Apparatus and method for purifying high-purity phosphorus trifluoride

Abstract

An apparatus for purifying high-purity phosphorus trifluoride according to one embodiment of the present invention comprises: a phosphorus trifluoride production unit including a reactor in which a phosphorus chloride compound solution and a metal fluoride salt react, and a purge device for vacuum-purging the reactor; a first freezing unit for cooling a phosphorus trifluoride mixed gas obtained from the phosphorus trifluoride production unit to remove unreacted materials contained in the phosphorus trifluoride mixed gas; and a second freezing unit for cooling the phosphorus trifluoride mixed gas obtained from the first freezing unit with liquid nitrogen to remove purge gas and hydrogen chloride (HCl).

Description

High-purity phosphorus trifluoride purification apparatus and purification method

[0001] The present invention relates to a high-purity phosphorus trifluoride purification apparatus and a purification method.

[0002] Phosphorus trifluoride is an industrial gas that can be used, for example, as a specialty gas. Specialty gases possess a purity higher than that required for general industrial applications and are intended for specific uses. Specialty gases may include electronic and semiconductor gases, standard gases, rare gases, and mixed gases.

[0003] Specifically, phosphorus trifluoride can be used as a specialty gas for semiconductors, such as for semiconductor manufacturing and research, and for TFT-LCD production. As one example, phosphorus trifluoride can be used in the etching or cleaning processes that are part of the semiconductor fabrication process. In this case, the purity of phosphorus trifluoride can affect the etching degree and pattern formation of the semiconductor wafer. Thus, to be used as a specialty gas for semiconductors, a higher purity is required than that required for general industrial gases.

[0004] Conventional technology is known for producing phosphorus trifluoride by reacting hydrogen fluoride with a phosphorus compound. However, hydrogen fluoride, the raw material, requires special caution during handling because its strong hydrogen bonding can cause violent exothermic reactions or explosions upon contact with moisture in the air. Furthermore, since not only hydrogen fluoride but also the byproducts generated therefrom are highly acidic substances, there are significant limitations to their application in industrial settings.

[0005] Therefore, efforts are required to find safe raw materials that can replace hydrogen fluoride in the production of high-purity phosphorus trifluoride. However, in conventional technology, it is not easy to optimize processes such as chemical reaction, purification, mixing, and extraction to ensure process safety by changing the types of reactants, while simultaneously increasing the purity of phosphorus trifluoride gas.

[0006] (Prior Art) JP 1998-245211 A

[0007] The present invention provides a method for producing high-purity phosphorus trifluoride that can replace hydrogen fluoride used as a reactant while achieving excellent selectivity for the product, phosphorus trifluoride.

[0008] One embodiment of the present invention provides a method for producing high-purity phosphorus trifluoride that can improve the overall reaction rate or shorten the time to reach the equilibrium conversion rate of phosphorus trifluoride.

[0009] One embodiment of the present invention can provide a phosphorus trifluoride purification apparatus and a purification method capable of suppressing the generation of byproduct HCl.

[0010] One embodiment of the present invention can provide a phosphorus trifluoride purification apparatus and purification method that increases the purity and yield of phosphorus trifluoride.

[0011] One embodiment of the present invention can provide a phosphorus trifluoride purification apparatus and purification method that increase economic efficiency by increasing the reaction rate of the phosphorus trifluoride production reaction.

[0012] The problems of the present invention are not limited to those described above. A person skilled in the art to which the present invention pertains will have no difficulty understanding additional problems of the present invention from the overall contents of this specification.

[0013] A high-purity phosphorus trifluoride purification apparatus, which is an embodiment of the present invention, comprises: a phosphorus trifluoride production unit including a reactor in which a phosphorus chloride compound solution and a metal fluoride salt react, and a purging device for vacuum purging the reactor; a first freezing unit for cooling a phosphorus trifluoride mixed gas obtained from the phosphorus trifluoride production unit to remove unreacted substances contained in the phosphorus trifluoride mixed gas; and a second freezing unit for cooling the phosphorus trifluoride mixed gas obtained from the first freezing unit with liquid nitrogen to remove purging gas and hydrogen chloride (HCl).

[0014] It may further include an adsorption unit that additionally removes hydrogen chloride contained in the above phosphorus trifluoride.

[0015] The above reactor may be a batch type or a continuous type reactor.

[0016] The cooling temperature of the first freezing part may be -10 to -30℃.

[0017] The cooling temperature of the second freezing part above may be -200 to -180℃.

[0018] It may further include a phosphorus trifluoride storage tank connected to the above-mentioned adsorption unit and storing phosphorus trifluoride.

[0019] A method for purifying high-purity phosphorus trifluoride, which is an embodiment of the present invention, comprises: a phosphorus trifluoride production step of producing phosphorus trifluoride using a phosphorus chloride compound solution and a metal fluoride salt; a low-temperature freezing step of cooling the phosphorus trifluoride mixed gas obtained in the phosphorus trifluoride production step to remove reactants contained in the phosphorus trifluoride; and a nitrogen freezing step of cooling the phosphorus trifluoride mixed gas obtained in the low-temperature freezing step with liquid nitrogen to remove purge gas and hydrogen chloride (HCl).

[0020] The method may further include an adsorption step for additionally removing hydrogen chloride contained in the phosphorus trifluoride mixed gas obtained in the above nitrogen freezing step.

[0021] The phosphorus trifluoride manufacturing step may include: a step of introducing a metal fluoride salt into a reactor; a step of vacuum purging the inside of the reactor with an inert gas; a step of introducing a mixture of a phosphorus chloride compound and a solvent into the reactor to produce a phosphorus trifluoride mixture; and a step of capturing phosphorus trifluoride from the phosphorus trifluoride mixture.

[0022] The above low-temperature freezing step may be a step of cooling the phosphorus trifluoride to -10 to -30℃.

[0023] The nitrogen freezing step may be a step of cooling the phosphorus trifluoride to -200 to -180°C.

[0024] The above adsorption step may be a step of removing hydrogen chloride (HCl) contained in phosphorus trifluoride using an adsorbent.

[0025] The above adsorbent may be at least one selected from the group consisting of activated carbon, alumina, silica gel, zeolite, and metal oxide.

[0026] The phosphorus trifluoride purification apparatus and purification method of one embodiment of the present invention replace hydrogen fluoride used as a reactant while achieving excellent selectivity for the product, phosphorus trifluoride.

[0027] The purification apparatus and purification method of phosphorus trifluoride, which is an embodiment of the present invention, can improve the overall reaction rate or shorten the time required to reach the equilibrium conversion rate of phosphorus trifluoride.

[0028] The high-purity phosphorus trifluoride purification apparatus and purification method, which are embodiments of the present invention, can suppress the generation of byproduct HCl.

[0029] The high-purity phosphorus trifluoride purification apparatus and purification method, which are embodiments of the present invention, can increase the purity and yield of phosphorus trifluoride.

[0030] The high-purity phosphorus trifluoride purification apparatus and purification method, which is an embodiment of the present invention, can increase economic efficiency by increasing the reaction rate of the phosphorus trifluoride production reaction.

[0031] FIG. 1 is a diagram illustrating an exemplary high-purity phosphorus trifluoride purification apparatus, which is an embodiment of the present invention.

[0032] FIG. 2 is a flowchart exemplarily illustrating a method for purifying high-purity phosphorus trifluoride, which is an embodiment of the present invention.

[0033] Preferred embodiments of the present invention will be described below with reference to the attached drawings. However, embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below.

[0034] In addition, embodiments of the present invention are provided to more fully explain the present invention to those with average knowledge in the relevant technical field.

[0035] In drawings, the shapes and sizes of elements may be exaggerated for clearer explanation.

[0036] In describing the embodiments of the present invention, if it is determined that a detailed description of known technology related to the present invention may unnecessarily obscure the essence of the present invention, such detailed description will be omitted. Furthermore, the terms described below are defined considering their functions in the present invention, and these may vary depending on the intentions or conventions of the user or operator. Therefore, such definitions should be based on the content throughout this specification. The terms used in this specification are merely for describing the embodiments of the present invention and should not be limited in any way. Unless explicitly stated otherwise, expressions in the singular form include the meaning of the plural form.

[0037] In this description, expressions such as “include” or “equipped” are intended to refer to certain characteristics, numbers, steps, actions, elements, parts or combinations thereof, and should not be interpreted to exclude the existence or possibility of one or more other characteristics, numbers, steps, actions, elements, parts or combinations thereof other than those described.

[0038] Unless otherwise specifically defined in the specification of the present invention, % units mean weight %.

[0039] Unless otherwise specifically defined in the specification of the present invention, alphabetic symbols represent the element represented by the corresponding element symbol.

[0040] The present invention will be described in detail below through each embodiment or example of the invention. It should be noted that each embodiment or example described in this specification is not limited to a single embodiment or example, but may also be combined with other embodiments or examples. Accordingly, the citation of claims in the patent claims is merely an example of an embodiment, and the technical concept of the present invention should not be interpreted as being limited only to a combination with the cited claims; rather, combinations with various claims are also included within the scope of the technical concept of the present invention.

[0041] Phosphorus trifluoride purification device

[0042] A high-purity phosphorus trifluoride purification device (10), which is an embodiment of the present invention, increases economic efficiency by suppressing the generation of HCl, which is a byproduct of the conventional phosphorus trifluoride manufacturing method, while simultaneously manufacturing and purifying phosphorus trifluoride with increased yield and purity.

[0043] FIG. 1 is a diagram illustrating an exemplary high-purity phosphorus trifluoride purification apparatus (10) according to one embodiment of the present invention. Referring to FIG. 1, the high-purity phosphorus trifluoride purification apparatus (10) according to one embodiment of the present invention comprises: a phosphorus trifluoride manufacturing unit (100) comprising a reactor in which a phosphorus chloride compound solution and a metal fluoride salt react, and a purging device for vacuum purging the reactor; a first freezing unit (200) for cooling the phosphorus trifluoride mixed gas obtained from the phosphorus trifluoride manufacturing unit (100) to remove unreacted substances contained in the phosphorus trifluoride mixed gas; and a second freezing unit (300) for cooling the phosphorus trifluoride mixed gas obtained from the first freezing unit (200) with liquid nitrogen to remove the purging gas and hydrogen chloride (HCl).

[0044] The above phosphorus trifluoride manufacturing unit (100) may be a device for manufacturing phosphorus trifluoride using a phosphorus chloride compound solution and a metal fluoride salt. When manufacturing phosphorus trifluoride using a phosphorus chloride compound solution and a metal fluoride salt, the amount of hydrogen chloride (HCl) produced as a byproduct can be suppressed.

[0045] The above metal fluoride salt may be a salt in which a metal and fluorine are combined.

[0046] The above metal fluoride salt may be a compound represented by the following chemical formula 1.

[0047] [Chemical Formula 1]

[0048] (M a ) n F m

[0049] In the above chemical formula 1, M a is an alkali metal or an alkaline earth metal, and n and m are each independently 1 to 3, and said n and m are real numbers. Specifically, the fluoride metal salt may be at least one selected from the group consisting of sodium fluoride (NaF), potassium fluoride (KF), calcium fluoride (CaF2), magnesium fluoride (MgF2), etc., and more specifically may be sodium fluoride (NaF).

[0050] The above phosphorus chloride compound may be phosphorus trichloride.

[0051] In addition, the phosphorus chloride compound solution is obtained by dissolving a phosphorus chloride compound in a solvent, and the solvent may be an organic solvent.

[0052] The above organic solvent may be a polar solvent. Specifically, the solvent may be at least one selected from the group consisting of acetonitrile, (THF)Tetrahydrofuran, toluene, NMP (N-methyl-2-pyrrolidone), dimethylformamide (DMF), etc. The solvent may increase the reactivity of a metal fluoride salt with a phosphorus chloride compound that has low reactivity.

[0053] One embodiment of the present invention may further include a catalyst. The catalyst may shorten the time required to reach an equilibrium conversion rate.

[0054] The above catalyst may be a compound represented by the following chemical formula 2.

[0055] [Chemical Formula 2]

[0056] (M b ) x O m

[0057] (In the above chemical formula 2, M b is at least one selected from Sb, Fe, Sn, Ti, and Al, x is 1 or 2, and m is 1 to 3.)

[0058] Alternatively, the catalyst may be a compound represented by the following chemical formula 3.

[0059] [Chemical Formula 3]

[0060] M C F l

[0061] (In the above chemical formula 3, M Cis at least one selected from Sb, Fe, Sn, Ti, and Al, and l is 3 or 4.)

[0062] Specifically, the catalyst may be at least one selected from the group consisting of diantimony trioxide (Sb2O3), antimony fluoride (SbF3), iron trioxide (Fe2O3), iron fluoride (FeF3), tin fluoride (SnF4), titanium fluoride (TiF4), aluminum fluoride (AlF3), etc., and specifically, it may be diantimony trioxide (Sb2O3). The catalyst can increase the reactivity of a phosphorus chloride compound solution and a metal fluoride salt.

[0063] The above-mentioned phosphorus trifluoride manufacturing unit (100) may be a single unit, or two or more manufacturing units may be connected in parallel or in series.

[0064] However, since the reaction rate of phosphorus trifluoride formation reaction is slow for phosphorus chloride compounds and metal fluoride salts, the reaction rate can be increased by adding a solvent and a catalyst.

[0065] The phosphorus trifluoride manufacturing unit (100) described above may include a reactor and a purge device. The phosphorus trifluoride manufacturing method is described in detail in the phosphorus trifluoride purification method described later.

[0066] The phosphorus trifluoride produced in the above phosphorus trifluoride manufacturing unit (100) may contain approximately 10% by-products such as HCl, HF, unreacted phosphorus chloride compounds, solvents, etc. For use as an etching gas for semiconductors, a high-purity gas of at least 3N to 4N is required.

[0067] Accordingly, a high-purity phosphorus trifluoride purification device (10) which is an embodiment of the present invention may include a first freezing section (200), a second freezing section (300), and an adsorption section.

[0068] Referring to FIG. 1, the first freezing unit (200) is connected to the phosphorus trifluoride manufacturing unit (100) and may be a device for cooling the phosphorus trifluoride mixed gas obtained from the phosphorus trifluoride manufacturing unit (100) to remove unreacted substances contained in the phosphorus trifluoride mixed gas.

[0069] The unreacted material contained in the phosphorus trifluoride mixed gas separated and removed in the first freezing section (200) may be a byproduct HF, an unreacted phosphorus chloride compound, a solvent, etc.

[0070] The cooling temperature of the first freezing unit (200) may be -10 to -30°C. In the above temperature range, by-products such as HF, unreacted phosphorus chloride compounds, solvents, etc., may be separated into a liquid phase, and phosphorus trifluoride may be collected in a gas phase.

[0071] Referring to FIG. 1, the second freezing unit (300) is connected to the first freezing unit (200) and may be a device for removing purge gas and hydrogen chloride by cooling the phosphorus trifluoride mixed gas obtained from the first freezing unit (200) with liquid nitrogen.

[0072] The second freezing unit (300) may be a cooler using liquid nitrogen, and may additionally be equipped with a vacuum pump to reduce the internal pressure.

[0073] The purge gas separated and removed in the first freezing section (200) may be the purge gas used as a vacuum purge in the phosphorus trifluoride manufacturing section (100). The purge gas may be an inert gas, such as nitrogen, helium, etc.

[0074] The cooling temperature of the second freezing section (300) may be -200 to -180°C. In the above temperature range, purge gas and hydrogen chloride may be separated into a gaseous phase, and phosphorus trifluoride may be separated into a liquid phase, then reheated to vaporize and collect.

[0075] Referring to FIG. 1, one embodiment of the present invention may further include an adsorption unit for removing hydrogen chloride (HCl) contained in the phosphorus trifluoride. The adsorption unit may be connected to the second freezing unit (300) and may be a device for additionally removing hydrogen chloride contained in the phosphorus trifluoride.

[0076] The above adsorption unit may use an adsorbent. The adsorbent may be at least one selected from the group consisting of activated carbon, alumina, silica gel, zeolite, and metal oxide, and specifically, CaX (Ca-exchanged zeolite X), K-AC (Potassium-impregnated activated carbon), etc.

[0077] In addition, one embodiment of the present invention may further include a phosphorus trifluoride storage tank (500) connected to the adsorption unit and storing phosphorus trifluoride.

[0078] The phosphorus trifluoride obtained by the high-purity phosphorus trifluoride purification device (10) of one embodiment of the present invention has a purity of 99% by weight or more, specifically 99.8% by weight or more, more specifically 99.9% by weight or more, and may have a high purity of 3N to 4N.

[0079] Method for purifying phosphorus trifluoride

[0080] A high-purity phosphorus trifluoride purification method, which is an embodiment of the present invention, enhances economic efficiency by suppressing the generation of HCl, which is a byproduct of conventional phosphorus trifluoride manufacturing methods, while simultaneously manufacturing and purifying phosphorus trifluoride with increased yield and purity.

[0081] FIG. 2 is a flowchart of a method for purifying high-purity phosphorus trifluoride, which is an embodiment of the present invention. Referring to FIG. 2, a method for purifying high-purity phosphorus trifluoride, which is an embodiment of the present invention, comprises: a phosphorus trifluoride manufacturing step (S10) for manufacturing phosphorus trifluoride using a phosphorus chloride compound solution and a metal fluoride salt; a low-temperature freezing step (S20) for cooling the phosphorus trifluoride mixed gas obtained in the phosphorus trifluoride manufacturing step (S10) to remove reactants contained in the phosphorus trifluoride; and a nitrogen freezing step (S30) for cooling the phosphorus trifluoride mixed gas obtained in the low-temperature freezing step (S20) with liquid nitrogen to remove purge gas and hydrogen chloride (HCl).

[0082] The phosphorus trifluoride manufacturing step (S10) may include: a step of introducing a metal fluoride salt into a reactor; a step of vacuum purging the inside of the reactor with an inert gas; a step of introducing a mixture of a phosphorus chloride compound, a solvent, and a catalyst into the reactor to produce a phosphorus trifluoride (PF3) mixture; and a step of capturing phosphorus trifluoride from the phosphorus trifluoride mixture.

[0083] In one embodiment of the present invention, the metal fluoride salt introduced into the reactor may be the metal fluoride salt described above in the phosphorus trifluoride purification device.

[0084] The above reactor may be a closed-type reactor. Specifically, the above reactor may be a batch-type reactor or a continuous type.

[0085] Since moisture and / or oxygen inside the reactor can react with phosphorus chloride, a reactant of phosphorus trifluoride, to produce HCl, in one embodiment of the present invention, moisture and / or oxygen inside the reactor can be removed by vacuum purging the inside of the reactor with an inert gas.

[0086] The above inert gas is not particularly limited, but may be, for example, nitrogen, helium, etc.

[0087] In one embodiment of the present invention, a mixture of a phosphorus chloride compound, a solvent, and a catalyst may be prepared first and then introduced into the reactor.

[0088] The phosphorus chloride compound, solvent, and catalyst mentioned above may each be the same as those described above in the phosphorus trifluoride purification apparatus.

[0089] Phosphorus trifluoride can be prepared as shown in the following formula (1) to minimize the generation of HCl in the reaction product. In this case, NaF in formula (1) is described as an example of the metal fluoride salt.

[0090] [Equation (1)]

[0091] PCl3 + NaF → PF3 + 3NaCl

[0092] The weight ratio of the phosphorus chloride compound and the metal fluoride salt may be 1:1.5 to 1:20. Specifically, it may be 1:2.5 to 1:10. When the weight ratio of the phosphorus chloride compound and the metal fluoride salt is within the range described above, the formation of by-products can be suppressed, and in such cases, the conversion rate and reaction yield can be further improved.

[0093] Meanwhile, phosphorus chloride compounds and metal fluoride salts exist in liquid and solid phases, respectively, making it difficult for the two substances to react. Therefore, a medium is required to facilitate ion exchange between P-Cl and the metal salt-fluoride ions, and a solvent capable of dissolving the metal fluoride salt can fulfill this role.

[0094] The weight ratio of the phosphorus chloride compound and the solvent may be 3:1 to 10:1, specifically 4:1 to 8:1. Within this range, solubility characteristics are improved, and the final yield may be further improved. One embodiment of the present invention may additionally include a catalyst. The catalyst may shorten the time required to reach an equilibrium conversion rate.

[0095] The weight ratio of the solvent and the catalyst included in the above mixture may be 1:0.1 to 1:0.0001. If the weight ratio of the catalyst to the solvent exceeds 1:0.1, economic efficiency may decrease and catalytic activity may be lowered, and if it is less than 1:0.0001, the role of the catalyst may become negligible.

[0096] Phosphorus trifluoride produced by the above method may contain approximately 10% by weight of by-products such as HCl, HF, unreacted phosphorus chloride compounds, solvents, etc. For use as an etching gas for semiconductors, a high-purity gas of at least 3N to 4N is required.

[0097] Accordingly, a method for purifying high-purity phosphorus trifluoride, which is an embodiment of the present invention, may include a low-temperature freezing step (S20), a nitrogen freezing step (S30), and an adsorption step (S40).

[0098] Referring to FIG. 2, the low-temperature freezing step (S20) may be a step of cooling the phosphorus trifluoride mixed gas obtained in the phosphorus trifluoride manufacturing step (S10) to remove unreacted substances contained in the phosphorus trifluoride mixed gas.

[0099] The unreacted material contained in the phosphorus trifluoride mixed gas separated and removed in the above low-temperature freezing step (S20) may be a byproduct HF, an unreacted phosphorus chloride compound, a solvent, etc.

[0100] The temperature of the above low-temperature freezing step (S20) may be -10 to -30℃. In the above temperature range, by-products such as HF, unreacted phosphorus chloride compounds, solvents, etc., may be separated into a liquid phase, and phosphorus trifluoride may be collected in a gaseous phase.

[0101] Referring to FIG. 2, the nitrogen freezing step (S30) may be a step of removing purge gas and hydrogen chloride (HCl) by cooling the phosphorus trifluoride mixed gas obtained in the low-temperature freezing step (S20) with liquid nitrogen.

[0102] The above nitrogen freezing step (S30) may be a step of cooling using liquid nitrogen and may additionally include a step of reducing the pressure to a vacuum.

[0103] The purge gas separated and removed in the above low-temperature freezing step (S20) may be the purge gas used as a vacuum purge in the phosphorus trifluoride manufacturing unit (100). The purge gas may be an inert gas, for example, nitrogen, helium, etc.

[0104] The temperature of the nitrogen freezing step (S30) may be -200 to -180℃. In this temperature range, purge gas and hydrogen chloride may be separated into a gaseous phase, and phosphorus trifluoride may be separated into a liquid phase, then reheated to vaporize and collect.

[0105] Referring to FIG. 2, one embodiment of the present invention may further include an adsorption step (S40) for additionally removing hydrogen chloride contained in the phosphorus trifluoride mixed gas obtained in the nitrogen freezing step (S30).

[0106] The above adsorbent may be the same as the adsorbent described above.

[0107] Phosphorus trifluoride obtained by the high-purity phosphorus trifluoride purification method of one embodiment of the present invention may have a purity of 99% by weight or more, specifically 99.8% by weight or more, more specifically 99.9% by weight or more, and may have a high purity of 3N or higher.

[0108] Examples

[0109] The present invention will be described in detail below through examples. However, it should be noted that the examples described below are intended merely to illustrate and embody the present invention and are not intended to limit the scope of the present invention. This is because the scope of the present invention is determined by the matters described in the patent claims and matters reasonably inferred therefrom.

[0110] 1. Comparative Example 1

[0111] In a closed reactor, the weight ratio of NaF as a metal fluoride, Acetonitrile solvent, and Sb2O3 catalyst was set to 9.2:1:0.003, and NaF was added in such a way that it was sufficiently submerged.

[0112] Afterwards, PCl3 was added in an amount equal to 1 / 3 of the NaF equivalent ratio (molar ratio) to prepare a mixed solution, and then introduced into a 25℃ reactor to produce PF3.

[0113] Subsequently, the components of the obtained gas were analyzed using a mass spectrum, and the results are shown in Table 1 below.

[0114] 2. Comparative Example 2

[0115] The gas generated in Comparative Example 1 was used to remove unreacted PCl3, solvent Acetonitrile, and byproduct HF through a first freezing section at -20℃.

[0116] Subsequently, the components of the obtained gas were analyzed using a mass spectrum, and the results are shown in Table 1 below.

[0117] 3. Example 1

[0118] The gas obtained in Comparative Example 1 above was cooled and condensed in a second freezing section containing liquid nitrogen (LN2; -196°C) to remove purge gas, and the temperature was raised to -120 to -100°C to obtain PF3 gas.

[0119] Subsequently, the components of the obtained gas were analyzed using a mass spectrum, and the results are shown in Table 1 below.

[0120] 4. Example 2

[0121] The PF3 gas obtained in Example 1 above was adsorbed with a CaX (Ca-exchanged zeolite X) adsorbent.

[0122] Subsequently, the obtained gas components were analyzed using a mass spectrum and are shown in Table 1 below.

[0123] 5. Example 3

[0124] The PF3 gas obtained in Example 1 above was adsorbed with a K-AC (Potassium-impregnated activated carbon) adsorbent.

[0125] Subsequently, the obtained gas components were analyzed using a mass spectrum and are shown in Table 1 below.

[0126] Weight Ratio (wt%) PF3HClHF Solvent PCl3 Example 1 99.87 0.13000 Example 2 99.94 0.06000 Example 3 99.93 0.07000 Comparative Example 184.57 8.274 381.65 1.13 Comparative Example 289.306 592.78 0.76 0.57

[0127] Referring to Table 1 above, it can be confirmed that the purity of PF3 in Examples 1 to 3, purified by the first freezing section and the second freezing section, exceeds 99 weight%.

[0128] Furthermore, it can be confirmed that Examples 2 and 3, which were additionally purified by the adsorption unit, have a low HCl concentration.

[0129] On the other hand, it can be confirmed that the purity of PF3 is low when purification is not performed (Comparative Example 1) or when purification is performed using only the first frozen portion (Comparative Example 2).

[0130] Although embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and it will be obvious to those skilled in the art that various modifications and variations are possible within the scope of the technical concept of the present invention as described in the claims.

[0131] [Explanation of the symbol]

[0132] 10: Phosphorus trifluoride purification device 100: Phosphorus trifluoride manufacturing unit

[0133] 200: 1st freezing section 300: 2nd freezing section

[0134] 400: Adsorption unit 500: Phosphorus trifluoride storage tank

Claims

1. A phosphorus trifluoride manufacturing unit comprising a reactor in which a phosphorus chloride compound solution and a metal fluoride salt react, and a purging device for vacuum purging the reactor; A first freezing unit for cooling the phosphorus trifluoride mixed gas obtained from the phosphorus trifluoride manufacturing unit to remove unreacted substances contained in the phosphorus trifluoride mixed gas; and A high-purity phosphorus trifluoride purification apparatus comprising a second freezing section that cools the phosphorus trifluoride mixed gas obtained from the first freezing section with liquid nitrogen to remove purge gas and hydrogen chloride (HCl).

2. In Paragraph 1, A high-purity phosphorus trifluoride purification apparatus further comprising an adsorption unit for additionally removing hydrogen chloride contained in the above phosphorus trifluoride.

3. In Paragraph 1, The above reactor is a high-purity phosphorus trifluoride purification device, which is a batch or continuous reactor.

4. In Paragraph 1, A high-purity phosphorus trifluoride purification device in which the cooling temperature of the first freezing section is -10 to -30℃.

5. In Paragraph 1, A high-purity phosphorus trifluoride purification device in which the cooling temperature of the second freezing section is -200 to -180℃.

6. In Paragraph 2, A high-purity phosphorus trifluoride purification device further comprising a phosphorus trifluoride storage tank connected to the adsorption unit and storing phosphorus trifluoride.

7. A phosphorus trifluoride manufacturing step of producing phosphorus trifluoride using a phosphorus chloride compound solution and a metal fluoride salt; A low-temperature freezing step for cooling the phosphorus trifluoride mixed gas obtained in the above phosphorus trifluoride manufacturing step to remove reactants contained in the phosphorus trifluoride; and A method for purifying high-purity phosphorus trifluoride, comprising a nitrogen freezing step in which the phosphorus trifluoride mixed gas obtained from the above low-temperature freezing step is cooled with liquid nitrogen to remove purge gas and hydrogen chloride (HCl).

8. In Paragraph 7, A method for purifying high-purity phosphorus trifluoride, further comprising an adsorption step for additionally removing hydrogen chloride contained in the phosphorus trifluoride mixed gas obtained from the nitrogen freezing step above.

9. In Paragraph 7, The above phosphorus trifluoride manufacturing step is, Step of introducing a metal fluoride salt into a reactor; A step of vacuum purging the interior of the reactor with an inert gas; A step of preparing a phosphorus trifluoride mixture by introducing a mixture of a phosphorus chloride compound and a solvent into the reactor; and A method for purifying high-purity phosphorus trifluoride, comprising the step of capturing phosphorus trifluoride from the above phosphorus trifluoride mixture.

10. In Paragraph 7, A method for purifying high-purity phosphorus trifluoride, wherein the above low-temperature freezing step is a step of cooling the phosphorus trifluoride to -10 to -30℃.

11. In Paragraph 7, A method for purifying high-purity phosphorus trifluoride, wherein the nitrogen freezing step is a step of cooling the phosphorus trifluoride to -200 to -180°C.

12. In Paragraph 8, A method for purifying high-purity phosphorus trifluoride, wherein the above adsorption step is a step of removing hydrogen chloride (HCl) contained in phosphorus trifluoride using an adsorbent.

13. In Paragraph 12, A method for purifying high-purity phosphorus trifluoride, wherein the adsorbent is at least one selected from the group consisting of activated carbon, alumina, silica gel, zeolite, and metal oxide.

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