Compositions and containers containing compositions

Abstract

A composition comprising octafluorocyclobutane, and comprising at least one of iodine and an iodine-containing perfluoroalkyl compound, the content of the aforementioned iodine and iodine-containing perfluoroalkyl compound being 1,000 mol ppm or less relative to the total molar amount of the composition.

Description

Technical Field

[0001] This disclosure relates to compositions and containers containing compositions. Background Technology

[0002] Etching is a method used in semiconductor manufacturing processes to process a desired surface shape by removing unwanted thin film portions from a semiconductor substrate. For example, Patent Document 1 discloses the use of octafluorocyclobutane to etch interlayer insulating films on a semiconductor substrate.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2001-267294 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] However, according to the Fifth Intergovernmental Panel on Climate Change (IPCC) report, octafluorocyclobutane has a global warming potential (GWP) of 9,540, resulting in a significant environmental impact upon leakage. Furthermore, octafluorocyclobutane is a colorless and odorless gas at 25°C and 1 atmosphere, making leaks difficult to detect. It should be noted that the fragrances or colorants commonly used to detect leaks can degrade the etching performance.

[0008] This disclosure is made in view of the above circumstances, and relates to providing compositions with excellent etching performance and easily noticeable leaks, and containers containing the compositions.

[0009] Solution for solving the problem

[0010] This disclosure includes the following methods.

[0011] <1> A composition comprising octafluorocyclobutane and at least one of iodine and an iodine-containing perfluoroalkyl compound.

[0012] The content of at least one of the aforementioned iodine and iodine-containing perfluoroalkyl compounds is less than 1,000 mol ppm relative to the total molar amount of the composition.

[0013] <2> according to <1> The composition wherein the content of at least one of the aforementioned iodine and iodine-containing perfluoroalkyl compounds is 10 mol ppm or more relative to the total molar amount of the composition.

[0014] <3> according to <1> or <2> The composition wherein the aforementioned iodine-containing perfluoroalkyl compound is at least one selected from the group consisting of 1,2-diiodoperfluoroethane, 1,4-diiodoperfluorobutane, 1,6-diiodoperfluorohexane, 1,8-diiodoperfluorooctane, 1-iodoperfluoroethane, 1-iodoperfluoropropane, 1-iodoperfluorobutane, 2-iodoperfluoropropane, 1-iodoperfluoropentane, 1-iodoperfluorohexane, 1-iodoperfluoroheptane, and 1-iodoperfluorooctane.

[0015] <4> according to <1> ~ <3> The composition according to any one of the following methods, wherein the content of the aforementioned iodine-containing perfluoroalkyl compound is less than 500 mol ppm relative to the total molar amount of the composition.

[0016] <5> according to <1> ~ <4> The composition described in any one of the following examples further comprises water.

[0017] <6> according to <5> The composition wherein the content of the aforementioned water is less than 1,000 mol ppm relative to the total molar amount of the composition.

[0018] <7> according to <1> ~ <6> The composition described in any one of the following is used in etching, refrigerant, heat transfer medium, foaming agent or resin monomer.

[0019] <8> A container containing a composition, comprising: a container and a filling thereof. <1> ~ <7> The composition described in any one of the following statements.

[0020] <9> according to <8> The container containing the composition, wherein the container is made of stainless steel, chromium-molybdenum steel, or carbon steel.

[0021] The effects of the invention

[0022] According to this disclosure, compositions with excellent etching performance and easy-to-detect leaks, as well as containers containing the compositions, can be provided. Detailed Implementation

[0023] The following describes one embodiment of the present disclosure in detail. However, the present disclosure is not limited to the following embodiment. In the following disclosure, its constituent elements (including element steps, etc.) are not essential unless specifically stated otherwise. The same applies to numerical values ​​and their ranges; the present disclosure is not limited thereto.

[0024] In this disclosure, the numerical range represented by "~" includes the values ​​recorded before and after "~" as the lower limit and upper limit, respectively.

[0025] In the numerical ranges described in this disclosure, the upper or lower limit of a numerical range can be replaced by the upper or lower limit of other numerical ranges described in different stages. Furthermore, the upper or lower limit of a numerical range described in this disclosure can be replaced by the values ​​shown in the embodiments. The upper and lower limits can be arbitrarily combined to form a numerical range, provided they do not contradict each other.

[0026] In this disclosure, when a composition contains multiple substances equivalent to each component, unless otherwise specified, the content or percentage of each component in the composition refers to the total content or percentage of the multiple substances present in the composition.

[0027] In this disclosure, when using "or" or "or" to list multiple elements, multiple elements can be selected in combination, unless otherwise expressly stated, as long as there is no technical contradiction.

[0028] In this disclosure, even when elements are expressed in a singular form, the existence of multiple elements is not excluded unless otherwise expressly stated, provided that no technical contradiction arises.

[0029] In this disclosure, multiple examples described individually can be combined to form new methods as long as they do not contradict each other.

[0030] Composition

[0031] The compositions disclosed herein comprise octafluorocyclobutane and at least one of iodine and iodine-containing perfluoroalkyl compounds.

[0032] The content of at least one of the aforementioned iodine and iodine-containing perfluoroalkyl compounds is less than 1,000 mol ppm relative to the total molar amount of the composition.

[0033] The compositions disclosed herein are compositions with excellent etching performance and easy-to-notice leaks.

[0034] The iodine and iodine-containing perfluoroalkyl compounds contained in the compositions of this disclosure are both light brown to brown, thus allowing for visual confirmation of leaks in the composition. On the other hand, iodine and iodine-containing perfluoroalkyl compounds tend to degrade etching performance. Therefore, in order to achieve excellent etching performance and facilitate easy detection of leaks, the compositions of this disclosure contain at least a certain amount of iodine and at least one of the iodine-containing perfluoroalkyl compounds. It should be noted that this disclosure is not limited to the above-described mechanisms.

[0035] Octafluorocyclobutane

[0036] The compositions disclosed herein contain octafluorocyclobutane (hereinafter also referred to as "C-318").

[0037] From the viewpoint that leakage is easily noticeable, the content of C-318 relative to the total molar amount of the composition disclosed herein is preferably less than 100,000 mol%, more preferably 99.999 mol% or less, and even more preferably 99.990 mol% or less.

[0038] From the viewpoint of etching performance, the content of C-318 relative to the total molar amount of the composition disclosed herein is preferably 98.000 mol% or more, more preferably 99.000 mol% or more, further preferably 99.900 mol% or more, particularly preferably 99.990 mol% or more, and most preferably 99.999 mol% or more.

[0039] In this disclosure, the content of C-318 in the composition is determined using a gas chromatograph under the following determination conditions.

[0040] Main unit: 7890GC (manufactured by Agilent Technologies Inc.)

[0041] Detector: Flame Ionization Detector (FID)

[0042] Column: DB-1301 (manufactured by Agilent Technologies Inc.)

[0043] There are no particular restrictions on how C-318s can be obtained. They can be commercially available C-318s or C-318s manufactured using known methods.

[0044] Specifically, one method for manufacturing C-318 is described in International Publication No. 2023 / 282241. According to this method, in the process of manufacturing hexafluoropropylene from tetrafluoroethylene, a mixture of C-318 and octafluorobutene is obtained as a byproduct. Then, after hydrogenating the octafluorobutene to generate C-318, the composition containing C-318 and octafluorobutane is distilled to obtain high-purity C-318.

[0045] Another method for manufacturing C-318 is the one described in Japanese Patent Application Publication No. 2004-168753. According to this method, C-318 is obtained as a byproduct in the process of producing α,ω-diiodoperfluoroalkane by reacting 1,2-diiodoperfluoroethane with tetrafluoroethylene.

[0046] In addition to the methods mentioned above, the following methods can also be cited as manufacturing methods for the C-318.

[0047] Specifically, 1,2-diiodoperfluoroethane was heated to 230°C and reacted for 10 hours, then cooled to 40°C, the gas phase was recovered and distilled to obtain high-purity C-318.

[0048] <At least one of iodine and iodine-containing perfluoroalkyl compounds>

[0049] The compositions disclosed herein comprise at least one of iodine and an iodine-containing perfluoroalkyl compound.

[0050] The compositions disclosed herein may contain only iodine and either an iodine-containing perfluoroalkyl compound. Preferably, the compositions disclosed herein contain C-318 and iodine, and do not contain an iodine-containing perfluoroalkyl compound. The compositions disclosed herein may also contain C-318 and an iodine-containing perfluoroalkyl compound, and do not contain iodine.

[0051] The compositions disclosed herein may contain both iodine and iodine-containing perfluoroalkyl compounds.

[0052] When the composition disclosed herein comprises both iodine and an iodine-containing perfluoroalkyl compound, the molar ratio of iodine to the iodine-containing perfluoroalkyl compound is not particularly limited, but from the viewpoint that leakage is easily noticeable, it is preferably 3 / 1 or more, more preferably 5 / 1 or more, and even more preferably 10 / 1 or more. From the viewpoint of corrosion inhibition, the molar ratio of iodine to the iodine-containing perfluoroalkyl compound is preferably 10 / 1 or less, more preferably 5 / 1 or less, and even more preferably 3 / 1 or less.

[0053] In the compositions disclosed herein, the content of at least one of iodine and iodine-containing perfluoroalkyl compounds is 1,000 mol ppm or less relative to the total molar amount of the composition. From the viewpoint of excellent etching performance, the content of at least one of iodine and iodine-containing perfluoroalkyl compounds in the compositions disclosed herein is preferably 900 mol ppm or less relative to the total molar amount of the composition, more preferably 700 mol ppm or less, and even more preferably 500 mol ppm or less.

[0054] When the composition disclosed herein contains both iodine and an iodine-containing perfluoroalkyl compound, the total content of iodine and the iodine-containing perfluoroalkyl compound in the composition is preferably 1,000 mol ppm or less, more preferably 900 mol ppm or less, even more preferably 700 mol ppm or less, and particularly preferably 500 mol ppm or less.

[0055] From the viewpoint that leakage is easily noticeable, the content of at least one of iodine and iodine-containing perfluoroalkyl compounds in the compositions disclosed herein is preferably 10 mol ppm or more, more preferably 100 mol ppm or more, further preferably 300 mol ppm or more, and particularly preferably 500 mol ppm or more.

[0056] When the composition disclosed herein contains both iodine and an iodine-containing perfluoroalkyl compound, the total content of iodine and the iodine-containing perfluoroalkyl compound in the composition is preferably 10 mol ppm or more, more preferably 100 mol ppm or more, even more preferably 300 mol ppm or more, and particularly preferably 500 mol ppm or more.

[0057] In this disclosure, the total content of iodine and iodine-containing perfluoroalkyl compounds in the composition is determined by the sum of the content of iodine in the composition and the content of iodine-containing perfluoroalkyl compounds in the composition, as described later.

[0058] (iodine)

[0059] In the compositions disclosed herein, from the viewpoint of etching performance and inhibiting corrosion of the container filled with the composition, the iodine content relative to the total molar amount of the composition is preferably 1,000 mol ppm or less, more preferably 900 mol ppm or less, further preferably 700 mol ppm or less, and particularly preferably 500 mol ppm or less.

[0060] From the viewpoint that leakage is easily noticeable, the iodine content relative to the total molar amount of the composition is preferably 100 mol ppm or more, more preferably 300 mol ppm or more, and even more preferably 500 mol ppm or more.

[0061] In this disclosure, the iodine content in the composition is determined by ion chromatography analysis of the absorbent obtained by absorbing the test sample into an aqueous solution of sodium thiosulfate under the following test conditions.

[0062] Measurement equipment: ICS-5000 (manufactured by Thermo Fisher Scientific)

[0063] Column: AS11-HC (Made by Thermo Fisher Scientific)

[0064] (Iodine-containing perfluoroalkyl compounds)

[0065] In this disclosure, iodine-containing perfluoroalkyl compounds refer to perfluoroalkyl compounds in which one or more hydrogen atoms are replaced by iodine atoms.

[0066] There are no particular limitations on the types and number of iodine-containing perfluoroalkyl compounds. The number of types of iodine-containing perfluoroalkyl compounds contained in the compositions disclosed herein can be 0 or more, 1 or more, 2 or more, 3 or more, 4 or more, 5 or more, 7 or more, or 10 or more. The aforementioned number of types can be less than 10, less than 7, less than 5, less than 4, less than 3, less than 2, or less than 1.

[0067] Iodine-containing perfluoroalkyl compounds can be either straight-chain or branched.

[0068] The molecular weight of the iodine-containing perfluoroalkyl compound can be 200 or higher, 300 or higher, or 400 or higher; from the viewpoint of ease of handling, 200 or higher is preferred. The molecular weight of the iodine-containing perfluoroalkyl compound can be 500 or lower, 450 or lower, or 400 or lower; from the viewpoint of easy detection of leaks, 400 or lower is preferred. That is, if the molecular weight of the iodine-containing perfluoroalkyl compound is too high, the boiling point becomes high, making it difficult to vaporize, and thus leaks are not easily detected.

[0069] The iodine-containing perfluoroalkyl compound is preferably at least one selected from the group consisting of 1,2-diiodoperfluoroethane, 1,4-diiodoperfluorobutane, 1,6-diiodoperfluorohexane, 1,8-diiodoperfluorooctane, 1-iodoperfluoroethane, 1-iodoperfluoropropane, 1-iodoperfluorobutane, 2-iodoperfluoropropane, 1-iodoperfluoropentane, 1-iodoperfluorohexane, 1-iodoperfluoroheptane, and 1-iodoperfluorooctane, more preferably at least one selected from 1,2-diiodoperfluoroethane and 1,4-diiodoperfluorobutane, and even more preferably 1,2-diiodoperfluoroethane.

[0070] Iodine-containing perfluoroalkyl compounds are preferably diiodoperfluoroalkyl compounds.

[0071] In the compositions disclosed herein, from the viewpoint of etching performance and inhibiting corrosion of the container filled with the composition, the content of the iodine-containing perfluoroalkyl compound relative to the total molar amount of the composition is preferably 500 mol ppm or less, more preferably 300 mol ppm or less, and even more preferably 100 mol ppm or less.

[0072] From the viewpoint that leakage is easily noticeable, the content of the iodine-containing perfluoroalkyl compound relative to the total molar amount of the composition is preferably 10 mol ppm or more, more preferably 50 mol ppm or more, and even more preferably 100 mol ppm or more.

[0073] In this disclosure, the content of iodine-containing perfluoroalkyl compounds in the composition is determined using a gas chromatograph under the following testing conditions. In the case where multiple iodine-containing perfluoroalkyl compounds are present in the composition of this disclosure, the content of the iodine-containing perfluoroalkyl compounds refers to the total content of these multiple iodine-containing perfluoroalkyl compounds.

[0074] Main unit: 7890GC (manufactured by Agilent Technologies Inc.)

[0075] Detector: Flame Ionization Detector (FID)

[0076] Column: DB-1301 (manufactured by Agilent Technologies Inc.)

[0077] <Water>

[0078] The compositions disclosed herein may contain water.

[0079] In the compositions disclosed herein, from the viewpoint of etching performance, the water content relative to the total molar amount of the composition is preferably 1,000 mol ppm or less, more preferably 500 mol ppm or less, and even more preferably 200 mol ppm or less.

[0080] The water content relative to the total molar amount of the composition is preferably 10 mol ppm or more, more preferably 50 mol ppm or more, and even more preferably 100 mol ppm or more.

[0081] In this disclosure, the water content in the composition is determined by measuring the moisture content using a dew point meter DewStar S-2 (manufactured by Shinei Technology Co., Ltd.).

[0082] <Additives>

[0083] The compositions disclosed herein may contain additives.

[0084] Examples of additives include nitrogen, oxygen, argon, carbon dioxide, fluorinated carbon, tetrafluoroethylene, known leak detection substances other than iodine or iodine-containing perfluoroalkyl compounds, stabilizers, or polymerization inhibitors.

[0085] The content of nitrogen, oxygen, argon, carbon dioxide, fluorinated carbon, or tetrafluoroethylene in the compositions disclosed herein is not particularly limited. The content of nitrogen, oxygen, argon, carbon dioxide, fluorinated carbon, or tetrafluoroethylene relative to the total molar amount of the composition may be 50 mol ppm or more, 100 mol ppm or more, or 200 mol ppm or more, respectively. The content of nitrogen, oxygen, argon, carbon dioxide, fluorinated carbon, or tetrafluoroethylene relative to the total molar amount of the composition may be 500 mol ppm or less, 250 mol ppm or less, or 100 mol ppm or less, respectively.

[0086] Examples of substances that can be used for leak detection include ultraviolet fluorescent dyes, odorous gases, and odor masking agents.

[0087] Examples of previously known ultraviolet fluorescent dyes include those described in U.S. Patent No. 4,249,412, Japanese Patent Publication No. 10-502,737, Japanese Patent Publication No. 2007-511,645, Japanese Patent Publication No. 2008-500,437, and Japanese Patent Publication No. 2008-531,836.

[0088] As odor masking agents, examples include previously known fragrances such as those listed in Japanese Patent Publication No. 2008-500437 and Japanese Patent Publication No. 2008-531836.

[0089] When using a leak detection substance, a solubilizer that improves the solubility of the leak detection substance in the composition can be used. Examples of solubilizers include those described in Japanese Patent Application Publication Nos. 2007-511645, 2008-500437, and 2008-531836.

[0090] The content of the leak detection substance is only required to be within the range that does not significantly reduce the effectiveness of this disclosure, preferably 2% by mass or less, and more preferably 0.5% by mass or less, relative to 100% by mass of the composition.

[0091] Stabilizers are components that improve the stability of a composition to heat and oxidation. Examples of known stabilizers include, for instance, oxidation resistance enhancers, heat resistance enhancers, and metal deactivators.

[0092] Examples of antioxidants and heat resistance enhancers include N,N'-diphenylphenyldiamine, p-octyldiphenylamine, p,p'-dioctyldiphenylamine, N-phenyl-1-naphthylamine, N-phenyl-2-naphthylamine, N-(p-dodecyl)phenyl-2-naphthylamine, di-1-naphthylamine, di-2-naphthylamine, N-alkylphenthiazine, 6-(tert-butyl)phenol, 2,6-di(tert-butyl)phenol, 4-methyl-2,6-di(tert-butyl)phenol, and 4,4'-methylenebis(2,6-di-tert-butylphenol). One or more antioxidants and heat resistance enhancers may be used.

[0093] Examples of metal deactivators include imidazole, benzimidazole, 2-mercaptobenzothiazole, 2,5-dimethylmercaptothiadiazole, salicylaldehyde diacetylamine, pyrazole, benzotriazole, methylbenzotriazole, 2-methylbenzimidazole, 3,5-dimethylpyrazole, methylenebis-benzotriazole, organic acids or their esters, primary, secondary or tertiary aliphatic amines, amine salts of organic or inorganic acids, heterocyclic nitrogen-containing compounds, amine salts of alkyl phosphate esters or their derivatives, etc.

[0094] The content of the stabilizer is only required to be within the range that does not significantly reduce the effect of the present disclosure, and is preferably 0.01 to 5% by mass relative to 100% of the composition, more preferably 0.05 to 3% by mass, further preferably 0.1 to 2% by mass, even more preferably 0.25 to 1.5% by mass, and particularly preferably 0.5 to 1% by mass.

[0095] There are no particular limitations on the type of polymerization inhibitor used; it can be appropriately selected from commonly used inhibitors. There can be only one type of inhibitor, or there can be two or more.

[0096] Examples of polymerization inhibitors include 4-methoxy-1-naphthol, hydroquinone, hydroquinone methyl ether, dimethyl tert-butylphenol, 2,6-di-tert-butyl-p-cresol, and benzotriazole.

[0097] The content of the polymerization inhibitor is not particularly limited, but is preferably 0.01 to 5% by mass, more preferably 0.05 to 3% by mass, further preferably 0.1 to 2% by mass, even more preferably 0.25 to 1.5% by mass, and particularly preferably 0.5 to 1% by mass, relative to the total amount of the composition.

[0098] <Application>

[0099] The compositions disclosed herein can be used in a variety of applications, such as as refrigerants, heat transfer media, foaming agents, or resin monomers, exemplified by etching for forming microstructures such as semiconductors or liquid crystals. The compositions disclosed herein can be used for etching SiO2.

[0100] <Method for preparing the composition>

[0101] The formulation method of the disclosed compositions is not particularly limited and can be formulated by known methods. The disclosed compositions can be obtained by mixing C-318 with iodine and at least one of iodine-containing perfluoroalkyl compounds.

[0102] Alternatively, the composition of this disclosure is obtained by heating 1,2-diiodoperfluoroethane to 200-300°C and reacting for 1-10 hours or more, then cooling to 20-50°C, recovering the gas phase, and distilling. More specifically, the composition of this disclosure is obtained by heating 1,2-diiodoperfluoroethane to 230°C and reacting for 10 hours, then cooling to 40°C, recovering the gas phase, and distilling.

[0103] (Dehydration)

[0104] The compositions disclosed herein can be dehydrated. Dehydration can be carried out by known methods. Examples of methods for dehydrating the composition include reacting the composition with water or using a dehydrating agent (water adsorbent) in the composition. Alternatively, azeotropic dehydration, distillation, or membrane separation can also be performed.

[0105] As a method of reaction with water, metallic potassium, metallic sodium, lithium aluminum hydride, calcium hydride, phosphorus pentoxide, calcium oxide, magnesium oxide, potassium hydroxide, sodium hydroxide, concentrated sulfuric acid, calcium sulfate, magnesium sulfate, sodium sulfate, calcium chloride, zinc chloride, or potassium carbonate can be used.

[0106] As a method of using a dehydrating agent, zeolite, activated carbon, activated alumina, or silica gel can be used. As a specific dehydration method, dehydration is achieved by contacting the dehydrating agent with the composition. For example, the composition of this disclosure in a gaseous or liquid state can be passed through a dehydration tower filled with the dehydrating agent. One dehydrating agent can be used alone, or two or more can be used in combination.

[0107] Of the above, the preferred method for dehydration, which has minimal impact on the composition and allows for easy dehydration, is the method using zeolite. Examples of zeolites include synthetic zeolites having the chemical composition shown in the following chemical formulas (Z1) or (Z2).

[0108] K x Na y (AlO2) 12 (SiO2) 12 ·27H2O (Z1)

[0109] (In equation (Z1), x+y=12, x:y=4:6~8:2.)

[0110] K x Na y (AlO2) 86 (SiO2) 106 ·276H2O (Z2)

[0111] (In formula (Z2), x+y=86, x:y=4:6~8:2.)

[0112] Zeolites are classified into several grades based on the type of zeolite used as raw material; examples include zeolites 3A, 4A, and 5A. Zeolites 3A, 4A, and 5A refer to synthetic zeolites with a pore size of 0.25~0.45 nm. Commercially available products include molecular sieves 3A (MS-3A), 4A (MS-4A), and 5A (MS-5A) (all manufactured by Union Showa KK), with MS-3A or MS-4A being preferred. Commercially available X-type zeolites include molecular sieve 13X; in addition to zeolites 3A, 4A, or 5A, molecular sieve 13X can also be used in combination. It should be noted that the pore size of zeolites can be determined using a volumetric gas adsorption method. Examples of adsorbed gases used in volumetric gas adsorption methods include N2, CO2, CH4, H2, or Ar.

[0113] Drying methods for compositions using molecular sieves include: placing the composition and molecular sieve in a sealed container and allowing it to stand; or filling a column with molecular sieve and allowing the composition to pass through or circulate therein; etc. As an example of the standing method, 1 to 50 g, preferably 3 to 30 g, of molecular sieve per 1 kg of composition can be added to a container that is not easily permeable to external air, sealed, and left to stand for 1 to 5 days for dehydration.

[0114] Containers Containing Compositions

[0115] The container containing the composition disclosed herein has: a container, and the composition of the present disclosure filled within the aforementioned container.

[0116] The container is preferably made of stainless steel, chromium-molybdenum steel, or carbon steel. From the viewpoint of corrosion resistance, stainless steel is more preferred, while from the viewpoint of cost-effectiveness, carbon steel is more preferred.

[0117] Example

[0118] The present disclosure is described in more detail below through embodiments, but the present disclosure is not limited to the following embodiments as long as it does not depart from its spirit. Examples 1 to 6 are embodiments, and Examples 7 and 8 are comparative examples.

[0119] (Formulation of the composition)

[0120] The compositions of Examples 1 to 8 were prepared using C-318 (manufactured by Resonac Corporation), 1,2-diiodotetrafluoroethane (manufactured by FUJIFILM Wako Pure Chemical Corporation) as 1,2-diiodotetrafluoroalkane, iodine (manufactured by FUJIFILM Wako Pure Chemical Corporation), and water, by the following method.

[0121] Iodine was added to a 100 mL pressure-resistant glass cylinder with a pressure resistance of 1.0 MPaG or higher, and the pressure was adjusted to a reduced pressure. 1,2-Diiodotetrafluoroethane and water were then added sequentially to the pressure-resistant glass cylinder, with the amounts of iodine, 1,2-diiodotetrafluoroethane, and water respectively in the compositions listed in Table 1 below (unit: ppm moles). The pressure-resistant glass cylinder was then cooled to -40°C, and C-318 was added until the total molar amount of the composition reached 100%, then the temperature was restored to 25°C for mixing.

[0122] (Etching performance)

[0123] A semiconductor substrate was prepared having a SiO2 film with a thickness of approximately 1 μm on a Si substrate, and further having a resist pattern with a hole diameter of 0.21 μm thereon. The semiconductor substrate was etched using the compositions of Examples 1-8 described in Table 1 as etching gases. The etching conditions were set as follows: discharge power 600 W, bias power 200 W, gas pressure 3 mTorr (0.399 Pa), and electron density 8 × 10⁻⁶. 10 ~2×10 11 cm-3 The electron temperature is 5~7 eV.

[0124] Etching performance was evaluated based on the SiO2 etching rate value according to the following criteria. The results are shown in Table 1. The higher the SiO2 etching rate value, the higher the production efficiency, and therefore, the better the etching performance.

[0125] A: The SiO2 etching rate exceeds 5.5 and is below 7.0 μm / min.

[0126] B: The SiO2 etching rate exceeds 4.0 and is below 5.5 μm / min.

[0127] C: The etching rate of SiO2 exceeds 2.5 and is below 4.0 μm / min.

[0128] (color)

[0129] The color of each composition in Examples 1-8 was visually confirmed. The results are shown in Table 1. When the composition is colored, leakage of the composition can be easily confirmed.

[0130] (Storage stability)

[0131] The storage stability of the metals used in the containers was confirmed by simulating the storage of the compositions described in Examples 1 to 8 below in containers. As a test method, a colorless, pressure-resistant glass barrel in which the contents could be seen was prepared, and the various metal sheets shown in Table 1 below were put into the barrel. The above compositions were then further filled under reduced pressure and allowed to stand for 30 days.

[0132] -Appearance-

[0133] The appearance of the metal sheet after the aforementioned settling was visually confirmed according to the following criteria. A and B represent practically permissible ranges. The results are shown in Table 1.

[0134] A: It is almost impossible to detect staining or rust on the metal surface.

[0135] B: The metal surface is partially stained brown or purple and rusted.

[0136] C: The metal surface is almost entirely stained brown or purple and rusted.

[0137] -Erosion Degree-

[0138] The metal sheet, after being left to stand for the aforementioned period, was further left to stand directly inside the barrel for 30 days, and its mass was measured. Based on the change in mass of the metal sheet before and after being placed in the barrel, the annual erosion depth (mm / year) was calculated with reference to JIS Z 2383:1998 (ISO 9226:1992). Based on the obtained erosion depth values, the degree of erosion of the metal sheet was evaluated according to the following criteria. The results are shown in Table 1.

[0139] A: Erosion depth is less than 0.005 mm / year.

[0140] B: Erosion depth is greater than 0.005 mm and less than 0.02 mm / year.

[0141] C: Erosion depth is 0.02 mm / year or more.

[0142] [Table 1]

[0143]

[0144] Based on the above, the compositions of Examples 1-6 exhibit excellent etching performance and allow for easy detection of leaks. Furthermore, the compositions of Examples 1-6 also demonstrate excellent storage stability of the metals.

[0145] It should be noted that the entire disclosure of Japanese Patent Application No. 2024-013759, filed on January 31, 2024, is incorporated herein by reference. Furthermore, all documents, patent applications, and technical standards described in this specification are incorporated herein by reference to the same extent as their respective specific and separately described instances.

[0146] Industrial availability

[0147] The compositions disclosed herein exhibit excellent etching performance and allow for easy detection of leaks. These compositions can be used as etching gases in semiconductor manufacturing processes to remove unwanted thin film portions from a semiconductor substrate and process it into a desired surface shape.

Claims

1. A composition comprising octafluorocyclobutane and at least one of iodine and an iodine-containing perfluoroalkyl compound. The content of at least one of the iodine and the iodine-containing perfluoroalkyl compound is less than 1,000 mol ppm relative to the total molar amount of the composition.

2. The composition according to claim 1, wherein, The content of at least one of the iodine and the iodine-containing perfluoroalkyl compound is more than 10 mol ppm relative to the total molar amount of the composition.

3. The composition according to claim 1 or 2, wherein, The iodine-containing perfluoroalkyl compound is at least one selected from the group consisting of 1,2-diiodoperfluoroethane, 1,4-diiodoperfluorobutane, 1,6-diiodoperfluorohexane, 1,8-diiodoperfluorooctane, 1-iodoperfluoroethane, 1-iodoperfluoropropane, 1-iodoperfluorobutane, 2-iodoperfluoropropane, 1-iodoperfluoropentane, 1-iodoperfluorohexane, 1-iodoperfluoroheptane, and 1-iodoperfluorooctane.

4. The composition according to claim 1 or 2, wherein, The content of the iodine-containing perfluoroalkyl compound is less than 500 mol ppm relative to the total molar amount of the composition.

5. The composition according to claim 1 or 2, further comprising water.

6. The composition according to claim 5, wherein, The water content is less than 1,000 mol ppm relative to the total molar amount of the composition.

7. The composition according to claim 1 or 2, used as an etching agent, refrigerant, heat transfer medium, foaming agent or resin monomer.

8. A container containing a composition, comprising: a container, and the composition of claim 1 or 2 filled within the container.

9. The container containing the composition according to claim 8, wherein, The container is made of stainless steel, chromium-molybdenum steel, or carbon steel.

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