Method and system for recycling reactive gas

Abstract

To provide a method for reusing a reactive gas by which the reduction of production cost and the reduction of environmental load are realized in the production of electronic parts.SOLUTION: A method for reusing a reactive gas includes a step I of chemical reaction treatment using a reactive gas, a step II of separating and recovering an unreacted reactive gas from a used gas discharged as a result of the chemical reaction treatment, a step III of detoxifying and draining the remaining used gas, and a step IV of chemically reacting and reusing the separated and recovered used and unreacted reactive gas. The used and unreacted reactive gas is reused so that the consumption ratio P (%) of the unused reactive gas represented by the following formula (S1) becomes a predetermined value. (Consumption ratio P of unused reactive gas) = (A-D) / A * 100 (S1) A is the input volume of the unused reactive gas, and D is the volume of the used and unreacted reactive gas to be subjected to abatement and wastewater treatment in step III SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method and system for recycling reactive gases. [Background technology]

[0002] 2. Description of the Related Art Various techniques are used in manufacturing electronic components including semiconductor devices such as semiconductors and liquid crystal displays. For example, chemical vapor deposition (CVD) is a film-forming technology used to form thin films. In the film-forming process using CVD, raw material gases for the target thin film are supplied to a reaction vessel called a chamber, and energy such as heat, plasma, or light is applied to deposit the film on the wafer through a chemical reaction. In addition to the film-forming process using the CVD method, the chamber also performs other processes, such as an etching process in which holes are created in the film through an ionization reaction using reactive gases, and an annealing process in which silicon wafers whose Si crystal structure has been destroyed by ion implantation and turned amorphous are heated to improve their crystallinity.

[0003] These processes are called dry processes because they mainly use gases, as opposed to processes that use liquids (wet) such as water or chemicals. This dry process is a processing step for product materials and components, and various processing steps can be performed in a single chamber. It is necessary to keep the chamber clean as needed to prevent the gases used in each process and the generated dust from affecting the wafers produced through these various processes. For this reason, it is important to insert a chamber cleaning process between dry processes. For example, in the film formation process using the aforementioned CVD method, deposits accumulate on the inner surface of the chamber. If these deposits peel off during the process and fall onto the film, they can become fine particles on the wafer, causing problems. Therefore, after each film formation process, a chamber cleaning process using a reactive gas is performed to clean the inside of the chamber, and the film formation process and chamber cleaning process are repeated. The timing of the chamber cleaning process is adjusted appropriately depending on the purpose. In addition, the cleaning gas type and cleaning process time are also adjusted appropriately based on the gas type used in product manufacturing. Currently, each product manufacturer and other organizations use their own unique methods (recipe) for determining these timings, cleaning gas types, cleaning process times, etc., based on experiments, experience, etc.

[0004] Nitrogen trifluoride (NF3) gas is widely used as a reactive gas in chamber cleaning processes to remove Si deposits. This cleaning process involves generating SiF4 (gas) from F radicals generated by the following reaction: NF3 + plasma ⇒ N + 3F (radical) Si + 4F ⇒ SiF4 (gas)↑ In addition to NF3, the reactive gas may be various other gases such as hexafluoroethane (C2F6) or carbonyl fluoride (COF2).

[0005] Although the reactive gas has a high cleaning effect, it has a very high global warming potential (GWP), and if released directly into the atmosphere, it will have a negative impact on the environment. Therefore, the used gas (exhaust gas) containing unreacted reactive gas is decomposed and rendered harmless in a detoxification device installed downstream of the chamber. Furthermore, the fluorine generated is recovered as calcium fluoride (CaF2) or disposed of as sludge in a wastewater treatment device.

[0006] The detoxification equipment uses various detoxification methods depending on the type of used gas to be treated. For example, there are combustion, catalytic, adsorption, and plasma decomposition types, and these are selected and used depending on the type of gas. For example, in the case of NF3 gas, the combustion type is widely used, in which the gas is combusted together with fuel, oxidatively decomposed, and detoxified (see, for example, Patent Document 1). Furthermore, Patent Document 2 describes a technology for suppressing the formation of deposits in an exhaust gas treatment facility by combusting exhaust gas and supplying alkaline service water to the exhaust gas treatment facility. Patent Document 3 describes a wastewater treatment technology for treating scrubber wastewater from a treatment device for fluorine-containing exhaust gas and returning it to the exhaust gas treatment facility. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 4-290524 [Patent Document 2] Japanese Patent Publication No. 2022-72981 [Patent Document 3] Japanese Patent Publication No. 2022-70609 Summary of the Invention [Problem to be solved by the invention]

[0008] It is generally known that dry processes using reactive gases, such as chamber cleaning processes, have a low reaction rate (the proportion of the reactive gas introduced that contributes to the process). While depending on the process and recipe, the reaction rate can be as low as less than 1%, and typically ranges from several percent to several tens of percent (the percentages are based on volume). Therefore, the used gas after the dry process contains a large amount of unreacted reactive gas, and is discharged as is and treated in a detoxification device or the like in a downstream stage. It is important to recover and reuse the unreacted reactive gas contained in this used gas (used unreacted reactive gas) from the viewpoint of reducing production costs and reducing environmental loads. However, as mentioned above, each electronic component manufacturer uses its own recipe, and the reaction rate, which is one part of the recipe, varies. This means that the amount of used and unreacted reactive gas emitted varies depending on the electronic component manufacturer. Moreover, the recipe is often kept confidential as it is the electronic component manufacturer's know-how. In addition, in the case of the chamber cleaning process, the recipe used, such as the number of cleanings and the time, varies depending on the state of the deposits in the chamber, which further changes the reaction rate of the reactive gas and makes it unstable. Under these circumstances, it is becoming difficult to uniformly formulate a method for reusing reactive gases as a measure to reduce manufacturing costs and environmental impact.

[0009] In view of the above circumstances, an object of the present invention is to provide a method for recycling reactive gases that can reduce manufacturing costs and environmental loads even when various recipes are used in the manufacture of electronic components. Another object of the present invention is to provide a reactive gas recycling system suitable for carrying out the above-mentioned reactive gas recycling method. [Means for solving the problem]

[0010] The present invention provides the following technical means. [1] Step I of chemical reaction treatment using reactive gas in the manufacture of electronic components; A process II separates and recovers the used and unreacted reactive gas from a portion of the used gas that contains the used and unreacted reactive gas and is discharged as a result of the chemical reaction treatment; and a process III detoxifies and discharges the remaining used gas. and step IV of introducing the separated and recovered used unreacted reactive gas into the chemical reaction treatment for reuse, The reactive gas used in the step I includes an unused reactive gas and the used, unreacted reactive gas that has been separated and recovered, A method for recycling reactive gas, which recycles the used and unused reactive gas so that a consumption rate P (%) of the unused reactive gas shown in the following formula (S1) becomes a predetermined value. (Consumption rate of unused reactive gas P) = (AD) / A × 100 (S1) A: The volume of the unused reactive gas D: The volume of the used, unreacted reactive gas to be detoxified and treated for wastewater in the step III. [2] Step I of chemical reaction treatment using reactive gas in the manufacture of electronic components; A process II separates and recovers the used and unreacted reactive gas from a portion of the used gas that contains the used and unreacted reactive gas and is discharged as a result of the chemical reaction treatment; and a process III detoxifies and discharges the remaining used gas. and step IV of introducing the separated and recovered used unreacted reactive gas into the chemical reaction treatment for reuse, The reactive gas used in the step I includes an unused reactive gas and the used, unreacted reactive gas that has been separated and recovered, A method for recycling a reactive gas, which sets the separation and recovery rate Q (%) of the used, unreacted reactive gas, shown in the following formula (S2), to a predetermined value. (Separation and recovery rate of used unreacted reactive gas Q) = E / C × 100 (S2) C: The volume of the used, unreacted reactive gas contained in the used gas discharged as a result of step I. E: The volume of the used unreacted reactive gas separated and recovered in step II. [3] The method for recycling reactive gas according to [1], wherein the consumption rate P of the unused reactive gas is set to 50% or more. [4] The method for recycling reactive gas according to [2], wherein the separation and recovery rate Q of the used, unreacted reactive gas is set to 50% or more. [5] The method for recycling a reactive gas according to any one of [1] to [4], wherein the chemical reaction treatment step is an etching step. [6] The method for recycling a reactive gas according to any one of [1] to [4], wherein the chemical reaction treatment is chamber cleaning. [7] The method for recycling a reactive gas according to any one of [1] to [4], wherein the reactive gas is a perfluoro compound gas, and the used gas is a nitrogen-containing perfluoro compound gas. [8] The method for recycling a reactive gas according to any one of [1] to [4], wherein the reactive gas contains at least one of NF3, C2F6, ClF3, SF6, and COF2. [9] An apparatus I for performing a chemical reaction process using a reactive gas in the manufacture of electronic components; A device II separates and recovers the used unreacted reactive gas from a portion of the used gas that contains the used unreacted reactive gas and is discharged as a result of the chemical reaction treatment, and a device III detoxifies and treats the remaining used gas as wastewater. and a device IV for introducing the separated and recovered used unreacted reactive gas into the chemical reaction treatment for reuse, The reactive gas used in the device I includes unused reactive gas and the used, unreacted reactive gas that has been separated and recovered, A reactive gas recycling system having a function of recycling the used and unused reactive gas so that the consumption rate P (%) of the unused reactive gas shown in the following formula (S1) becomes a predetermined value. (Consumption rate of unused reactive gas P) = (AD) / A × 100 (S1) A: The volume of the unused reactive gas D: The volume of the used, unreacted reactive gas that is detoxified and treated for wastewater in the device III.

[10] An apparatus I for chemical reaction treatment using reactive gases in the manufacture of electronic components; A device II separates and recovers the used unreacted reactive gas from a portion of the used gas that contains the used unreacted reactive gas and is discharged as a result of the chemical reaction treatment, and a device III detoxifies and treats the remaining used gas as wastewater. and a device IV for introducing the separated and recovered used unreacted reactive gas into the chemical reaction treatment for reuse, The reactive gas used in the device I includes unused reactive gas and the used, unreacted reactive gas that has been separated and recovered, A reactive gas reuse system having a function of setting the separation and recovery rate Q (%) of the used, unreacted reactive gas shown in the following formula (S2) to a predetermined value. (Separation and recovery rate of used unreacted reactive gas Q) = E / C × 100 (S2) C: The volume of the used, unreacted reactive gas contained in the used gas discharged as a result of the chemical reaction treatment by the device I. E: Volume of the used unreacted reactive gas separated and recovered in the device II [Effects of the Invention]

[0011] According to the method for recycling reactive gases of the present invention, it is possible to reduce manufacturing costs and environmental loads even when various recipes are used in the manufacture of electronic components. Furthermore, according to the reactive gas recycling system of the present invention, the above-mentioned reactive gas recycling method can be suitably carried out. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic diagram showing an embodiment of a system used in a reactive gas recycling method of the present invention. [Figure 2] FIG. 10 is a schematic diagram showing the configuration of an apparatus used in a comparative example. [Figure 3] FIG. 1 is a schematic diagram of patterns 1-1 and 1-2 of Example 1. [Figure 4] 1 is a schematic diagram of patterns 1-3 and 1-4 of Example 1. FIG. [Figure 5] FIG. 1 is a schematic diagram of patterns 1-5 and 1-6 of Example 1. [Figure 6] FIG. 1 is a schematic diagram of Pattern 1-7 of Example 1. [Figure 7] FIG. 1 is a schematic diagram of a pattern of Comparative Example 1. [Figure 8] FIG. 1 is a schematic diagram of pattern 2-1 of Example 2. [Figure 9] FIG. 10 is a schematic diagram of pattern 2-2 of Example 2. [Figure 10] FIG. 10 is a schematic diagram of Pattern 2-3 of Example 2. [Figure 11] FIG. 1 is a schematic diagram of pattern 2-4 of Example 2. [Figure 12] FIG. 1 is a schematic diagram of pattern 2-5 of Example 2. [Figure 13] FIG. 10 is a schematic diagram of a pattern of Comparative Example 2. DETAILED DESCRIPTION OF THE INVENTION

[0013] A preferred embodiment of the reactive gas recycling method of the present invention (hereinafter also referred to as the "recycling method of the present invention") will be described below with reference to the drawings. However, the reactive gas recycling method of the present invention and the recycling system described below are not limited to those using the configuration of system 100 shown in Figure 1, except as defined in the present invention.

[0014] First, "reactive gas" refers to a gas used in a chemical reaction in a chamber in a manufacturing method for electronic components, including semiconductor products, and includes various types depending on the object to be reacted. For example, perfluoro compound (PFC) gas can be mentioned. The perfluoro compound gas includes nitrogen trifluoride (NF3), sulfur hexafluoride (SF6), trifluoromethane (CHF3), tetrafluoromethane (CF 4)These include various gases such as nitrogen trifluoride (NF3), hexafluoroethane (C2F6), octafluoropropane (C3F8), and octafluorocyclobutane (C4F8). Among these, nitrogen trifluoride (NF3), hexafluoroethane (C2F6), chlorine trifluoride (ClF3), sulfur hexafluoride (SF6), and carbonyl fluoride (COF2) are used as cleaning gases. The "chemical reaction process" using the reactive gas includes various processes carried out using the reactive gas in the manufacturing method of electronic components, such as etching and chamber cleaning. Furthermore, examples of "electronic components" include semiconductor products such as semiconductors, semiconductor memories such as flash memories, liquid crystal displays, LED (Light Emitting Diode) devices, and solar power generation devices. The reactive gas recycling method and system of the present invention can be applied not only to the etching process and chamber cleaning process described above, but also to the recovery and reuse of various gases used in semiconductor manufacturing, such as impurity implantation processes using PH3 (phosphine) and B2H6 (diborane), film formation processes such as silicon nitride film formation using high-purity ammonia, silicon oxide film formation using nitrous oxide, SiH4, SiH2Cl2, and TEOS (tetraethoxysilane), and wiring processes using WF6 (tungsten hexafluoride).

[0015] The system 100 shown in FIG. 1 includes, as an example of an apparatus configuration, a chemical reaction processing unit 10, a used gas collection and distribution unit 20, a separation and recovery unit 30 for used gas EG, and a detoxification processing unit 40.

[0016] In the chemical reaction processing unit 10, step I of chemical reaction processing using reactive gas RG is performed. That is, the chemical reaction processing unit 10 serves as the chemical reaction processing device I. The reactive gas RG used in step I includes unused reactive gas RG1 and previously used, unreacted reactive gas RG2 that has been separated and recovered. The separation and recovery step II described above is carried out in the spent gas collection and distribution section 20 and the separation and recovery section 30 for the spent gas EG. That is, the spent gas collection and distribution section 20 and the separation and recovery section 30 for the spent gas EG constitute the separation and recovery device II. The above-mentioned detoxification and wastewater treatment step III is carried out in the spent gas collection and distribution section 20 and the detoxification treatment section 40. That is, the spent gas collection and distribution section 20 and the detoxification treatment section 40 constitute the detoxification and wastewater treatment device III. The above-mentioned reuse step IV is carried out in the separation and recovery section 30 and the chemical reaction treatment section 10. That is, the separation and recovery section 30 and the chemical reaction treatment section 10 serve as the reuse device IV.

[0017] In this way, the system 100 interconnects the above-described apparatus components to separate and recover the used, unreacted reactive gas RG2 from the used gas EG containing the used, unreacted reactive gas RG2 discharged as a result of a chemical reaction process using the reactive gas RG in the manufacture of electronic components, and reuses the separated and recovered used, unreacted reactive gas RG2 in the chemical reaction process. That is, the system 100 is equipped with a mechanism for circulating and reusing the reactive gas RG. Note that the used, unreacted reactive gas RG2 does not include gas that cannot be reused in the chemical reaction process, such as reactive gas used in chamber cleaning that remains decomposed to generate radicals.

[0018] In the above mechanism, the unused reactive gas RG2 is reused so that the consumption rate P (%) of the unused reactive gas RG1 shown in the following formula (S1) reaches a predetermined value. (Consumption rate of unused reactive gas P) = (AD) / A × 100 (S1) A: Input volume of unused reactive gas RG1 D: Volume of the used, unreacted reactive gas RG2 to be detoxified and treated for wastewater in the step III

[0019] Additionally, in system 100, the following parameters related to reactive gas RG are relevant: B: The volume of reactive gas RG introduced in step I (A+E) C: The volume of the used, unreacted reactive gas RG2 contained in the used gas EG discharged as a result of the step I (D+E) E: Volume (CD) of the used, unreacted reactive gas RG2 separated and recovered in step II

[0020] The above parameters relating to the reuse of the reactive gas RG are shown below in combination with the above steps I to IV. A+E=B→[Process I]→C→[Process II] →E→[Process IV]→* (*↑) →[Process III]→D

[0021] "The consumption rate P (%) shown in formula (S1) becomes a predetermined value" means not only actually calculating the consumption rate P and making it a predetermined value, but also calculating the remaining rate and deciding to reuse the used and unused reactive gas RG2, so that the consumption rate P shown in formula (S1) becomes a predetermined value as a result. The "remaining rate" is the rate of the volume (D) of the used and unreacted reactive gas RG2 that is not used in step I and is detoxified and treated for wastewater in step III out of the input volume (A) of the unused reactive gas RG1, and is a value expressed as remaining rate = D / A × 100 (%), 100 - consumption rate P (%). In either case, making the consumption rate P (%) shown in formula (S1) a predetermined value means controlling the difference between the input volume A of unused reactive gas RG1 and the volume D of unreacted reactive gas RG to be detoxified and treated for wastewater to a constant ratio. In other words, it means controlling the relationship between the inlet and outlet in a system for circulating and reusing reactive gas RG. This makes it possible to efficiently reuse the reactive gas RG even if the input volume B of the reactive gas RG (RG1 and RG2), the reaction rate of the reactive gas RG in the chamber of step I, or the volume C of the used, unreacted reactive gas RG2 discharged as a result of the reaction rate is unknown. For example, if the consumption rate P is increased above a certain level, the "volume D of unreacted reactive gas RG sent to abatement and wastewater treatment" is reduced accordingly, so whether the reaction rate is high or low, the "volume E of used unreacted reactive gas RG2 separated and recovered" (= CD) is automatically adjusted accordingly, realizing efficient reuse of the reactive gas RG. This type of reuse allows the reactive gas RG to be used to its maximum effect. As a result, even if various recipes are used in the manufacture of electronic components, it is possible to reduce manufacturing costs and environmental loads.

[0022] At the same time, as mentioned above, the volume of used gas EG sent for abatement and wastewater treatment is reduced, which reduces the load on the abatement and wastewater treatment equipment, the investment costs for new equipment depending on the treatment scale, the floor space required for the abatement and wastewater treatment equipment, and operating costs. This also reduces the amount of used gas EG released into the environment after abatement. This is an appealing point for electronic component manufacturers from the perspective of ESG (Environmental Social Governance), and could be an even more positive motivation for adoption. Furthermore, by controlling the consumption rate P to a predetermined value using the reactive gas recycling method of the present invention, it is possible to reduce the amount of unused reactive gas RG1 (virgin gas) purchased and reduce the cost (initial running) of gas recovery equipment, thereby further reducing the manufacturing costs of electronic components. In particular, as described above, with the increasing number of layers and heights in 3D-NAND flash memories and the like, the number of steps in the film formation and chamber cleaning processes increases, and the amount of reactive gas RG used and the amount of exhaust gas treatment also increase. Therefore, the effect of reducing manufacturing costs and environmental loads according to the present invention becomes more important and significant. The reactive gas RG recycling method of the present invention and the recycling system described below, which have such effects, are extremely significant in view of the recent heightened global environmental awareness and the geopolitical risk issues surrounding natural gas resources such as F-based gases.

[0023] From the above viewpoint, the consumption rate P is preferably 50% or more, more preferably 80% or more, and even more preferably 90% or more.

[0024] From the same viewpoint as above, the separation and recovery rate Q (%) of the used, unreacted reactive gas RG2 shown in the following formula (S2) is set to a predetermined value. (Separation and recovery rate of used unreacted reactive gas Q) = E / C × 100 (S2)

[0025] Setting the separation and recovery rate Q of the used, unreacted reactive gas RG2 shown in equation (S2) to a predetermined value means controlling the ratio of the volume E of the separated and recovered used, unreacted reactive gas RG2 to the volume C of the used, unused reactive gas RG2 discharged as a result of step II to a constant value. If the separation and recovery rate Q is set to a certain level or higher, the ratio of the volume E of the separated and recovered used, unreacted reactive gas RG2 will increase, and the volume D of the used, unreacted reactive gas RG2 sent to detoxification and wastewater treatment will decrease. This increases the reuse (circulation) rate of the used, unreacted reactive gas RG2. At the same time, it will be possible to reduce the load on the abatement and wastewater treatment equipment and the investment costs for new equipment depending on the treatment scale, reduce the floor space required for the abatement and wastewater treatment equipment, and reduce operating costs, which will be an appealing point to the public.

[0026] From the above viewpoint, the aforementioned separation and recovery rate Q is preferably 50% or more, more preferably 80% or more, and even more preferably 90% or more.

[0027] It is also preferable to simultaneously satisfy the requirement for the consumption rate P in the above formula (S1) and the requirement for the separation and recovery rate Q in the above formula (S2). Specifically, it is preferable to achieve the aforementioned preferred range of the consumption rate P in the formula (S1) while setting the separation and recovery rate Q in the formula (S2) to greater than 0 (zero)%, and it is more preferable to achieve the aforementioned preferred range of the separation and recovery rate Q in the formula (S2) while setting the aforementioned preferred range of the consumption rate P in the formula (S1) while setting the separation and recovery rate Q in the formula (S2) to greater than 0 (zero)%. This makes it possible to further increase the reuse (circulation) rate of the used, unreacted reactive gas RG2 that is separated and recovered.

[0028] Regarding the aforementioned "A+E=B→[Step I]", the method of introducing unused reactive gas RG1 and used, unreacted reactive gas RG2 can include various forms as long as the requirements of the aforementioned formula (S1) or formula (S2) are met. For example, a mixed gas of unused reactive gas RG1 and used, unreacted reactive gas RG2 may be introduced into the chemical reaction process of step I. Alternatively, the chemical reaction process in [Step I] may be divided into a pre-processing step and a post-processing step, with the pre-processing step using the used, unreacted reactive gas RG2 and the post-processing step using the unused reactive gas RG1. This means that the pre-processing step uses the used, unreacted reactive gas RG2, while the post-processing step uses the unused reactive gas RG1 for finishing. This reduces concerns about yield degradation due to the use of the used, unreacted reactive gas. Furthermore, in the pre-processing, not only can the used, unreacted reactive gas RG2 be used without being mixed with the unused reactive gas RG1, but also a mixed gas of the used, unreacted reactive gas RG2 and the unused reactive gas RG1 can be used in order to further reduce the above concerns.

[0029] Each part of the system 100 will be described below.

[0030] (Chemical reaction processing unit 10) The chemical reaction processing unit 10 has a chamber 13 for carrying out the chemical reaction process using a reactive gas in the manufacturing process of the electronic component, as described above, and a mass flow controller (MFC) 11 and a valve 12 connected to the chamber 13. The system 100 may have one or more chambers 13. In Fig. 1, four chambers 13 (131 to 134) are provided. Supply lines for a reactive gas (e.g., NF3 gas) RG and a purge gas (e.g., nitrogen (N2) gas) PG1 are connected to each chamber 13 via mass flow controllers 11 (MFC1 to 8 and MFC13 to 16) and valves 12 (B1 to B8 and B13 to B16), respectively. The mass flow controller 11 controls the flow rate (supply volume) of the above gas. The valve 12 opens and closes the gas flow path. These allow the above gas to be continuously supplied while adjusting the flow rate. The chamber 13 is a reaction vessel used in the manufacturing process of electronic components. For example, processes such as thin film formation by CVD on wafers such as semiconductors, etching, and annealing are included. In addition, a chamber cleaning process is also included. The chamber cleaning process is a process for maintaining a clean interior of the chamber 13 so that various processes can be performed appropriately in a single chamber 13. For example, during the thin-film formation process on a wafer using the CVD method, deposits (e.g., SiO2 films) may accumulate on the inner surface of the chamber 13. The chamber cleaning process removes these deposits and cleans the interior of the chamber 13 before the next process. Depending on the deposition conditions (film type, thickness, etc.), the chamber cleaning process may be repeated not just once but multiple times to clean the interior of the chamber 13. For example, with the increasing number of layers and thicknesses in 3D-NAND flash memories and the like, the number of steps in the film formation and chamber cleaning processes tends to increase. This increases the amount of reactive gas used and the amount of exhaust gas treatment required. The reactive gas reuse method of the present invention is significant in addressing these recent trends.

[0031] In the present invention, the reactive gas RG includes an unused (new) reactive gas RG1 and a used, unreacted reactive gas RG2. The used, unreacted reactive gas RG2 is a gas separated and recovered from the used gas EG discharged as a result of the chemical reaction process (this separation and recovery will be described later). The used, unreacted reactive gas RG2 is basically separated and recovered on-site in the same system 100, but this is not necessarily limited to this. For example, the used, unreacted reactive gas RG2 may be separated and recovered off-site, or separated and recovered by another company (separated and recovered from another factory, etc.).

[0032] 1, the supply of unused (new) reactive gas RG1 and used, unreacted reactive gas RG2 is controlled by separate mass flow controllers 11 and valves 12. Specifically, the unused reactive gas RG1 passes through new supply lines L1-L4 and is controlled by MFCs 1-4 and valves B1-B4 connected thereto, and is supplied to each of the chambers 131-134. The used, unreacted reactive gas RG2 passes through reuse supply lines L13-L16 and is controlled by MFCs 13-16 and valves B13-B16 connected thereto, and is supplied to each of the chambers 131-134. This makes it possible to separately control the timing of supplying the unused reactive gas RG1 and the used, unreacted reactive gas RG2 to the chamber 13. This also makes it possible to separately control the flow rates (supply volumes) of the unused reactive gas RG1 and the used, unreacted reactive gas RG2, and further to control the volume ratio of the two gases.

[0033] The chemical reaction process using the reactive gas RG (RG1 and RG2) is carried out in a flow system environment in which the reactive gas RG is flowed into the chamber 13 while the outlet is evacuated by an exhaust vacuum pump 21 (211 to 214) described later.

[0034] In the system 100, it is preferable to supply the aforementioned purge gas PG1 to each of the chambers 131 to 134. The purge gas PG1 is supplied to each of the chambers 131 to 134 from supply lines L5 to L8 via MFCs 5 to 8 and valves B5 to B8. The purge gas PG1 is used to replace and exhaust gases used in various processes within the chambers 131 to 134, and is used to prevent residual gas and contamination. Examples of gas species for the purge gas PG1 include inert gas, air (atmosphere), and oxygen. Examples of the inert gas include rare gases such as nitrogen (N2) gas, argon gas, and helium gas. The purity of the gas is preferably 99.9% or higher, more preferably 99.99% or higher, and the fewer impurities in the gas, the better. The impurities include methane, oxygen, carbon dioxide, and moisture when the purge gas PG1 is an inert gas, and fine particles and moisture when the purge gas PG1 is air and oxygen.

[0035] (Spent gas collection and distribution unit 20) The used gas collection and distribution unit 20 has an exhaust vacuum pump (VP) 21 that sucks in the used gas EG discharged from the chamber 13, and a switching valve 22 connected to the exhaust vacuum pump 21. The number of exhaust vacuum pumps 21 and the switching valves 22 connected to the exhaust vacuum pumps 21 is equal to the number of chambers 13. 1, exhaust vacuum pumps 21 (211-214) are connected to exhaust lines L17-L20 at the outlets of the four chambers 131-134. The exhaust vacuum pumps 21 (211-214) are connected to switching valves 22 (221-224) via exhaust lines L21-L24. This allows the used gas EG exhausted from each of the chambers 131-134 to be transported to the next process. Furthermore, it is preferable to supply a purge gas PG2 to exhaust lines L17-L20 at the outlets of the chambers 131-134. The purge gas PG2 is supplied to each exhaust line L17-L20 from supply lines L9-L12 via MFCs 9-12 and valves B9-B12. The purge gas PG2 is used to prevent pipe blockage due to dust or the like of fine particles (deposits) discharged from the chambers 131-134, and to dilute the gas to below the lower explosive limit (LEL) of a flammable gas (e.g., silane gas). The gas species of the purge gas PG2 can be the same as that of the purge gas PG1.

[0036] The used gas EG includes both reacted and unreacted reactive gases RG (RG1 and RG2), because the reaction rate of the reactive gases RG in the chemical reaction process in the chamber 13 remains constant (for example, the reaction rate is less than 1% at the lowest, and typically several to several tens of percent).

[0037] The switching valves 22 (221 to 224) are connected to the separation and recovery section 30 via recovery lines L25 to L28, and to the detoxification treatment section 40 via detoxification lines L29 to L32. As a result, the switching valves 22 (221 to 224) distribute the spent gas EG (including used, unreacted reactive gas RG2) sucked by the exhaust vacuum pump to the separation and recovery section 30 and the abatement treatment section 40. The distribution is performed by the switching valve 22 switching between recovery lines L25 to L28 connected to the separation and recovery section 30 and abatement lines L29 to L32 connected to the abatement treatment section 40 depending on the flow status of the spent gas EG. The switching may be performed based on time if the process recipe is fixed, since the gas to be recovered will flow at a specific time.

[0038] From the viewpoint of performing the switching with more accuracy, it is preferable to provide an analyzer 23 (231 to 234) that analyzes the properties of the used gas EG, and to determine the timing of the switching based on the analysis results of the analyzer 23. For example, it is preferable to measure the concentration of the used, unreacted reactive gas RG2 in the used gas EG with the analyzer 23, and to recover the gas by switching the valve in a high concentration range or time period that allows efficient recovery. Various devices that can analyze the properties of gas can be used as the analyzer 23. For example, the analyzer 23 may be any of an FT-IR (Fourier transform infrared spectrophotometer), a GC (gas chromatography), and an MS (mass spectrometer), or a device that can perform a combination of these.

[0039] (Separation and recovery section 30) The separation and recovery section 30 has a configuration in which a recovered gas receiving tank 31, a recovery device 32, and a recovered gas tank 33 are connected to one another by gas lines. The used gas EG is joined via recovery lines L25 to L28 by switching the switching valves 22 (221 to 224), and is collected in a recovered gas receiving tank 31, where it is purified by a recovery device 32.

[0040] In the recovery device 32, the used, unreacted reactive gas RG2 contained in the used gas EG is recovered by the purification process (for example, the used, unreacted NF3 gas is separated and recovered from the diluted N2 and reaction products (SiH4, etc.) added to remove the fine particles that are being discharged). Various devices capable of separating and recovering the used, unreacted reactive gas RG2 from the used gas EG can be used as the recovery device 32. For example, the recovery device 32 may be a device capable of implementing any one of the common gas separation methods (cryogenic distillation, PSA (Pressure Swing Adsorption) / TSA (Temperature Swing Adsorption), membrane treatment, chromatography, etc.), or a combination of two or more of these methods.

[0041] The recovered gas tank 33 stores the recovered, used, unreacted reactive gas RG2. The recovered gas tank 33 is connected to the above-mentioned reuse supply lines L13 to L16. As a result, the stored, used, unreacted reactive gas RG2 is supplied to each chamber 13 (131 to 134) via MFC13 to MFC16 and valves B13 to B16. The used and unreacted reactive gas RG2 stored in the recovered gas tank 33 may be supplied entirely to each chamber 13 (131 to 134), or only a portion of it may be supplied.

[0042] This allows the system 100 to repeatedly separate, recover, and reuse the used, unreacted reactive gas RG2. That is, the system 100 allows the reactive gas RG to be circulated and reused within the apparatus configuration. In such a system for circulating and reusing the reactive gas RG, the consumption rate P and the separation and recovery rate Q described above can be realized.

[0043] The used, unreacted reactive gas RG2 that is separated, recovered, and reused is a gas containing purge gases PG1 and PG2 because purge gases PG1 and PG2 are used before and after chamber 13 as described above. For example, if reactive gas RG is a perfluoro compound gas and purge gases PG1 and PG2 are nitrogen (N2) gas, the used, unreacted reactive gas RG2 is a nitrogen-containing perfluoro compound gas. In this case, in order to efficiently recover unreacted reactive gas RG2 from used gas EG, it is preferable to determine the timing of switching of switching valve 22 so as to recover gas with a high concentration of reactive gas RG2 based on the analysis results of analyzer 23 (231-234) that analyzes the properties of used gas EG. For example, rather than supplying all of the used gas EG containing used, unreacted reactive gas RG2 (e.g., NF3 gas) to the recovery device, it is preferable to limit the recovery to used gas EG having a certain concentration or higher. For example, by separating and recovering used gas EG from the early to middle stages of chamber cleaning, and sending the latter half, when the used, unreacted reactive gas RG2 becomes diluted, to the detoxification treatment unit 40, the amount of gas processed by the recovery device 32 is reduced, and the recovery device 32 can be made smaller.

[0044] (Abatement processing department 40) The detoxification treatment unit 40 has a configuration in which an exhaust gas receiving tank 41, a detoxification device 42, a detoxification outlet tank 43, and a wastewater treatment device 44 are connected to one another by lines. The used gas EG is joined via the abatement lines L29 to L32 by switching the switching valves 22 (221 to 224), and is collected in the exhaust gas receiving tank 41 and treated in the abatement device .

[0045] The detoxification device 42 detoxifies harmful substances, including used, unreacted reactive gas RG2, in the used gas EG. Furthermore, the detoxification device 42 discharges wastewater in which components derived from the decomposed harmful substances (e.g., HF) are dissolved in supply water, and the wastewater is stored in a detoxification outlet tank 43. Various devices capable of carrying out the above treatment can be used as the abatement device 42. For example, the abatement device 42 may be a device capable of carrying out any one of abatement methods based on various principles, such as combustion, catalytic, or plasma, or a combination of two or more of these methods.

[0046] The wastewater treatment device 43 removes the components derived from the harmful substances from the wastewater transferred from the abatement outlet tank 43, and performs wastewater treatment, or disposes of the wastewater as sludge.

[0047] 1, the separation and recovery section 30 and the detoxification treatment section 40 are arranged in a one-to-one correspondence with the chemical reaction treatment section 10 and the spent gas collection and distribution section 20, but this is not limiting. For example, one separation and recovery section 30 and one detoxification treatment section 40 may be arranged for a plurality of chemical reaction treatment sections 10 and spent gas collection and distribution sections 20.

[0048] The reactive gas recycling system of the present invention is a system for carrying out the reactive gas recycling method of the present invention. That is, the reactive gas recycling system of the present invention is a system having an apparatus configuration (for example, a combination of the above-mentioned devices) for recycling the reactive gas described above, and having a function of setting the consumption rate P or the separation and recovery rate Q to a predetermined value. [Example]

[0049] The present invention will be described in more detail below based on examples, but the present invention should not be construed as being limited thereto.

[0050] The following examples and comparative examples illustrate a chamber cleaning process in semiconductor manufacturing as a specific example of a chemical reaction process in the manufacture of electronic components. The chamber cleaning process removes Si precipitates deposited in the chamber as a result of a film formation process on a wafer by CVD. NF3 gas is used as the reactive gas RG (RG1 and RG2). The time for gas supply for the film formation process by CVD is omitted. The time for purging between chamber cleaning processes and the time for loading and unloading wafers is also omitted. The number of chambers 13 to be cleaned is four. The amount of Si precipitates adhering to the inside of the chambers 13 during the film formation process by the CVD method is constant, and the amount of NF3 gas (flow rate x time) required to remove them is also constant. The amount of NF3 gas required for one cleaning in one chamber is 10 mL / min × 10 min = 100 mL, which is 400 mL for four chambers. However, in Example 2 and Comparative Example 2, the NF3 gas volume is doubled to 800 mL (equivalent to four chambers and two cleanings).

[0051] The reaction rate R shown in the examples and comparative examples is shown below together with the separation recovery rate Q and consumption rate P mentioned above. Reaction rate R: (BC) / B×100 Separation recovery rate Q: E / C x 100 Consumption rate P=(AD) / A×100 A: Volume of unused NF3 gas (RG1) B: The volume of NF3 gas (RG) introduced in step I (A+E) C: The volume (D+E) of the used and unreacted NF3 gas (RG2) contained in the used gas EG discharged as a result of the step I. D: The volume (CE) of the used, unreacted NF3 gas (RG2) to be detoxified and treated for wastewater in the step III E: Volume (CD) of the used, unreacted NF3 gas (RG2) separated and recovered in step II

[0052] [Example 1] (1) Pattern 1-1 A chamber cleaning process is performed using the apparatus 100 shown in Fig. 1, and a method for recycling NF3 gas (reactive gas RG) shown in Table 1 and Fig. 3 is implemented. A mixed gas of unused NF3 gas (RG1) and used but unused NF3 gas (RG2) is introduced into the chamber 13 (131 to 134). The consumption rate P is set to 50%. The reaction rate R of the NF3 gas in the chamber 13 is set to 30%. (2) Pattern 1-2 The method for recycling the reactive gas RG shown in Table 1 and FIG. 3 is carried out in the same manner as in Pattern 1, except that unused NF3 gas (RG1) and used but unused NF3 gas (RG2) are separately introduced into the chamber 13 (131 to 134). (3) Pattern 1-3 The method for reusing NF3 gas (reactive gas RG) shown in Table 1 and FIG. 4 is carried out in the same manner as in Pattern 1, except that the consumption rate P is set to 80%. (4) Pattern 1-4 The method for reusing NF3 gas (reactive gas RG) shown in Table 1 and FIG. 4 is carried out in the same manner as in Pattern 1, except that the consumption rate P is set to 90%. (5) Pattern 1-5 The method for recycling NF3 gas (reactive gas RG) shown in Table 1 and FIG. 5 is carried out in the same manner as in Pattern 1, except that the consumption rate P is set to 80% under the condition that the reaction rate R of NF3 gas (reactive gas RG) in chamber 13 is 50%. (6) Pattern 1-6 The method for recycling NF3 gas (reactive gas RG) shown in Table 1 and FIG. 5 is carried out in the same manner as in Pattern 1, except that the consumption rate P is set to 90% under the condition that the reaction rate R of NF3 gas (reactive gas RG) in chamber 13 is 50%. (7) Pattern 1-7 The method for recycling NF3 gas (reactive gas RG) shown in Table 1 and FIG. 6 is carried out in the same manner as in Pattern 1, except that the consumption rate P is set to 90% under the condition that the reaction rate R of NF3 gas (reactive gas RG) in chamber 13 is 80%.

[0053] [Comparative Example 1] The chamber cleaning process shown in Table 1 is carried out using the apparatus shown in FIG. That is, except that the NF3 gas (reactive gas RG) is not reused (the used, unreacted NF3 gas (RG2) is separated, recovered, and reused from the used gas EG), the chamber cleaning process shown in Table 1 and Figure 7 is carried out in the same manner as pattern 1-1 of Example 1.

[0054] [Table 1]

[0055] (i) Regardless of whether the input form is Pattern 1-1 or 1-2, the consumption rate P of 50% implemented under the reuse of NF3 gas (reactive gas RG) is approximately 1.7 times the consumption rate P of 30% in Comparative Example 1, indicating that NF3 gas (reactive gas RG) can be effectively utilized. Furthermore, by setting the consumption rate P to 50%, the separation and recovery rate Q of used and unused NF3 gas (RG2) becomes 57.1%, and this can be reintroduced into the chamber cleaning process, thereby reducing the input volume A of unused (new) NF3 gas (RG1) by 40% compared to Comparative Example 1 (reducing manufacturing costs). Furthermore, by separating, recovering, and reusing the used and unused NF3 gas (RG2), the volume D of used, unreacted NF3 gas (RG2) subjected to detoxification and wastewater treatment can be reduced by 57% compared to Comparative Example 1 (reducing costs for detoxification, etc.). (ii) In Patterns 1-3, the consumption rate P of 80% achieved with the reuse of NF3 gas (reactive gas RG) is approximately 2.7 times the consumption rate P of 30% in Comparative Example 1, demonstrating that NF3 gas (reactive gas RG) can be effectively utilized. Furthermore, by setting the consumption rate P to 80%, the separation and recovery rate Q of used and unused NF3 gas (RG2) becomes 89.3%, and this can be reintroduced into the chamber cleaning process, thereby reducing the input volume A of unused (new) NF3 gas (RG1) by 63% compared to Comparative Example 1 (reducing manufacturing costs). Furthermore, by separating, recovering, and reusing the used and unused NF3 gas (RG2), the volume D of used and unreacted NF3 gas (RG2) subjected to detoxification and wastewater treatment can be reduced by 89% compared to Comparative Example 1 (reducing costs for detoxification, etc.). (iii) In Patterns 1-4, the consumption rate P of 90% achieved by reusing NF3 gas (reactive gas RG) is three times the consumption rate P of 30% in Comparative Example 1, demonstrating that NF3 gas (reactive gas RG) can be effectively utilized. Furthermore, by setting the consumption rate P to 90%, the separation and recovery rate Q of used and unused NF3 gas (RG2) becomes 95.2%, and this can be reintroduced into the chamber cleaning process, thereby reducing the input volume A of unused (new) NF3 gas (RG1) by 67% compared to Comparative Example 1 (reducing manufacturing costs). Furthermore, by separating and recovering and reusing the used and unused NF3 gas (RG2), the volume D of used and unreacted NF3 gas (RG2) subjected to detoxification and wastewater treatment can be reduced by 95% compared to Comparative Example 1 (reducing costs for detoxification, etc.). (iv) In Pattern 1-5, under chemical reaction treatment conditions with a higher reaction rate R than in Pattern 1-3, a lower separation and recovery rate Q of 75.0% than in Pattern 1-3 was achieved, and a consumption rate P of 80%, indicating that NF3 gas (reactive gas RG) can be utilized more effectively than in Comparative Example 1. The input volume A of unused (new) NF3 gas (RG1) can be reduced by 38% (reduced manufacturing costs) compared to Comparative Example 1. In addition, the volume D of used, unreacted NF3 gas (RG2) to be detoxified and treated for wastewater can be reduced by 82% (reduced costs for detoxification, etc.) compared to Comparative Example 1. (v) In Pattern 1-6, under chemical reaction treatment conditions with a higher reaction rate R than in Pattern 1-4, a lower separation and recovery rate Q of 88.9% than in Pattern 1-4 and a consumption rate P of 90% were achieved, indicating that NF3 gas (reactive gas RG) can be utilized more effectively than in Comparative Example 1. The input volume A of unused (new) NF3 gas (RG1) can be reduced by 45% compared to Comparative Example 1 (reducing manufacturing costs). In addition, the volume D of used, unreacted NF3 gas (RG2) to be detoxified and treated for wastewater can be reduced by 92% compared to Comparative Example 1 (reducing costs for detoxification, etc.). (vi) In Pattern 1-7, under chemical reaction treatment conditions with a higher reaction rate R than in Pattern 1-4, a lower separation and recovery rate Q of 55.6% than in Pattern 1-4 was achieved, and a consumption rate P of 90%, indicating that NF3 gas (reactive gas RG) can be used more effectively than in Comparative Example 1. The input volume A of unused (new) NF3 gas (RG1) can be reduced by 11% (reduced manufacturing costs) compared to Comparative Example 1. In addition, the volume D of used, unreacted NF3 gas (RG2) to be detoxified and treated for wastewater can be reduced by 87% (reduced costs for detoxification, etc.) compared to Comparative Example 1.

[0056] Furthermore, as shown in patterns 1-1, 1-3, and 1-4 of Example 1, when the reaction rate R is constant, by increasing the consumption rate P, it is possible to reduce both the input volume A of unused (new) NF3 gas (RG1) and the volume D of used, unreacted NF3 gas to be detoxified and discharged, without changing the recipe. As shown in patterns 1-5 to 1-7 of Example 1, even if the reaction rate R changes, i.e., even if the reaction rate R is not disclosed, the consumption rate P can be kept constant while varying the separation and recovery rate Q, and NF3 gas (reactive gas RG) can be reused efficiently and without waste.

[0057] [Example 2] (1) Pattern 2-1 The chamber cleaning process is performed twice at two different reaction rates R (30% and 50%). The separation and recovery rate Q is varied according to each reaction rate R, and the consumption rate P is set to 80%. Other than this, the chamber cleaning process is performed in the same manner as in Example 1, and the method for recycling NF3 gas (reactive gas RG) shown in Table 2 and Figure 8 is implemented. A mixed gas of unused NF3 gas (RG1) and used but unused NF3 gas (RG2) is introduced into chamber 13 (131-134). (2) Pattern 2-2 The method for reusing NF3 gas (reactive gas RG) shown in Table 2 and FIG. 9 is carried out in the same manner as in pattern 2-1, except that the consumption rate P is set to 90%. (3) Pattern 2-3 The method for recycling NF3 gas (reactive gas RG) shown in Table 2 and Figure 10 is carried out in the same manner as pattern 2-1, except that the consumption rate P is varied according to the two types of reaction rates R (30% and 50%) to set the separation and recovery rate Q = 50%. (4) Pattern 2-4 The method for reusing NF3 gas (reactive gas RG) shown in Table 2 and FIG. 11 is carried out in the same manner as in Pattern 2-3, except that the separation and recovery rate Q is set to 80%. (5) Pattern 2-5 The method for reusing NF3 gas (reactive gas RG) shown in Table 2 and FIG. 12 is carried out in the same manner as in Pattern 2-3, except that the separation and recovery rate Q is set to 90%.

[0058] Comparative Example 2 The chamber cleaning process shown in Table 2 and Figure 13 is carried out in the same manner as pattern 2-1 of Example 2, except that NF3 gas (reactive gas RG) is not reused (separated, recovered, and reused from the used, unreacted NF3 gas (RG2) from the used gas EG).

[0059] [Table 2]

[0060] As shown in Table 2, the numerical values ​​of each pattern in Example 2 and Comparative Example 2 are compared below as the sum of the two chamber cleaning processes (two types of reaction rates R) (where the reaction rate R, separation and recovery rate Q, and consumption rate P are average values). (i) In Pattern 2-1, the consumption rate P of 80% achieved by reusing NF3 gas (reactive gas RG) is twice the consumption rate P of 40% (=(30+50) / 2)% in Comparative Example 2, demonstrating that NF3 gas (reactive gas RG) can be effectively utilized. Furthermore, by setting the consumption rate P to 80%, the separation and recovery rate Q of used and unused NF3 gas (RG2) becomes 82.1% (=(89.3+75.0) / 2). This gas is then reintroduced into the chamber cleaning process, reducing the input volume A of unused (new) NF3 gas (RG1) by 50% compared to Comparative Example 2 (reducing manufacturing costs). Furthermore, by separating, recovering, and reusing the used and unused NF3 gas (RG2), the volume D of used, unreacted NF3 gas (RG2) subjected to detoxification and wastewater treatment can be reduced by 83% compared to Comparative Example 2 (reducing costs for detoxification, etc.). (ii) In Pattern 2-2, the consumption rate P of 90% achieved by reusing NF3 gas (reactive gas RG) is 2.25 times the consumption rate P of 40% (=(30+50) / 2)% in Comparative Example 2, demonstrating that NF3 gas (reactive gas RG) can be effectively utilized. Furthermore, by setting the consumption rate P to 90%, the separation and recovery rate Q of used and unused NF3 gas (RG2) is 92.1% (=(95.2+88.9) / 2). This gas is then reintroduced into the chamber cleaning process, reducing the input volume A of unused (new) NF3 gas (RG1) by 55.5% compared to Comparative Example 2 (reducing manufacturing costs). Furthermore, by separating, recovering, and reusing the used and unused NF3 gas (RG2), the volume D of used, unreacted NF3 gas (RG2) subjected to detoxification and wastewater treatment can be reduced by 92.5% compared to Comparative Example 2 (reducing costs for detoxification, etc.). (iii) In Pattern 2-3, by maintaining the separation and recovery rate P at a constant value of 50%, the consumption rate P becomes 56.4 (= (46.2 + 66.7) / 2)%, which is 1.41 times the consumption rate P of 40 (= (30 + 50) / 2)% in Comparative Example 2, indicating that NF3 gas (reactive gas RG) can be effectively utilized. Furthermore, by setting the separation and recovery rate Q to 50%, this can be reintroduced into the chamber cleaning process, thereby reducing the input volume A of unused (new) NF3 gas (RG1) by 30% compared to Comparative Example 2 (reducing manufacturing costs). Furthermore, by separating and recovering the used, unused NF3 gas (RG2) and reusing it, the volume D of used, unreacted NF3 gas (RG2) to be detoxified and treated for wastewater can be reduced by 50% compared to Comparative Example 2 (reducing costs for detoxification, etc.). (iv) In Pattern 2-4, by keeping the separation and recovery rate P constant at 80%, the consumption rate P becomes 75.8 (= (68.2 + 83.3) / 2)%, which is 1.9 times the consumption rate P of 40 (= (30 + 50) / 2)% in Comparative Example 2, indicating that NF3 gas (reactive gas RG) can be effectively utilized. Furthermore, by setting the separation and recovery rate Q to 80%, this can be reintroduced into the chamber cleaning process, thereby reducing the input volume A of unused (new) NF3 gas (RG1) by 48% compared to Comparative Example 2 (reducing manufacturing costs). Furthermore, by separating and recovering the used, unused NF3 gas (RG2) and reusing it, the volume D of used, unreacted NF3 gas (RG“) to be detoxified and treated for wastewater can be reduced by 80% compared to Comparative Example 2 (reducing costs for detoxification, etc.). (v) In Pattern 2-5, by maintaining the separation and recovery rate P at a constant value of 90%, the consumption rate P becomes 86.0 (= (81.1 + 90.9) / 2)%, which is 2.15 times the consumption rate P of 40 (= (30 + 50) / 2)% in Comparative Example 2, indicating that NF3 gas (reactive gas RG) can be effectively utilized. Furthermore, by setting the separation and recovery rate Q to 90%, this can be reintroduced into the chamber cleaning process, thereby reducing the input volume A of unused (new) NF3 gas (RG1) by 54% compared to Comparative Example 2 (reducing manufacturing costs). Furthermore, by separating and recovering the used, unused NF3 gas (RG2) and reusing it, the volume D of used, unreacted NF3 gas (RG2) to be detoxified and treated for wastewater can be reduced by 90% compared to Comparative Example 2 (reducing costs for detoxification, etc.).

[0061] Furthermore, by keeping the consumption rate P constant at 80% and 90% in patterns 2-1 and 2-2 of Example 2, even if there is a chamber cleaning process in which the reaction rate R varies between 30% and 50%, operation is possible at a high consumption rate P, and NF3 gas (reactive gas RG) can be used efficiently and without waste. In patterns 2-3 to 2-5 of Example 2, by keeping the separation and recovery rate Q constant at 50%, 80%, and 90%, respectively, even if there is a chamber cleaning process in which the reaction rate R changes between 30% and 50%, operation is possible at a high consumption rate P, and NF3 gas (reactive gas RG) can be used efficiently and without waste. Furthermore, compared to patterns 2-3 to 2-5 of Example 2, patterns 2-1 and 2-2 of Example 2 can directly increase the consumption rate P and reduce the input volume A of unused (new) NF3 gas, making them superior in terms of reducing manufacturing costs. [Explanation of symbols]

[0062] 10 Chemical reaction processing section 11. MFC1~16 Mass flow controllers 12. B1~B16 valves 13, 131-134 Chambers 20 Spent gas collection and distribution section 21, 211-214 Exhaust vacuum pump 22, 221~224 Switching valve 23, 231~234 Analyzer 30 Separation and Recovery Section 31 Recovered gas receiving tank 32 Recovery device 33 Recovery Gas Tank 40 Harm removal treatment department 41 Exhaust gas receiving tank 42 Abatement equipment 43 Abatement outlet tank 44 Wastewater treatment equipment 100 devices

Claims

1. Step I of chemical reaction treatment using reactive gas in manufacturing electronic components; a step II of separating and recovering the used and unreacted reactive gas from a portion of the used gas that contains the used and unreacted reactive gas and is discharged as a result of the chemical reaction treatment; and a step III of detoxifying and discharging the remaining used gas. and step IV of introducing the separated and recovered used, unreacted reactive gas into the chemical reaction treatment for reuse, The reactive gas used in the step I includes an unused reactive gas and the used, unreacted reactive gas that has been separated and recovered, A method for recycling a reactive gas, comprising recycling the used and unused reactive gas so that a consumption rate P of the unused reactive gas, as shown in the following formula (S1), becomes a predetermined value. (Consumption rate P of unused reactive gas) = ​​(A - D) / A x 100 (S1) A: the input volume of the unused reactive gas D: The volume of the used, unreacted reactive gas to be detoxified and discharged in the step III

2. Step I of chemical reaction treatment using reactive gas in manufacturing electronic components; a step II of separating and recovering the used and unreacted reactive gas from a portion of the used gas that contains the used and unreacted reactive gas and is discharged as a result of the chemical reaction treatment; and a step III of detoxifying and discharging the remaining used gas. and step IV of introducing the separated and recovered used, unreacted reactive gas into the chemical reaction treatment for reuse, The reactive gas used in the step I includes an unused reactive gas and the used, unreacted reactive gas that has been separated and recovered, A method for recycling a reactive gas, wherein the separation and recovery rate Q of the used, unreacted reactive gas, represented by the following formula (S2), is set to a predetermined value. (Separation and recovery rate Q of used unreacted reactive gas) = ​​E / C × 100 (S2) C: the volume of the used, unreacted reactive gas contained in the used gas discharged as a result of step I E: Volume of the used, unreacted reactive gas separated and recovered in step II

3. 2. The method for recycling reactive gas according to claim 1, wherein the consumption rate P of the unused reactive gas is set to 50% or more.

4. 3. The method for recycling reactive gas according to claim 2, wherein the separation and recovery rate Q of the used, unreacted reactive gas is set to 50% or more.

5. 5. The method for recycling reactive gases according to claim 1, wherein the chemical reaction treatment step is an etching step.

6. 5. The method for recycling reactive gases according to claim 1, wherein the chemical reaction process is chamber cleaning.

7. 5. The method for recycling a reactive gas according to claim 1, wherein the reactive gas is a perfluoro compound gas, and the used gas is a nitrogen-containing perfluoro compound gas.

8. The reactive gas is NF ３ , C ２ F ６ , ClF ３ , S.F. ６ , and COF ２ The method for recycling a reactive gas according to any one of claims 1 to 4, comprising at least one of the following:

9. an apparatus I for performing a chemical reaction process using a reactive gas in the manufacture of electronic components; a device II for separating and recovering the used and unreacted reactive gas from a portion of the used gas that contains the used and unreacted reactive gas and is discharged as a result of the chemical reaction treatment; and a device III for detoxifying and discharging the remaining used gas. and a device IV for introducing the separated and recovered used unreacted reactive gas into the chemical reaction treatment for reuse, The reactive gas used in the device I includes unused reactive gas and the used, unreacted reactive gas that has been separated and recovered, A reactive gas recycling system having a function of recycling the used and unused reactive gas so that the consumption rate P (%) of the unused reactive gas shown in the following formula (S1) becomes a predetermined value. (Consumption rate P of unused reactive gas) = ​​(A - D) / A x 100 (S1) A: the input volume of the unused reactive gas D: The volume of the used, unreacted reactive gas that is detoxified and discharged in the device III

10. an apparatus I for chemical reaction processing using reactive gases in the manufacture of electronic components; a device II for separating and recovering the used and unreacted reactive gas from a portion of the used gas that contains the used and unreacted reactive gas and is discharged as a result of the chemical reaction treatment; and a device III for detoxifying and discharging the remaining used gas. and a device IV for introducing the separated and recovered used unreacted reactive gas into the chemical reaction treatment for reuse, The reactive gas used in the device I includes unused reactive gas and the used, unreacted reactive gas that has been separated and recovered, A reactive gas reuse system having a function of setting the separation and recovery rate Q of the used, unreacted reactive gas shown in the following formula (S2) to a predetermined value. (Separation and recovery rate Q of used unreacted reactive gas) = ​​E / C × 100 (S2) C: the volume of the used, unreacted reactive gas contained in the used gas discharged as a result of the chemical reaction treatment by the device I E: Volume of the used unreacted reactive gas separated and recovered in the device II

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