Supercritical processing composition, supercritical processing method, supercritical processing device, and container

Abstract

The present invention provides: a supercritical processing composition that contains a halogenated olefin having two carbon atoms and carbon dioxide, wherein the content of the carbon dioxide is 76.4 mass% or more with respect to the total amount of the halogenated olefin having two carbon atoms and the carbon dioxide; a supercritical processing method and a supercritical processing device using the same; and a container containing the supercritical processing composition.

Description

Composition for supercritical processing, supercritical processing method, supercritical processing apparatus, and container

[0001] The present disclosure relates to a composition for supercritical processing, a supercritical processing method, a supercritical processing apparatus, and a container.

[0002] Halogen-containing compounds are widely used in various technologies. For example, applications of halogen-containing compounds as supercritical fluids for supercritical processing are being considered.

[0003] High-performance semiconductor devices known as large-scale integrated circuits (LSIs), which have a stacked structure of integrated circuits formed on the surface of a substrate such as a semiconductor wafer (hereinafter also referred to as "wafer"), are rapidly becoming smaller and more highly integrated through scaling. In the manufacturing process of semiconductor devices that form such microstructures, a liquid processing step (hereinafter also referred to as "wet process") using a liquid is typically performed, such as removing contaminants such as minute dust particles and native oxide films from the wafer surface using a cleaning liquid such as a chemical solution. When removing liquids adhering to the wafer surface in wet processes, a supercritical processing method using a fluid in a supercritical or subcritical state is known. This is because supercritical fluids have the advantage of not generating surface tension and thus not acting on capillary forces that cause pattern collapse, making them suitable for drying microstructures.

[0004] As a supercritical processing composition that serves as a supply source of a supercritical fluid or a subcritical fluid, alcohols such as isopropyl alcohol (IPA) (see Patent Document 1), carbon dioxide (CO ２ In addition to halogen atom-free compounds such as hydrofluoroethers (HFEs), hydrofluorocarbons (HFCs) (see Patent Documents 3 and 4), hydrofluoroolefins (HFOs), and hydrochlorofluoroolefins (HCFOs) (see Patent Document 5), etc. have been investigated.

[0005] JP 2013-179245 A JP 2007-281148 A JP 2011-187570 A JP 2014-022566 A JP 2017-157716 A

[0006] Alcohols such as IPA, which are being considered as compositions for supercritical processing, are highly flammable and may cause fires if leaked. Furthermore, the hydroxyl groups in the molecules may damage substrates. Some HFEs and HFCs have low flammability and moderate boiling points, critical temperatures, and critical pressures. However, although they have a low ozone depletion potential (ODP), they have a high global warming potential (GWP), raising concerns about their poor environmental performance. Some HCFOs have low flammability and moderate boiling points, critical temperatures, and critical pressures, but because they contain chlorine in their molecules, there are concerns that they may affect coexisting materials in high-temperature environments. Some HFOs have low ODPs and GWPs and moderate critical temperatures and critical pressures, but many are flammable. CO ２ has a low critical temperature of 31.0°C, but a high critical pressure of 7.4 MPa abs, which requires an apparatus withstand pressure, resulting in excessive weight and volume of the apparatus. Therefore, as a composition for supercritical processing that serves as a supply source of supercritical fluids and subcritical fluids, there is a demand for a composition that has a low GWP, a relatively low critical temperature and critical pressure, is easy to handle, and has reduced flammability.

[0007] Furthermore, halogen-containing compounds are being considered for use in wood preservative treatment solutions to protect wood from fungal decay and insect attack. Supercritical fluids may also be applicable to wood preservative treatment solutions in order to enhance the penetration of preservatives. Therefore, in the field of wood preservative treatment, a composition that is easy to handle due to its low GWP, relatively low critical temperature, and relatively low critical pressure, and that exhibits reduced flammability, is desired.

[0008] In view of the above circumstances, the present disclosure provides a composition for supercritical processing that has a low GWP and relatively low critical temperature and critical pressure, making it easy to handle and suppressing flammability; a supercritical processing method and supercritical processing apparatus using the composition; and a container containing the composition for supercritical processing.

[0009] Means for solving the above problems include the following aspects: <1> A composition for supercritical processing comprising a halogenated olefin having two carbon atoms and carbon dioxide, wherein the content of the carbon dioxide relative to the total amount of the halogenated olefin having two carbon atoms and the carbon dioxide is 76.4 mass% or more, and wherein the amount of oxygen relative to the total amount of the composition for supercritical processing is less than 1.0 volume%. <2> A composition for supercritical processing according to <1>, comprising a halogenated olefin having two carbon atoms and carbon dioxide, wherein the content of the carbon dioxide relative to the total amount of the halogenated olefin having two carbon atoms and the carbon dioxide is 79.5 mass% or more, and wherein the amount of oxygen relative to the total amount of the composition for supercritical processing is less than 1.0 volume%. <3> The composition for supercritical processing according to <1> or <2>, wherein the halogenated olefin having two carbon atoms comprises at least one selected from the group consisting of 1,1-difluoroethylene, (E)-1,2-difluoroethylene, (Z)-1,2-difluoroethylene, and trifluoroethylene. <4> The composition for supercritical processing according to any one of <1> to <3>, wherein the halogenated olefin having two carbon atoms is 1,1-difluoroethylene. <5> The composition for supercritical processing according to <4>, wherein the content of the carbon dioxide relative to the total amount of the 1,1-difluoroethylene and the carbon dioxide is 80.0 mass% or more. <6> The composition for supercritical processing according to any one of <1> to <5>, further comprising an organic solvent having a boiling point higher than that of the halogenated olefin having two carbon atoms and the carbon dioxide, and used for supercritical cleaning of an article. <7> The composition for supercritical treatment according to any one of <1> to <5>, further comprising a wood preservative and used for supercritical penetration of the wood preservative into wood.<8> The composition for supercritical processing according to <7>, wherein the wood preservative comprises at least one selected from the group consisting of ammonium-based wood preservatives, triazole-based wood preservatives, neonicotinoid-based wood preservatives, phenylpyrazole-based wood preservatives, phenylpyrrole-based wood preservatives, benzoylphenylurea-based wood preservatives, anthranilic diamide-based wood preservatives, strobilurin-based wood preservatives, pyrethroid-based wood preservatives, and fatty acid metal salts. <9> A method for supercritical processing of an article, comprising contacting the article with the composition for supercritical processing according to any one of <1> to <8> in a supercritical state. <10> The method for supercritical processing of an article according to <9>, wherein the composition for supercritical processing is heated, pressurized, or heated and pressurized to bring the C2 halogenated olefin and the carbon dioxide into the supercritical state. <11> The method for supercritical processing of an article according to <9> or <10>, wherein, after the contact, the composition for supercritical processing is cooled, depressurized, or cooled and depressurized. <12> The method for supercritical processing of an article according to <9> dependent on <6>, wherein, after the contact, the organic solvent is separated from the composition for supercritical processing. <13> The method for supercritical processing of an article according to any one of <9> to <12>, wherein the article is a substrate having a wafer and a structure laminated on the wafer. <14> The method for supercritical processing of an article according to any one of <9> to <12>, wherein the article is wood. <15> A supercritical processing apparatus comprising: the composition for supercritical processing according to any one of <1> to <6>; a storage section configured to store the composition for supercritical processing; a chamber configured to accommodate an object; a heating section configured to heat the composition for supercritical processing; a supply section configured to supply the composition for supercritical processing into the chamber; and a discharge section configured to discharge the composition for supercritical processing from the chamber. <16> The supercritical processing apparatus according to <15>, wherein the object is a substrate having a wafer and a structure stacked on the wafer. <17> A container containing a composition for supercritical processing, comprising the composition for supercritical processing according to any one of <1> to <8> and a container for storing the composition for supercritical processing.

[0010] According to the present disclosure, there are provided a composition for supercritical processing that has a low GWP and relatively low critical temperature and critical pressure, making it easy to handle and suppressing flammability; a supercritical processing method and supercritical processing apparatus using the same; and a container containing the composition for supercritical processing.

[0011] 1 is a schematic diagram of a supercritical processing apparatus according to one embodiment. 2 is a schematic diagram of a supercritical processing apparatus according to one embodiment. 3 is a schematic diagram of a supercritical processing apparatus according to one embodiment. 4 is a schematic diagram of a supercritical processing apparatus according to one embodiment. 5 is a schematic diagram of a supercritical processing apparatus according to one embodiment. 6 is a schematic diagram of a supercritical processing apparatus according to one embodiment. 7 is a schematic diagram of a supercritical processing apparatus according to one embodiment. 8 is a schematic diagram of a ２ CO relative to the total amount ２ The horizontal axis represents the content of HFO-1132a and CO ２ , and HFO-1132a and CO relative to the total amount of air ２ In the examples, the total content of HFO-1132a and CO was plotted on the vertical axis. ２ CO relative to the total amount ２ The horizontal axis represents the content of HFO-1132a and CO ２ , and HFO-1132a and CO relative to the total amount of air ２ 1 is a graph plotting the total content of

[0012] Hereinafter, modes for carrying out embodiments of the present disclosure will be described in detail. However, the embodiments of the present disclosure are not limited to the following embodiments. In the following embodiments, components (including element steps, etc.) are not essential unless otherwise specified. The same applies to numerical values ​​and their ranges, and they do not limit the embodiments of the present disclosure.

[0013] In the present disclosure, the term "process" includes not only processes that are independent of other processes, but also processes that cannot be clearly distinguished from other processes as long as the purpose of the process is achieved. In the present disclosure, numerical ranges indicated using "to" include the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In numerical ranges described in stages in the present disclosure, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another staged numerical range. Furthermore, in numerical ranges described in the present disclosure, the upper or lower limit value of that numerical range may be replaced with a value shown in the examples. In the present disclosure, each component may contain multiple corresponding substances. When multiple substances corresponding to each component are present in a composition, the content or amount of each component means the total content or amount of the multiple substances present in the composition, unless otherwise specified. In the present disclosure, a combination of two or more preferred embodiments is a more preferred embodiment. In the present disclosure, even when an element is described in the singular, this does not exclude the presence of multiple substances unless technical contradiction arises, unless otherwise specified. In this disclosure, unless otherwise specified, the proportion of each component in a supercritical processing composition refers to the proportion of each component when the supercritical processing composition is in a gaseous state. In this disclosure, "supercritical processing" refers to a process in which a supercritical fluid is brought into contact with an object. "Supercritical processing" includes, for example, supercritical drying, supercritical cleaning, and supercritical permeation. Supercritical drying refers to drying an object using a supercritical fluid, supercritical cleaning refers to cleaning an object using a supercritical fluid, and supercritical permeation refers to permeating an agent or the like into an object using a supercritical fluid. In this disclosure, "bringing a supercritical processing composition to a supercritical state" refers to bringing at least the specific olefin and carbon dioxide in the supercritical processing composition to a supercritical state. Similarly, "a supercritical processing composition in a supercritical state" refers to a supercritical processing composition in which the specific olefin and carbon dioxide in the supercritical processing composition are at least in a supercritical state. In the present disclosure, when an embodiment is described with reference to drawings, the configuration of the embodiment is not limited to the configuration shown in the drawings.Furthermore, the sizes of the components in each drawing are conceptual, and the relative relationships between the sizes of the components are not limited to these.

[0014] In this disclosure, fluoroolefin refers to an unsaturated hydrocarbon compound having a carbon-carbon double bond that contains fluorine atoms as halogen atoms but no chlorine atoms in the molecule. Fluoroolefins may or may not contain hydrogen atoms in the molecule. In this disclosure, chloroolefins refer to unsaturated hydrocarbon compounds having a carbon-carbon double bond that contains chlorine atoms as halogen atoms but no fluorine atoms in the molecule. Chloroolefins may or may not contain hydrogen atoms in the molecule. In this disclosure, chlorofluoroolefins refer to unsaturated hydrocarbon compounds having a carbon-carbon double bond that contain fluorine atoms and chlorine atoms as halogen atoms in the molecule. Chlorofluoroolefins may or may not contain hydrogen atoms in the molecule. In this disclosure, fluorocarbons refer to saturated hydrocarbon compounds that contain fluorine atoms as halogen atoms but no chlorine atoms in the molecule. Fluorocarbons may or may not contain hydrogen atoms in the molecule. In this disclosure, chlorofluorocarbons refer to saturated hydrocarbon compounds that contain fluorine atoms and chlorine atoms as halogen atoms in the molecule. Chlorofluorocarbons may or may not contain hydrogen atoms in the molecule. In this disclosure, chlorofluoroalkyne refers to an acetylenic hydrocarbon compound containing fluorine and chlorine atoms as halogen atoms in the molecule. Chlorofluoroalkyne may or may not contain hydrogen atoms in the molecule. In this disclosure, hydrofluoroolefin refers to an unsaturated hydrocarbon compound having a carbon-carbon double bond that contains fluorine atoms as halogen atoms but no chlorine atoms in the molecule, and that contains hydrogen atoms. In this disclosure, hydrochlorofluoroolefin refers to an unsaturated hydrocarbon compound having a carbon-carbon double bond that contains fluorine and chlorine atoms as halogen atoms and that contains hydrogen atoms in the molecule. In this disclosure, hydrofluorocarbon refers to a saturated hydrocarbon compound that contains fluorine atoms as halogen atoms but no chlorine atoms, and that contains hydrogen atoms in the molecule. In this disclosure, hydrofluoroether refers to an ether compound that contains fluorine atoms as halogen atoms but no chlorine atoms, and that contains hydrogen atoms in the molecule.

[0015] <Composition for Supercritical Processing> The composition for supercritical processing of the present disclosure comprises a halogenated olefin having two carbon atoms and carbon dioxide, wherein the carbon dioxide content is 76.4 mass% or more relative to the total amount of the halogenated olefin having two carbon atoms and the carbon dioxide, and the amount of oxygen relative to the total amount of the composition for supercritical processing is less than 1.0 volume%. Hereinafter, the halogenated olefin having two carbon atoms is also referred to as a "specific olefin." The composition for supercritical processing of the present disclosure has a low GWP and relatively low critical temperature and critical pressure, making it easy to handle and suppressing flammability. For example, the composition for supercritical processing of the present disclosure is difficult to combust at 20°C even when leaked into air, regardless of the amount of air.

[0016] In one embodiment, the composition for supercritical processing contains a specific olefin and carbon dioxide, the content of the carbon dioxide relative to the total amount of the specific olefin and the carbon dioxide is 79.5 mass% or more, and the amount of oxygen relative to the total amount of the composition for supercritical processing is less than 1.0 volume%. The composition for supercritical processing of this embodiment is unlikely to burn even when leaked into air at a higher temperature, for example, 60°C, regardless of the amount of air.

[0017] For example, Patent Document 5 discloses various hydrofluoroolefins, specifically hydrochlorofluoroolefins having 3 or 4 carbon atoms. However, hydrochloroolefins having 3 or 4 carbon atoms have relatively high boiling points and high critical temperatures. On the other hand, specific olefins have relatively low boiling points and low critical temperatures, making them easy to handle. On the other hand, although some specific olefins are flammable, the composition for supercritical processing of the present disclosure can suppress flammability by containing carbon dioxide at a specific ratio. Each component contained in the composition for supercritical processing of the present disclosure will be described in detail below.

[0018] (Specific olefin) The specific olefin is not particularly limited as long as it is an olefin having two carbon atoms and contains at least one halogen atom. From the viewpoints of low environmental load and suppression of flammability, the specific olefin preferably contains a fluorine atom and / or a chlorine atom, and more preferably contains a fluorine atom. The number of halogen atoms in the specific olefin is preferably 2 to 4, more preferably 2 or 3. In addition, generally, the fewer the number of hydrogen atoms in the olefin, the lower the flammability tends to be. From this viewpoint, the number of hydrogen atoms in the specific olefin is preferably 2 or less, and may be 1 or less. One specific olefin may be used alone, or two or more specific olefins may be used in combination.

[0019] From the viewpoint of ease of handling, the boiling point of the specific olefin is preferably −20° C. or lower, more preferably −40° C. or lower, even more preferably −60° C. or lower, and particularly preferably −80° C. or lower. The boiling point of the specific olefin may be −100° C. or higher. From this viewpoint, the boiling point of the specific olefin is preferably −100 to −20° C., more preferably −100 to −40° C., even more preferably −100 to −60° C., and particularly preferably −100 to −80° C.

[0020] From the viewpoint of ease of handling when the specific olefin is in a supercritical state, the critical temperature of the specific olefin is preferably 100°C or lower, more preferably 75°C or lower, and even more preferably 50°C or lower. From the viewpoint of the pressure resistance of a container containing the specific olefin, the critical temperature of the specific olefin is preferably 20°C or higher, and more preferably 25°C or higher. From such viewpoints, the critical temperature of the specific olefin is preferably 20 to 100°C, more preferably 20 to 75°C, and even more preferably 25 to 50°C.

[0021] From the viewpoint of ease of handling when brought into a supercritical state, the critical pressure of the specific olefin is preferably 7.5 MPa abs or less, more preferably 7.0 MPa abs or less, and even more preferably 6.5 MPa abs or less. The critical pressure of the specific olefin is preferably 2.0 MPa abs or more, more preferably 2.5 MPa abs or more, and even more preferably 3.0 MPa abs. From such viewpoints, the critical pressure of the specific olefin is preferably 2.0 to 7.5 MPa abs, more preferably 2.5 to 7.0 MPa abs, and even more preferably 3.0 to 6.5 MPa abs.

[0022] The GWP of the specific olefin is preferably 500 or less, more preferably 200 or less, even more preferably 150 or less, particularly preferably 100 or less, even more preferably 50 or less, even more preferably 20 or less, even more preferably 15 or less, even more preferably 10 or less, even more preferably 7 or less, even more preferably 5 or less, even more preferably 4 or less, and even more preferably 3 or less. Unless otherwise specified, the GWP is the 100-year value from the Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report (AR6).

[0023] Examples of the specific olefin include 1,1-difluoroethylene, (E)-1,2-difluoroethylene, (Z)-1,2-difluoroethylene, vinyl fluoride, tetrafluoroethylene, trifluoroethylene, etc. Among these, 1,1-difluoroethylene, (E)-1,2-difluoroethylene, (Z)-1,2-difluoroethylene, and trifluoroethylene are preferred, and from the viewpoint of ease of handling, 1,1-difluoroethylene, (E)-1,2-difluoroethylene, and trifluoroethylene are more preferred, and 1,1-difluoroethylene is even more preferred.

[0024] 1,1-Difluoroethylene and carbon dioxide have similar boiling points and exhibit excellent azeotropic properties, and therefore a composition for supercritical processing containing 1,1-difluoroethylene and carbon dioxide has the particular advantage of being less susceptible to changes in the composition ratio even when circulated and used in a device that involves gas-liquid separation.

[0025] The following table lists the boiling points, critical temperatures, critical pressures, and GWPs of specific olefins that can be used in the supercritical processing composition of the present disclosure, as well as other compounds used for supercritical processing. In the table, "N.D." indicates that the boiling point is not listed in the IPCC Sixth Assessment Report (AR6), and is presumed to be 10 or less based on the structure of the compound.

[0026]

[0027] The content of the specific olefin relative to the total amount of the supercritical processing composition is preferably 15.05% by volume or less, more preferably 14.5% by volume or less, and even more preferably 14.0% by volume or less, from the viewpoint of suppressing flammability. From the viewpoints of low environmental impact and ease of handling due to low critical temperature and critical pressure, the content is preferably 3.0% by volume or more, more preferably 4.0% by volume or more, and even more preferably 5.0% by volume or more. From these viewpoints, the content is preferably 3.0 to 15.05% by volume, more preferably 4.0 to 14.5% by volume, and even more preferably 5.0 to 14.0% by volume. Of these, it is preferable that the specific olefin is 1,1-difluoroethylene, and the content of 1,1-difluoroethylene is in the above-mentioned range. When the composition for supercritical processing contains a specific olefin and an organic solvent having a boiling point higher than that of carbon dioxide, or a wood preservative, as described below, it is preferable that the content of the specific olefin or the content of 1,1-difluoroethylene relative to the total amount of components excluding the specific olefin and the organic solvent having a boiling point higher than that of carbon dioxide, or the wood preservative, is within the above-mentioned range.

[0028] (Carbon dioxide) The composition for supercritical processing contains carbon dioxide. The carbon dioxide content relative to the total amount of the specific olefin and carbon dioxide is 76.4 mass% or more, and from the viewpoint of reducing flammability, it is preferably 79.5 mass% or more, more preferably 80.0 mass% or more, and even more preferably 80.5 mass% or more. From the viewpoint of better exhibiting the functions of the specific olefin, the content is preferably 97.0 mass% or less, more preferably 96.0 mass% or less, and even more preferably 95.0 mass% or less. From such viewpoints, the content is preferably 76.4 to 97.0 mass%, more preferably 79.5 to 97.0 mass%, even more preferably 80.0 to 96.0 mass%, and particularly preferably 80.5 to 95.0 mass%.

[0029] When the specific olefin is 1,1-difluoroethylene, the content of carbon dioxide relative to the total amount of 1,1-difluoroethylene and carbon dioxide is 76.4% by mass or more. From the viewpoint of reducing flammability, it is preferably 79.5% by mass, more preferably 80.0% by mass or more, even more preferably 80.5% by mass or more, particularly preferably 82.0% by mass or more, and extremely preferably 84.0% by mass or more. From the viewpoint of better exhibiting the functions of 1,1-difluoroethylene, the content is preferably 97.0% by mass or less, more preferably 96.0% by mass or less, and even more preferably 95.0% by mass or less. From such viewpoints, the content is preferably 76.4 to 97.0% by mass, more preferably 79.5 to 97.0% by mass, even more preferably 80.0 to 97.0% by mass, particularly preferably 80.5 to 97.0% by mass, extremely preferably 82.0 to 96.0% by mass, and even more preferably 84.0 to 95.0% by mass. In particular, when the content is 80.0% by mass or more, preferably 82.0% by mass or more, and more preferably 84.0% by mass or more, 1,1-difluoroethylene and carbon dioxide form a composition close to an azeotrope, and changes in the composition ratio are suppressed, which is advantageous for repeated use as a composition for supercritical processing.

[0030] From the viewpoint of reducing flammability, the carbon dioxide content relative to the entire composition for supercritical processing is preferably 76.4% by mass or more, more preferably 79.5% by mass or more, even more preferably 80.0% by mass or more, and particularly preferably 80.5% by mass or more. From the viewpoint of better exhibiting the function of the specific olefin, the content is preferably 97.0% by mass or less, more preferably 96.0% by mass or less, and even more preferably 95.0% by mass or less. From this viewpoint, the content is preferably 76.4 to 97.0% by mass, more preferably 79.5 to 97.0% by mass, even more preferably 80.0 to 96.0% by mass, and particularly preferably 80.5 to 95.0% by mass. When the composition for supercritical processing contains an organic solvent having a boiling point higher than that of the specific olefin and carbon dioxide, or a wood preservative, as described below, the carbon dioxide content relative to the total amount of components excluding the specific olefin, the organic solvent having a boiling point higher than that of carbon dioxide, or the wood preservative is preferably within the above-mentioned range.

[0031] (Oxygen) The composition for supercritical processing may or may not contain oxygen. The amount of oxygen in the composition for supercritical processing is less than 1.0 vol%. In other words, the composition for supercritical processing does not contain oxygen, or contains oxygen in an amount greater than 0 vol% and less than 1.0 vol%. The amount of oxygen in the composition for supercritical processing is preferably 0.5 vol% or less, more preferably 0.1 vol% or less, and even more preferably 0.06 vol% or less.

[0032] (Other Components) The composition for supercritical processing may or may not contain components other than the specific olefin, carbon dioxide, and oxygen. Examples of components other than the specific olefin, carbon dioxide, and oxygen include hydrofluoroolefins (HFOs) other than the specific olefins, hydrochlorofluoroolefins (HCFOs), hydrofluorocarbons (HFCs), and hydrofluoroethers (HFEs). The composition for supercritical processing may or may not contain an organic solvent having a boiling point higher than that of the specific olefin and carbon dioxide, as described below. Furthermore, the composition for supercritical processing may or may not contain a wood preservative, as described below.

[0033] The supercritical processing composition may or may not contain at least one component selected from the group consisting of halogenated olefins other than the specific olefins (e.g., fluoroolefins other than the specific olefins, chloroolefins other than the specific olefins, chlorofluoroolefins other than the specific olefins), fluorocarbons, chlorofluorocarbons, chlorofluoroalkynes, methanol, ethanol, acetone, hexane, ethylene, methane, chloromethane, dichloroethane, acetylene, 2-methyl-2-propanol, β-pinene, pentafluoroiodoethane, and carbon monoxide as a component other than the specific olefin, carbon dioxide, nitrogen, and oxygen (hereinafter also referred to as the "first specific trace component"). These components are thought to have the function of suppressing and stabilizing the decomposition of the specific olefin, although the reason for this is unclear. The first specific trace component is preferably non-flammable. Specifically, the first specific trace component is preferably Class 1 according to ASHRAE Standard 34 Refrigerant Safety Classification.

[0034] The first specific trace component may contain a fluoroolefin other than the specific olefin. Examples of the fluoroolefin other than the specific olefin include (E)-1,1,1,4,4,4-hexafluorobut-2-ene, (Z)-1,1,1,4,4,4-hexafluorobut-2-ene, 2,3,3,3-tetrafluoro-1-propene, (E)-1,3,3,3-tetrafluoropropene, (Z)-1,3,3,3-tetrafluoropropene, hexafluoropropene, and C ４ H ４ F ４ Examples of fluorinated hydrocarbons include those represented by the following formula: ４ H ４ F ４ Examples of the fluorohydrocarbon represented by the formula (I) include 1,3,4,4-tetrafluoro-1-butene, 3,4,4,4-tetrafluoro-1-butene, 1,1,2,3-tetrafluoro-1-butene, and 2,4,4,4-tetrafluoro-1-butene.

[0035] The first specific trace component may contain a chloroolefin other than the specific olefin. Examples of the chloroolefin other than the specific olefin include chloroethylene, 1,1-dichloroethylene, 1,2-dichloroethylene, 1,1,2-trichloroethylene, and 1,1,2,2-tetrachloroethylene.

[0036] The first specific minor component may contain a chlorofluoroolefin other than the specific olefin. Examples of the chlorofluoroolefin other than the specific olefin include (E)-1-chloro-2,3,3,3-tetrafluoropropene, (Z)-1-chloro-2,3,3,3-tetrafluoropropene, (E)-1-chloro-3,3,3-trifluoropropene, (Z)-1-chloro-3,3,3-trifluoropropene, 1,1-dichloro-2,3,3,3-tetrafluoropropene, (Z)-2-chloro-1,3,3,3-tetrafluoropropene, (E)-2-chloro-1,3,3,3-tetrafluoropropene, 2-chloro-1,1,3,3,3-pentafluoro-1-propene, 2-chloro-3,3,3-trifluoropropene, 1,2-dichloro-1-fluoroethene, and 1,1,2-trichloro-2-fluoroethene.

[0037] The first specific trace component may contain a fluorocarbon. Examples of the fluorocarbon include monofluoromethane, difluoromethane, trifluoromethane, tetrafluoromethane, fluoroethane, 1,1-difluoroethane, 1,2-difluoroethane, 1,1,1-trifluoroethane, 1,1,2-trifluoroethane, 1,1,1,2-tetrafluoroethane, 1,1,2,2-tetrafluoroethane, 1,1,1,2,2-pentafluoroethane, 1,1,1,2-tetrafluoropropane, 1,1,1,3,3-pentafluoropropane, 1,1,1,2,2,3,3-heptafluoropropane, C ４ H ６ F ４ and octafluorocyclobutane. ４ H ６ F ４Examples of the fluorohydrocarbon represented by the formula include 1,1,2,3-tetrafluorobutane.

[0038] The first specific trace component may include a chlorofluorocarbon, such as chlorodifluoromethane, chlorotrifluoromethane, 1-chloro-1,1-difluoroethane, 1-chloro-1,2-difluoroethane, 1-chloro-2,2-difluoroethane, 1,1-dichloro-1-fluoroethane, 1,1-dichloro-2-fluoroethane, 1,2-dichloro-2-fluoroethane, 2-chloro-1,1,1,2-tetrafluoropropane, 1,3-dichloro-1,1,2,2,3-pentafluoropropane, and 3,3-dichloro-1,1,1,2,2-pentafluoropropane.

[0039] The first specific trace component may include a chlorofluoroalkyne, such as 1-chloro-3,3,3-trifluoro-1-propyne.

[0040] When the supercritical processing composition contains a first specific trace component, the content of the first specific trace component relative to the total amount of the supercritical processing composition (when two or more types of first specific trace components are contained, the total content) is preferably 15,000 ppm by mass or less, and more preferably 10,000 ppm by mass or less, from the viewpoint of ensuring stability. The content may be 0 ppm by mass or more, 4 ppm by mass or more, 50 ppm by mass or more, or 100 ppm by mass or more. From this viewpoint, the content is preferably 0 to 15,000 ppm by mass, may be 50 to 10,000 ppm by mass, or may be 100 to 10,000 ppm by mass.

[0041] The composition for supercritical processing may contain, but preferably does not contain, at least one trace component (hereinafter also referred to as "second specific trace component") selected from the group consisting of chlorine, hydrogen fluoride, hydrogen chloride, acetic acid, carbonyl fluoride, phosgene, trifluoroacetic acid fluoride, acetyl chloride, carbon monoxide, formyl chloride, and chloroform. From the viewpoint of reducing the possibility that the second specific trace component may react with the metal material or dissolve in water and come into contact with the metal material, thereby causing deterioration or embrittlement of the metal material, the content of the second specific trace component relative to the total amount of the supercritical processing composition (when two or more types of second specific trace components are included, the total content) is preferably 5,000 ppm by mass or less, more preferably 3,000 ppm by mass or less, even more preferably 1,000 ppm by mass or less, particularly preferably 500 ppm by mass or less, extremely preferably 250 ppm by mass or less, even more preferably 100 ppm by mass or less, even more preferably 50 ppm by mass or less, even more preferably 20 ppm by mass or less, and even more preferably 0 ppm by mass. The content may be 5 ppm by mass or more, or may be 10 ppm by mass or more. From this viewpoint, the content is preferably 0 to 5,000 ppm by mass, and may be 5 to 3,000 ppm by mass.

[0042] The composition for supercritical processing may contain a first specific trace component and a second specific trace component. When the composition for supercritical processing contains the first specific trace component and the second specific trace component, the preferred ranges of the contents of these components are as described above.

[0043] In addition to the above, the composition for supercritical processing may or may not contain impurities arising from the production process, such as hexafluoropropene, 2,3,3,3-tetrafluoropropene, and chlorodifluoromethane.

[0044] From the viewpoint of favorably exhibiting the performance of the specific olefin and carbon dioxide, the total content of the specific olefin and carbon dioxide relative to the total amount of the composition for supercritical processing is preferably 98.0% by volume or more, more preferably 99.0% by volume or more, even more preferably 99.5% by volume or more, and may be 100% by volume. When the composition for supercritical processing contains an organic solvent having a boiling point higher than that of the specific olefin and carbon dioxide, or a wood preservative, as described below, the total content of the specific olefin and carbon dioxide relative to the total amount of components excluding the organic solvent having a boiling point higher than that of the specific olefin and carbon dioxide, or the wood preservative, is preferably within the above-mentioned range. When the specific olefin is 1,1-difluoroethylene, from the viewpoint of favorably exhibiting the performance of the 1,1-difluoroethylene and carbon dioxide, the total content of the 1,1-difluoroethylene and carbon dioxide relative to the total amount of the composition for supercritical processing is preferably 98.0% by volume or more, more preferably 99.0% by volume or more, even more preferably 99.5% by volume or more, and may be 100% by volume. When the composition for supercritical processing contains the specific olefin and an organic solvent having a boiling point higher than that of carbon dioxide, or a wood preservative, as described below, it is preferable that the total content of 1,1-difluoroethylene and carbon dioxide relative to the total amount of components excluding the specific olefin and the organic solvent having a boiling point higher than that of carbon dioxide, or the wood preservative, is within the above-mentioned range.

[0045] (Characteristics and Use of Composition for Supercritical Processing) The composition for supercritical processing of the present disclosure may be in a gaseous state at 25° C., or may be in a state in which gas and liquid coexist.

[0046] The supercritical processing composition is used for supercritical processing. Specifically, the supercritical processing composition of the present disclosure is brought into contact with an article in a supercritical state. Examples of supercritical processing include supercritical cleaning and supercritical infiltration.

[0047] -Supercritical Cleaning- In one embodiment, the supercritical processing composition may be used for supercritical cleaning of an article. Examples of the article include a substrate having a wafer and a structure laminated on the wafer. In one embodiment, the supercritical processing composition is used for supercritical cleaning of an article and further comprises an organic solvent having a boiling point higher than that of the specific olefin and carbon dioxide. In another embodiment, the supercritical processing composition is used for supercritical cleaning of an article and does not comprise an organic solvent having a boiling point higher than that of the specific olefin and carbon dioxide. The organic solvent may be an organic solvent used to treat the article by a wet process, or it may be an organic solvent used to prevent the article from drying out. Because the organic solvent has a high boiling point and a high critical temperature, it tends to exist without reaching a supercritical state under conditions in which the specific olefin and carbon dioxide reach a supercritical state. Furthermore, when the supercritical processing composition of the present disclosure comprises an organic solvent having a boiling point higher than that of the specific olefin and carbon dioxide, the specific olefin is less likely to evaporate compared to when the composition does not contain the organic solvent. This makes it easier to prevent the collapse of the uneven pattern on the substrate due to the evaporation of the specific olefin, for example, when the supercritical processing composition is supplied to a semiconductor device substrate.

[0048] The boiling point of the organic solvent having a higher boiling point than the specific olefin and carbon dioxide is preferably 25.0°C or higher, more preferably 30.0°C or higher, even more preferably 35.0°C or higher, particularly preferably 60.0°C or higher, and extremely preferably 80.0°C or higher, from the viewpoint of being able to exist as a liquid under conditions in which the specific olefin and carbon dioxide are gaseous. From the viewpoint of reducing residue remaining on the substrate, the boiling point is preferably 100.0°C or lower. From this viewpoint, the boiling point is preferably 25.0 to 100.0°C, more preferably 30.0 to 100.0°C, even more preferably 35.0 to 100.0°C, particularly preferably 60.0 to 100.0°C, and extremely preferably 80.0 to 100.0°C.

[0049] Examples of organic solvents having a boiling point higher than that of the specific olefin and carbon dioxide include alcohols such as n-butyl acetate, propylene glycol methyl ether acetate, n-heptane, n-decane, dibutyl ether, isoamyl ether, isopropyl alcohol, normal propyl alcohol, ethyl alcohol, and methyl alcohol. Among these, from the viewpoint of availability, ethyl alcohol, methyl alcohol, and isopropyl alcohol are preferred, and isopropyl alcohol is more preferred. In particular, when the specific olefin is 1,1-difluoroethylene, 1,1-difluoroethylene has a relatively low critical temperature of about 30°C and is likely to reach a supercritical state even without being placed in a high-temperature environment, so that a commonly used organic solvent can be used without having to separately consider the thermal stability of the organic solvent.

[0050] The ratio of the organic solvent having a boiling point higher than those of the specific olefin and carbon dioxide to the total amount of the specific olefin and carbon dioxide is preferably 1:100 to 1:1, and more preferably 1:10 to 1:3, on a volume basis. The content of the organic solvent is preferably within a range in which the composition for supercritical processing is non-flammable under the conditions of supercritical processing.

[0051] -Supercritical impregnation- In one embodiment, the composition for supercritical treatment may be used for supercritical impregnation. In one embodiment, the composition for supercritical treatment further contains a wood preservative and is used for supercritical impregnation of the wood preservative into wood. By treating wood with a composition for supercritical treatment containing a wood preservative, the wood preservative can be efficiently impregnated into the wood. Since specific olefins have a relatively low critical temperature and are easily brought into a supercritical state without being placed in a high-temperature environment, the composition for supercritical treatment of the present disclosure can be suitably used as a composition for supercritical impregnation. Furthermore, since the critical pressure of specific olefins is lower than that of carbon dioxide, there is an advantage in that equipment design is easier from the standpoint of pressure resistance.

[0052] The wood preservative may be a fungicide, insecticide, preservative, anti-termite agent, or anti-fungal agent for eliminating wood-destroying fungi or wood-eating insects (such as termites). The wood preservative is preferably dissolved in a specific olefin.

[0053] Examples of wood preservatives include ammonium-based wood preservatives, triazole-based wood preservatives, neonicotinoid-based wood preservatives, phenylpyrazole-based wood preservatives, phenylpyrrole-based wood preservatives, benzoylphenylurea-based wood preservatives, anthranilic diamide-based wood preservatives, strobilurin-based wood preservatives, pyrethroid-based wood preservatives, fatty acid metal salts, etc. One type of wood preservative may be used alone, or two or more types may be used in combination.

[0054] Ammonium-based wood preservatives include didecyldimethylammonium chloride, N,N-didecyl-N-methyl-polyoxyethyl-ammonium propionate, and N-alkylbenzyldimethylammonium chloride.

[0055] Triazole wood preservatives include (2RS,3RS;2RS,3SR)-2-(4-chlorophenyl)-3-cyclopropyl-1-(1H-1,2,4-triazol-1-yl)butan-2-ol, (RS)-1-p-chlorophenyl-4,4-dimethyl-3-(1H-1,2,4-triazol-1-ylmethyl)pentan-3-ol, and 1-[[2-(2,4-dichlorophenyl)-4-propyl-1,3-dioxolan-2-yl]methyl]-1H-1,2,4-triazole.

[0056] Neonicotinoid wood preservatives include (E)-N1-[(6-chloro-3-pyridyl)methyl]-N2-cyano-N1-methylacetamidine, 1-[(6-chloro-3-pyridinyl)methyl]-4,5-dihydro-N-nitro-1H-imidazol-2-amine, (E)-1-(2-chloro-1,3-thiazol-5-ylmethyl)-3-methyl-2-nitroguanidine, and (EZ)-3-(2-chloro-1,3-thiazol-5-ylmethyl)-5-methyl-1,3,5-oxadiazinan-4-ylidene(nitro)amine.

[0057] Phenylpyrazole wood preservatives include 5-amino-1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-4-[(trifluoromethyl)sulfonyl]-1H-pyrazole-3-carbonitrile.

[0058] Phenylpyrrole wood preservatives include 4-(2,2-difluoro-1,3-benzodioxol-4-yl)pyrrole-3-carbonitrile.

[0059] Benzoylphenylurea wood preservatives include 1-[3,5-dichloro-4-(3-chloro-5-trifluoromethyl-2-pyridyloxy)phenyl]-3-(2,6-difluorobenzoyl)urea and (RS)-1-[3-chloro-4-(1,1,2-trifluoro-2-trifluoromethoxyethoxy)phenyl]-3-(2,6-difluorobenzoyl)urea.

[0060] Anthranilic diamide wood preservatives include 3-bromo-N-[4-chloro-2-methyl-6-(methylcarbamoyl)phenyl]-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxamide.

[0061] Strobilurin wood preservatives include methyl {2-[1-(4-chlorophenyl)pyrazol-3-yloxymethyl]phenyl}(methoxy)carbamate.

[0062] Examples of pyrethroid wood preservatives include (±)-α-cyano-3-phenoxybenzyl (+)-cis, trans-chrysanthemate, 2-(4-ethoxyphenyl)-2-methylpropyl-3-phenoxybenzyl ether, 4-ethoxyphenyl[3-(4-fluoro-3-phenoxyphenyl)propyl]dimethylsilane, and 2-methylbiphenyl-3-ylmethyl(Z)-(1RS,3RS)-3-(2-chloro-3,3,3-trifluoroprop-1-enyl)-2,2-dimethylcyclopropanecarboxylate. , (Z)-(S)-2-methyl-4-oxo-3-(penta-2,4-dienyl)cyclopent-2-enyl (1R)-trans-2,2-dimethyl-3-(2-methylprop-1-enyl)cyclopropanecarboxylate, (Z)-(S)-2-methyl-4-oxo-3-(penta-2,4-dienyl)cyclopent-2-enyl (+)-trans-chrysanthemate, and 3-phenoxybenzyl 2-(2,2-dichlorovinyl)-3,3-dimethyl-1-cyclopropanecarboxylate.

[0063] Specific examples of fatty acid metal salts include zinc naphthenate, copper naphthenate, zinc tertiary carboxylate, and zinc versatate.

[0064] Other agents include zinc oxide, cupric oxide, copper (II) oxide, copper (II) oxide, copper (II) hydroxide, 4-bromo-2-(4-chlorophenyl)-1-ethoxymethyl-5-(trifluoromethyl)pyrrole-3-carbonitrile, (EZ)-2'-[2-(4-cyanophenyl)-1-(α,α,α-trifluoro-m-tolyl)ethylidene]-4-(trifluoromethoxy)carbanilohydrazide, (RS)-1-methyl-2-nitro-3-(tetrahydro-3-furylmethyl)guanidine, 3-iodo-2-propynyl butylcarbamate, 2-phenylphenol, and coal tar-based creosote oil.

[0065] The content of the wood preservative is preferably 0.002 to 30% by mass, and more preferably 0.01 to 20% by mass, based on the total amount of the composition for supercritical processing. In this embodiment, the composition for supercritical processing may or may not contain a surfactant, water, etc. Examples of surfactants include nonionic surfactants, anionic surfactants, and cationic surfactants.

[0066] The water content is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 3% by mass or less, based on the total amount of the composition for supercritical processing. It is more preferable that the composition is substantially free of water. When the water content is within the above range, an increase in the moisture content of wood is suppressed when the composition for supercritical processing is brought into contact with wood, thereby suppressing dimensional fluctuations of the wood. "Substantially free of water" means that the water content is below the detection limit when measured by a known method and common technical knowledge in the technical field.

[0067] When a supercritical treatment composition is used for supercritical penetration of a wood preservative into wood, the supercritical treatment composition containing the wood preservative is contacted with the wood, and the specific olefin and carbon dioxide in the supercritical treatment composition are brought into a supercritical state by heating, pressurizing, or heating and pressurizing. This allows the wood preservative to penetrate into the wood and dry the wood. Methods for contacting the supercritical treatment composition with wood include brushing the supercritical treatment composition onto the wood surface, spraying the supercritical treatment composition onto the wood surface, and immersing the wood in the supercritical treatment composition. The wood preservative is preferably dissolved in the specific olefin, and by the above-mentioned treatment, the wood preservative adheres to the surface of the wood together with the specific olefin and penetrates from the surface to the interior of the wood.

[0068] <Method for Supercritical Processing of an Article> The method for supercritical processing of an article according to the present disclosure includes a step of contacting the article with the composition for supercritical processing according to the present disclosure in a supercritical state.

[0069] In one embodiment, the method for supercritical processing of an article may further include a step of filling a container containing the article with the composition for supercritical processing of the present disclosure. In filling, the container may be filled with the composition for supercritical processing prepared by preparing each component in a specific ratio, or each component may be filled separately into the container so that the components in the container have a specific ratio.

[0070] In one embodiment, the method for supercritical processing of an article may further include a step of heating, pressurizing, or heating and pressurizing the composition for supercritical processing to bring the specific olefin and carbon dioxide into a supercritical state. After filling a container containing the article with the composition for supercritical processing, the specific olefin and carbon dioxide may be brought into a supercritical state by heating and / or pressurizing. This has the advantage of reducing the amount of equipment that needs to be designed to be heat- and pressure-resistant. The composition for supercritical processing, which has been brought into a supercritical state in advance by heating and / or pressurizing, may be filled into a container containing the article. This has the advantage of suppressing fluctuations in the composition ratio due to the step of filling the specific olefin and carbon dioxide. The heating and / or pressurizing conditions are selected so that the composition for supercritical processing is brought into a supercritical state. The heating temperature is equal to or higher than the critical temperatures of the specific olefin and carbon dioxide, and may be 60.0°C or lower from the viewpoint of process simplicity. Furthermore, the pressurizing pressure is equal to or higher than the critical pressure of the specific olefin and carbon dioxide, and may be 8.0 MPa or lower from the viewpoint of process simplicity.

[0071] In one embodiment, the method for supercritical processing of an article may further include a step of separating the organic solvent from the composition for supercritical processing after contacting the composition for supercritical processing with the article. Separation of the organic solvent can be carried out, for example, by gas-liquid separation, by discharging the specific olefin and carbon dioxide or the organic solvent under conditions in which the specific olefin and carbon dioxide in the composition for supercritical processing are in the gas phase and the organic solvent is in the liquid phase. The separated organic solvent, specific olefin, and carbon dioxide can each be reused.

[0072] When the azeotropic property of the specific olefin and carbon dioxide in the composition for supercritical processing is high, the composition ratio changes little, and therefore the composition for supercritical processing, after being subjected to a separation step as necessary, can be circulated within the system and used repeatedly.

[0073] In one embodiment, the method for supercritical processing of an article further comprises a step of cooling, depressurizing, or cooling and depressurizing the composition for supercritical processing after contacting the composition with the article. By cooling and / or depressurizing, the composition for supercritical processing that was in a supercritical state can be brought to a non-supercritical state. For example, the specific olefin and carbon dioxide in the composition for supercritical processing can be converted to a gas by cooling and / or depressurizing, and then further cooled to liquefy.

[0074] The article is, for example, a substrate having a wafer and a structure stacked on the wafer. Here, the structure refers to any structure formed on a wafer. For example, the substrate may be a substrate having a pattern formed on the surface of a wafer in a semiconductor device. The substrate may be a substrate after element isolation etching in the manufacturing process of a dynamic random access memory (DRAM). The substrate may be a substrate obtained by wet-etching a mold after forming capacitor electrodes in the manufacturing process of a DRAM. Alternatively, the substrate may be a substrate after fin etching in a FinFET. The substrate may be a substrate after forming nanowires or nanosheets. By treating a substrate having a fine pattern using the supercritical processing method of the present disclosure, the substrate can be suitably cleaned while suppressing pattern collapse. In one aspect, the article is a substrate having a wafer and a structure stacked on the wafer, and the supercritical processing method may be performed in a semiconductor manufacturing apparatus.

[0075] Alternatively, the article may be, for example, wood. The type of wood is not particularly limited. By treating wood with the supercritical treatment method of the present disclosure using the supercritical treatment composition containing the wood preservative of the present disclosure, the wood preservative can be suitably impregnated into the wood.

[0076] <Supercritical Processing Apparatus> The supercritical processing apparatus of the present disclosure comprises a supercritical processing section including the above-described supercritical processing composition of the present disclosure, a storage section configured to store the supercritical processing composition, a chamber configured to accommodate an object, a heating section configured to heat the supercritical processing composition, a supply section configured to supply the supercritical processing composition into the chamber, and a discharge section configured to discharge the supercritical processing composition from the chamber.

[0077] FIG. 1 shows a schematic diagram of an example of a supercritical processing section in a supercritical processing apparatus. The supercritical processing section 10 includes a storage section 12 configured to store a supercritical processing composition, a chamber 20 configured to accommodate an item S, a heating section 22 configured to heat the supercritical processing composition, a supply section 18 configured to supply the supercritical processing composition into the chamber 20, and a discharge section 24 configured to discharge the supercritical processing composition from the chamber 20. The supercritical processing section 10 in FIG. 1 further includes a pressurizing section 14, a heating section 16, a separating section 26, and a cooling section 28, and the supply section 18 and the discharge section 24 are equipped with flow rate adjusting sections 18a and 24a, respectively. The supercritical processing composition stored in the storage section 12 is brought to a supercritical state through the pressurizing section 14 and the heating section 16 and supplied to the chamber 20. An article S, which is the target of supercritical processing, is contained in the chamber 20, and the article S is subjected to supercritical processing using the supplied supercritical processing composition. After supercritical processing, the composition for supercritical processing in the chamber 20 is transferred to the separation section 26 through the discharge section 24, and a liquid L (e.g., an organic solvent) is separated as needed by gas-liquid separation. The composition for supercritical processing is transferred to the cooling section 28 and cooled. A filter for removing particles may be provided in the flow path leading from the storage section 12 to the pressurizing section 14, and / or the flow path leading from the pressurizing section 14 to the heating section 16, and / or the flow path leading to the chamber 20.

[0078] 1 , for example, a composition for supercritical processing in a gaseous or liquid state may be converted to a supercritical state via the pressurizing unit 14 and the heating unit 16 and then filled into the chamber 20. Alternatively, a composition for supercritical processing in a gaseous or liquid state may be filled into the chamber 20 in a gaseous state via the pressurizing unit 14 and the heating unit 16, and then heated by the heating unit 22 to be converted to a supercritical state.

[0079] 2 shows a schematic diagram of another example of a supercritical processing section in a supercritical processing apparatus. The supercritical processing section 30 includes a storage section 32 configured to store a supercritical processing composition, a chamber 40 configured to accommodate an item S, a heating section 42b configured to heat the supercritical processing composition, a supply section 38 configured to supply the supercritical processing composition into the chamber 40, and a discharge section 44 configured to discharge the supercritical processing composition from the chamber 40. The storage section 32 is equipped with a heating section 42a, and the chamber 40 is equipped with a heating section 42b. The supercritical processing section 30 further includes a separation section 46 and a cooling section 48, and the supply section 38 and the discharge section 44 are equipped with flow rate adjustment sections 38a and 44a, respectively. The supercritical processing composition brought to a supercritical state in the storage section 32 is supplied to the chamber 40 via the supply section 38. An object S, which is the object of supercritical processing, is accommodated in the chamber 40, and the object S is subjected to supercritical processing using the supplied supercritical processing composition. After supercritical processing, the supercritical processing composition in the chamber 40 is transferred to the separation section 46 through the discharge section 44, and a liquid L is separated by gas-liquid separation as needed. The supercritical processing composition is transferred to the cooling section 48 and cooled. The supply section 38 may be provided with a filter for removing particles. Note that the supercritical processing apparatus of the present disclosure is not limited to the embodiments shown in FIGS. 1 and 2 .

[0080] The supercritical processing apparatus of the present disclosure may further include a control unit that controls heating and / or pressurization of the composition for supercritical processing, supply to the chamber, discharge from the chamber, separation, cooling, etc.

[0081] In one embodiment, the article is a substrate having a wafer and a structure laminated thereon, the details of which are as described above.

[0082] <Container> In one aspect, a container containing a supercritical processing composition is provided, comprising the supercritical processing composition of the present disclosure and a container for housing the supercritical processing composition. The container is not particularly limited as long as it is capable of storing the supercritical processing composition. In the container, the material of the portion that comes into contact with the supercritical processing composition is preferably a resin material, a metal material, or a glass material. For example, the container may be a container entirely made of a resin material or a metal material, a container with a multilayer structure in which the innermost layer is made of a resin material or a metal material, or a container having a coating of a resin material or a metal material in the portion that comes into contact with the supercritical processing composition. Alternatively, the container may be a glass container or a glass-lined container.

[0083] Resin materials include polyvinyl chloride resin (PVC), polyethylene resin (PE), polypropylene resin (PP), polystyrene resin (PS), acrylonitrile butadiene styrene resin (ABS), acrylonitrile styrene resin (AS), polymethyl methacrylic resin (PMMA), polyvinyl alcohol resin (PVA), polyvinylidene chloride resin (PVDC), polyethylene terephthalate resin (PET), polyamide (nylon) resin (PA), polyacetal resin (POM), polycarbonate resin (PC), polyphenylene ether resin (PPE), polybutylene terephthalate resin (PBT), polyvinylidene fluoride resin (PVDF), and perfluoroalkoxyalkane. Resin compositions containing at least one selected from the group consisting of polytetrafluoroethylene resin (PFA), polytetrafluoroethylene resin (PTFE), polysulfone resin (PSU), polyethersulfone resin (PES), polyphenylene sulfide resin (PPS), polyarylate resin (PAR), polyamideimide resin (PAI), polyetherimide resin (PEI), polyetheretherketone resin (PEEK), polyimide resin (PI), phenolic resin (PF), urea resin (UF), melamine resin (MF), unsaturated polyester resin (UP), epoxy resin (EP), silicone resin (SI), polyurethane resin (PUR), epoxy-phenolic resin, and phenol-butyral resin are preferred.

[0084] The metal material is preferably a metal selected from the group consisting of iron, copper, aluminum, stainless steel, titanium, nickel, zinc, tin, brass, magnesium, chromium, lead, silver, tungsten, and tantalum; an alloy containing at least one metal selected from the group; or a compound containing at least one metal selected from the group. Examples of alloys include nickel-chromium plating, solder, and tin plating. Examples of compounds containing metals include alumite sulfate, zinc phosphate, and iron phosphate.

[0085] Examples of glass materials include soda lime glass, borosilicate glass, and quartz glass.

[0086] The vessel body and the portion that comes into contact with the supercritical processing composition may be made of different materials. Examples of materials for the vessel body include iron (steel), stainless steel, carbon steel, manganese steel, chromium-molybdenum steel, other low-alloy steels, aluminum alloys, and glass. Examples of stainless steel include SUS316, SUS304, and JFE443CT.

[0087] The shape and size of the container can be designed according to the purpose. For example, the container may be a storage tank, which is a fixed storage container, a transportable container, a shipping container, etc. Examples of transportable containers include 1 L glass bottles, 20 L pails, 200 L drums, ton containers, aerosol cans, and high-pressure gas containers (non-refillable containers, welded containers, seamless containers, etc.). Examples of shipping containers include tank trucks, ISO containers, and self-loaders.

[0088] The storage container may be hermetically sealed. The method for sealing the storage container is not particularly limited, and examples thereof include a method of sealing with a screw cap or a method of sealing with a valve. Elastic members such as cushioning materials or sealing materials that increase airtightness may also be used.

[0089] Examples of materials for the elastic member include styrene-butadiene rubber (SBR), isoprene rubber (IR), butadiene rubber (BR), ethylene-propylene rubber (EPM), urethane rubber (U), chloroprene rubber (CR), nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), fluororubber (FKM) in which carbon-hydrogen bonds exist in part of the main chain, perfluoroelastomer in which the main chain is completely fluorinated, chlorinated polyethylene (CM), acrylic rubber (ACM), polysulfide rubber (T), epichlorohydrin rubber, styrene-based thermoplastic elastomer, olefin-based thermoplastic elastomer, ester-based thermoplastic elastomer, urethane-based thermoplastic elastomer, amide-based thermoplastic elastomer, PVC-based thermoplastic elastomer, and fluorine-based thermoplastic elastomer.

[0090] In a preferred embodiment, the container may have a container body made of a metal material and an iron phosphate coating or zinc phosphate coating that covers the portion of the container body that comes into contact with the supercritical processing composition. The metal material that constitutes the container body is preferably iron (steel), and cold-rolled steel (SPCC) can be used. The composition of the iron phosphate coating is FePO ４ ・2H ２ The thickness of the iron phosphate coating is generally 1 μm or less, and may be 0.5 μm or less. The composition of the zinc phosphate coating is Zn ３ (P.O. ４ ) ２ ・4H ２ O or Zn ２ Fe(PO ４ ) ２ ・4H ２ The zinc phosphate coating is generally 5 μm or less in thickness, preferably 3 μm to 5 μm. The iron phosphate coating or zinc phosphate coating can be formed by a known phosphate treatment (also known as Parker treatment).

[0091] In another preferred embodiment, the container may have a container body made of a metal material and a resin layer covering a portion of the container body that comes into contact with the supercritical processing composition. The metal material constituting the container body is preferably iron (steel) or stainless steel. The resin material constituting the resin layer is preferably phenolic resin (PF), epoxy resin (EP), polyethylene resin (PE), epoxy-phenolic resin, or phenol-butyral resin. The phenolic resin may be a condensate derived from a phenolic compound by a conventionally known method. Examples of phenolic compounds include bisphenol A, bisphenol B, bisphenol F, 1,1-bis(4-hydroxyphenyl)ethane, phenol (carbolic acid), m-cresol, m-ethylphenol, 3,5-xylenol, m-methoxyphenol, o-cresol, p-cresol, p-tert-butylphenol, p-ethylphenol, 2,3-xylenol, 2,5-xylenol, p-tert-aminophenol, p-nonylphenol, p-phenylphenol, and p-cyclohexylphenol. The epoxy resin may be a condensate derived from an epoxy compound by a conventionally known method. Examples of epoxy compounds include glycidyl ethers, glycidyl esters, glycidyl amines, linear aliphatic epoxides, alicyclic epoxides, and hydantoin-type epoxies. Resins having a siloxane bond and an epoxy structure may also be used. The epoxy-phenolic resin may be a mixed resin of the above-mentioned phenolic resin and the above-mentioned epoxy resin. A resin having at least a phenolic structure and an epoxy structure may also be used. The phenol-butyral resin may be a mixed resin of the above-mentioned phenolic resin and butyral resin (PVB). A resin having at least a phenolic structure and a vinyl butyral structure may also be used.

[0092] In another preferred embodiment, the container may be a storage container having a container body made of a metal material and a metal plating layer covering a portion of the container body that comes into contact with the supercritical processing composition. The metal material constituting the container body is preferably iron (steel), stainless steel, carbon steel, or a light alloy. The metal plating layer preferably contains at least one selected from the group consisting of zinc, tin, copper, and brass.

[0093] Next, embodiments of the present disclosure will be described in detail using examples, but the embodiments of the present disclosure are not limited to these examples.

[0094] <Combustion Test> In the following examples, the flammability of the supercritical processing composition was evaluated by a combustion test. The combustion test was carried out by measuring the temperature rise inside the test vessel before and after ignition using a measuring device based on Explosion Limit Measurement Method A in Article 2, Paragraph 1, A and B of the General High-Pressure Gas Safety Regulations. Ignition was carried out by discharge from an electrode placed in the center of the vessel. The discharge was carried out under ignition conditions of 16 kV, 50 mA, and 0.23 seconds, in accordance with the discharge energy of ASTM E681. The details of the test conditions and the evaluation criteria are as follows:

[0095] (Test conditions) Test vessel: 2 L capacity spherical stainless steel vessel Test gas: supercritical processing composition, dry air, and moisture Test temperature: 20°C ± 5°C or 60°C ± 5°C Test pressure: 101.3 kPa ± 0.7 kPa (absolute pressure) Moisture: 0.0088 g ± 0.0005 g per 1 g of dry air (moisture content at 50% relative humidity at 23°C) Ignition method: AC discharge, voltage 16 kV, current 50 mA, 0.23 seconds Electrode position: center of vessel, electrode spacing 4.0 mm Stirring conditions: 300 rpm, 10 minutes

[0096] (Evaluation criteria) - If the temperature rise in the test container before and after ignition is 50°C or more: Flame spread (flammable: A) - If the temperature rise in the test container before and after ignition is less than 50°C: Flame does not spread (non-flammable: B)

[0097] 1. CO to HFO-1132a ２ Additive effect: Adds non-flammable CO to flammable HFO-1132a. ２After preparing a composition for supercritical processing by adding HFO-1132a, water and dry air were further mixed to obtain air with a relative humidity of 50% at 23°C, and the temperature rise inside the test vessel before and after discharge ignition under the above test conditions (test temperature: 60°C ± 5°C) was observed. In this test, HFO-1132a alone (Nos. A1 to A3), or HFO-1132a and CO ２ The mixtures (Nos. A4 to A6) were regarded as supercritical processing compositions, and in order to confirm that flammability would be suppressed if each supercritical processing composition leaked into the air, dry air and air prepared with water were mixed and evaluated.

[0098] The mass ratio, volume ratio, and test results of each component are shown in the table below. In the table below, "mass ratio / composition for supercritical processing" refers to the total amount of the composition for supercritical processing (i.e., HFO-1132a and CO ２ The "volume ratio / (composition for supercritical processing + air)" represents the mass ratio of each component when the total amount of the composition for supercritical processing and air is taken as 100% by volume. From Nos. A4 to A6, the composition for supercritical processing contains CO ２ It was confirmed that the temperature rise inside the test vessel can be suppressed by adding

[0099]

[0100] 2. CO of HFO-1132a ２ Non-flammable by mixing HFO-1132a with CO ２ After preparing a composition for supercritical processing by adding HFO-1132a and CO, water and dry air were further mixed to obtain air with a relative humidity of 50% at 23°C, and the temperature rise inside the test vessel was observed before and after discharge ignition under the above test conditions. ２ The mixture was regarded as a supercritical processing composition, and in order to confirm that non-flammability could be ensured even if each supercritical processing composition leaked into the air, an evaluation was carried out by mixing air in a predetermined ratio.

[0101] The mass ratio, molar ratio, and volume ratio of each component, as well as the test results, are shown in Table 3 (test temperature: 20°C ± 5°C) and Table 4 (test temperature: 60°C ± 5°C). In the tables below, "mass ratio / composition for supercritical processing" refers to the total amount of the composition for supercritical processing (i.e., HFO-1132a and CO ２ The "molar ratio / composition for supercritical processing" represents the mass ratio of each component when the total amount of the composition for supercritical processing (i.e., the total amount of HFO-1132a and CO ２ The "volume ratio / (composition for supercritical processing + air)" represents the molar ratio of each component when the total amount of the composition for supercritical processing and air is taken as 100 vol%.

[0102]

[0103] Based on the results in Table 3, HFO-1132a and CO ２ CO relative to the total amount ２ The horizontal axis represents the content (mass%) of HFO-1132a and CO ２ , and HFO-1132a and CO relative to the total amount of air ２ The total content (volume %) of HFO-1132a and CO is plotted on the vertical axis in a graph shown in Figure 3. ２ It was confirmed that the flammable range was suppressed by adding HFO-1132a and CO. ２ CO ２ By making the amount of HFO-1132a and CO ２ It was found that the supercritical processing composition containing HFO-1132a and CO is non-flammable regardless of the ratio of HFO-1132a and CO ２ Contains HFO-1132a and CO ２ CO relative to the total amount ２ 3 shows that a composition for supercritical processing having a content of 76.4 mass % or more of HFO-1132a and CO can be guaranteed to be non-flammable even when leaked into the air. ２ CO relative to the total amount ２The right side of the dashed line (indicated as "non-combustible"; including 76.4% by mass) represents the range of the Examples, and the left side of the dashed line (indicated as "combustible"; not including 76.4% by mass) represents the range of the Comparative Examples.

[0104]

[0105] Based on the results in Table 4, HFO-1132a and CO ２ CO relative to the total amount ２ The horizontal axis represents the content (mass%) of HFO-1132a and CO ２ , and HFO-1132a and CO relative to the total amount of air ２ The total content (volume %) of HFO-1132a and CO is plotted on the vertical axis in a graph shown in Figure 4. ２ It was confirmed that the flammable range was suppressed by adding HFO-1132a and CO. ２ CO ２ By making the amount of HFO-1132a and CO 79.5 mass % or more, ２ It was found that the supercritical processing composition containing HFO-1132a and CO is non-flammable regardless of the ratio of HFO-1132a and CO ２ Contains HFO-1132a and CO ２ CO relative to the total amount ２ 4 shows that a composition for supercritical processing having a content of 79.5 mass % or more can be guaranteed to be non-flammable even when leaked into the air. ２ CO relative to the total amount ２ The right side of the dashed line (indicated as "non-flammable"; including 79.5% by mass) represents the range of the examples.

[0106] Furthermore, when a similar test was carried out using HFO-1123 instead of HFO-1132a, the boundary value of the carbon dioxide content at which the composition for supercritical processing became non-flammable was found to be lower.

[0107] As shown above, a composition for supercritical processing was obtained which is easy to handle and has reduced flammability due to its low critical temperature and critical pressure.

[0108] The disclosure of Japanese Patent Application No. 2024-129228, filed on August 5, 2024, is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards mentioned herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard was specifically and individually indicated to be incorporated by reference.

[0109] 10, 30 Supercritical processing section 12, 32 Storage section 14 Pressurizing section 16 Heating section 18, 38 Supply section 18a, 38a Flow rate adjusting section 20, 40 Chamber 22, 42a, 42b Heating section 24, 44 Discharge section 24a, 44a Flow rate adjusting section 26, 46 Separation section 28, 48 Cooling section S Article L Liquid

Claims

1. A composition for supercritical processing comprising a halogenated olefin having two carbon atoms and carbon dioxide, wherein the content of the carbon dioxide relative to the total amount of the halogenated olefin having two carbon atoms and the carbon dioxide is 76.4 mass% or more, and wherein the amount of oxygen relative to the total amount of the composition for supercritical processing is less than 1.0 volume%.

2. A composition for supercritical processing according to claim 1, comprising a halogenated olefin having two carbon atoms and carbon dioxide, wherein the content of the carbon dioxide relative to the total amount of the halogenated olefin having two carbon atoms and the carbon dioxide is 79.5 mass% or more, and wherein the amount of oxygen relative to the total amount of the composition for supercritical processing is less than 1.0 volume%.

3. The composition for supercritical processing according to claim 1, wherein the halogenated olefin having two carbon atoms comprises at least one selected from the group consisting of 1,1-difluoroethylene, (E)-1,2-difluoroethylene, (Z)-1,2-difluoroethylene, and trifluoroethylene.

4. The composition for supercritical processing according to claim 1, wherein the halogenated olefin having two carbon atoms is 1,1-difluoroethylene.

5. The composition for supercritical processing according to claim 4, wherein the content of said carbon dioxide relative to the total amount of said 1,1-difluoroethylene and said carbon dioxide is 80.0 mass % or more.

6. The composition for supercritical processing according to claim 1, further comprising the halogenated olefin having two carbon atoms and an organic solvent having a boiling point higher than that of carbon dioxide, and used for supercritical cleaning of an article.

7. The supercritical treatment composition according to claim 1, further comprising a wood preservative and used for supercritical penetration of said wood preservative into wood.

8. The supercritical processing composition according to claim 7, wherein the wood preservative comprises at least one selected from the group consisting of ammonium-based wood preservatives, triazole-based wood preservatives, neonicotinoid-based wood preservatives, phenylpyrazole-based wood preservatives, phenylpyrrole-based wood preservatives, benzoylphenylurea-based wood preservatives, anthranilic diamide-based wood preservatives, strobilurin-based wood preservatives, pyrethroid-based wood preservatives, and fatty acid metal salts.

9. A method for supercritical processing of an article, comprising contacting the article with the composition for supercritical processing according to any one of claims 1 to 8 in a supercritical state.

10. The method for supercritical processing of an article according to claim 9, wherein the composition for supercritical processing is heated, pressurized, or heated and pressurized to bring the halogenated olefin having two carbon atoms and the carbon dioxide into the supercritical state.

11. The method for supercritical processing of an article according to claim 9, wherein after said contacting, said supercritical processing composition is cooled, depressurized, or cooled and depressurized.

12. The method for supercritical processing of an article according to claim 9, which is dependent on claim 6, wherein after said contacting, said organic solvent is separated from said supercritical processing composition.

13. The method of supercritical processing of an article according to claim 9, wherein the article is a substrate having a wafer and a structure stacked on the wafer.

14. The method of supercritical processing of an article according to claim 9, wherein the article is wood.

15. A supercritical processing apparatus comprising: a supercritical processing composition according to any one of claims 1 to 6; a storage unit configured to store the supercritical processing composition; a chamber configured to accommodate an object; a heating unit configured to heat the supercritical processing composition; a supply unit configured to supply the supercritical processing composition into the chamber; and a discharge unit configured to discharge the supercritical processing composition from the chamber.

16. The supercritical processing system of claim 15, wherein the article is a substrate having a wafer and a structure stacked on the wafer.

17. A container containing a composition for supercritical processing, comprising the composition for supercritical processing according to any one of claims 1 to 8 and a container for containing the composition for supercritical processing.

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