Disilane concentration device and concentration method

Abstract

The invention belongs to the technical field of special gas separation, and particularly relates to a disilane concentration device and a disilane concentration method. The device comprises a booster pump, a hydrogen separation device and a pressure swing adsorption tower which are sequentially arranged along the material flow direction. The concentration method comprises the following steps: firstly, increasing the pressure of disilane-containing raw material gas synthesized by a silane thermal polymerization method, and then separating hydrogen in the disilane-containing raw material gas to obtain dehydrogenated mixed gas; and carrying out pressure swing adsorption on the dehydrogenated mixed gas, adsorbing disilane and propyl silane, finally desorbing to obtain concentrated disilane gas, and recycling the rest of gas. According to the invention, disilane concentration with low energy consumption and high recovery rate is realized, and an efficient technical scheme is provided for semiconductor material manufacturing.

Description

Technical Field

[0001] The present application belongs to the technical field of special gas separation, and specifically relates to a disilane concentration device and a concentration method. Background Art

[0002] Several methods are currently available for the industrial production of disilane: magnesium silicide, silane thermal polymerization, silane glow discharge, and hexachlorodisilane reduction. The magnesium silicide and hexachlorodisilane reduction methods suffer from high raw material costs, excessive waste, gas-liquid-solid separations, and other issues. The silane glow discharge method is inefficient, prone to silicon powder deposition, and unstable discharge.

[0003] The silane thermal polymerization method has become the preferred path for the current industrial production of disilane due to its three core advantages: a mature raw material supply chain, strong equipment versatility, and a controllable reaction process. In particular, driven by collaboration with the polysilicon industry chain, catalyst development, and separation technology upgrades, its dominant position will be further consolidated. However, the silane thermal polymerization method has the following problems: Because the single conversion efficiency is low (<10%), the silane generated by the reaction needs to be condensed and collected, the generated hydrogen needs to be discharged from the system, and the unreacted silane needs to be separated from the reaction products before entering the reactor for reaction. Therefore, the energy consumption of liquid nitrogen and electricity in the process of condensation and recycling remains high. Existing industrial equipment uses cryogenic cold traps to separate hydrogen and cryogenic distillation to separate silane and collect disilane, which consumes very high energy. For example, Chinese patent publication number CN115403048B discloses a method for purifying disilane, which includes the following steps: S1, solid removal: passing the mixed gas through a filter for solid removal, discharging solid waste from the filter, and obtaining a mixed gas after solid removal; S2, primary distillation: passing the mixed gas after solid removal through a de-weighting tower for primary distillation to remove heavy impurities; S3, membrane separation: passing the mixed gas after primary distillation through a membrane separator, and removing hydrogen from the mixed gas through an organic polymer reverse osmosis membrane that does not react with monosilane and disilane; S4, secondary distillation: passing the mixed gas after membrane separation treatment through a de-lighting tower for secondary distillation to remove monosilane, thereby finally obtaining high-purity disilane. For example, Chinese patent publication CN116534863B discloses a highly efficient purification method, apparatus, and application for obtaining silane and disilane. This method utilizes a single-stage, multi-layer adsorption process combined with a single-stage, multi-layer separation tower distillation process to thoroughly remove impurities such as hydrogen, nitrogen, oxygen, ammonia, and metals from the silane and disilane gas mixture, reducing the total impurity content to less than 1 ppm while simultaneously obtaining silane and disilane gases with a purity of 99.9999% or higher. However, these methods for purifying disilane directly remove impurities from the reaction product, involving drying, removal of heavy components, and removal of light components. Each process requires significant energy consumption. Furthermore, due to the low conversion efficiency of the silicothermal method, impurity removal consumes even greater energy.

[0004] Therefore, it is urgent to develop a disilane concentration method to reduce energy consumption and improve raw material recovery in the subsequent purification process. Summary of the Invention

[0005] In view of the fact that existing industrial devices in the prior art use low-temperature cold traps to separate hydrogen, and low-temperature distillation to separate monosilane and collect disilane, which consume very high energy, the present application proposes a disilane concentration device and concentration method.

[0006] The technical solution of this application is as follows:

[0007] On the one hand, the present application provides a disilane concentration device, comprising a booster pump, a hydrogen separation device, and a pressure swing adsorption tower arranged in sequence along the material flow direction, wherein the booster pump is connected to the hydrogen separation device, and the hydrogen separation device is connected to the pressure swing adsorption tower.

[0008] Wherein, the booster pump is used to increase the pressure of the disilane-containing raw material gas synthesized by the silane thermal polymerization method;

[0009] The hydrogen separation device is used to receive the disilane-containing raw gas pressurized by the booster pump and separate the hydrogen from the disilane-containing raw gas to obtain a dehydrogenated mixed gas;

[0010] The pressure swing adsorption tower unit is used to separate disilane and trisilane from the dehydrogenated mixed gas to obtain concentrated disilane.

[0011] Preferably, the hydrogen separation device is provided with a hydrogen separation membrane, which is a hollow fiber membrane made of polysulfone, and the hydrogen / silane separation factor of the hydrogen separation membrane is ≥30.

[0012] Preferably, the pressure swing adsorption tower is filled with a molecular sieve adsorbent, and the pore size of the molecular sieve adsorbent is 0.5 to 0.6 nm.

[0013] Preferably, the molecular sieve adsorbent is any one of zeolite molecular sieve or carbon molecular sieve.

[0014] On the other hand, the present application provides a method for concentrating disilane, comprising the following steps:

[0015] Step S1. First, the pressure of the disilane-containing raw gas synthesized by the silane thermal polymerization method is increased, and then the hydrogen in the disilane-containing raw gas is separated to obtain a dehydrogenated mixed gas;

[0016] Step S2: The dehydrogenated mixed gas is subjected to pressure swing adsorption, disilane and trisilane are adsorbed and finally desorbed to obtain concentrated disilane gas, and the remaining gas is recycled.

[0017] Preferably, the pressure of the disilane-containing raw material after pressurization is 0.8 to 1.2 MPa.

[0018] Preferably, the pressure of the disilane-containing raw material after pressurization is 1.0 MPa.

[0019] Beneficial effects:

[0020] This application pressurizes the feed gas synthesized by silane thermal polymerization to 0.8-1.2 MPa to provide power for subsequent separation. A hydrogen separation device incorporates a polysulfone hollow fiber membrane, utilizing the significant size difference between hydrogen molecules and silane gases to separate hydrogen from the silane-containing feed gas. Finally, disilane and trisilane are adsorbed through the molecular sieving effect, while monosilane, due to its small size, passes directly through, achieving disilane concentration and monosilane recovery.

[0021] In summary, this device, through membrane separation of hydrogen and disilane enrichment, addresses the high energy consumption associated with product separation from silane thermal polymerization. It achieves low-energy, high-recovery disilane concentration, providing a highly efficient technical solution for semiconductor material manufacturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is the disilane concentration process route of this application;

[0023] Figure 2 This is the disilane concentration device of this application.

[0024] Figure ID:

[0025] 1. Booster pump; 2. Hydrogen separation device; 3. Pressure swing adsorption tower. DETAILED DESCRIPTION

[0026] In order to further illustrate the technical means and effects adopted by this application to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of this application are described in detail below in combination with the accompanying drawings and preferred embodiments.

[0027] The disilane-containing feedstock gas used in this application was prepared via silane thermal polymerization. The content of each component in the feedstock is shown in Table 1. The low hydrogen content and significant molecular diameter difference between the hydrogen and other components in the disilane-containing feedstock gas synthesized by silane thermal polymerization in this application allow for a large separation factor using membrane separation. Disilane and trisilane, as macromolecules with low content and large molecular diameters, are therefore enriched via adsorption. Silane, a high-content, small-molecule component, is returned to the reactor as an unadsorbed component to continue the reaction.

[0028] Table 1

[0029] Components <![CDATA[SiH4]]> <![CDATA[Si2H6]]> <![CDATA[Si3H 10 ]]> <![CDATA[H2]]> content 89％ 4.5％ 0.8％ 5.7％ Component diameter 0.408nm 0.49nm~0.53nm 0.53nm~0.6nm 0.283nm

[0030] Device example

[0031] This device example provides a disilane concentration device, which specifically includes a booster pump 1, a hydrogen separation device 2, and a pressure swing adsorption tower 3, which are sequentially arranged along the material flow direction.

[0032] Among them, the booster pump 1 is used to increase the pressure of the disilane-containing raw gas synthesized by the silane thermal polymerization method; the hydrogen separation device 2 is equipped with a hydrogen separation membrane, which is used to receive the disilane-containing raw gas pressurized by the booster pump 1 and separate the hydrogen in the disilane-containing raw gas to obtain a dehydrogenated mixed gas; the hydrogen separation membrane is a hollow fiber membrane made of polysulfone. The effective membrane area of ​​the device based on this application is 6m 2 In order to further achieve better separation effect, several groups of hydrogen separation membranes can be set up.

[0033] The pressure swing adsorption tower 3 is used to separate disilane and trisilane from the dehydrogenated mixed gas to obtain concentrated disilane. In order to fully recover disilane from silane, multiple pressure swing adsorption towers 3 can be provided.

[0034] Implementation principle of the device:

[0035] First, the disilane-containing raw gas is fed into the booster pump 1, where it is pressurized. The boosted disilane-containing raw gas then enters the hydrogen separation device 2, where hydrogen is separated by the hydrogen separation membrane, and the remaining dehydrogenated mixed gas enters the pressure swing adsorption tower 3.

[0036] Under the action of the adsorbent in the pressure swing adsorption tower 3, disilane and trisilane are adsorbed, and the molecular diameter of monosilane is smaller than the pore size of the adsorbent, so it passes through the adsorbent for recycling. Disilane and trisilane are finally collected by desorption and enter the subsequent process.

[0037] Example 1

[0038] Based on the device provided in the device example, this embodiment provides a method for concentrating disilane, which is as follows:

[0039] Step S1. The disilane-containing raw material gas synthesized by the silane thermal polymerization method enters the booster pump 1 at a flow rate of 100 L / min and a pressure of 0.0 MPa, and is pressurized to 1.0 MPa by the booster pump 1.

[0040] Then it enters the hydrogen separation device 2, where the hydrogen in the disilane-containing feed gas is separated by the hydrogen separation membrane to obtain a dehydrogenated mixed gas. The hydrogen separation membrane used in this embodiment is a hollow fiber membrane made of polysulfone. The diameter of the hydrogen separation membrane is 100 mm, the membrane length is 1000 mm, and the separation factor is 30. The effective membrane area is 6 m 2 , intake pressure 1.0MPa.

[0041] Step S2: The dehydrogenated mixed gas is passed into a pressure swing adsorption tower (PSA) 3. The adsorption towers have a diameter of 108 mm and a bed height of 1500 mm. Pressure swing adsorption is performed. Disilane and trisilane are adsorbed and desorbed to produce concentrated disilane gas. The remaining gas is recovered. The adsorption and desorption parameters are: an adsorption cycle of 10 minutes, a regeneration cycle of 2 minutes, and a desorption pressure of -0.09 MPa. Zeolite molecular sieve with a pore size of 0.5 nm is used as the adsorbent.

[0042] Example 2

[0043] Based on the device provided in the device example, this embodiment provides a method for concentrating disilane, which is as follows:

[0044] Step S1. The disilane-containing raw material gas synthesized by the silane thermal polymerization method enters the booster pump 1 at a flow rate of 100 L / min and a pressure of 0.0 MPa, and is pressurized to 0.8 MPa by the booster pump 1.

[0045] Then it enters the hydrogen separation device 2, where the hydrogen in the disilane-containing feed gas is separated by the hydrogen separation membrane to obtain a dehydrogenated mixed gas. The hydrogen separation membrane used in this embodiment is a hollow fiber membrane made of polysulfone. The diameter of the hydrogen separation membrane is 100 mm, the membrane length is 1000 mm, and the separation factor is 50. The effective membrane area is 6 m 2 , intake pressure 1.0MPa.

[0046] Step S2: The dehydrogenated mixed gas is passed into a pressure swing adsorption tower (PSA) 3. The adsorption towers have a diameter of 108 mm and a bed height of 1500 mm. Pressure swing adsorption is performed. Disilane and trisilane are adsorbed and desorbed to produce concentrated disilane gas. The remaining gas is recovered. The adsorption and desorption parameters are: an adsorption cycle of 10 minutes, a regeneration cycle of 2 minutes, and a desorption pressure of -0.09 MPa. The adsorbent is a zeolite molecular sieve with a pore size of 0.55 nm.

[0047] Example 3

[0048] Based on the device provided in the device example, this embodiment provides a method for concentrating disilane, which is as follows:

[0049] Step S1. The disilane-containing raw material gas synthesized by the silane thermal polymerization method enters the booster pump 1 at a flow rate of 100 L / min and a pressure of 0.0 MPa, and is pressurized to 1.2 MPa by the booster pump 1.

[0050] Then it enters the hydrogen separation device 2, where the hydrogen in the disilane-containing feed gas is separated by the hydrogen separation membrane to obtain a dehydrogenated mixed gas. The hydrogen separation membrane used in this embodiment is a hollow fiber membrane made of polysulfone. The diameter of the hydrogen separation membrane is 100 mm, the membrane length is 1000 mm, and the separation factor is 70. The effective membrane area is 6 m2 , intake pressure 1.0MPa.

[0051] Step S2: The dehydrogenated mixed gas is passed into a pressure swing adsorption tower (PSA) 3. The adsorption towers have a diameter of 108 mm and a bed height of 1500 mm. Pressure swing adsorption is performed. Disilane and trisilane are adsorbed and desorbed to produce concentrated disilane gas. The remaining gas is recovered. The adsorption and desorption parameters are: an adsorption cycle of 10 minutes, a regeneration cycle of 2 minutes, and a desorption pressure of -0.09 MPa. A carbon molecular sieve with a pore size of 0.6 nm is used as the adsorbent.

[0052] Detection and Analysis

[0053] The gas contents of hydrogen separated by the hydrogen separation membrane, disilane after concentration, and monosilane that penetrated were detected, and the results are shown in Table 2.

[0054] Table 2

[0055]

[0056] As can be seen from Examples 1-3 and Table 3, the present invention effectively concentrates low-concentration disilane synthesis gas through membrane separation to remove hydrogen and pressure swing adsorption to separate silane from disilane and trisilane, while allowing the recovered monosilane to continue reacting. It should be noted that because only one set of hydrogen separation membranes was used in Examples 1-3, the hydrogen outlet contained a certain concentration of monosilane, but the total amount was not significant. If the silane recovery rate is further considered, an additional set of hydrogen separation membranes could be added to further separate the hydrogen and silane.

[0057] The above description is merely a preferred embodiment of the present application and does not constitute any form of limitation to the present application. Although the present application has been disclosed as above with preferred embodiments, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to equivalent embodiments using the technical contents disclosed above without departing from the scope of the technical solution of the present application. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application are still within the scope of the technical solution of the present application.

Claims

1. A disilane concentration device, characterized in that: It includes a booster pump, a hydrogen separation device, and a pressure swing adsorption tower which are arranged in sequence along the material flow direction. Wherein, the booster pump is used to increase the pressure of the disilane-containing raw material gas synthesized by the silane thermal polymerization method; The hydrogen separation device is used to receive the disilane-containing raw gas pressurized by the booster pump and separate the hydrogen from the disilane-containing raw gas to obtain a dehydrogenated mixed gas; The pressure swing adsorption tower unit is used to separate disilane and trisilane from the dehydrogenated mixed gas to obtain concentrated disilane.

2. A disilane concentration device according to claim 1, characterized in that: The hydrogen separation device is provided with a hydrogen separation membrane, which is a hollow fiber membrane made of polysulfone. The hydrogen / silane separation factor of the hydrogen separation membrane is ≥30.

3. A disilane concentration device according to claim 1, characterized in that: The pressure swing adsorption tower is filled with a molecular sieve adsorbent, and the pore size of the molecular sieve adsorbent is 0.5-0.6 nm.

4. A disilane concentration device according to claim 3, characterized in that: The molecular sieve adsorbent is any one of zeolite molecular sieve or carbon molecular sieve.

5. The concentration method of a disilane concentration device according to claims 1 to 4, characterized in that: The steps include: Step S1. First, the pressure of the disilane-containing raw gas synthesized by the silane thermal polymerization method is increased, and then the hydrogen in the disilane-containing raw gas is separated to obtain a dehydrogenated mixed gas; Step S2: The dehydrogenated mixed gas is subjected to pressure swing adsorption, disilane and trisilane are adsorbed and finally desorbed to obtain concentrated disilane gas, and the remaining gas is recycled.

6. A disilane concentration method according to claim 5, characterized in that: The pressure of the disilane-containing raw material after pressurization is 0.8-1.2 MPa.

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