Device and process for preparing electronic-grade disilane through cyclic pyrolytic reaction

Abstract

The invention provides a device and a process for preparing electronic-grade disilane through cyclic pyrolytic reaction. According to the device, high-order silane is generated on the basis of a pyrolysis polymerization reaction of crude monosilane, after preliminary separation is conducted through the circulating tower, heavy components are subjected to rectification twice to be subjected to light component removal and heavy component removal respectively, then purification twice is conducted to remove water, oxygen and metal ions, electronic-grade disilane is obtained, continuous production is achieved, and the production cost is reduced. And the raw materials can be prepared on the basis of crude monosilane which is a byproduct of electronic-grade silane, so that the economic benefit is high, and a new choice is provided for the preparation of the electronic-grade disilane.

Description

Technical Field

[0001] The invention relates to the technical field of silane preparation, and in particular to a device and a process for preparing electronic-grade disilane through a cyclic pyrolysis reaction. Background Art

[0002] With the rapid development of semiconductor ultra-large-scale integrated circuits, memory chip capacity and number of layers, the demand for ultra-high purity disilane used in the manufacturing process in the above fields is increasing. In advanced process semiconductor manufacturing, electronic grade disilane can be used in processes such as chemical vapor deposition (CVD) and atomic layer deposition (ALD) to deposit high-quality silicon films. These films play a key role in integrated circuits, such as serving as gate insulation layers of transistors, diffusion barriers for source and drain electrodes, etc. Disilane has high reactivity and selectivity, and can achieve efficient deposition processes at lower temperatures, which helps to reduce energy consumption and thermal stress in the chip manufacturing process, while improving production efficiency and chip performance. For example, in chip manufacturing with a process of 7 nanometers and below, disilane can be used to deposit extremely thin silicon germanium (SiGe) or silicon carbon (SiC) alloy films to improve the performance and reliability of transistors. In addition, electronic grade disilane can be used as a doping source for semiconductor doping processes. By introducing disilane in the CVD or ion implantation process, the doping concentration and depth can be precisely controlled, thereby achieving regulation of the electrical properties of semiconductor materials.

[0003] There are many methods for preparing electronic-grade disilane. The current process mainly involves purifying a very small amount of disilane obtained by the reaction through multi-stage separation during the production of silane by the silicon-magnesium alloy method to obtain electronic-grade disilane. This method requires a large amount of liquid ammonia to be circulated in the front-end process, and the content of disilane obtained is relatively low, which cannot meet the needs of large-scale semiconductor industrialization. Secondly, through the electrocatalytic method, the monosilane is discharged and ionized in the reactor, so that the silicon-hydrogen bonds are separated and combined to form silicon-silicon bonds, and disilane is generated and then separated and purified. The next is the organic catalytic conversion method of monosilane: using monosilane as a raw material, a catalytic reaction is carried out in a fixed bed reactor to obtain a reaction product including monosilane, disilane and hydrogen. After a series of separation and purification, disilane is obtained. Precious metal organic catalysts such as dimethyl titanocene and ethylene bis(triphenylphosphine) platinum are used in this process, and some organic solvents are also used, and the reaction activity is difficult to control.

[0004] Chinese patent document CN112647085A discloses a method for electrocatalytic synthesis of high-purity disilane, which uses a voltage of 100 to 380V to electrocatalyze the reaction of monosilane, and then obtains disilane through multi-stage separation and purification. This method requires precise control of the discharge voltage and residence time between the plates, and the electrocatalytic conversion efficiency is low, and the high silane impurity content is high.

[0005] Chinese patent document CN116768216A discloses a method for synthesizing disilane, which uses lithium aluminum hydride or sodium aluminum hydride to react with hexachlorodisilane in a solvent, and then collects the disilane through a cold trap. This method requires the use of high-purity hexachlorodisilane, and the raw material is difficult to obtain widely. In addition, due to the addition of organic solvents, the final separation of disilane is more difficult, and the organic content in the product is relatively high.

[0006] Chinese patent document CN117185299A discloses a method for preparing disilane using an organic metal catalyst. Monosilane is used as a raw material and passed into a reactor containing organic catalysts Cp2Ti(CH3)2 and / or (Ph3P)2Pt(C2H4) to obtain disilane. The catalytic conversion rate of monosilane in this method is extremely low, and the precise synthesis of the organic catalyst is difficult, so it cannot be promoted and used on a large scale.

[0007] Chinese patent document CN114180580A describes a method for the continuous production of disilane, which uses silicon powder and metal powder to obtain metal silicide under high temperature and discharge environment, and then reacts with strong acid to generate disilane. This method requires the use of plasma high temperature (2000-6000°C), and has extremely high requirements on the reactor material. At the same time, the acidolysis product of the metal silicide is a large amount of monosilane, which cannot be recycled, so the total yield of disilane is low.

[0008] Therefore, it is necessary to propose a method for preparing electronic-grade disilane to solve the technical problems existing in the existing process, such as harsh reaction conditions, low reaction efficiency, and the inability to achieve higher product purity. Summary of the invention

[0009] The present invention proposes a device and process for preparing electronic-grade disilane by cyclic pyrolysis reaction, which solves the technical problems existing in the existing process, such as harsh reaction conditions, low reaction efficiency, difficult catalyst preparation, and inability to achieve higher product purity.

[0010] The technical solution of the present invention is achieved in this way:

[0011] The first aspect of the present invention is to provide a device for preparing electronic grade disilane by cyclic pyrolysis reaction, comprising a preheating unit, a reactor, a filter, a circulation tower, a first distillation tower and a second distillation tower, a purifier and a second purifier connected in sequence; wherein:

[0012] The preheating unit is connected to the upper part of the reactor and is used for feeding and preheating monosilane; the lower part of the reactor is connected to the filter; the reactor is used for thermal decomposition and polymerization of monosilane to generate disilane;

[0013] The circulation tower is used for pre-separation and removal of monosilane; the first distillation tower and the second distillation tower are used for light removal and heavy removal respectively;

[0014] The first purifier is used to remove water and oxygen; the second purifier is used to remove metal ions to obtain electronic grade disilane.

[0015] Further, the preheating unit comprises a preheater and a heater connected in series; the filter is connected to the heat exchange medium layer of the preheater;

[0016] Furthermore, a cooler is provided between the filter and the circulation tower.

[0017] Furthermore, a circulation pipe is arranged at the top of the circulation tower and is connected to the preheating unit via a compressor.

[0018] Furthermore, a reflux pipe 1 is provided at the top of the circulation tower and is connected to the upper part of the circulation tower. The reflux pipe 1 is provided with a production pipe 1 for producing non-condensable gas.

[0019] Furthermore, a reflux pipe 2 is provided at the top of the distillation tower 1 and is connected to the upper part of the distillation tower 1; and a production pipe 2 is provided on the reflux pipe 2 for producing non-condensable gas.

[0020] Preferably, the extraction pipe 2 is connected to the feed end of the circulation tower.

[0021] Further, the purifier 1 is filled with metal oxides; and / or the purifier 2 is filled with metal cation exchange resins.

[0022] The second aspect of the present invention is to provide a process for preparing electronic grade disilane by cyclic pyrolysis reaction, the steps comprising:

[0023] S1. Crude monosilane is heated to 380-450°C and enters into a packed reactor for thermal decomposition and polymerization reaction;

[0024] S2. The product obtained in step S1 is filtered to remove microsilica powder, cooled and enters a circulation tower to separate light components and heavy components. The operating pressure of the circulation tower is 1.0 to 2.8 MPa, the operating temperature of the tower top is -55 to -30 ° C, and the operating temperature of the tower bottom is 10 to 60 ° C;

[0025] S3. The heavy components separated by the circulating tower are removed by removing light components in the distillation tower 1 and heavy components in the distillation tower 2, and then the heavy components are produced; the light components include hydrogen, monosilane, nitrogen, methane, and carbon monoxide; the heavy components include chlorosilane and water;

[0026] S4. The light components extracted from the second distillation tower are purified for the first time and the second time to obtain electronic grade disilane; the first purification is used to remove water and oxygen; the second purification is used to remove metal ions.

[0027] Furthermore, the operating pressure of the distillation tower 1 is 0.6-1.5 MPA, the operating temperature of the tower top is 30-50° C., and the operating temperature of the tower bottom is 35-55° C.;

[0028] Furthermore, the operating pressure of the second distillation tower is 0.4-1.3 MPA, the operating temperature of the tower top is 20-45°C, and the operating temperature of the tower bottom is 30-50°C.

[0029] Furthermore, the light components separated by the circulation tower are used as reactor feed;

[0030] Furthermore, the light components separated by the circulation tower are condensed to discharge the non-condensable components and then refluxed to the upper part of the circulation tower;

[0031] Furthermore, the light component separated by the distillation tower 1 is condensed to extract the non-condensable component 2, which is then refluxed to the upper part of the distillation tower 1, and the non-condensable component 2 is used as feed for the circulation tower.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The device for preparing electronic-grade disilane of the present invention generates high-order silane based on the thermal decomposition polymerization reaction of crude monosilane. After preliminary separation through a circulation tower, the heavy component is subjected to two rectifications to remove light and heavy components respectively, and then subjected to two purifications to remove water, oxygen, and metal ions to obtain electronic-grade disilane, thereby realizing continuous production. Moreover, the raw material can be prepared based on the crude monosilane produced as a by-product of electronic-grade silane, with high economic benefits, providing a new option for the preparation of electronic-grade disilane.

[0034] The preparation process of the present invention adopts a non-catalytic cyclic reaction system with high reaction efficiency. The one-time conversion rate of monosilane can reach 8-15%, and the monosilane can be fully utilized in a cycle. The normal temperature distillation integrated technology is adopted, and the energy consumption is low. The water is removed to below 10 ppb by using a metal oxide purifier, which solves the problem that the water is difficult to be completely separated in the distillation operation. The metal cation exchange resin can efficiently remove metal impurities, which solves the inefficient method of removing metal impurities in the distillation operation by simple distillation, and improves the preparation efficiency of electronic grade disilane.

[0035] In the preparation method of the present invention, light components are extracted from the top of the circulation tower and circulated to the reactor, and non-condensable components are extracted from the top of the distillation tower and circulated to the circulation tower. The above multi-circulation method can effectively improve the yield of disilane prepared by thermal decomposition polymerization, further reduce the preparation cost, and is suitable for industrial application. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 Schematic diagram of the device for preparing electronic grade disilane by cyclic pyrolysis reaction according to the present invention.

[0038] Figure 1 The accompanying drawings are denoted as follows:

[0039] 100, reflux pipe 1; 101, circulation pipe; 200, reflux pipe 2; L1, production pipe 1; L2, production pipe 2; C1, compressor; E1, preheater; E2, electric heater; E3, cooler 1; E4, cooler 2; E5, cooler 3; E6, cooler 4; F1, filter; P1, pump 1; P2, pump 2; P3, pump 3; P4, pump 4; P5, pump 5; R1, reactor; FT1, circulation tower; T1, distillation tower 1; T2, distillation tower 2; V1, storage tank 1; V2, storage tank 2; A1, purifier 1; A2, purifier 2. DETAILED DESCRIPTION

[0040] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] Reference Figure 1 In one embodiment, a device for preparing electronic grade disilane by cyclic pyrolysis reaction is provided, comprising a preheating unit, a reactor R1, a filter F1, a circulating tower FT1, a distillation tower T1 and a distillation tower T2, a purifier A1 and a purifier A2 connected in sequence; wherein:

[0042] The preheating unit is connected to the upper part of the reactor R1 for feeding and preheating monosilane; the lower part of the reactor R1 is connected to the filter F1; the reactor R1 is used for thermal decomposition and polymerization of monosilane to generate disilane;

[0043] The circulating tower FT1 is used for pre-separation and removal of monosilane; the distillation tower T1 and the distillation tower T2 are respectively used for removal of light components and heavy components; the light components include hydrogen, monosilane, nitrogen, methane, and carbon monoxide; the heavy components include chlorosilane and water;

[0044] The purifier A1 is used to remove water and oxygen; the purifier A2 is used to remove metal ions to obtain electronic grade disilane.

[0045] In the above embodiment, the preparation device can generate high-order silane based on the thermal decomposition polymerization reaction of crude monosilane. After preliminary separation through a circulation tower, the heavy component is further distilled twice to remove light and heavy components respectively, and then purified twice to remove water, oxygen, and metal ions to obtain electronic-grade disilane, thereby realizing continuous production. The raw material can be prepared based on the crude monosilane produced as a by-product of electronic-grade silane, which has high economic benefits and provides a new option for the preparation of electronic-grade disilane.

[0046] In a preferred embodiment, the preheating unit includes a preheater E1 and a heater E2 connected in series; the filter F1 is connected to the heat exchange medium layer of the preheater E1; the hot material after the reaction is filtered by the filter and used to preheat the feed in the preheater E1 to improve the heat utilization efficiency.

[0047] In a preferred embodiment, the filter F1 is provided with multiple parallel connections for maintenance and switching to ensure continuous operation of the system. A cooler E3 is provided between the filter F1 and the circulating tower FT1, preferably connected in series with the preheater E1 described above, for cooling the material to an appropriate temperature before entering the circulating tower FT1 for separation.

[0048] In a preferred embodiment, the reactor R1 is filled with random packings such as stainless steel Raschig rings, ball rings, and step rings to increase the reaction area of ​​monosilane in the reactor. Monosilane is thermally decomposed through silicon-hydrogen bonds and silicon-silicon bond polymerization in the reactor R1 to generate disilane, trisilane, or higher-order silanes.

[0049] In a preferred embodiment, a circulation pipe 101 is provided at the top of the circulation tower FT1 and is connected to the preheating unit via a compressor C1. A reflux pipe 100 is provided at the top of the circulation tower FT1 and is connected to the upper part of the circulation tower FT1, which is used for circulating feed to improve the utilization rate of monosilane and further improve the yield of disilane; the reflux pipe 100 is provided with a production pipe L1 for producing non-condensable gas. Specifically, the reflux pipe 100 is provided with a cooler E4, a storage tank V1, and a pump P2 in sequence from the top of the circulation tower FT1 to the reflux feed end, which are used for top reflux and power guarantee; the material discharge end of the cooler E4 is also provided with an upward extension pipeline and is connected to the cooler E5, and the discharge end of the cooler E5 is provided with a production pipe L1, which is used to condense and produce non-condensable gas to the external tail gas absorption system.

[0050] In a preferred embodiment, the top of the distillation tower T1 is provided with a reflux pipe 200 connected to the upper part of the distillation tower T1 via a cooler E6; the material output end of the cooler E6 is provided with a production pipe L2 for producing non-condensable gas, including non-condensable silane. The production pipe L2 is connected to the feed end of the circulation tower FT1 (not shown in the figure) for circulating feed and improving the recovery rate.

[0051] In a preferred embodiment, the purifier A1 is filled with metal oxides, such as γ-Al2O3, which can further remove moisture and oxygen; the purifier A2 is filled with metal cation exchange resins, such as alkali metal (sodium / potassium) styrene cation exchange resins, which can further remove metal ions. Purifier A1 and purifier A2 are each provided with multiple parallel connections for maintenance and switching to ensure continuous operation of the system.

[0052] In some embodiments, the kettle of the circulating tower FT1 is provided with an electric heating system (not shown in the figure), and the heat source of the kettle reheater is provided by heating the heat transfer oil in the shell side. The kettle of the circulating tower FT1 uses a pump P1 to circulate the heat transfer oil in the shell side to increase the heat exchange efficiency. Similarly, the kettle reboilers of the distillation tower T1 and the distillation tower T2 are also equipped with an electric heating system (not shown in the figure), and the heat source of the kettle reheater is provided by heating the heat transfer oil in the shell side respectively. Pump three 3 and pump four P4 are used to circulate the heat transfer oil in the shell side to increase the heat exchange efficiency. The output end of the purifier two A2 is connected to the storage tank two V2 and the pump five P5 for the filling pump to increase the pressure, and then enters the subsequent analysis and filling system as the final ultra-high purity disilane product for semiconductors.

[0053] As a conventional setting in the field, the above-mentioned device also includes a power pump for providing material transfer, a valve for pipeline control, and instruments for monitoring working conditions, which will not be described in detail here.

[0054] In one embodiment, reference Figure 1 , a process for preparing electronic grade disilane based on cyclic pyrolysis is proposed, the steps comprising:

[0055] 1) Crude monosilane produced as a byproduct of electronic grade silane is preheated to 200-300°C in preheater E1, and then enters electric heater E2 to be heated to 380-450°C. After heating, the gas enters reactor R1; monosilane undergoes pyrolysis of silicon-hydrogen bonds and polymerization of silicon-silicon bonds in reactor R1 to generate disilane, trisilane or higher-order silanes, wherein the amount of monosilane converted to disilane is about 8-15%;

[0056] 2) The product obtained from the reaction in the reactor R1 first passes through the filter F1 to remove the microsilica powder that may be generated by the thermal decomposition of monosilane during the reaction. The gas from the filter F1 enters the preheater E1, which reduces its own temperature to 150-250°C while preheating the raw gas. The gas from the preheater E1 enters the cooler E3, where the gas temperature is reduced to 40-55°C by circulating water.

[0057] 3) After cooling in cooler E3, the gas enters the circulation tower FT1. The operating pressure of the circulation tower FT1 is 1.0 to 2.8 MPA, the operating temperature of the tower top is -55 to -30°C, and the operating temperature of the tower bottom is 10 to 60°C. Part of the gas at the top of the tower is pressurized by the circulation compressor C1 through the circulation pipe 101, and then returns to the crude monosilane raw material pipeline and enters the preheater E1 for use as a circulating reaction gas. The other part of the gas passes through the reflux pipe 100, and is condensed to a temperature of -45 to -70°C by cooler E4 and a condensation temperature of -80 to -150°C by cooler E5. The non-condensable gas is discharged to the tail gas absorption system through the extraction pipe L1. The condensate enters the storage tank V1 from the output end of cooler E4, and is refluxed into the upper part of the circulation tower FT1 through pump P2 as the tower reflux liquid.

[0058] 4) The material mainly containing disilane extracted from the bottom of the circulating tower FT1 enters the distillation tower-T1 for light removal treatment. The operating pressure of the distillation tower-T1 is 0.6-1.5MPA, the operating temperature of the top of the tower is 30-50°C, and the operating temperature of the bottom of the tower is 35-55°C. It mainly removes hydrogen, monosilane, nitrogen, methane, carbon monoxide and other substances contained in disilane. After the top gas is condensed by the cooler 4E6, the gas containing non-condensable silane returns to the circulating tower FT1 through the extraction pipe 2L2 for recycling, and the condensate returns to the upper part of the distillation tower-T1 as reflux liquid.

[0059] 5) The disilane extracted from the bottom of the distillation tower T1 after the light components are removed enters the distillation tower T2 from the middle for heavy component removal. The operating pressure of the distillation tower T2 is 0.4-1.3MPA, the operating temperature of the top is 20-45°C, and the operating temperature of the bottom is 30-50°C. The distillation tower T2 mainly removes impurities such as chlorosilane and water contained in the disilane.

[0060] 6) The light components extracted from the top of the distillation tower T2 enter the purifier A1 filled with metal oxides to deeply remove impurities such as water and oxygen that have not been removed from the distillation system, so that the water and oxygen content is reduced to less than 10ppb. The deeply dehydrated product enters the purifier A2 filled with metal cation exchange resin to remove the metal ion content in the material to less than 10ppt. The material after the metal ion removal is electronic grade disilane.

[0061] In the above embodiment, the preparation process uses the disproportionation method to produce the effluent of monosilane, realizing the comprehensive high-value utilization of the exhaust gas; a non-catalytic cyclic reaction system is adopted, the reaction efficiency is high, and the monosilane conversion rate can reach 8-15%, while the monosilane is fully utilized in a cycle to improve the yield. Combined with metal oxide dehydration, metal cation exchange resin, and room temperature distillation integrated technology. The metal oxide purifier removes water to less than 10ppb, solving the problem that water is difficult to completely separate in the distillation operation; the metal cation exchange resin can efficiently remove metal impurities, solving the inefficient method of removing metal impurities in the distillation operation is just simple distillation.

[0062] In the above embodiment, the filter F1, the purifier A1, and the purifier A2 respectively adopt a parallel dual system to provide a continuous stable fully automatic control preparation process, which ensures the stability of product quality and the consistency of product batches and is suitable for industrial production.

[0063] In a preferred embodiment, the refrigerant used for cooling of cooler 2 E4, cooler 3 E5 and cooler 4 E6 can be liquid fluorine to ensure the condensation effect.

[0064] In the above embodiment, the disilane obtained by the preparation process is analyzed, and the higher-order silanes such as trisilane, hydrogen, monosilane, nitrogen, methane, carbon monoxide, chlorosilane, moisture, and metal ions are all controlled within the impurity control range of electronic grade content. The purity of disilane reaches above 6N, meeting the standard requirements of electronic grade.

[0065] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A device for preparing electronic grade disilane by cyclic pyrolysis reaction, characterized in that: The invention comprises a preheating unit, a reactor (R1), a filter (F1), a circulation tower (FT1), a distillation tower 1 (T1), a distillation tower 2 (T2), a purifier 1 (A1), and a purifier 2 (A2) which are connected in sequence; wherein: The preheating unit is connected to the upper part of the reactor (R1) for feeding and preheating monosilane; the lower part of the reactor (R1) is connected to the filter (F1); the reactor (R1) is used for thermal decomposition and polymerization of monosilane to generate disilane; The circulation tower (FT1) is used for pre-separation and removal of monosilane; the distillation tower 1 (T1) and the distillation tower 2 (T2) are used for light removal and heavy removal respectively; The purifier one (A1) is used to remove water and oxygen; the purifier two (A2) is used to remove metal ions to obtain electronic grade disilane.

2. The device according to claim 1, characterized in that The preheating unit comprises a preheater (E1) and a heater (E2) connected in series; the filter (F1) is connected to the heat exchange medium layer of the preheater (E1); And / or, a cooler (E3) is provided between the filter (F1) and the circulation tower (FT1).

3. The device according to claim 1, characterized in that The top of the circulation tower (FT1) is provided with a circulation pipe (101) which is connected to the preheating unit via a compressor (C1).

4. The device according to claim 1 or 3, characterized in that The top of the circulation tower (FT1) is provided with a reflux pipe (100) connected to the upper part of the circulation tower (FT1), and the reflux pipe (100) is provided with a production pipe (L1) for producing non-condensable gas.

5. The device according to claim 1, characterized in that The top of the distillation tower 1 (T1) is provided with a reflux pipe 2 (200) connected to the upper part of the distillation tower 1 (T1); the reflux pipe 2 (200) is provided with a production pipe 2 (L2) for producing non-condensable gas.

6. The device according to claim 5, characterized in that The extraction pipe 2 (L2) is connected to the feed end of the circulation tower (FT1).

7. The device according to claim 1, characterized in that The purifier 1 (A1) is filled with metal oxides; and / or, the purifier 2 (A2) is filled with metal cation exchange resins.

8. A process for preparing electronic grade disilane by cyclic pyrolysis reaction, characterized in that the steps include: S1. The crude monosilane produced as a byproduct of electronic grade silane is heated to 380-450°C and enters the packing reactor for thermal decomposition and polymerization reaction; S2. The product obtained in step S1 is filtered to remove microsilica powder, cooled and enters a circulation tower (FT1) to separate light components and heavy components. The operating pressure of the circulation tower is 1.0 to 2.8 MPa, the operating temperature of the tower top is -55 to -30 ° C, and the operating temperature of the tower bottom is 10 to 60 ° C; S3. The heavy components separated by the circulation tower (FT1) are removed by the distillation tower 1 (T1) to remove the light components, and the distillation tower 2 (T2) to remove the heavy components before being produced; the light components include hydrogen, monosilane, nitrogen, methane, and carbon monoxide; the heavy components include chlorosilane and water; S4. The light components extracted from the distillation tower 2 (T2) are purified for the first time and the second time to obtain electronic grade disilane; the first purification is used to remove water and oxygen; the second purification is used to remove metal ions.

9. The process according to claim 8, characterized in that The operating pressure of the distillation tower 1 (T1) is 0.6-1.5 MPA, the operating temperature of the tower top is 30-50°C, and the operating temperature of the tower bottom is 35-55°C; And / or, the operating pressure of the second distillation tower (T2) is 0.4-1.3 MPA, the operating temperature of the top of the tower is 20-45°C, and the operating temperature of the bottom of the tower is 30-50°C.

10. The process according to claim 8, characterized in that The light components separated by the circulating tower (FT1) are used as reactor feed; and / or, the light components separated by the circulation tower (FT1) are condensed to discharge the non-condensable components and then refluxed to the upper part of the circulation tower (FT1); And / or, the light component separated by the distillation tower (T1) is condensed to produce the non-condensable component (T1) and then refluxed to the upper part of the distillation tower (T1), and the non-condensable component (T1) is used as feed for the circulation tower (FT1).

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