Method for cleaning a device for tin compounds and a cleaned device obtained thereby

Abstract

A method for efficiently and safely cleaning a device for tin compounds and a device for highly purified tin compounds are provided. A method for cleaning a device that has come into contact with a tin compound having formula (1) comprises at least steps (A) to (C) in the order shown: (A) cleaning the device with an aprotic solvent; (B) cleaning the device with an acidic aqueous solution and / or an alkaline aqueous solution; and (C) cleaning the device with ultrapure water having a resistivity of 17 MΩ·cm at 25°C; RpSnXm(1) R is a hydrocarbon group, p is an integer from 0 to 3, X is a hydrolytic substituent, and m = 4-p.

Description

Technology Field Cross-reference regarding related applications This application claims priority to U.S. Provisional Application No. 63 / 617,788, filed January 5, 2024, which is currently pending, the entire disclosure of said application incorporated herein by reference. Technology field The present invention relates to a method for cleaning a device for tin compounds and a cleaned device obtained thereby, and more specifically, to a method for efficiently and safely cleaning a device for tin compounds and a device purified to a high purity obtained thereby. Background Technology In recent years, along with a paradigm shift toward a highly information-oriented society, there is a demand to handle larger amounts of information at faster speeds and with higher accuracy. Semiconductor technologies, such as integrated circuits utilizing semiconductors, are advancing remarkably day by day. Conventional chemically amplified resists (CARs) have potential drawbacks when used in EUV lithography, particularly due to their low absorption coefficient in the EUV region, which can lead to diffuse blurring of photoactive species or line edge roughness. Therefore, there remains a need for improved EUV photoresist materials with characteristics such as thinner thickness, better absorbance, and excellent etch resistance. For this reason, liquid CVD materials such as organotin compounds have recently begun to be used as resists, particularly for EUV applications. To achieve high-quality film formation, materials of extremely high purity are required. Therefore, before using tin compounds as CVD materials, impurities such as water, residual solvent used in synthesis, and metal impurities must be removed by distillation or other means (Patent Literature 1), and the introduction of impurities must be avoided as much as possible. Prior art literature Japanese Patent Publication No. 2020-530199 The problem to be solved However, tin compounds react with oxygen and water to form stanoxane compounds, which may remain attached to the equipment for tin compounds and become impurities during subsequent synthesis or storage, or potentially cause a decrease in the purity of the tin compounds. Therefore, in light of this background, the present invention aims to discover an efficient and safe method for cleaning a device for tin compounds and to provide a device purified to a high purity for tin compounds. means of solving the problem As a result of intensive research to solve these challenges, the inventors have identified a method for efficiently and safely cleaning devices for tin compounds by adopting a special cleaning process when cleaning equipment that comes into contact with a specific tin compound and is contaminated with impurities. That is, the present invention has the following aspects: [1] A method for cleaning a device in contact with a tin compound having chemical formula (1), wherein the method comprises at least steps (A) to (C), wherein step (B) is performed after step (A) and step (C) is performed after step (B); (A) A step of cleaning the device with an aprotic solvent, (B) a step of cleaning the device with an acidic aqueous solution and / or an alkaline aqueous solution, and (C) A step of cleaning the device with ultrapure water having a resistivity value of 17 MΩ·cm at 25℃ (C), R p SnX m (1) Here, R is a hydrocarbon group, p is an integer from 0 to 3, X is a hydrolytic substituent, and m = 4-p. [2] A method for cleaning a device according to [1], wherein step (B) is performed sequentially without any other cleaning steps in between step (A). [3] A method for cleaning a device for tin compounds described in [1] or [2], wherein, after step (A), a drying step is performed, and then step (B) is performed sequentially. [4] A method for cleaning a device for tin compounds described in any one of [1] to [3], wherein, after step (A), a step of cleaning with alcohol and a drying step are performed, and then step (B) is performed in succession. [5] A method for cleaning a device for tin compounds described in any one of [1] to [4], wherein the aprotic solvent comprises at least one solvent selected from the group consisting of aromatic hydrocarbons, aliphatic hydrocarbons, esters, and ethers. [6] A method for cleaning a device for tin compounds described in any one of [1] to [5], wherein the acidic aqueous solution is a 3 to 30 mass% aqueous nitric acid solution. [7] A method for cleaning a device for tin compounds described in any one of [1] to [6], wherein the pH of the alkaline aqueous solution is 11.5 or lower. [8] A method for cleaning a device for tin compounds described in any one of [1] to [7], wherein the alkaline aqueous solution is at least one aqueous solution selected from the group consisting of phosphate, sodium hydroxide, and potassium hydroxide. [9] A method for cleaning a device for tin compounds as described in [8], wherein the concentration of sodium hydroxide and / or potassium hydroxide is 0.5 to 2 mass%.

[10] A method for cleaning a device for tin compounds described in any one of [1] to [9], wherein, after step (C), a drying step is performed.

[11] A method for cleaning a device for tin compounds described in any one of [1] to

[10] , wherein p in the general formula (1) is 0 or 1.

[12] [1] A method for cleaning an apparatus for tin compounds described in any one of [1] to

[11] , wherein the tin compound represented by the general formula (1) is t-butyltris(dimethylamino)tin, n-butyltris(dimethylamino)tin, t-butyltris(diethylamino)tin, di-t-butylbis(dimethylamino)tin, sec-butyltris(dimethylamino)tin, n-pentyltris(dimethylamino)tin, isobutyltris(dimethylamino)tin, Isopropyltris(dimethylamino)tin, t-butyltri-t-butoxytin, n-butyltri-t-butoxytin, isopropyltri-t-butoxytin, isopropyltri-t-amyloxytin, t-butyltri-t-amyloxytin, tetra-t-butoxytin, tetrakis(dimethylamino)tin, 1-methyl-1-cyclopentyltris(dimethylamino)tin, and A method comprising at least one selected from the group consisting of 1-methyl-1-cyclopentyltri-t-butoxytin.

[13] A device for a tin compound that is in contact with a tin compound represented by the above general formula (1) and is cleaned by a cleaning method described in any one of [1] to

[12] .

[14] A device for tin compounds as described in

[13] , which is a container for storing tin compounds.

[15] A device for tin compounds as described in

[13] , wherein ultrapure water having a resistivity of 17 MΩ·cm at 25°C is filled into the device and, when left at 25°C for 1 hour, the content of each metal element chromium, iron, magnesium, nickel, sodium, and potassium is 1.5 mass ppb or less.

[16] A device for a tin compound obtained by cleaning a device that has contact with a tin compound having the chemical formula (1) described in

[13] , wherein when the device is filled with ultrapure water having a resistivity of 17 MΩ·cm at 25°C and left for 1 hour at 25°C, the increase in the amount of halogen ions in the water is 100 mass ppb or less, and the increase in the amount of particles having a particle size of 0.5 μm or more is 100 / mL or less.

[17]

[13] A device for tin compounds as described in

[13] , wherein a tin compound having the chemical formula (1) is placed in the device, sealed under an inert gas atmosphere, and stored at 25°C for 1 month, the purity of the tin compound decreases to 0.1 mass% or less.

[18] As a device for tin compounds described in

[13] , when the device is vacuum dried and then filled with helium at 34.5 kPa, the valve seat leakage amount measured by the helium detection device is 5×10 -9 Pa·m 3 / s less than, device.

[19]

[15] to

[17] A device for tin compounds as described in any one of

[15] to

[17] , a device that is a container for storing tin compounds.

[20] A method for forming a pattern for a semiconductor, comprising the steps of: using a device for a tin compound that contacts a tin compound having the chemical formula (1), depositing a tin compound having the chemical formula (1) on a substrate to obtain a thin film; exposing the thin film to radiation; and developing the exposed thin film, wherein the device for the tin compound is a tin compound storage container in which ultrapure water having a resistivity of 17 MΩ·cm at 25°C is filled and, when left at 25°C for 1 hour, the content of each metal element Cr, Fe, Mg, Ni, Na, and K is 1.5 mass ppb or less.

[0001] R p SnX m (1) Here, R is a hydrocarbon group, p is an integer from 1 to 3, X is a hydrolytic substituent, and m = 4-p.

[21] A method for manufacturing a semiconductor, comprising the step of performing the pattern forming method described in

[20] . Effects of the invention The method for cleaning an apparatus for tin compounds according to the present disclosure enables the apparatus to be cleaned efficiently and safely. Furthermore, the apparatus cleaned by the method according to the present disclosure is purified to a high purity and the generation of impurities is suppressed, so that, consequently, it becomes an apparatus that does not cause a decrease in the purity of the tin compound. Specific details for implementing the invention The present invention will be described below with reference to examples of embodiments for carrying out the present invention. However, the present invention is not limited to the following embodiments. Unless otherwise specified, any numerical value should be understood as modified by the term "approximately" in all examples. Accordingly, numerical values ​​typically include ± 10% of the stated value. For example, references to temperature such as "10°C" or "approximately 10°C" include 9°C and 11°C and all temperatures in between. All numeric ranges expressed in this disclosure explicitly include all possible sub-ranges and all individual numeric values ​​within such ranges, including integers and fractional and decimal amounts of values ​​within such ranges, unless the context clearly indicates otherwise. Note that in the present invention, when expressing "α to β (α and β are any number)," unless otherwise specified, it includes the meaning of "α or greater and β or less" along with the meaning of "preferably greater than α" or "preferably less than β." Furthermore, when expressing "α or greater (α is any number)" or "β or less (β is any number)," it includes the meaning of "preferably greater than α" or "preferably less than β." Moreover, "γ and / or δ (γ and δ are any components)" means that it means at least one of γ and δ, only γ, only δ, and three types of γ and δ. One embodiment of the method for cleaning a device for a tin compound according to the present invention (hereinafter sometimes referred to as "the cleaning method") is a method for cleaning a device in contact with a tin compound having the formula (1), comprising at least the following steps (A) to (C) in this order: (A) A step of cleaning the device with an aprotic solvent, (B) a step of cleaning the device with an acidic aqueous solution and / or an alkaline aqueous solution, and (C) A step of cleaning the device with ultrapure water having a resistivity of 17 MΩ·cm at 25℃; R p SnX m(1) In chemical formula (1), R is a hydrocarbon group, p is an integer from 1 to 3, X is a hydrolytic substituent, and m = 4-p. Another embodiment of the cleaning method is a cleaning method in which, after step (A), a step of cleaning with alcohol and a drying step are performed, and then steps (B) and (C) are performed. Specific tin compounds The present cleaning method is applied to devices in contact with specific tin compounds. The tin compound of the present invention is of the general formula "R p SnX m It refers to a tin compound expressed as ". In the above chemical formula, "R" is a hydrocarbon group, preferably a hydrocarbon group having 1 to 30 carbon atoms, more preferably a hydrocarbon group having 1 to 15 carbon atoms, more preferably a hydrocarbon group having 1 to 10 carbon atoms, and even more preferably a hydrocarbon group having 2 to 6 carbon atoms. Examples of saturated hydrocarbon groups include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, a 1-methylcyclopentyl group, etc., and examples of unsaturated hydrocarbon groups include a vinyl group, a 2-propenyl group, etc. Examples of aromatic hydrocarbon groups include a phenyl group, a toryl group, a benzyl group, a phenethyl group, etc. In addition, in the above chemical formula, "X" represents a hydrolytic substituent, such as a halogen, an amino group, an alkoxy group (-OR'), an alkinide (R'C≡C), an azide (N3-), a dialkylamino group (-NR'2)(-NR'R"), an N-alkyl-N-alkoxycarbonylamino group (-N(R')C(O)R')(-N(R')C(O)R")(-N(R")C(O)R'), an alkoxycarbonyl group (-OCOR'), an N-alkylcarbamoyl group (-N(H)C(O)R'), etc. R' and R" are each independently hydrocarbon groups having 1 to 10 carbon atoms. Among these, X is preferably a dialkylamino group, an alkoxy group, an N-alkyl-N-alkoxycarbonylamino group, a halogen, or an alkoxycarbonyl group, more preferably a dialkylamino group or an alkoxy group, particularly preferably a dialkylamino group (-NR'2) or an alkoxy group (-OR'). In the above chemical formula, "p" is an integer from 0 to 3, "m" is an integer from 1 to 4, and m = 4-p. Preferably, p is 0 or 1. When p is 0 or 1, three or four hydroxyl groups are introduced as the hydrolyzable group hydrolyzes, and these undergo dehydration condensation to form a compound (stanoxan) having a network structure of Sn-O-Sn bonds, which is difficult to dissolve in general solvents, thus the application of this cleaning method is expected. Among the above tin compounds, a tin compound represented by the following general formula (2) ("monoalkyl tin compound") is particularly preferred. RSnX3(2) In chemical formula (2), R is a hydrocarbon group having 1 to 30 carbon atoms, and X represents a hydrolytic substituent. Examples of compounds represented by chemical formula (2) include t-butyltris(dimethylamino)tin, n-butyltris(dimethylamino)tin, t-butyltris(diethylamino)tin, sec-butyltris(dimethylamino)tin, n-pentyltris(dimethylamino)tin, isobutyltris(dimethylamino)tin, isopropyltris(dimethylamino)tin, t-butyltri-t-butoxytin, n-butyltri-t-butoxytin, isopropyltri-t-butoxytin, isopropyltri-t-amyloxytin, t-butyltri-t-amyloxytin, 1-methyl-1-cyclopentyltris(dimethylamino)tin, 1-methyl-1-cyclopentyltri-t-butoxytin, etc. These may be used alone or in combination of two or more. The molecular weight of the above tin compound is typically 200 to 900. Considering that a specific level of vapor pressure is required when used for CVD, this is preferably 240 to 700, more preferably 260 to 600, and even more preferably 280 to 500. The tin compound may be a single compound or a mixture of two or more types of compounds. When two or more tin compounds are mixed, it is preferable that the difference in molecular weight between the two is 100 or less, as they may volatilize simultaneously during the film formation process by CVD; more preferably, the difference is 50 or less, more preferably 30 or less, and particularly preferably 15 or less. Also, for the same reason, it is preferable that the mixture is a mixture of isomers having the same molecular weight. Device for Tin Compounds The apparatus for tin compounds included in the cleaning method described in this specification includes all equipment or devices capable of coming into contact with tin compounds in all industrial processes, such as the synthesis, purification, and storage (preservation) of tin compounds. Examples of devices for tin compounds include, for example, a synthesis device, a distillation purification device, a filtration device, a container for storage or preservation, and piping connecting the same. The size of the device, particularly the size of the container, is typically 0.1 to 100 L, preferably 0.1 to 30 L and more preferably 0.5 to 10 L from the viewpoint of easily demonstrating the effects of the present invention. These devices and piping are typically manufactured from stainless steel, but may also be formed from nickel-based corrosion-resistant alloys such as Inconel. To improve corrosion resistance inside storage containers and piping, the interiors of containers and piping made of metal materials may be coated with resin materials such as fluoropolymer resins. The above tin compounds react with oxygen and water to produce impurities including stanoxan compounds and low molecular weight tin oxide compounds, which cause scale. To efficiently remove such tin impurities from the device, the present cleaning method includes the following cleaning steps. <Step of washing with an aprotic solvent (A)> In the step of cleaning with an aprotic solvent (aprotic solvent cleaning step) (A), the device is cleaned with an aprotic solvent. Tin compounds attached to the device are dissolved in the aprotic solvent and washed away. Additionally, stanoxan compounds and the like remaining in the device are not dissolved in the aprotic solvent but can be physically washed away in this aprotic solvent cleaning step (A). When X in chemical formula (1) has a highly hydrolytic group such as a dialkylamino group, the stanoxan compound is easily formed, and the cleaning effect of the present invention tends to be obtained more effectively. Suitable aprotic solvents that can be used include aromatic hydrocarbons such as toluene, xylene, benzene, etc.; aliphatic hydrocarbons such as hexane, heptane, octane, cyclohexane, methylcyclohexane, etc.; esters such as ethyl acetate, butyl acetate, butyl propionate, etc.; and ethers such as diethyl ether, diisopropyl ether, methyl tertiary butyl ether, cyclopentyl methyl ether, tetrahydrofuran, 1,4-dioxane, etc. These solvents may be used alone or as a mixture of two or more. The cleaning method is not particularly limited, and any known cleaning method for devices used in the synthesis and preservation of compounds may be appropriately adopted. For example, in the case of a synthesis device, the method may include sending the reaction product to the next step, attaching a recovery line, filling the reaction vessel with an aprotic solvent, and recovering the aprotic solvent from the recovery line. Additionally, the device may be disassembled and then washed, immersed, or wiped with an aprotic solvent. When cleaning by spraying, the cleaning effect can be enhanced by spraying the aprotic solvent together with air, and it is also possible to apply ultrasonic vibrations when filling the device with the solvent or immersing the device in the solvent. It is also possible to combine different cleaning methods. In order to prevent the toxicity and flammability of decomposition products, such as amines, generated during cleaning, the atmosphere during cleaning is preferably an environment with reduced oxygen concentration or an inert gas atmosphere such as nitrogen, argon, or helium. In such an environment, it is preferable to perform cleaning by setting the atmosphere in contact with the cleaning surface, for example, to a nitrogen atmosphere with an oxygen concentration of 0.1 volume% or less that has been passed through a microfilter. The number of cleaning cycles or cycles is not particularly limited, and while it is possible to perform cleaning only once, it is preferably performed 2 to 5 times to obtain a sufficient cleaning effect. The cleaning temperature is also not particularly limited, but is preferably 0 to 70°C, more preferably 0 to 50°C, and even more preferably 10 to 30°C. The amount of aprotic solvent used during cleaning is preferably 0.1 to 10.0 L / m² per unit area of ​​the cleaned surface. 2 , more preferably 0.2 to 5.0 L / m 2 , more preferably 0.2 to 2.0 L / m 2 am. In addition, it is also possible to clean by filling the container with an aprotic solvent, in which case an aprotic solvent with a volume nearly equal to the container capacity is used. A preferred embodiment of the present invention is to perform a step (step (B)) of washing with an acidic aqueous solution or an alkaline aqueous solution without going through a step of washing with alcohol after washing with an aprotic solvent. Aprotic solvents and aqueous solutions have low solubility in each other and are insoluble. Therefore, it is generally considered that after cleaning with an aprotic solvent, a step of cleaning with alcohol as described below is performed once to completely remove the aprotic solvent, and then cleaning with an acidic or alkaline aqueous solution is attempted. However, if tin compounds remain in the container, cleaning the container may become difficult because the tin compounds may hydrolyze, adhere, or scale due to the trace amounts of moisture accompanying the alcohol. Furthermore, when alcohol is used, safety issues arise when attempting cleaning with nitric acid in a subsequent step. For example, a mixture of ethanol and nitric acid is explosive. This is generally caused by gas generation, but ethyl nitrate is also produced. In general, nitric acid esters are explosive, and a solution of ethanol and nitric acid poses a risk of explosion when the nitric acid concentration is 10 mass% or higher. Of course, it is possible to wash with pure water after alcohol cleaning and then wash with nitric acid, or to wash with nitric acid after sufficient drying, but this prolongs the process. <Alcohol cleaning step> In the present invention, it is preferable to perform a step of cleaning with an acidic aqueous solution and / or an alkaline aqueous solution (step (B)) without performing a step of cleaning with alcohol (alcohol cleaning step), but it is also possible to perform an alcohol cleaning step on the premise of adding a drying step or a step of cleaning with pure water after the alcohol cleaning step. The alcohol is not particularly limited and any of aliphatic alcohols, cyclic alcohols, and aromatic alcohols may be used, and either monohydric or polyhydric alcohols may be used. Among these, aliphatic monohydric alcohols are preferred, and suitable alcohols include methanol, ethanol, propanol, isopropanol, n-butanol, isobutanol, sec-butanol, t-butanol, 1-pentanol, 2-pentanol, 3-pentanol, cyclopentanol, 1-hexanol, 2-hexanol, 3-hexanol, 1-heptanol, 2-heptanol, 3-heptanol, 1-octanol, isooctanol, 2-ethylhexanol, isononyl alcohol, lauryl alcohol, etc. The number of carbon atoms in the alcohol is preferably 1 to 12, more preferably 1 to 6, and even more preferably 1 to 3, and methanol is particularly preferred. These alcohols may have substituents such as alkyl groups. These alcohols can be used alone or in combination of two or more. The cleaning method, atmosphere during cleaning, number of cleaning cycles, cleaning temperature, amount of cleaning solution, etc. are the same as in the aprotic solvent cleaning step (A). <Step (B) of cleaning with an acidic aqueous solution and / or an alkaline aqueous solution> As a step (B) of cleaning with an acidic aqueous solution and / or an alkaline aqueous solution, for example, (i) step (B) can be performed sequentially following step (A) without any other steps in between, (ii) step (B) can be performed sequentially after a drying step following step (A), and (iii) step (B) can be performed sequentially after an alcohol cleaning step and a drying step following step (A). Among these, (i) is preferred in terms of process simplification and safety. The above drying step can be performed by referring to the drying step following the ultrapure water washing step described below. Additionally, as a step (B) of cleaning with an acidic aqueous solution and / or an alkaline aqueous solution, at least one of a step of cleaning with an acidic aqueous solution (B-1) and a step of cleaning with an alkaline aqueous solution (B-2) may be used, but it is preferable to use any one of these for the sake of process simplification. [Step of cleaning with acidic aqueous solution (B-1)] In the step of cleaning with an acidic aqueous solution, the device is cleaned with an acidic aqueous solution. In this step (B-1), it is used to dissolve residues that were not dissolved in the aprotic solvent cleaning step (A), for example, to clean by dissolving scale that is deposited in the joints or dents of the device and is soluble in acid. Since the mixing of alcohol and acid can entail a risk of explosion, when cleaning with alcohol, the alcohol must be removed through a drying step before cleaning with an acidic aqueous solution. The acidic aqueous solution is not particularly limited as long as it is an acidic aqueous solution with a pH of less than 6, but preferably has a pH of 5 or lower, more preferably has a pH of 1 or lower. Among these, an aqueous nitric acid solution having oxidizing power is preferred, and a diluted aqueous nitric acid solution that does not form passivation is more preferred. The concentration of nitric acid in the aqueous nitric acid solution is typically 3 to 30 mass%, preferably 5 to 25 mass%, more preferably 8 to 20 mass%. The cleaning method, atmosphere during cleaning, number of cleaning cycles, cleaning temperature, amount of cleaning solution, etc. are the same as in the aprotic solvent cleaning step (A). [Step of cleaning with an alkaline aqueous solution (B-2)] The tin compound supplied to the device of the present embodiment is soluble in both acidic and alkaline aqueous solutions because tin is an amphoteric element. Therefore, it is preferable to perform cleaning with an alkaline aqueous solution instead of, or in addition to, cleaning with an acidic aqueous solution. Depending on the type of scale and impurities generated, some are easily soluble in acid and others are easily soluble in alkali; thus, if there are substances that are not soluble in an acidic aqueous solution, an alkaline aqueous solution is used. As a raw material for the alkaline aqueous solution, substances that generate hydroxide ions in an aqueous solution may be used without special limitations; however, among these, aqueous solutions of oxides or hydroxides of alkali metals and aqueous solutions of oxides or hydroxides of alkaline earth metals are preferably used. The pH of the alkaline aqueous solution is sufficient if it is greater than 7, but preferably 9 or higher, more preferably 11 or higher; however, since exceeding 12 can corrode stainless steel, it is preferably 11.5 or lower. Examples of alkaline aqueous solutions may include sodium hydroxide aqueous solution and potassium hydroxide aqueous solution. Phosphates may also be used as alkaline aqueous solutions, and the alkaline aqueous solution is preferably at least one aqueous solution selected from the group consisting of phosphates, sodium hydroxide, and potassium hydroxide, and it is more preferable for the phosphate to be used together with sodium hydroxide and potassium hydroxide. As phosphates, dipotassium phosphate, tripotassium phosphate, potassium pyrophosphate, monosodium phosphate, disodium phosphate, trisodium phosphate, sodium pyrophosphate, tripotassium phosphate, sodium metaphosphate, etc. are mentioned. These may be used alone or in combination of two or more. The concentration of sodium hydroxide and / or potassium hydroxide in the alkaline aqueous solution is typically 0.5 to 2 mass%, preferably 1 to 1.9 mass%, and when phosphate is included, the concentration of phosphate in the alkaline aqueous solution is typically 5 to 15 mass%, and it is desirable to adjust the pH of the alkaline aqueous solution to 11.5 or lower. In addition, depending on the type of container, some may dissolve in strong alkalis; in such cases, it is possible to use an aqueous solution of an alkali metal salt of a weak acid, such as sodium carbonate, sodium bicarbonate, sodium sulfite, or sodium acetate. A preferred embodiment of the present invention is to perform a step (B) of cleaning with an acidic aqueous solution and / or an alkaline aqueous solution after a step (A) of cleaning with an aprotic solvent. Here, "sequentially" means that no other cleaning step is performed between the step (A) of cleaning with an aprotic solvent and the step (B) of cleaning with an acidic aqueous solution and / or an alkaline aqueous solution. That is, the fact that the two steps are performed sequentially can be understood to mean that they are performed without an intervening cleaning step between them. <Step of cleaning with ultrapure water (C)> The step of cleaning with ultrapure water (ultrapure water cleaning step) (C) is performed after the step of cleaning with an acidic aqueous solution and / or an alkaline aqueous solution (B), and is a step for removing impurities and fine particles remaining in the apparatus. The cleaning solution used in the step of cleaning with ultrapure water (C) is ultrapure water having a resistivity of 17 MΩ·cm at 25°C. Although the theoretical resistivity of pure water is 18.24 MΩ·cm, for the sake of production efficiency, it is preferable that the resistivity of the water used in the method of the present disclosure be 17 MΩ·cm. Resistivity can be measured, for example, with a commercially available electrical conductivity meter. The cleaning method, number of cleaning cycles, cleaning temperature, amount of cleaning solution, etc. are the same as in the aprotic solvent cleaning step (A). It is preferable to perform the cleaning step with ultrapure water in a class 1000-level cleanroom. It is preferable that the step (C) of cleaning with ultrapure water is the final cleaning step. Since stanoxane compounds having Sn-O-Sn bonds are generated by the hydrolysis of tin compounds and tend to solidify under atmospheric pressure, making cleaning difficult, it is preferable to perform the cleaning step under an inert gas atmosphere such as nitrogen, argon, or helium. <Drying Stage> After the ultrapure water cleaning step (C), a drying step for the device for tin compounds may be performed. The drying step may be performed by spraying or injecting an inert gas (such as pure nitrogen) at a chemical clean level. For example, in the case of nitrogen gas, it is performed by continuously replacing the gas in the device with a gas heated to 60°C until the dew point temperature reaches -60°C (7 ppm RH or less) to completely remove moisture. Device for tin compounds after cleaning An embodiment of the present disclosure also includes an apparatus for tin compounds cleaned by the cleaning method described herein. Since the apparatus for tin compounds of one embodiment of the present invention is highly purified, it is preferable to use it as a container for storing high-purity tin compounds after purification. This storage container (not limited to a storage container, but includes any device for a tin compound capable of storing water) has the characteristic that when filled with ultrapure water having a resistivity of 17 MΩ·cm at 25°C, which is used as a cleaning solution in the ultrapure water cleaning step (C), and left at 25°C for 1 hour, the content of metal elements other than tin (e.g., chromium (Cr), iron (Fe), magnesium (Mg), nickel (Ni), sodium (Na), molybdenum (Mo), potassium (K), etc.) is 1.5 mass ppb or less for each. The content of each element is more preferably 1 mass ppb or less, even more preferably 0.3 mass ppb or less, and particularly preferably 0.3 mass ppb or less. That is, the water after being placed in the container is hardly contaminated even after being placed in the container compared to its purity before being placed in the container. In addition, it is desirable that the increase in halogen ions in water be 100 mass ppb or less, and the increase in the number of particles with a particle size of 0.5 μm or more be 100 / mL or less. It is preferable that the increase in halogen ions be 50 mass ppb or less, and more preferable that it be 30 mass ppb or less. It is preferable that the increase in the number of particles with a particle size of 0.5 μm or more be 50 / mL or less, and more preferable that it be 10 / mL or less. In addition, for the metal elements other than tin, it is preferable that the increase in the metal element be 1.0 mass ppb or less for each. The method for quantifying halogen ions and metal elements and the method for measuring the number of particles with a diameter of 0.5 μm or more will be described later in the examples. As the apparatus for tin compounds of the present embodiment is highly purified as described above, even when tin compounds are stored, the tin compounds are not significantly affected by impurities from the equipment, and their purity is not reduced. For example, in the case of the apparatus for tin compounds, when tin compounds are placed in a storage container under an inert gas atmosphere, sealed, and stored at 45°C for 3 months, the decrease in purity of the tin compounds is 0.1 mass% or less. As for the inert gas, examples such as argon, helium, and nitrogen may be mentioned, among which nitrogen is preferred. When the inert gas is nitrogen, since the presence of oxygen and moisture tends to cause a decrease in the purity of the tin compounds, it is desirable to set the oxygen concentration in the nitrogen atmosphere to 1 ppm or less (by volume) and the dew point to -60°C (7 ppm RH or less). If the device for tin compounds is a container, it is desirable for the container for storing high-purity tin compounds after purification to have high sealing properties, for example, in the helium leakage test mentioned above, the amount of helium leakage is typically 5×10 -9 Pa·m 3 / s or less, preferably 1×10 -9 Pa·m 3 / s is less than [Helium Leak Test] It is desirable to perform a leak test after the drying step, and this is done as in (I) and (II) below. (I) After purging the device for tin compounds with helium several times (typically twice, preferably three times) through an air-operated valve, fill the device with helium up to 345 kPa and maintain it for 4 hours to ensure there is no leakage. (II) If the above device is a vessel, completely dry the vessel once under vacuum (vacuum drying), then fill the vessel with helium up to 34.5 kPa and connect a helium detector equipped with a VCR® and KF adapter manufactured by Cosmo Tech Co., Ltd. Check the amount of leakage in the valve seat. For example, leakage in the valve seat can be checked at the connector part of the metal gasket type. There are no specific limitations on the capacity of the container, but 100 mL to 300 L is preferred when considering cases where it is used in conjunction with other devices or transported. [Example] The present invention will be described below with reference to examples, but the present invention is not limited to the following examples without departing from the essence of the invention. Note that in the examples, "%" refers to a mass basis. The quantitative methods for halogen ions, particle counts, and metal elements are as follows; typically, measurements are performed on ultrapure water after filling a container. Additionally, the method for measuring the purity of isopropyltris(dimethylamino)tin is as follows. [Quantitative Method for Halogen Ions] Ion chromatography ("ISC-3000" manufactured by Dionex Corporation) was used. [Method for measuring the number of particles with a size of 0.5 µm or larger] The number of particles with a particle size of 0.5 μm or larger was measured using a laser light scattering particle counter ("AZ-SO2 / LS-200" manufactured by Particle Measuring Systems (PMS) Co., Ltd.). [Method for Quantifying Metal Elements] Quantitative analysis of metal elements was performed using ICP-MS (High-frequency emission mass spectrometer, "Agilent 7700" manufactured by Agilent Technologies). [Purity of Isopropyltris(dimethylamino)tin] Accurately weigh approximately 1g of isopropyltris(dimethylamino)tin, place it in an NMR tube with an inner diameter of 5mm, and 119 Quantitative analysis was performed using Sn-NMR spectra. Note that purity is based on tin atoms (mol%). The apparatus and conditions used are as follows. Measuring device: JNM ECZ-400 (Manufactured by Japan Electron Co., Ltd) <Example 1> First, the following container, ultrapure water, and tin compound were prepared. After placing the tin compound into the container and removing it, the used container was prepared as follows. (courage) Cleaning was performed on a sealable container with a capacity of 1 L. The material of the container is SUS316L. In addition to the valve (1) of the dip tube, which extends to the bottom of the container, the upper part of the container is equipped with two other valves (2 and 3), each of which is a three-way valve. These three three-way valves are each connected to two of the following locations after the container is connected: a gas supply port (nitrogen or noble gas), a cleaning liquid supply port (cleaning liquid of each step (A) to (C)), and a discharge port of the waste cleaning liquid container. (Ultrapure water) Ultrapure water was supplied as electro-deionized water (EDI water) from the "Arium®", a small ultrapure water production unit manufactured by Sartorius. (Tin compound) Isopropyltris(dimethylamino)tin (purity 99.8 mol%) was prepared. (Contact between tin compound and container) The above-mentioned cleaned container was prepared, and nitrogen heated to about 60°C was flowed through it until the dew point temperature was -60°C or lower, and it was dried for at least 8 hours. Isopropyltris(dimethylamino)tin was filled into the container in a clean room and left for 24 hours, after which the isopropyltris(dimethylamino)tin was removed from the container. -Device Cleaning- [Wash with aprotic solvent (1st)] n-heptane was prepared. Then, in a simple glove box with an oxygen concentration of 1 ppm or less, n-heptane was injected from valves (2 and 3), and after confirming that the waste liquid container overflowed from valve (1) (i.e., the container was filled with n-heptane), the injection was stopped. Next, the valve (1) was switched to flow toward the waste liquid container, and the valves (2 and 3) were switched to the gas supply direction, and while supplying nitrogen gas from the valves (2 and 3), n-heptane was disposed of through the valve (1) into the waste liquid container. [Wash with aprotic solvent (re-wash)] This step was repeated twice using about 1.2 L of n-heptane per cycle, and after emptying the container, the valve (1) of the dip tube was switched to the solvent supply side and the valves (2 and 3) were switched to the waste liquid container side. [Clean with acidic solution (1st)] A 10% aqueous nitric acid solution (pH 0) was prepared using electrolyzed deionized water and concentrated nitric acid. The 10% aqueous nitric acid solution was injected through the dip tube valve (1), and the solution was continuously injected through valves (2 and 3) until it overflowed. Afterward, the direction of the dip tube valve (1) was switched toward the waste liquid container side, and valves (2 and 3) were switched toward the gas supply side. While supplying nitrogen gas from valves (2 and 3), the entire amount of the 10% aqueous nitric acid solution was discharged into the waste liquid container through valve (1). [Wash with acidic solution (re-wash)] The cleaning cycle using the above 10% nitric acid aqueous solution was repeated twice with approximately 1.2 L of 10% nitric acid aqueous solution per cycle. When the container was emptied, the direction of the dip tube valve (1) was switched to the solvent receiving direction, and the valves (2 and 3) were switched to the waste liquid container side. [Clean with ultrapure water] Ultrapure water (electrolyzed deionized water) was injected through the dip tube valve (1) and discharged through the valves (2 and 3). The purity of the discharged electro-deionized water was measured using a resistivity meter. The electro-deionized water was continuously flowed until the resistivity reached at least 17.0 MΩ·cm. Typically, 8 to 10 L of electro-deionized water was flowed. The deep tube valve (1) was switched to the waste liquid container side, the valves (2 and 3) were switched to the gas supply side, and nitrogen was injected into the valves (2 and 3) to discharge the entire amount of electrolyzed water into the waste liquid container through the valve (1). [Borescope Visual Inspection] Inside the cleanroom, a borescope was inserted from each valve of the vessel to check for solid residues adhering to the surface. If solid residues were observed, the nitric acid cleaning step was repeated until it passed the visual inspection. In this embodiment, no solid residues were observed. [Drying stage] When the visual inspection is passed, the dip tube valve (1) is connected to the heated nitrogen supply side, and the valves (2 and 3) are connected in a manner that allows for venting through the dew point meter. Nitrogen at 60°C was supplied from the valve (1) and flowed until the dew point was -60°C or lower. Normally, nitrogen was flowed continuously for at least 8 hours. [Measurement Results] (Quantitative analysis of metal elements) After completing cleaning and other processes, quantitative analysis of metal elements was performed on the ultrapure water filled in the container, and the results are shown in Table 1 below. In Table 1 below, the content of metal elements was all less than 1.5 mass ppb. In addition, when the inside of the container was observed with a borescope, no precipitates were observed. (Helium leak measurement) After cleaning and drying the tin compound storage container, the following experiment was performed in a clean zone to verify airtightness. Helium was filled into the container through an air-operated valve, and the helium purge operation was performed three times. Afterward, helium was filled until it reached 345 kPa. It was then confirmed that there was no leakage for 4 hours. After completely drying the tin compound storage container by vacuum suction at 60°C for 24 hours, it was returned to 25°C, vacuum suction was performed, and helium was introduced until it reached 34.5 kPa. The leakage amount from the VCR (valve seat) was measured using a helium detector connected to a VCR® manufactured by Cosmo Tech and a KF adapter, and the result was 5×10 -10 Pa·m 3 / s was. (Purity of tin compounds after storage) When isopropyltris(dimethylamino)tin was placed in the above-mentioned device for tin compounds, sealed under an inert gas atmosphere (argon), and stored at 25°C for one month, the purity measurement results of the above-mentioned isopropyltris(dimethylamino)tin showed that the decrease in purity of the tin compound was about 0.01 mass%, and it was confirmed that the purity was hardly reduced. [Example 2] Isopropyltris(dimethylamino)tin (purity 99.8 mol%) was prepared. As a storage container for this, a 1000 mL container made of SUS316L material was prepared. Isopropyltris(dimethylamino)tin was filled into the storage container in a glove box under a nitrogen atmosphere and left for 24 hours, after which the isopropyltris(dimethylamino)tin was removed from the container and the container was dried. [Cleaning with aprotic solvent] n-heptane was prepared, and the storage container was rinsed and cleaned in a simple glove box under a nitrogen atmosphere with an oxygen concentration of 1 ppm or less, and an aprotic solvent washing step was performed. Rinsing was performed three times with 400 mL. [Clean with alcohol] Methanol with a moisture content of 10 ppm or less was prepared, and the storage container was rinsed and cleaned in a simple glove box under a nitrogen atmosphere, followed by an alcohol cleaning step. Rinsing was performed three times with 400 mL. [dry] A drying step was performed by spraying and injecting pure nitrogen gas of a chemical clean level heated to 60℃. [Clean with acidic solution] A 10% aqueous nitric acid solution was prepared as the acidic aqueous solution, and the storage container was rinsed and cleaned in a simple glove box under a nitrogen atmosphere with an oxygen concentration of 0.1 volume% or less, and the acidic aqueous solution cleaning step was performed. Rinsing was performed twice with 400 mL. [Clean with ultrapure water] Ultrapure water (resistivity at 25°C: 17 MΩ·cm or higher) was prepared, and the storage container was rinsed and cleaned in a simple glove box under a nitrogen atmosphere, and an ultrapure water washing step was performed. Rinsing was performed three times with 400 mL. [Measurement Results] (Quantitative analysis of halogen ions and measurement of particle count) Ultrapure water (resistivity at 25°C: 17 MΩ·cm or higher) was filled into a storage container that had undergone cleaning and other processes, sealed, and left at 25°C for 1 hour. Quantitative analysis of halogen ions and measurement of particle counts were performed on the filled ultrapure water. As a result, compared to ultrapure water before charging, the increase in halogen ions was 50 mass ppb, and the increase in particles larger than 0.5 μm was 30 / mL. (Quantitative analysis of metal elements) Quantitative analysis of metal elements was performed on the charged ultrapure water, and the results are shown in Table 2 below. In Table 2 below, the content of metal elements was all less than 1.5 mass ppb. In addition, when the inside of the container was observed with a borescope, no precipitates were observed. (Helium leak measurement) After cleaning and drying the tin compound storage container, the following experiment was performed in a clean zone to verify airtightness. Helium was filled into the container through an air-operated valve, and the helium purge operation was performed three times. Afterward, helium was filled until it reached 345 kPa. It was then confirmed that there was no leakage for 4 hours. After completely drying the tin compound storage container by vacuum suction at 60°C for 24 hours, it was returned to 25°C, vacuum suction was performed, and helium was introduced until it reached 34.5 kPa. The leakage amount from the VCR (valve seat) was measured using a helium detector connected to a VCR® manufactured by Cosmo Tech and a KF adapter, and the result was 5×10 -10 Pa·m 3 / s was. Since there is a possibility that explosive nitric acid esters may be formed when alcohol reacts with nitric acid, it should be noted that when cleaning with nitric acid after alcohol cleaning, the alcohol must be thoroughly dried or sufficiently removed with ultrapure water or the like before proceeding. (Purity of tin compounds after storage) When isopropyltris(dimethylamino)tin was placed in the above-mentioned device for tin compounds, sealed under an inert gas atmosphere (argon), and stored at 25°C for one month, the purity measurement results of the above-mentioned isopropyltris(dimethylamino)tin showed that the decrease in purity of the tin compound was about 0.01 mass%, and it was confirmed that the purity was hardly reduced. [Example 3] Isopropyltris(dimethylamino)tin (purity 99.8 mol%) was prepared. As a storage container for this, a 1000 mL container made of SUS316L material was prepared. Isopropyltris(dimethylamino)tin was filled into the storage container in a glove box under a nitrogen atmosphere and left for 24 hours, after which the isopropyltris(dimethylamino)tin was removed from the container and the container was dried. [Cleaning with aprotic solvent] n-heptane was prepared, and the storage container was rinsed and cleaned in a simple glove box under a nitrogen atmosphere with an oxygen concentration of 0.1 volume% or less, and an aprotic solvent washing step was performed. Rinsing was performed three times with 400 mL. [dry] A drying step was performed by spraying and injecting pure nitrogen gas of a chemical clean level heated to 60℃. [Clean with alkaline aqueous solution] A 1.8% sodium hydroxide aqueous solution (pH 13.7) was prepared as an alkaline aqueous solution, and the storage container was rinsed and cleaned in a simple glove box under a nitrogen atmosphere with an oxygen concentration of 0.1 volume% or less, and the alkaline aqueous solution cleaning step was performed. Rinsing was performed three times with 400 mL each time. [Clean with ultrapure water] Ultrapure water (resistivity at 25°C: 17 MΩ·cm) was prepared, and the storage container was rinsed and cleaned in a simple glove box under a nitrogen atmosphere, and an ultrapure water washing step was performed. Rinsing was performed three times with 400 mL each time. [Measurement Results] (Quantitative analysis of halogen ions and measurement of particle count) Ultrapure water (resistivity at 25°C: 17 MΩ·cm) was filled into a storage container that had undergone cleaning and other processes, sealed, and left at 25°C for 1 hour. Quantitative analysis of halogen ions and measurement of particle counts were performed on the filled ultrapure water. As a result, compared to ultrapure water before charging, the increase in halogen ions was 24 mass ppb, and the increase in particles larger than 0.5 μm was 3 / mL. (Quantitative analysis of metal elements) Metal elements in the charged ultrapure water were quantified using ICP-MS, and the results are shown in Table 3 below. In Table 3 below, the content of metal elements was all less than 1.5 mass ppb. In addition, when the inside of the container was observed with a borescope, no yellow precipitate was observed. (Helium leak measurement) After cleaning and drying the tin compound storage container, the following experiment was performed in a clean zone to verify airtightness. Helium was filled into the container through an air-operated valve, and the helium purge operation was performed three times. Afterward, helium was filled until it reached 345 kPa. It was then confirmed that there was no leakage for 4 hours. After completely drying the tin compound storage container by vacuum suction at 60°C for 24 hours, it was returned to 25°C, vacuum suction was performed, and helium was introduced until it reached 34.5 kPa. The leakage amount from the VCR (valve seat) was measured using a helium detector connected to a VCR® manufactured by Cosmo Tech and a KF adapter, and the result was 5×10 -10 Pa·m 3 / s was. (Purity of tin compounds after storage) When isopropyltris(dimethylamino)tin was placed in the above-mentioned apparatus for tin compounds, sealed under an inert gas atmosphere (nitrogen), and stored at 25°C for one month, the purity measurement results of the above-mentioned isopropyltris(dimethylamino)tin showed that the decrease in purity of the tin compound was about 0.01 mass%, and it was confirmed that the purity was hardly reduced. <Comparative Example 1: Acid washing → Pure water washing → Alkaline washing → Pure water washing → Drying> Isopropyltris(dimethylamino)tin (purity 99.8 mol%) was prepared. As a storage container for this, a 1000 mL container made of SUS316L material was prepared. Isopropyltris(dimethylamino)tin was filled into the storage container and left for 24 hours inside a glove box under a nitrogen atmosphere, after which the isopropyltris(dimethylamino)tin was removed from the container and the container was dried. [Clean with acidic solution] A 10% aqueous nitric acid solution was prepared as the acidic aqueous solution, and the storage container was rinsed and cleaned in a simple glove box under a nitrogen atmosphere with an oxygen concentration of 0.1 volume% or less, and the acidic aqueous solution cleaning step was performed. The rinsing was performed once with 400 mL. The rinsing was performed only once because brown gas (nitrogen oxides) was generated and a precipitate was formed when the 10% aqueous nitric acid solution was first injected. [Clean with ultrapure water] Ultrapure water (resistivity at 25°C: 17 MΩ·cm) was prepared, and the storage container was rinsed and cleaned in a simple glove box under a nitrogen atmosphere, and an ultrapure water washing step was performed. Rinsing was performed three times with 400 mL each time. [Clean with alkaline aqueous solution] A 1.8% sodium hydroxide aqueous solution was prepared as an alkaline aqueous solution, and the storage container was rinsed and cleaned in a simple glove box under a nitrogen atmosphere with an oxygen concentration of 0.1 volume% or less, and the alkaline aqueous solution cleaning step was performed. Rinsing was performed three times with 400 mL each time. [Clean with ultrapure water] Ultrapure water (resistivity at 25°C: 17 MΩ·cm) was prepared, and the storage container was rinsed and cleaned in a simple glove box under a nitrogen atmosphere, and an ultrapure water washing step was performed. Rinsing was performed three times with 400 mL each time. [dry] A drying step was performed by spraying and injecting pure nitrogen gas of a chemical clean level heated to 60℃. [Measurement Results] A storage container that had undergone cleaning and other processes was used, and the interior was inspected using a borescope, revealing fine sediment. Since sediment was observed during visual inspection, it is evident that satisfactory cleaning was not achieved, even without performing other measurements. <Example 4> First, a container, ultrapure water, and a tin compound were prepared in the same manner as in Example 1, and the container was prepared after the tin compound was placed in and removed from the container. -Device Cleaning- [Wash with aprotic solvent (1st)] n-hexane was prepared. Subsequently, n-hexane was injected through valves (2 and 3) inside a simple glove box with an oxygen concentration of 1 ppm or less, and flow was confirmed in the transparent tube connected to valve (1) (i.e., confirmed that n-hexane was filled in the container), and the injection was stopped. Afterwards, the valve (1) was switched to flow toward the waste liquid container, the valves (2 and 3) were switched to the gas supply direction, and while supplying nitrogen gas from the valves (2 and 3), n-hexane was disposed of through the valve (1) into the waste liquid container. [Wash with aprotic solvent (re-wash)] This step was repeated twice using about 1.2 L of n-hexane per cycle, and after emptying the container, the valve (1) of the dip tube was switched to the solvent supply side and the valves (2 and 3) were switched to the waste liquid container side. [Clean with acidic solution (1st)] A 20% aqueous nitric acid solution (pH 0) was prepared using electrolyzed deionized water and concentrated nitric acid. The 20% aqueous nitric acid solution was injected through the dip tube valve (1), and the solution was continuously injected through valves (2 and 3) until it overflowed. Subsequently, the direction of the dip tube valve (1) was switched toward the waste liquid container side, and valves (2 and 3) were switched toward the gas supply side. While supplying nitrogen gas from valves (2 and 3), the entire amount of the 20% aqueous nitric acid solution was discharged into the waste liquid container through valve (1). [Wash with acidic solution (re-wash)] The cleaning cycle using the above 20% nitric acid aqueous solution was repeated twice with approximately 1.2 L of 20% nitric acid aqueous solution per cycle. When the container was emptied, the direction of the dip tube valve (1) was switched to the solvent receiving direction, and the valves (2 and 3) were switched to the waste liquid container side. [Clean with ultrapure water] Ultrapure water (electrolyzed deionized water) was injected through the dip tube valve (1) and discharged through the valves (2 and 3). The purity of the discharged electro-deionized water was measured using a resistivity meter. The electro-deionized water was continuously flowed until the resistivity reached at least 17.0 MΩ·cm. Typically, 8 to 10 L of electro-deionized water was flowed. The deep tube valve (1) was switched to the waste liquid container side, the valves (2 and 3) were switched to the gas supply side, and nitrogen was injected into the valves (2 and 3) to discharge the entire amount of electrolyzed water into the waste liquid container through the valve (1). [Borescope Visual Inspection] Inside the cleanroom, a borescope was inserted from each valve of the vessel to check for solid residues adhering to the surface. If solid residues were observed, the nitric acid cleaning step was repeated until it passed the visual inspection. In this embodiment, no solid residues were observed. This cleaning method enables the efficient and high-level purification of equipment for tin compounds after synthesis or storage, thereby making it possible to suppress the incorporation or generation of impurities and fine particles during subsequent synthesis or storage of tin compounds. Tin compounds synthesized or stored using equipment highly purified by this cleaning method are suitable for use as raw materials for semiconductors and other applications. In the above embodiments, specific embodiments of the present invention have been presented, but such embodiments are merely illustrative and are not intended to limit the invention. Various modifications obvious to those skilled in the art are intended to be included within the scope of the present invention.

Claims

Claim 1 A method for cleaning an apparatus in contact with a tin compound having chemical formula (1), wherein the method comprises at least steps (A) to (C), wherein step (B) is performed after step (A) and step (C) is performed after step (B); (A) a step of cleaning the apparatus with an aprotic solvent; (B) a step of cleaning the apparatus with an acidic aqueous solution and / or an alkaline aqueous solution; and (C) a step of cleaning the apparatus with ultrapure water having a resistivity of 17 MΩ·cm at 25°C; R p SnX m (1) Here, R is a hydrocarbon group, p is an integer from 0 to 3, X is a hydrolytic substituent, and m = 4-p. Claim 2 A method for cleaning a device according to claim 1, wherein step (B) is performed sequentially after step (A) without any other intervening cleaning step. Claim 3 A method for cleaning a device for tin compounds according to claim 1, further comprising, after step (A), performing a drying step and then sequentially performing step (B). Claim 4 A method for cleaning a device for tin compounds according to claim 1, wherein, after step (A), a step of cleaning with alcohol and a drying step are performed, and then step (B) is performed sequentially. Claim 5 A method for cleaning a device for tin compounds according to claim 1, wherein the aprotic solvent comprises at least one solvent selected from the group consisting of aromatic hydrocarbons, aliphatic hydrocarbons, esters, and ethers. Claim 6 A method for cleaning a device for tin compounds according to claim 1, wherein the acidic aqueous solution is an aqueous nitric acid solution having a concentration of 3 to 30 mass%. Claim 7 A method for cleaning a device for tin compounds according to claim 1, wherein the pH of the alkaline aqueous solution is 11.5 or lower. Claim 8 A method for cleaning a device for tin compounds according to claim 1, wherein the alkaline aqueous solution is at least one solution selected from the group consisting of a phosphate solution, a sodium hydroxide solution, and a potassium hydroxide solution. Claim 9 A method for cleaning a device for tin compounds according to claim 8, wherein the concentration of sodium hydroxide and / or potassium hydroxide is 0.5 to 2 mass%. Claim 10 A method for cleaning a device for tin compounds according to claim 1, further comprising the step of performing a drying step after step (C). Claim 11 A method for cleaning a device for tin compounds according to claim 1, wherein the value of p in chemical formula (1) is 0 or 1. Claim 12 In claim 1, the tin compound having chemical formula (1) is t-butyltris(dimethylamino)tin, n-butyltris(dimethylamino)tin, t-butyltris(diethylamino)tin, di-t-butylbis(dimethylamino)tin, sec-butyltris(dimethylamino)tin, n-pentyltris(dimethylamino)tin, isobutyltris(dimethylamino)tin, isopropyltris(dimethylamino)tin, t-butyltri-t-butoxytin, n-butyltri-t-butoxytin, isopropyltri-t-butoxytin, isopropyltri-t-amyloxytin, t-butyltri-t-amyloxytin, tetra-t-butoxytin, tetrakis(dimethylamino)tin, 1-methyl-1-cyclopentyltris(dimethylamino)tin, and A method for cleaning a device for a tin compound, comprising at least one selected from the group consisting of 1-methyl-1-cyclopentyltri-t-butoxytin. Claim 13 An apparatus for tin compounds that is in contact with a tin compound having chemical formula (1) and cleaned by the cleaning method according to claim 1. Claim 14 In paragraph 13, a device for tin compounds, which is a container for storing tin compounds. Claim 15 An apparatus for tin compounds according to claim 13, wherein ultrapure water having a resistivity of 17 MΩ·cm at 25°C is filled into the apparatus and, when left at 25°C for 1 hour, the content of each metal element sodium, potassium, magnesium, iron, chromium, and nickel is 1.5 mass ppb or less. Claim 16 An apparatus for tin compounds according to claim 13, wherein ultrapure water having a resistivity of 17 MΩ·cm at 25°C is filled into the apparatus and, when left at 25°C for 1 hour, the increase in the concentration of halogen ions in the water is 100 mass ppb or less and the increase in the number of particles having a diameter of 0.5 μm or more is 100 particles / mL or less. Claim 17 A device for a tin compound according to claim 13, wherein a tin compound having chemical formula (1) is placed in the device, sealed under an inert gas atmosphere, and stored at 25°C for 1 month, and the reduction in purity of the tin compound is 0.1 mass% or less. Claim 18 In paragraph 13, when the device is vacuum dried and then filled with helium at 34.5 kPa, the amount of helium leaking from the joint portion measured by the helium detector is 5×10 -9 Pa·m 3 Device for tin compounds, with / s or less. Claim 19 In paragraph 15, a device for tin compounds, which is a container for storing tin compounds. Claim 20 A method for forming a pattern for a semiconductor, comprising the steps of: using a device in contact with a tin compound having the chemical formula (1) to deposit a tin compound having the chemical formula (1) on a substrate to obtain a thin film; exposing the thin film to radiation; and developing the exposed thin film, wherein the device is a tin compound storage container in which ultrapure water having a resistivity of 17 MΩ·cm at 25°C is filled and, when left at 25°C for 1 hour, the content of each metal element sodium, potassium, magnesium, iron, chromium, and nickel is 1.5 mass ppb or less. R p SnX m (1) Here, R is a hydrocarbon group, p is an integer from 1 to 3, X is a hydrolytic substituent, and m = 4-p.

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