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 fluorine-containing compounds selected from a group consisting of tetrafluoroboric acid, hexafluorosilicic acid, hexafluoroaluminic acid, hexafluorotitanic acid and their salts, which is 0.001-20 mass% to total mass of the composition; and one or more compounds selected from a group consisting of C4-13 alkyl phosphonic acid, C4-13 alkyl phosphonic ester, C4-13 alkyl phosphonic acid, and their salts, which is 0.0001-10 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) 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 mass% based on the total amount of the composition; and (B)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 added in an amount of 0.0001 to 10% by mass based on the total amount of the composition. 13. An aqueous composition comprising: [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, further comprising hydrogen fluoride (HF). [4] The composition according to [3] above, wherein the component (A) is hexafluorosilicic acid or a salt thereof (e.g., an ammonium salt). [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 4-13 Alkylphosphonic acid (preferably C 5-11 Alkylphosphonic acids, more preferably C 5-9 Alkylphosphonic acid, more preferably C 6-8 The composition according to any one of the above [1] to [5], wherein the compound (a) is an alkylphosphonic acid.

[0007] [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; The alkyl phosphate salt 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.

[0008] [6b] The composition according to any one of the above [1] to [6a], which is a composition for removing dry etching residues (for example, zirconia-based dry etching residues) after dry etching. [6c] The composition according to any one of the above [1] to [6b], which is a composition for preventing corrosion of a wiring material (e.g., cobalt or a cobalt alloy) of an electronic device to be cleaned. [6d] The composition according to any one of the above [1] to [6c], wherein the alkylphosphonic acid excludes dodecylphosphonic acid. [7] The composition according to any one of the above [1] to [6], wherein the alkyl phosphonic acid, the alkyl phosphonic acid ester, and the alkyl phosphoric acid have 2 or less alkyl chains. [8] The composition according to any one of the above [1] to [7], wherein the number of alkyl chains in the alkyl phosphonic acid, the alkyl phosphonic acid ester, and the alkyl phosphoric acid is 1. [9] A method for cleaning an electronic device, comprising the step of contacting the composition according to any one of the above [1] to [8] with the electronic device.

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

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

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

[0009] The aqueous composition according to a preferred embodiment of the present invention can efficiently remove dry etching residues (e.g., zirconium-based dry etching residues, titanium-based dry etching residues, polymer-based dry etching residues, etc.) while protecting wiring metal materials such as cobalt or cobalt alloys, silicon nitride, interlayer insulating films, etc. from corrosion. The cleaning method according to a preferred embodiment of the present invention has a good anticorrosive effect on wiring metal materials such as cobalt or cobalt alloys, silicon nitride, interlayer insulating films, etc., and has a good ability to remove dry etching residues, so that high-precision, high-quality electronic devices can be produced with good yields in the manufacturing process of electronic devices such as semiconductor elements. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is a schematic cross-sectional view of one embodiment of a semiconductor element having a structure including a zirconia-based hard mask 2, cobalt or cobalt alloy 3, a low dielectric constant interlayer insulating film 5, and silicon nitride 6 before removing dry etching residue 1. [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. [Diagram 3] 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. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] 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 mass% based on the total amount of the composition; and (B) C 4-13 Alkylphosphonic acid, C 4-13 Alkylphosphonates, C 4-13 The composition contains one or more compounds selected from alkyl phosphoric acids and salts thereof in an amount of 0.0001 to 10% by mass based on the total amount 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 0.001% by mass and 20% by mass. The aqueous composition according to the present invention will be described in detail below.

[0012] [Component (A): Fluorine-containing compound] The fluorine-containing compound used in the present invention is selected from tetrafluoroboric acid, hexafluorosilicic acid, hexafluoroaluminic acid, hexafluorotitanic acid, and their salts.The salts of these compounds include, 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, strontium salt, barium salt, etc.Among these compounds, hexafluorosilicic acid or its salt (e.g., ammonium salt) is particularly preferred. The content of the fluorine-containing compound in the composition is 0.001 to 20 mass % based on the total amount of the composition, preferably 0.005 to 10 mass %, more preferably 0.01 to 5 mass %, and particularly preferably 0.03 to 2 mass %. In the present invention, in addition to the above-mentioned fluorine-containing compound, hydrogen fluoride, ammonium fluoride, etc. can be appropriately blended. The blending amount can be appropriately determined taking into consideration the blending amounts of other components, and is, for example, 0.001 to 10 mass % based on the total amount of the composition, preferably 0.005 to 1 mass %, and more preferably 0.01 to 0.1 mass %.

[0013] [Component (B): alkyl phosphonic acid, alkyl phosphoric acid, or a salt thereof, etc.] (B1) Alkylphosphonic acid, alkylphosphonic acid ester, or salts thereof The alkylphosphonic acid used in the present invention is a C 4-13Alkylphosphonic 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 part of the alkylphosphonic acid may be linear or branched, but linear is preferred. When the alkyl part 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, 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 of the general formula R 1 P(=O)(OH) 2 (R 1 is an alkyl group), and the general formula R 1 P(=O)(OR 2 ) 2 (R 1 is an alkyl group, R 2 is an alkyl group or hydrogen; 2 wherein at least one of the alkyl groups is an alkyl group), may also be used in the aqueous composition. The alkyl phosphonate esters described herein also include alkyl esters of phosphonic acid (phosphonate esters). That is, alkyl phosphonates represented by the general formula R 1 P(=O)(OR 2 ) 2 (R 1 is hydrogen, R 2 is an alkyl group or a hydrogen atom; 2wherein at least one of the groups is an alkyl group), may also be used in the aqueous composition, as referred to herein as alkyl phosphonates. 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. R 1 P(=O)(OR 2 ) 2 (A) (In the general formula (A), R 1 , and R 2 are each independently an alkyl group or a hydrogen atom; provided that R 1 and two R's 2 At least one of these 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 R in the above general formula (A) is an alkylphosphonic acid ester. 1 and R 2 The alkyl chains each independently preferably have 4 to 12 carbon atoms, more preferably 6 to 11 carbon atoms, and even more preferably 8 to 10 carbon atoms.

[0015] The alkyl group of the alkylphosphonate ester, i.e., R 1 and R 2 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., R 1 and R 2The total number of alkyl chains in the alkyl phosphonate ester is preferably 2 or less. 1 P(=O)(OR 2 ) 2 Of these, R 1 and R 2 Although it is also possible to use a group in which all of R are alkyl groups, 1 is an alkyl group, and R 2 or R 1 is hydrogen and R 2 More preferably, an alkylphosphonic acid having only a single alkyl chain, i.e., R 1 P(=O)(OR 2 ) 2 R 1 and two R 2 Among these, it is preferable to use one in which only one of them is an alkyl group. Particularly preferable is R 1 It is preferred to use those in which only the alkyl group is used.

[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] Examples of the alkylphosphonic acid or a salt thereof 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, and 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, salts of the above-mentioned alkylphosphonic acid esters can also be used. For example, examples of the salts of the alkylphosphonic acid esters include those corresponding to the above-mentioned salts of the alkylphosphonic acids.

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

[0019] (B2) Alkyl phosphoric acid or its salt 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. 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.

[0020] In the aqueous composition of the present invention, the alkyl phosphoric acid may be a monoalkyl ester of phosphoric acid, a dialkyl ester, or a trialkyl ester. 3 ) 3 (R 3 R of phosphoric acid is represented by 3 Not only monoalkyl esters of phosphoric acid in which only one of R is substituted with an alkyl group, 3 Dialkyl esters in which two of R are substituted with alkyl groups; and 3 In the aqueous composition of the present invention, trialkyl esters in which all of the alkyl chains are substituted with alkyl groups may also be used. However, dialkyl esters (represented by the above general formula P(=O)(OR 3 ) 3 R 3 where both are alkyl groups) and monoalkyl esters (the above general formula P(=O)(OR 3 ) 3 R 3 is preferably a monoalkyl ester having one alkyl chain. That is, the alkyl phosphate is preferably a monoalkyl ester having one alkyl chain (the above R 3 It is preferred that the alkyl group has an alkyl group represented by the following formula:

[0021] Alkyl phosphates have a total of 4 to 13 carbon atoms, regardless of the number of ester bonds. 5-11 Alkyl phosphate esters are preferred, more preferably C 5-9 Alkyl phosphate esters, more preferably C 6-8 An alkyl phosphate ester is used. In addition, the above general formula P(=O)(OR 3 ) 3 R 3 The alkyl chain of the alkyl phosphate 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. 3) 3 R 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 a monoalkyl ester or dialkyl ester of the above 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] Examples of the alkyl phosphoric acid or a salt thereof 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, and mixtures thereof. Preferably used alkyl phosphoric acids or salts thereof are 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 concentration of alkyl phosphoric acid or its salt is preferably 0.0002 to 2 mass%, more preferably 0.0003 to 0.5 mass%, and particularly preferably 0.0003 to 0.1 mass%, based on the total amount of the composition.

[0025] [(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 99.9999 mass %, and preferably 97.95 to 99.9697 mass %.

[0026] [Other ingredients] The aqueous composition of the present invention may contain additives that have been conventionally used in aqueous compositions for semiconductors, provided that the purpose of the present invention is not impaired. 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 acids, alkalis, 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, JP-T-2013-533631.

[0027] [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), water, and, if necessary, other components, and stirring until homogenous. The pH range of the aqueous composition 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, it is possible to efficiently remove dry etching residues (e.g., zirconium-based dry etching residues, titanium-based dry etching residues, polymer-based dry etching residues, etc.) while protecting wiring metal materials such as cobalt or cobalt alloys, silicon nitride, interlayer insulating films, etc. from corrosion.

[0028] [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 "cleaning liquid") in a wet etching process (or a process before or after the wet etching process). For example, the cleaning liquid is stored 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 is 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) process. 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.

[0029] [Electronic devices to be cleaned / manufactured] The cleaning target and the electronic device to be manufactured by the present invention 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-arsenic, gallium-phosphorus, indium-phosphorus, indium-gallium-arsenic, and indium-aluminum-arsenic, and oxide semiconductors such as chromium oxide. Particularly preferred examples of the electronic device to be cleaned by the present invention include elements using cobalt or cobalt alloy wiring materials, zirconia-based hard masks, silicon nitride (SiN), and low dielectric constant interlayer insulating films (e.g., tetraethoxysilicate films).

[0030] The dry etching residues targeted in the present invention are, for example, those generated when a via or a trench is formed in a low dielectric constant interlayer insulating film by dry etching using a zirconia-based hard mask as a mask. A part of the dry etching residue is generated by contact between the etching gas and the zirconia-based hard mask. Therefore, in this case, the target dry etching residue contains zirconium. EXAMPLES

[0031] 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.

[0032] [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.

[0033] <Wafer with film>: For damage evaluation of silicon nitride, low dielectric constant interlayer insulating film and cobalt The wafers used were made of silicon nitride, a low-k interlayer insulating film, and cobalt. The low-k interlayer insulating film was made of TEOS (tetraethoxysilicate), a type of low-k interlayer insulating film. Each film was formed as follows. (1) Silicon nitride (SiN): A 1000 Å thick film is deposited on silicon using plasma-enhanced chemical vapor deposition. (2) TEOS: A 1000 Å thick film is deposited on silicon by chemical vapor deposition. (3) Cobalt: Deposited by physical vapor deposition to a thickness of 2000 Å on silicon.

[0034] [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. N: Removal of dry etching residues was slightly insufficient. P: Dry etching residue was not sufficiently removed. E and G ratings were considered pass.

[0035] <Film thickness> The film thickness of the wafer with a film was measured using a fluorescent X-ray device SEA1200VX (film thickness measurement device A) manufactured by SII NanoTechnology Inc., or an optical film thickness meter n&k1280 (film thickness measurement device B) manufactured by n&k technology. For the wafer with a cobalt film, the film thickness was measured using film thickness measurement device A, and for the wafers with a silicon nitride film and a TEOS film, the film thickness was measured using film thickness measurement device B.

[0036] <E.R. (etching rate)> Each wafer with a 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. For silicon nitride, it was 2 Å / min or less, for TEOS it was 5 Å / min or less, and for cobalt, the case where the E.R. was 5 Å / min or less was considered qualified.

[0037] <Measurement of pH value> The pH values of the aqueous compositions in each example and comparative example were measured at 25 °C using a pH meter (pH meter F-52 manufactured by Horiba, Ltd.).

[0038] [Examples 1 to 14 and Comparative Examples 1 to 11] For the tests, evaluation wafer A and wafers with a silicon nitride film, a TEOS film, and a cobalt film were used. They were immersed in the aqueous composition (cleaning solution) 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. Regarding evaluation wafer A, all were immersed for 3 minutes, and the wafers after the treatment were observed with an SEM. The wafers with a silicon nitride film, a TEOS film, and a cobalt film were immersed for 30 minutes, and the E.R. was calculated from the film thickness before and after the treatment. In Examples 1 to 14, it can be seen that while preventing damage to silicon nitride (SiN), TEOS, and cobalt, the dry etching residues were completely removed. On the other hand, in Comparative Examples 1 to 11 in Table 2, it can be seen that there are cases where damage to cobalt cannot be suppressed, where dry etching residues cannot be removed, and where dry etching residues cannot be removed while sufficiently preventing damage to silicon nitride and TEOS.

[0039] [Table 1]

[0040] [Table 2] [Industrial Applicability]

[0041] The aqueous composition according to a preferred embodiment of the present invention can efficiently remove dry etching residues while protecting wiring metal materials such as cobalt or cobalt alloys, silicon nitride, interlayer insulating films, and the like from corrosion. The etching solution, cleaning solution, and cleaning method according to the preferred embodiments of the present invention have a good anticorrosive effect on wiring metal materials such as cobalt or cobalt alloys, silicon nitride, interlayer insulating films, and the like, and have a good ability to remove dry etching residues, so that high-precision, high-quality electronic devices can be manufactured with a good yield in the manufacturing process of electronic devices such as semiconductor elements. [Explanation of symbols]

[0042] 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) 0.03 to 2 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) one or more compounds selected from C6-13 alkyl phosphonic acid, C6-13 alkyl phosphoric acid, and salts thereof are contained in an amount of 0.0003 to 0.1 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 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) 0.03 to 2 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) one or more compounds selected from C6-13 alkyl phosphonic acid, C6-13 alkyl phosphoric acid, and salts thereof are contained in an amount of 0.0003 to 0.1 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 pH of the aqueous composition is in the range of 0 to 7. A method for manufacturing the electronic device.

3. (A) 0.03 to 2 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) C ６－１３ Alkylphosphonic acid, C ６－１３ An etching solution comprising an aqueous composition containing 0.0003 to 0.1 mass % of one or more compounds selected from alkyl phosphoric acids and salts thereof 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 pH of the aqueous composition is in the range of 0 to 7. The etching solution.

4. (A) 0.03 to 2 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) a cleaning liquid comprising an aqueous composition containing 0.0003 to 0.1 mass % of one or more compounds selected from a C6-13 alkyl phosphonic acid, a C6-13 alkyl phosphoric acid, and salts thereof, 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 pH of the aqueous composition is in the range of 0 to 7. The cleaning solution.

5. The cleaning solution described in claim 4, further containing hydrogen fluoride (HF).

6. A cleaning solution described in claim 4 or 5, wherein the (A) component is hexafluorosilicic acid or a salt thereof.

7. A cleaning solution described in any one of claims 4 to 6, wherein the number of alkyl chains in the alkyl phosphonic acid and the alkyl phosphoric acid is 2 or less.

8. A cleaning solution described in any one of claims 4 to 7, wherein the number of alkyl chains in the alkyl phosphonic acid and the alkyl phosphoric acid is 1.

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