: cleaning / manufacturing method for electronic devices] The aqueous composition according to the present invention can remove dry etching residues by contacting it with an electronic device (e.g., a semiconductor element) as an aqueous cleaning composition (hereinafter also referred to as a "cleaning liquid") in a wet etching step (or steps before or after the wet etching step). As a contact method, for example, the cleaning liquid is placed in a cleaning container, and the electronic device to be cleaned is immersed in the cleaning liquid to remove the dry etching residues and clean the electronic device. Alternatively, the electronic device can be treated by a single-wafer cleaning method to remove the dry etching residues and clean the electronic device. The aqueous cleaning composition can be suitably used as an etching liquid in addition to a dry etching residue removing liquid (cleaning liquid). The aqueous composition can also be used as a cleaning liquid for cleaning an electronic device after a chemical mechanical polishing (CMP) step. Thus, the aqueous composition according to the present invention can be suitably used in a cleaning method having a step of cleaning an electronic device, and in a manufacturing method for an electronic device including such a step. 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 cleaning conditions and the electronic device (e.g., semiconductor element) used. The time for using the cleaning solution of the present invention is usually 0.2 to 60 minutes. The time can be appropriately selected depending on the cleaning conditions and the electronic device (e.g., semiconductor element) used. As a rinsing solution after using the cleaning solution of the present invention, an organic solvent, water, carbonated water, or ammonia water can be used.

[0033] [Electronic devices to be cleaned / manufactured] The cleaning target and manufacturing target electronic device for which the present invention can be suitably used are, for example, semiconductor elements and display elements, and the intermediate product after the dry etching process is usually the cleaning target. The semiconductor elements and display elements are substrate materials such as silicon, amorphous silicon, polysilicon, and glass, insulating materials such as silicon oxide, silicon nitride, silicon carbide and their derivatives, materials such as cobalt, cobalt alloys, tungsten, and titanium-tungsten, compound semiconductors such as gallium-arsenide, gallium-phosphorus, indium-phosphorus, indium-gallium-arsenide, and indium-aluminum-arsenide, and oxide semiconductors such as chromium oxide. Particularly preferred examples of electronic devices to be cleaned by the present invention include elements using cobalt or cobalt alloy wiring materials, zirconia-based hard masks, and low-dielectric constant interlayer insulating films.

[0034] The dry etching residues targeted in the present invention are generated when forming vias or trenches in a low dielectric constant interlayer insulating film by dry etching using, for example, a zirconia-based hard mask. Some of the dry etching residues are generated by contact between the etching gas and the zirconia-based hard mask. Therefore, in this case, the targeted dry etching residues contain zirconium. EXAMPLES

[0035] The present invention will be specifically described below with reference to examples, but the embodiments can be modified as appropriate as long as the effects of the present invention are achieved. Unless otherwise specified, % means % by mass.

[0036] [Evaluation wafer] <Evaluation wafer A>: For evaluating the removal state of dry etching residues From the bottom up, silicon nitride, an interlayer insulating film, silicon nitride, zirconia, and a photoresist were deposited, and then the photoresist was patterned. Using the photoresist as a mask, the hard mask was dry-etched at predetermined locations, and the photoresist was then removed by ashing using oxygen plasma. Using the hard mask as a mask, vias were formed in the silicon nitride and interlayer insulating film by dry etching.

[0037] <Wafer with film>: For damage evaluation of cobalt and alumina Wafers with films of cobalt and alumina were produced under the following film formation conditions. (1) Cobalt: A film of 2000 Å thickness was formed on silicon by physical vapor deposition. (2) Alumina; a film is formed by physical vapor deposition onto silicon to a thickness of 1000 Å.

[0038] [Evaluation method] <Removal of dry etching residue> Evaluation wafer A was subjected to SEM observation after being treated with various aqueous compositions (cleaning liquids). Measuring equipment: Hitachi High-Technologies Corporation, ultra-high resolution field emission scanning electron microscope SU9000 (magnification 100,000 times) Judgment method: E: Dry etching residues were completely removed. G: Dry etching residues were almost completely removed. P: Dry etching residue was not sufficiently removed. E and G ratings were considered pass.

[0039] <Film thickness> The film thickness of the wafer with film was measured using a fluorescent X-ray apparatus 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. For the wafer with cobalt film, the film thickness was measured using film thickness measuring device A, and for the wafer with alumina film, the film thickness was measured using film thickness measuring device B.

[0040] <E.R. (etching rate)> Each wafer with film was treated with a cleaning solution, and the E.R. was calculated by dividing the film thickness difference before and after the treatment by the treatment time. In the case of cobalt, when the E.R. was 1 Å / min or less, and in the case of alumina, when the E.R. was 25 Å / min or less, it was regarded as a good product.

[0041] <Measurement of pH value> The pH values of the aqueous compositions in each example and reference example were measured at 25°C using a pH meter (pH meter F-52 manufactured by Horiba, Ltd.).

[0042] [Examples 1 to 31] In the test, evaluation wafer A and various wafers with films were used. They were immersed in the cleaning solutions described in Tables 1 and 2 at the treatment temperatures described in Tables 1 and 2, and then rinsed with ultrapure water and dried by spraying with dry nitrogen gas. For evaluation wafer A, the treatment was carried out for 5 minutes, and the treated wafer was observed by SEM. For various wafers with films, the wafer with cobalt film was treated for 30 minutes and the alumina was treated for 5 minutes. The E.R. was calculated from the film thickness before and after the treatment.

[0043] [Examples 1 to 31 and Reference Examples 1 to 23] In the test, evaluation wafer A, wafers with cobalt film, and wafers with alumina film were used. They were immersed in the aqueous compositions (cleaning solutions) described in Tables 1, 2, and 3 at 20°C or 50°C (refer to the treatment temperature item in the table), and then rinsed with ultrapure water and dried by spraying with dry nitrogen gas. For evaluation wafer A, all were immersed for 5 minutes, and the treated wafer was observed by SEM. The wafers with the cobalt film were immersed for 30 minutes, and the wafers with the alumina film were immersed for 5 minutes, and the ER was calculated from the film thickness before and after the treatment. It can be seen that in Examples 1 to 31, damage to cobalt is prevented. On the other hand, it is clear that the reference examples in Table 3 are not particularly suitable for the purpose of suppressing damage caused by cobalt. It is also clear that the HF-containing compositions in Tables 1 and 2 were able to remove the dry etching residues contained in evaluation wafer A. Furthermore, in the examples of Table 2, it can be seen that compositions containing barium compounds prevent damage to the alumina.

[0044] [Table 1]

[0045] [Table 2]

[0046] [Table 3] [Industrial Applicability]

[0047] The aqueous composition according to a preferred embodiment of the present invention exhibits good anticorrosive effect on cobalt or cobalt alloys even in a low pH range (eg, 4 or less). Furthermore, an aqueous composition according to another preferred embodiment of the present invention (for example, a composition containing hydrogen fluoride) exhibits a good anticorrosive effect on cobalt or cobalt alloys, and also has good removability of dry etching residues. Furthermore, the etching solution, cleaning solution, and cleaning method according to the preferred embodiments of the present invention have a good anticorrosive effect on wiring materials such as cobalt and a good ability to remove dry etching residues, making it possible to manufacture high-precision, high-quality electronic devices with good yields in the manufacturing process of electronic devices such as semiconductor elements. [Explanation of symbols]

[0048] 1. Zirconia-based dry etching residue 2. Zirconia-based hard mask 3. Cobalt or cobalt alloy 4. Alumina 5.Low-k Interlayer Insulating Film 6. Silicon nitride (SiN)

Claims

1. A method for cleaning an electronic device, comprising the step of contacting an aqueous composition with the electronic device, The aqueous composition comprises: (A) 0.001 to 0.5 mass% of one or more compounds selected from C6-13 alkylphosphonic acid, C6-13 alkylphosphoric acid, and salts thereof based on the total mass of the composition; and (B) an acid or a salt thereof other than a C6-13 alkylphosphonic acid and a C6-13 alkylphosphoric acid is contained in an amount of 0.001 to 10% by mass based on the total amount of the composition; the C6-13 alkylphosphonic acid is selected from the group consisting of 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 C6-13 alkyl phosphoric acid is selected from the group consisting of 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 phosphoric acid, and isodecyl phosphate; The acid or salt thereof of the component (B) is hydrofluoric acid, nitric acid, sulfuric acid, hydrochloric acid, phosphoric acid, acetic acid, or a salt thereof, The pH of the aqueous composition is in the range of 0 to 7. The method for cleaning the electronic device.

2. A method for producing an electronic device, comprising the step of contacting an aqueous composition with an electronic device, The aqueous composition comprises: (A) 0.001 to 0.5 mass% of one or more compounds selected from C6-13 alkylphosphonic acid, C6-13 alkylphosphoric acid, and salts thereof based on the total mass of the composition; and (B) an acid or a salt thereof other than a C6-13 alkylphosphonic acid and a C6-13 alkylphosphoric acid is contained in an amount of 0.001 to 10% by mass based on the total amount of the composition; the C6-13 alkylphosphonic acid is selected from the group consisting of 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 C6-13 alkyl phosphoric acid is selected from the group consisting of 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 phosphoric acid, and isodecyl phosphate; The acid or salt thereof of the component (B) is hydrofluoric acid, nitric acid, sulfuric acid, hydrochloric acid, phosphoric acid, acetic acid, or a salt thereof, The pH of the aqueous composition is in the range of 0 to 7. A method for manufacturing the electronic device.

3. (A) one or more compounds selected from C6-13 alkylphosphonic acid, C6-13 alkylphosphoric acid, and salts thereof, in an amount of 0.001 to 0.5 mass% based on the total mass of the composition; and (B) an etching solution containing an aqueous composition containing an acid or a salt thereof other than a C6-13 alkylphosphonic acid and a C6-13 alkylphosphoric acid in an amount of 0.001 to 10 mass% based on the total mass of the composition, the C6-13 alkylphosphonic acid is selected from the group consisting of 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 C6-13 alkyl phosphoric acid is selected from the group consisting of 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 phosphoric acid, and isodecyl phosphate; The acid or salt thereof of the component (B) is hydrofluoric acid, nitric acid, sulfuric acid, hydrochloric acid, phosphoric acid, acetic acid, or a salt thereof, The pH of the aqueous composition is in the range of 0 to 7. The etching solution.

4. (A) one or more compounds selected from C6-13 alkylphosphonic acid, C6-13 alkylphosphoric acid, and salts thereof, in an amount of 0.001 to 0.5 mass% based on the total mass of the composition; and (B) a cleaning liquid containing an aqueous composition containing an acid or a salt thereof other than a C6-13 alkylphosphonic acid and a C6-13 alkylphosphoric acid in an amount of 0.001 to 10 mass % based on the total mass of the composition, the C6-13 alkylphosphonic acid is selected from the group consisting of 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 C6-13 alkyl phosphoric acid is selected from the group consisting of 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 phosphoric acid, and isodecyl phosphate; The acid or salt thereof of the component (B) is hydrofluoric acid, nitric acid, sulfuric acid, hydrochloric acid, phosphoric acid, acetic acid, or a salt thereof, The pH of the aqueous composition is in the range of 0 to 7. The cleaning solution.

5. The cleaning solution according to claim 4, wherein the acid of component (B) is hydrofluoric acid.

6. A cleaning solution as described in claim 4 or 5, further comprising a barium compound.

7. The cleaning solution of claim 6, wherein the barium compound comprises at least one selected from barium nitrate, barium acetate, barium chloride and barium hydroxide.

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