KR102193572B1 - Method for generating high purity diborane using BF3 simultaneous reaction process and apparatus for the same - Google Patents

Abstract

The present invention relates to a high-purity diborane production method using a simultaneous BF ₃ reaction process and a production apparatus thereof, and the method for preparing diborane according to the present invention comprises NaBH ₄ (Sodium Borohydride) powder in a powder reactor at room temperature. a first step of dissolving in an ether)-based solvent to produce a mixed solution; The mixed solution was transferred to the main reactor using gravity and differential pressure, and BF ₃ (Boron trifluoride) gas was injected into the main reactor at a constant rate, and reacted with the mixed solution to cause impurities and diborane (B ₂ H ₆ : a second step of generating a first reaction gas in which diborane) gas is mixed; And a third step of purifying the first reaction gas by removing impurities through a purification process.

Description

TECHNICAL FIELD [Method for generating high purity diborane using BF3 simultaneous reaction process and apparatus for the same]

The present invention relates to a high-purity diborane manufacturing method and a manufacturing apparatus using the BF ₃ simultaneous reaction process, and more specifically, to minimize the risk of leakage of toxic substances, lower the manufacturing cost, and can be manufactured with high purity. The present invention relates to a high-purity diborane manufacturing method using a BF ₃ simultaneous reaction process capable of manufacturing diborane that can be used in semiconductor processes or other precision industrial processes, and a manufacturing apparatus therefor.

Diborane (diborane, or diborane) is a compound of hydrogen and boron having the formula B ₂ H ₆ . At room temperature, it is a colorless gas with a sweet scent. Since Diborane mixes well with air, it is easy to make an explosive mixture. It has the property of spontaneous ignition when it comes into contact with moist air, and is widely used as a rocket propellant. In addition, diborane gas is used as a P-type dopant for semiconductor equipment and is widely used in the electronics industry and its application fields.

Conventional techniques for preparing diborane include a method of synthesizing by reacting BF ₃ and LiH, a method of using BCl ₃ and LiAlH ₄ , and a method of using NaBH ₄ and three raw materials (BF ₃ , sulfuric acid, I). It is being introduced. Each reaction equation is as follows.

1) 8BF ₃ + 6LiH → 2B ₂ H ₆ + 6LiBF ₄

2) 4BCl ₃ + 3 LiAlH ₄ → 2B ₂ H ₆ + 3LiAlCl ₃

3) 4BF ₃ + 3NaBH ₄ → 2B ₂ H ₆ +3NaBF ₄

_{^{4) 2BH 4 - + 2H +}} ( sulfuric acid) → 2H ₂ + B ₂ H ₆

5) 4NaBH ₄ + I ₂ → 2NaI + H ₂ + B ₂ H ₆

However, since conventional technologies related to diborane manufacturing have focused on manufacturing low-purity diborane, it is difficult to apply to semiconductor processes that require high purity. Diborane gas contains many impurities such as hydrogen and higher borane. Because it is mixed, there is a problem that a considerable investment cost is required to equip a purification facility required for manufacturing with high purity, and the cost for manufacturing a high purity diborane is high.

In addition, although the BF ₃ -adduct intermediate, which is produced as an intermediate for the manufacture of diborane, is known to be a very unstable and dangerous material, it has a disadvantage in that it is treated as a separate process, which incurs considerable safety costs.

Republic of Korea Patent Publication No. 10-0731836 (2007.06.18.)

Accordingly, an object of the present invention is to provide a high-purity diborane manufacturing method and a manufacturing apparatus thereof using a simultaneous BF ₃ reaction process capable of overcoming the above-described conventional problems.

Another object of the present invention is to provide a high-purity diborane manufacturing method and a manufacturing apparatus for the BF ₃ simultaneous reaction process and continuous process that can minimize the process, reduce manufacturing cost, improve efficiency, and prevent safety accidents at the source. To provide.

According to the embodiment of the present invention to achieve some of the above technical problems, the method for preparing diborane according to the present invention is to dissolve NaBH ₄ (Sodium Borohydride) powder in an ether-based solvent in a powder reactor at room temperature. A first step of generating a mixed solution; The mixed solution was transferred to the main reactor using gravity and differential pressure, and BF ₃ (Boron trifluoride) gas was injected into the main reactor at a constant rate, and reacted with the mixed solution to cause impurities and diborane (B ₂ H ₆ : a second step of generating a first reaction gas in which diborane) gas is mixed; And a third step of purifying the first reaction gas by removing impurities through a purification process.

The purification process includes impurities and ether impurities formed by reacting BF ₃ (Boron trifluoride) with the ether solvent by allowing the first reaction gas to pass through a freezing trap at -60 to -80°C. Generating a second reaction gas by removing the first impurities by freezing or liquefying them; The second reaction gas is introduced into the adsorption tower, and secondary impurities including high-order borane, carbon dioxide (CO ₂ ), water vapor (H ₂ O), and methane gas (CH ₄ ) are removed using an adsorbent. Generating a reaction gas; Diborane having a high purity of 99.99% or more by removing the third impurity including hydrogen gas (H ₂ ) and methane gas (CH ₄ ) by introducing the third reaction gas into the distillation column and performing a distillation process using the difference in boiling point ( diborane) may be provided.

The distillation process includes a transfer step of transferring the third reaction gas to a distillation column; By maintaining the inside of the distillation column at a temperature of -100 to -140°C using a refrigerant, diborane (B ₂ H ₆ :diborane) gas is liquefied and moved to the bottom of the distillation column by gravity, and the third impurity is A first distillation step of maintaining the vaporized state and collecting and removing it at the top of the distillation column; A retransfer step of vaporizing the liquefied diborane using a vaporizer and transferring the vaporized diborane (B ₂ H ₆ :diborane) gas to the distillation column; A second distillation step of removing the fine impurity gas that has not been removed through the first distillation step may be provided by maintaining the inside of the distillation column at a temperature of -100 to -140°C using a refrigerant.

When the first reaction gas is generated in the main reactor of the second step, the powder reactor performs a process of dissolving NaBH ₄ (Sodium Borohydride) powder in an ether-based solvent to generate a mixed solution. It can be provided to the reactor.

The ether-based solvent is triglyme (Triethylene glycol dimethyl ether; C ₈ H ₁₈ O ₄ ) Alternatively, it may be tetraglyme (Tetraethylene glycol dimethyl ether; C ₁₀ H ₂₂ O ₅ ).

In the second step, in the main reactor, the temperature of the reactor may be maintained at 5 to 10° C. to minimize vaporization of impurities.

In the second step, BF ₃ (Boron trifluoride) gas may be slowly injected into the main reactor at a rate of 3 to 4 kg/hour.

Zeolite 4A (MS (Molecular sieve) 4A), activated carbon, and zeolite 13X (MS 13X) as adsorbents may be sequentially filled in the adsorption tower from bottom to top at a volume ratio of 1:1:1.

The adsorption tower may perform low-temperature adsorption at a reaction temperature of -30 to -20°C during the adsorption process, and high-temperature regeneration at a reaction temperature of 200 to 350°C during the regeneration process.

The vaporizer in the retransfer step may be maintained at a reaction temperature of 5 to 10 °C in order to minimize vaporization of impurities.

A storage step of storing diborane from which impurities have been removed after the second distillation step in a liquefied state in a storage tank may be provided.

The first to third steps may be performed in a pressure atmosphere lower than atmospheric pressure.

According to another embodiment of the present invention for achieving some of the above technical problems, the diborane production apparatus according to the present invention dissolves NaBH ₄ (Sodium Borohydride) powder in an ether-based solvent at room temperature to prepare a mixed solution. A powder (powder) reactor to generate; The mixed solution is transferred using gravity and differential pressure, and BF ₃ (Boron trifluoride) gas is injected into the transferred mixed solution at a constant speed, and reacted with the mixed solution to cause impurities and diborane (B ₂ H ₆ :diborane). A main reactor for generating a first reaction gas in which gas is mixed; And a purification unit that purifies the first reaction gas by removing impurities through a purification process.

The purification unit maintains a temperature of -60 to -80°C, and while the first reaction gas passes, BF ₃ (Boron trifluoride) reacts with the ether-based solvent to form a first containing impurities and ether impurities. A freezing trap for generating a second reaction gas by freezing or liquefying the secondary impurities; The second reaction gas is introduced to remove secondary impurities including high-order borane, carbon dioxide (CO ₂ ), water vapor (H ₂ O), and methane gas (CH ₄ ) by using an adsorbent. An adsorption module for generating a; A distillation column for generating diborane by removing third impurities including hydrogen gas (H ₂ ) and methane gas (CH ₄ ) by introducing the third reaction gas to perform a distillation process using the difference in boiling point. Can be equipped.

A vaporizer for vaporizing the liquefied diborane discharged from the distillation column to perform the distillation process again in the distillation column may be further provided.

The adsorption module includes two adsorption towers that alternately perform adsorption and regeneration processes, and a valve box for controlling opening and closing of valves connected to the two adsorption towers, and the adsorption tower is a zeolite 4A (MS (Molecular sieve) 4A), activated carbon, and zeolite 13X (MS 13X) may have a structure in which they are sequentially filled from the bottom to the top in a volume ratio of 1:1:1.

The adsorption tower may perform low-temperature adsorption at a reaction temperature of -30 to -20°C during the adsorption process, and high-temperature regeneration at a reaction temperature of 200 to 350°C during the regeneration process.

The linear speed of the second reaction gas passing through the adsorbent may be controlled through the valve box at 0.01 to 1 Nm/sec.

In the main reactor, a flowmeter or a mass flow controller (MFC) may be provided for uniformly injecting BF ₃ (Boron trifluoride) gas into the main reactor at a rate of 3 to 4 kg/hour.

L (length) / D (Depth) of the distillation column may be 10 to 15.

A storage tank for liquefying and storing diborane from which impurities have been removed through the distillation column; A charging unit for filling the cylinder with diborane stored in the storage tank may be further provided.

According to the present invention, it is possible to minimize the process, and the manufacturing efficiency and cost can be drastically reduced through the simultaneous reaction process and continuous process of BF ₃ , and the entire manufacturing/refining process is under atmospheric pressure (less than 0 bar _g ) vacuum Consisting of a process, it has the effect of maximizing safety by completely removing risk factors caused by internal ignition and air pollution. In addition, it is possible to manufacture high-purity diborane (B ₂ H ₆ (99.99% or more)) gas and has an advantage that can be applied not only to semiconductor processes but also to various industrial processes.

1 is a schematic block diagram of a diborane manufacturing apparatus for manufacturing a high-purity diborane (B ₂ H ₆ :diborane) according to an embodiment of the present invention,
Figure 2 is a concrete block diagram of Figure 1,
3 is a table showing manufacturing conditions, production amount, and recovery rate according to each of the Examples and Control Examples.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, without any intention other than to provide a thorough understanding of the present invention to those of ordinary skill in the art to which the present invention pertains.

1 is a schematic block diagram of a diborane manufacturing apparatus for manufacturing a high-purity diborane (B ₂ H ₆ :diborane) according to an embodiment of the present invention, and FIG. 2 is a detailed block diagram of FIG. 1.

As shown in FIGS. 1 and 2, the apparatus for producing diborane (B ₂ H ₆ :diborane) according to an embodiment of the present invention includes a reaction unit 100 and a purification unit 200. Additionally, a storage unit 300 may be provided.

The invention NaBH ₄ (Sodium Borohydride) and BF ₃ by reacting (Boron trifluoride) diborane lane containing the impurities to prepare the (B ₂ H ₆ diborane), and purified through the adsorption and distillation of high purity diborane lane (B ₂ H ₆ : It relates to a method and an apparatus for producing diborane).

In the reaction unit 100, in order to prepare diborane (B ₂ H ₆ :diborane), an ether-based solvent (eg, triglyme; Triethylene glycol dimethyl ether; C ₈ H ₁₈ O ₄ or tetraglyme; Tetraethylene glycol dimethyl) ether; C ₁₀ H ₂₂ O ₅ , etc.) was used, through which an intermediate, which is an adduct material of BF ₃ and ether, was made, and this process was configured to proceed simultaneously (or continuously) at once.

I.e., an ether (ether) a process and apparatus to melt the NaBH ₄ in series solvent by injecting BF ₃ creates the intermediate adduct material of BF ₃ with ether (ether) is diborane lane (B ₂ H ₆₎ produced at the same time load I'm using it. In this case, while preparing diborane (B ₂ H ₆ ) by slowly supplying BF ₃ , NaBH ₄ solution was prepared in another reactor (ie, powder reactor 110) to prepare diborane (B ₂ H ₆ ) step by step. Is done.

Summarizing this, it is as follows.

[Reaction Scheme]

4BF ₃ (BF ₃ ether) + 3NaBH ₄ → 2B ₂ H ₆ + 3NaBF ₄ (proceed in the presence of an ether-based solvent)

The preparation of diborane (B ₂ H ₆ ) through the reaction formula is characterized in that the reaction temperature is 0 to 40 ℃, the reaction pressure is carried out at less than atmospheric pressure (0 to -1 barg).

When diborane (B ₂ H ₆ ) is manufactured through the reaction unit 100, there is no process to remove impurities in the middle because the reaction proceeds continuously and simultaneously, unlike the conventional one. Therefore, the proportion of impurities (higher borane, methane, CO ₂ , Hydrocarbon, diethylene glycol monomethylether, alcohols, etc.) generated by decomposition of the ether-based solvent may be somewhat high. However, the reaction proceeds continuously at a time, so that the process is simple and the intermediate is not separately treated, so it is safe, and as shown in FIG. 3, the conversion rate (Control Example 1, about 50.9% → Example 1, 74.1%) is significantly increased. Able to know. In this case, the impurities generated in this case are removed by the purification unit 200 through an adsorption process (removing higher borane, CO _2, etc.) and a distillation process (removing methane, hydrogen, etc.), which are purification processes.

The purification unit 200 removes impurities such as higher borane, carbon dioxide (CO ₂ ), methane, and hydrogen through an adsorption process and a distillation process, which are purification processes, to provide high purity diborane (B ₂ H ₆ ). Will be manufactured.

The storage unit 300 includes a storage tank and a charging unit to store diborane (B ₂ H ₆ ) manufactured with high purity, and to be used for various purposes or mixed with various gases to be filled in a charging cylinder. .

As shown in FIG. 2, the reaction unit 100 includes a powder reactor 110 and a main reactor 120.

The volume of the powder reactor 110 is 300L, the volume of the main reactor 120 is 500L, and the inside may have a structure subjected to electrolytic polishing. A mixer may be built into the powder reactor 110 and the main reactor 120 so that the solution is well mixed.

In addition, the powder reactor 110 is further provided with a powder transfer pump (not shown), a liquid pump (not shown), etc. to stably supply NaBH ₄ and an ether-based solvent (eg, triglyme or tetraglyme). I can.

Diborane (B ₂ H ₆ ) For this preparation, NaBH ₄ (Sodium Borohydride) powder was added to an ether solvent (eg, triglyme; Triethylene glycol dimethyl ether) in a powder reactor 110 at room temperature (25° C.). ; C ₈ H ₁₈ O ₄ or tetraglyme; Tetraethylene glycol dimethyl ether; C ₁₀ H ₂₂ O ₅ , etc.) sufficiently (approximately 4-5 hours) to dissolve to form a mixed solution.

Since the solubility of NaBH ₄ in triglyme and tetraglyme, which is an ether solvent, is known to be about 4M at room temperature (25℃), it is controlled to dissolve within 5M (preferably 4.5~3M) in a slight excess at room temperature. Prevent problems such as valve clogging caused by particles).

In the powder reactor 110, NaBH ₄ is properly dissolved in an ether-based solvent through a built-in mixer. At this time, the upper portion of the raw material in the powder reactor 110 is used to remove impurities with an inert gas such as nitrogen, and a pressure lower than atmospheric pressure (gauge pressure of 0 atm _g or less) using a vacuum pump.

The main reactor 120 maintains a pressure lower than that of the powder reactor 110 after removing impurities by purging with an inert gas before the mixed solution is injected in the powder reactor 110. In addition, the main reactor 120 is positioned at a lower position than the powder reactor 110 so that gravity can be used.

Accordingly, the mixed solution is in the powder reactor 110 through gravity and differential pressure through the control of the pipe line (L1) and valve (V1) connected between the powder reactor 110 and the main reactor 120. It is transferred to the reactor 120.

In the main reactor 120, a first reaction gas in a form in which an impurity and a diborane (B ₂ H ₆ :diborane) gas are mixed by injecting BF ₃ (Boron trifluoride) gas at a constant rate and reacting with the mixed solution Will be created.

In the main reactor 120, BF ₃ is directly injected into the mixed solution to react. BF ₃ is preferably injected in a gas phase in a slightly excess amount than the reaction equivalent ratio using a flow meter or MFC (Mass Flow Controller). The BF ₃ is slowly injected (eg, injected at a rate of 3 to 4 kg/hour) to induce synthesis of an ether-based solvent and an adduct intermediate. For example, if the total injection volume of BF ₃ is 24.4 kg, divide it by 7 hours or more and inject evenly.

When the reaction proceeds while the main reactor 120 is maintained in a vacuum state, the main reactor 120 in a vacuum state contains some impurities, but diborane (B ₂ H ₆ ) gas is mainly generated and filled. . At this time, the temperature of the main reactor 120 is maintained at 5 to 10 degrees to minimize vaporization of impurities. Here, a mixed gas in which impurities and diborane (B ₂ H ₆ ) gas are mixed will be referred to as a first reaction gas.

While the main reactor 120 generates the first reaction gas, the powder reactor 110 continuously performs the process of generating the mixed solution and providing it to the main reactor 120. In this case, the powder reactor 110 may perform a process of generating the mixed solution after performing a process of removing impurities using an inert gas such as nitrogen. That is, when the mixed solution is generated and provided to the main reactor 120, the process of generating the mixed solution is performed after the impurity removal process is performed.

Meanwhile, when the reaction for generating the first reaction gas is completed, the main reactor 120 vents the waste solution and transfers it to a waste solution storage tank (not shown), and the first reaction gas is supplied to the purification unit 200 ).

Accordingly, the first reaction gas is continuously generated through the powder reactor 110 and the main reactor 120 and sent to the purification unit 200, and the diborane purified in the purification unit 220 is stored in the storage unit ( 300) will have a continuous flow.

Since a large number of impurities such as hydrogen and higher borane are mixed in the first reaction gas, purification of the first reaction gas is essential for high purity.

The purification process is performed through the purification unit 200.

As shown in FIG. 2, the purification unit 200 includes a refrigeration trap 210, an adsorption module 220, and a distillation column 240. Additionally, a vaporizer 250 may be further provided.

The freezing trap 210 is maintained at a temperature of -60 to -80°C, and while the first reaction gas passes, BF ₃ (Boron trifluoride) reacts with the ether-based solvent to form impurities and ether impurities. A second reaction gas is generated by freezing or liquefying the first impurities including the to be removed.

The adsorption module 220 introduces the second reaction gas and uses an adsorbent to provide secondary impurities including high-order borane, carbon dioxide (CO ₂ ), water vapor (H ₂ O), and methane gas (CH ₄ ). Is removed to generate a third reaction gas. Here, the higher borane may mean a material having a greater number of bonds (3 or more) of boron (B) than diborane.

The adsorption module 220 includes two adsorption towers 220a and 220b that alternately perform adsorption and regeneration processes, and a valve box for controlling the opening and closing of valves connected to the two adsorption towers 220a and 220b. (222a, 222b). In addition, the adsorption towers 220a and 220b have a structure in which zeolite 4A (MS (Molecular sieve) 4A), activated carbon and zeolite 13X (MS 13X) are sequentially filled from the bottom to the top in a volume ratio of 1:1:1. Can have. The adsorption module 220 alternately uses the first adsorption tower 220a and the second adsorption tower 220b through valve opening/closing control of the valve boxes 222a and 222b. Each of the adsorption towers 220a and 220b may have a volume of 50L.

The adsorption towers 220a and 220b operate high-temperature regeneration and low-temperature adsorption using heat medium oil operated at -40 to 400°C, or circulate the refrigerant at -30 to -20°C to adsorb nitrogen at low temperatures and use the heater 224 to It is also possible to operate a method of heating and regenerating at high temperature (200 ~ 350℃). At this time, the refrigerant is separated so that the refrigerant does not vaporize due to high temperature. That is, in each of the adsorption towers 220a and 220b, the reaction temperature of the adsorption tower is low-temperature adsorption at -30 to -20℃ during the adsorption process, and during the regeneration process, the reaction temperature of the adsorption tower is 200 to 350℃, so that high-temperature regeneration is performed It is possible to perform.

The distillation column 240 introduces the third reaction gas to perform a first distillation process using a difference in boiling point to remove third impurities including hydrogen gas (H ₂ ) and methane gas (CH ₄ ). It will create a diborane. A filler may be provided inside the distillation column 240 so that gas and liquid meet well. In addition, the distillation column may have a volume of 150L and a length-to-depth ratio (L(length)/D(Depth)) of 10 or more (preferably 10-15) to sufficiently distill.

The vaporizer 250 vaporizes the liquefied diborane discharged from the distillation column 240 to perform a second distillation process in which the distillation process is again performed in the distillation column 240.

Briefly looking at the purification process through the purification unit 200, first, the first reaction gas generated in the reaction unit 100 passes through the freezing trap 210. In the freezing trap 210, the ether impurities and the BF ₃ -adduct intermediate from the main reactor 120 are formed and decomposed impurities (impurities such as ethers with a short chain) are primarily It is filtered so that the second reaction gas is generated.

The second reaction gas is introduced into the valve box 222a through a pipe L3 connecting the freezing trap 210 and the valve box 222a. When the first adsorption tower 220a performs an adsorption process and the second adsorption tower 220b performs a regeneration process through the control of the valve boxes 222a and 222b, the second reaction gas is the first adsorption tower 220a. It flows through, and the higher borane through an adsorbent (approximately 1/3 of activated carbon by volume and 1/3 by volume of MS (Molecular sieve) 4A, and the remaining 1/3 by MS 13X) , It is possible to remove a significant amount of secondary impurities such as water vapor (H ₂ O), carbon dioxide (CO ₂ ), CH _4, etc., thereby generating a third reaction gas. At this time, the reaction temperature of the first adsorption tower 220a performing the adsorption process is maintained at -30 to -20°C, and a refrigerant may be used for this.

The valve boxes 222a and 222b may be adjusted so that the linear speed of the second reaction gas passing through the adsorbent is about 0.01 to 1 Nm/sec.

In the case of the second adsorption tower 220b, a regeneration process is performed, and in this case, the reaction temperature is heated to 200-350° C. by heating an inert gas or by using a heat medium or the like. In other words, if a heat medium oil that can be used up to -40 to 400°C is used, or each independently used, vent the refrigerant so that it does not vaporize. When the regeneration process is completed, the adsorption tower is replaced so that the first adsorption tower 220a performs the regeneration process and the second adsorption tower 220b performs the adsorption process, and from the first adsorption tower 220a to the second adsorption tower 220b. Before replacement, impurities inside the adsorption tower are finally removed through a vacuum process (0 to -1 bar _g below atmospheric pressure) using the vacuum pump 230.

The third reaction gas generated by removing the second impurities from the adsorption module 220 is transferred to the distillation column 240 along a pipe L4.

In the distillation column 240, H ₂ (bp: -252.76° C.) and CH ₄ (bp: 161.5° C.) through the use of the difference in boiling point (boiling point: -92.5° C.) of diborane (B ₂ H ₆ ). A first distillation process is performed to remove secondary impurities.

The inside of the distillation column 240 is maintained between -100 to -140°C by using a refrigerant (LN ₂ or a refrigerant that can be cooled, etc.), so that the diborane (B ₂ H ₆ ) is liquefied and moves downward in the direction of gravity. The third impurities that fall and contain hydrogen gas (H ₂ ) and methane gas (CH ₄ ) are vaporized and collected in the upper part, and are discharged to the outside using a valve (V5).

In the lower part of the distillation column 240, the liquefied diborane (B ₂ H ₆ ) is vaporized again through the vaporizer 250 and sent to the distillation column 240 to perform a second distillation process in which the distillation process is performed again. Thus, it is possible to remove fine impurities. At this time, the temperature of the vaporizer 250 is maintained at about 5 to 10° C. similar to the temperature of the reactor 120 to suppress generation of high-order borane due to high temperature. The second distillation process is performed in the same manner as the first distillation process, and liquefaction is performed in a pipe L6 connecting the distillation column 240 and the vaporizer 250 to perform the second distillation process. You can also install a pump.

Diborane in a liquefied state from which impurities have been removed by the distillation process is transferred to the storage unit 300 through a pipe L6 connecting the distillation column 240 and the storage tank 310 to be stored. And charged as needed.

The gaseous diborane purified by removing impurities in the distillation column 240 is the storage tank 310 through an upper pipe L5 connecting the distillation column 240 and the storage tank 310 Is transferred to.

Diborane (B ₂ H ₆ ) of high purity prepared by being purified through the purification unit 200 is GC-DID (Gas Chromatograph-Discharge Ionization Detector), GC-MS (Mass Spectrometry), FT-IR (Fourier Transform Infrared). ), ICP-MS (Inductively Coupled Plasma), etc., it was confirmed that purification is possible to have a purity of 99.99% or more.

The storage unit 300 may include a storage tank 310 and a charging unit 330 as shown in FIG. 2.

The storage tank 310 is for storing diborane from which impurities are removed through the distillation column 240, and the filling unit 330 stores diborane stored in the storage tank 310. It is for filling the cylinder.

The storage tank 310 stores high-purity diborane (B ₂ H ₆ ) at a liquefaction temperature (-100 to -140 degrees), and may have a volume of 250 L. In addition, it is possible to maintain the temperature of the storage tank 310 by using a refrigerant (LN ₂ or a refrigerant capable of cooling, etc.), and a vaporizer 320 may be provided. The vaporizer 320 was also maintained at about 5 to 10°C to suppress the generation of high-order borane.

The charging unit 330 is mixed with various gases or filled with a single gas for various uses.

Specific examples and control examples of the high-purity diborane production method using the simultaneous BF ₃ reaction process having the above-described configuration and the production apparatus thereof are as follows.

[Example 1] (Solvent: triglyme (Triethylene glycol dimethyl ether; C ₈ H ₁₈ O ₄ ))

9.86 kg of NaBH ₄ and 185 kg of Triglyme were introduced into the powder reactor 110 and sufficiently dissolved (preferably 4 to 5 hours) at room temperature with a mixer. After dissolving, the inside of the reactor 110 is sufficiently purged with nitrogen for external contamination and safety, and then maintained at a pressure lower than atmospheric pressure (preferably 500 mmHg _a or less). The main reactor 120 is prepared to be maintained at a pressure lower than atmospheric pressure (preferably 200 mmHg _a or less) after sufficiently purging with nitrogen. The mixed solution (NaBH ₄ solution) dissolved in the powder reactor 110 is transferred to the main reactor 120 due to a difference between gravity and pressure.

In the main reactor 120, the solution is mixed with a mixer, and BF ₃ is directly injected into the mixed solution through a tube that has penetrated to the bottom of the container. Using a BF ₃ cylinder, 24.4 kg is slowly injected through the MFC for 7 hours by bubbling. In the main reactor 120, a large amount of Triglyme and BF ₃ meet to form a BF _3- adduct intermediate, and as in the above-described reaction equation, a first reaction gas is generated and collected in the upper part of the main reactor 120. Here, since the reaction occurs rapidly, the temperature of the main reactor 120 is maintained at 10° C. lower than room temperature, and after the supply of BF ₃ is finished, it is raised to room temperature and partially dissolved diborane (B ₂ H ₆ ) is collected for about an hour. . After the reaction is complete, the waste solution is vented to the waste solution storage tank. This process is repeated 1 to 5 times to sufficiently distill and purify the distillation column 128 to collect the first reaction gas.

The refrigeration trap 210, which is the purification unit 200, is initially purged with nitrogen and managed at _a pressure lower than atmospheric pressure (200 mmHg _a or less), and first impurities are removed from the first reaction gas. . The first impurity is a volatile impurity formed by decomposing a triglyme while forming a BF ₃ -adduct intermediate or passing to the next process by vaporizing some triglyme in the main reactor 120, the reaction formula Volatile impurities formed by the occurrence of side reactions may be included. In order to liquefy and condense the first impurities, the freezing trap 210 was operated at -80°C.

The adsorption module 220 is initially purged with nitrogen and managed at _a pressure lower than atmospheric pressure (200 mmHg _a or less). Secondary impurities such as gaseous impurities CO ₂ , moisture (H ₂ O), and CH ₄ are removed using the adsorption module 220. When removing the secondary impurities, the temperature of the adsorption tower is maintained at -30 to -40°C, preferably -35°C to remove adsorption at a low temperature. The tower is exchanged on a 7-hour basis, and during regeneration, it is maintained at 250℃ for 4 hours and regenerated with nitrogen. High-temperature regeneration and low-temperature adsorption can be operated using heat medium oil operated at -40 to 400℃, or low-temperature adsorption is performed by circulating a refrigerant at -35 degrees Celsius, and high-temperature regeneration by heating nitrogen with a heater may be operated. At this time, the refrigerant is separated so that the refrigerant does not vaporize due to high temperature. In addition, the valve boxes 222a and 222b were adjusted so that the linear velocity of the adsorption tower was 0.01 to 1 Nm/sec by experience.

In the case of the distillation column 240, a refrigerant (LN ₂ or engineered fluid such as Novec 7200, etc.), which can be maintained at -130 degrees or less, flows separately to serve as a condenser, and gas phase diborane drawn in from the middle ( B ₂ H ₆ ) rises to the top, meets the condenser, goes down to the liquid, and goes down to the liquid from the top to allow the exchange to take place.

The entire distillation column 240 maintains a vacuum housing or thorough thermal insulation to maintain a low temperature so that the temperature of the lower portion is less than -100°C. It is designed to increase the contact area by filling the filling material in the middle. The material of the filler is made of SUS 316L. In the lower part of the distillation column 240, a space is maintained so that diborane (B ₂ H ₆ ) is liquefied and collected, and some diborane (B ₂ H ₆ ) has a structure that is vaporized at around 10°C through the vaporizer 250 and returned. . Through this, the hydrogen gas (H ₂ ) and methane gas (CH ₄ ) are induced so that the impurities of the tertiary impurities are collected in the upper part of the distillation column 240. The third impurities (H ₂ , CH _4, etc.) collected on the upper part are periodically vented through the vacuum pump 230 to maintain high purity.

In the case of the storage unit 300, it is possible to connect directly from the distillation column 240 to the filling unit 330, and use gravity through a pipe (L6) or a low-temperature liquid pump (not shown) to deboil the storage tank 310. Transfer lane (B ₂ H ₆ ). In the same manner as the distillation column, the storage tank 310 is maintained at -130°C or less at the top, so that the entire storage tank is kept warm to be less than -100°C. In the storage tank, the high-purity diborane (B ₂ H ₆ ) is connected to the charging unit 330 and mixed with various gases to make a product.

Diborane (B ₂ H ₆ ) manufactured by this method has a purity of 99.99% or more, a recovery rate of 74.1%, and is suitable for ultra-fine processes such as semiconductors, and can reduce production and safety costs with a simultaneous BF ₃ reaction process and a vacuum system. .

[Example 2] (Solvent: Tetraglyme (Tetraethylene glycol dimethyl ether; C ₁₀ H ₂₂ O ₅ ))

The conditions were the same as in Example 1, and the preparation was carried out using 230.7 kg of Tetraglyme. High-purity diborane (B ₂ H ₆ ) prepared according to Example 2 was prepared with 99.99% purity, and the recovery rate was 70.5%.

[Control Example 1] (Solvent: Diglyme (Diethylene glycol dimethyl ether, C ₆ H ₁₄ O ₃ ))

The same as the conditions of Example 1, but the solvent was used as Diglyme, and a method of separately generating the mixed solution in each of the powder reactor 110 and the main reactor 120 was used. That is, instead of the BF ₃ simultaneous reaction process and continuous process of the present invention in which a mixed solution is prepared in the powder reactor 110, and BF _3- adduct intermediate is continuously formed in the main reactor 120 and the first reaction gas is generated. In the method of generating a mixed solution in the powder reactor 110 and producing a first reaction gas, and generating a mixed solution in the main reactor 120 and producing a first reaction gas was used.

In the powder reactor 110, 9.86 kg of NaBH _{4 and} 99.9 kg of diglyme were mixed, but it did not melt at room temperature, so an attempt was made by raising the temperature to 35 degrees from the outside, but some did not melt. The main reactor 120) was slowly supplied with 24.4 kg of BF ₃ to 42 kg of Diglyme for 7 hours. Thereafter, the mixed solution in the powder reactor 110 was dropped into the main reactor 120 to prepare a first reaction gas. After the purification process, the high-purity diborane (B ₂ H ₆ ) prepared according to Example 1 was 99.99% pure, but the recovery rate was as low as 50.9%.

The reason for the low recovery rate in the control example is that the solvent used is Diglyme, and NaBH ₄ Even though the temperature was raised to 35 degrees for dissolution, NaBH ₄ was not sufficiently dissolved in the process to participate in the reaction, and the reason why the recovery rate was high in Example 1 of the present invention was to generate a mixed solution in the powder reactor 110 It is presumed that this is because the BF ₃ simultaneous reaction process and the continuous process of generating the BF ₃ -adduct intermediate in the main reactor 120 were used.

[Control Example 2] (Used solvent: Triglyme (Triethylene glycol dimethyl ether; C ₈ H ₁₈ O ₄ ))

The conditions were the same as in Comparative Example 1, and 9.86 kg of NaBH ₄ and the solvent were prepared using Triglyme, and 55.8 kg of Triglyme and 132.7 kg of Triglyme were added to the main reactor 120 and 132.7 kg of the powder reactor 110. High-purity diborane (B ₂ H ₆ ) prepared according to the control example was prepared with 99.99% purity, and the recovery rate was 33.7%.

3 shows the manufacturing conditions, production amount, and recovery rate according to each example and control example.

As shown in Figure 3, when compared to Comparative Examples 1 and 2, Examples 1 and 2 according to the present invention can obtain 99.99% high purity diborane (B ₂ H ₆ ) with a recovery rate of about 70% or more. Can be seen.

As described above, according to the present invention, it is possible to minimize the process, and the BF ₃ simultaneous reaction process can significantly reduce manufacturing efficiency and cost, and the entire manufacturing/refining process is below atmospheric pressure (0 bar _g or less). It consists of a vacuum process, and it has the effect of maximizing safety by completely removing risk factors caused by internal ignition and air pollution. In addition, it is possible to manufacture high-purity diborane (B ₂ H ₆ (99.99% or more)) gas and has an advantage that can be applied not only to semiconductor processes but also to various industrial processes.

Since the description of the above-described embodiment is merely an example with reference to the drawings for a more thorough understanding of the present invention, it should not be construed as limiting the present invention. In addition, it will be apparent to those of ordinary skill in the art to which the present invention pertains that various changes and changes can be made without departing from the basic principles of the present invention.

110: powder reactor 120: main reactor
210: refrigeration trap 220: adsorption module
240: distillation column 310: storage tank

Claims (21)

A first step of dissolving NaBH ₄ (Sodium Borohydride) powder in an ether-based solvent in a powder reactor at room temperature to produce a mixed solution;
The mixed solution was transferred to the main reactor using gravity and differential pressure, and BF ₃ (Boron trifluoride) gas was injected into the main reactor at a constant rate, and reacted with the mixed solution to cause impurities and diborane (B ₂ H ₆ : a second step of generating a first reaction gas in which diborane) gas is mixed;
A third step of purifying the first reaction gas by removing impurities through a purification process,
While the first reaction gas is generated in the main reactor of the second step, the process of generating the mixed solution is repeatedly performed in the powder reactor, and the mixed solution is continuously supplied to the main reactor for a continuous reaction. Makes this possible,
The purification process,
By allowing the first reaction gas to pass through a freezing trap of -60 to -80°C, BF ₃ (Boron trifluoride) reacts with the ether-based solvent to form impurities and primary impurities including ether impurities. Refrigerating or liquefying to remove the second reaction gas;
The second reaction gas is introduced into the adsorption tower, and secondary impurities including high-order borane, carbon dioxide (CO ₂ ), water vapor (H ₂ O), and methane gas (CH ₄ ) are removed using an adsorbent. Generating a reaction gas;
Diborane having a high purity of 99.99% or more by removing the third impurity including hydrogen gas (H ₂ ) and methane gas (CH ₄ ) by introducing the third reaction gas into the distillation column and performing a distillation process using the difference in boiling point ( Diborane manufacturing method comprising the step of generating). delete The method according to claim 1, wherein the distillation step,
A transfer step of transferring the third reaction gas to a distillation column;
By maintaining the inside of the distillation column at a temperature of -100 to -140°C using a refrigerant, diborane (B ₂ H ₆ :diborane) gas is liquefied and moved to the bottom of the distillation column by gravity, and the third impurity is A first distillation step of maintaining the vaporized state and collecting and removing it at the top of the distillation column;
A retransfer step of vaporizing the liquefied diborane using a vaporizer and transferring the vaporized diborane (B ₂ H ₆ :diborane) gas to the distillation column;
Dibo, characterized in that it comprises a second distillation step of removing the fine impurity gas that has not been removed through the first distillation step by maintaining the inside of the distillation column at a temperature of -100 ~ -140 ℃ using a refrigerant Lane manufacturing method. delete The method according to claim 1,
The ether-based solvent is triglyme (Triethylene glycol dimethyl ether; C ₈ H ₁₈ O ₄ ) Or tetraglyme (Tetraethylene glycol dimethyl ether; C ₁₀ H ₂₂ O ₅ ) Diborane production method, characterized in that. The method according to claim 1,
In the second step, the main reactor is a diborane manufacturing method, characterized in that the reactor temperature is maintained at 5 ~ 10 ℃ to minimize the vaporization of impurities. The method according to claim 1,
In the second step, BF ₃ (Boron trifluoride) gas is slowly injected into the main reactor at a rate of 3 to 4 kg/hour. The method according to claim 1,
Diborane manufacturing method, characterized in that the adsorption tower is sequentially filled with zeolite 4A (MS (Molecular sieve) 4A), activated carbon and zeolite 13X (MS 13X) as adsorbents in a volume ratio of 1:1:1 from bottom to top. The method according to claim 1,
The adsorption tower is a method for producing diborane, characterized in that during the adsorption process, the reaction temperature is -30 ~ -20 ℃ low temperature adsorption, and during the regeneration process, the reaction temperature is 200 ~ 350 ℃ high temperature regeneration. The method of claim 3,
Diborane production method, characterized in that the reaction temperature is maintained at 5 ~ 10 ℃ in the vaporizer in the retransfer step to minimize the vaporization of impurities. The method of claim 3,
And a storage step of storing diborane from which impurities have been removed after the second distillation step in a storage tank in a liquefied state. The method according to claim 1,
The first to third steps are diborane manufacturing method, characterized in that performed in a pressure atmosphere lower than atmospheric pressure. A powder reactor for generating a mixed solution by dissolving NaBH ₄ (Sodium Borohydride) powder in an ether-based solvent at room temperature;
The mixed solution is transferred using gravity and differential pressure, and BF ₃ (Boron trifluoride) gas is injected into the transferred mixed solution at a constant speed, and reacted with the mixed solution to cause impurities and diborane (B ₂ H ₆ :diborane). A main reactor for generating a first reaction gas in which gas is mixed;
And a purification unit for purifying the first reaction gas by removing impurities through a purification process,
While the first reaction gas is generated in the main reactor, the process of generating the mixed solution is repeatedly performed in the powder reactor, so that the mixed solution is continuously supplied to the main reactor to enable a continuous reaction,
The purification unit,
A temperature of -60 to -80°C is maintained, and while the first reaction gas passes, the impurities formed by reacting BF ₃ (Boron trifluoride) with the ether-based solvent and the first impurities including the ether impurities are frozen or A freezing trap for generating a second reaction gas by liquefaction and removal;
The second reaction gas is introduced to remove secondary impurities including high-order borane, carbon dioxide (CO ₂ ), water vapor (H ₂ O), and methane gas (CH ₄ ) by using an adsorbent. An adsorption module for generating a;
A distillation column for generating diborane by removing third impurities including hydrogen gas (H ₂ ) and methane gas (CH ₄ ) by introducing the third reaction gas to perform a distillation process using the difference in boiling point. Diborane manufacturing apparatus, characterized in that provided. delete The method of claim 13,
Diborane production apparatus, characterized in that further comprising a vaporizer to perform the distillation process again in the distillation column by vaporizing the liquefied diborane discharged from the distillation column. The method according to claim 13, wherein the adsorption module,
Two adsorption towers that alternately perform an adsorption process and a regeneration process, and a valve box for controlling opening and closing of valves connected to the two adsorption towers,
The adsorption tower has a structure in which zeolite 4A (MS (Molecular sieve) 4A), activated carbon and zeolite 13X (MS 13X) as adsorbents are sequentially filled from the bottom to the top in a volume ratio of 1:1:1. Rain manufacturing equipment. The method of claim 16,
The adsorption tower performs low-temperature adsorption at a reaction temperature of -30 to -20°C during the adsorption process, and performs high-temperature regeneration at a reaction temperature of 200 to 350°C during the regeneration process. The method of claim 16,
Diborane manufacturing apparatus, characterized in that the linear velocity of the second reaction gas passing through the adsorbent is controlled through the valve box to 0.01 ~ 1 Nm / sec. The method of claim 13,
In the main reactor, a flowmeter or MFC (Mass Flow Controller) for equally injecting BF ₃ (Boron trifluoride) gas into the main reactor at a rate of 3 to 4 kg/hour is provided. Device. The method of claim 13,
Diborane manufacturing apparatus, characterized in that the length-to-depth ratio (L(length)/D(Depth)) of the distillation column is 10-15. The method of claim 13,
A storage tank for liquefying and storing diborane from which impurities have been removed through the distillation column;
Diborane manufacturing apparatus, characterized in that further comprising a charging unit for filling the cylinder with diborane stored in the storage tank.

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