Liquid phase trichlorosilane boron phosphorus removal system

Abstract

This invention provides a liquid-phase trichlorosilane-boron-phosphorus removal system, comprising: a first adsorption tank; an inlet connected to the bottom of the first adsorption tank via an inlet pipe; a trichlorosilane storage tank connected to the outlet of the adsorption tank via an outlet pipe; a nitrogen heating tank connected to the outlet of the adsorption tank via a nitrogen pipe; and a waste gas treatment system connected to the inlet via a desorption gas pipe. The adsorbent inside the first adsorption tank is a microcrystalline material. Through this design, the removal system is compact, with a reasonable pipeline layout, reducing equipment complexity and installation and maintenance difficulty. Using microcrystalline material as the adsorbent, its unique pore structure and surface properties effectively adsorb boron and phosphorus impurities, exhibiting higher selectivity and adsorption capacity compared to traditional adsorbents, thus improving removal efficiency, thereby increasing production efficiency and reducing costs.

Description

Technical Field

[0001] This utility model relates to the field of trichlorosilane-boron-phosphorus removal technology, specifically to a liquid-phase trichlorosilane-boron-phosphorus removal system. Background Technology

[0002] In the semiconductor industry, the production process of liquid trichlorosilane (SiHCl3) is often accompanied by impurities such as hydrogen germanide and hydrogen arsine. These impurities can seriously affect the electrical performance and overall performance of semiconductor devices. Therefore, it is crucial to eliminate impurities such as boron and phosphorus to provide high-purity raw materials for the production of high-purity silicon materials.

[0003] Traditional purification methods include adsorption and distillation. The adsorption process typically involves passing trichlorosilane through an adsorbent material that can selectively capture boron and phosphorus impurities. However, traditional adsorbents have limited capacity, poor selectivity, and degrade over long-term operation, leading to a decrease in the purification efficiency of the adsorbent. The effectiveness of the adsorption process is also affected by operating conditions such as temperature, pressure, and flow rate.

[0004] Chinese patent CN220165843U, entitled "An Adsorption and Removal System for Boron and Phosphorus Impurities in Trichlorosilane," describes a system that adds two parallel adsorption mechanisms for removing boron and phosphorus. It uses a tubular structured adsorption resin to reduce the boron and phosphorus content in trichlorosilane. However, the tubular structure results in insufficient contact between the trichlorosilane and the adsorbent, leading to low adsorption efficiency. Summary of the Invention

[0005] This invention provides a liquid-phase trichlorosilane boron phosphorus removal system to solve the problem of low removal efficiency caused by insufficient contact in boron phosphorus adsorption and removal equipment.

[0006] To address the aforementioned problems, this utility model provides a liquid-phase trichlorosilane boron phosphorus removal system, comprising: a first adsorption tank, an inlet connected to the bottom of the first adsorption tank via an inlet pipe, a trichlorosilane storage tank connected to the adsorption tank outlet via an outlet pipe, a nitrogen heating tank connected to the adsorption tank outlet via a nitrogen pipe, and a waste gas treatment system connected to the inlet via a desorption gas pipe; the first adsorption tank includes: an adsorption tank inlet located at the bottom of the first adsorption tank, a distributor main pipe connected to the adsorption tank inlet via a dual-liquid isolation pump, and an adsorption collector, the distributor main pipe connecting to at least 3 layers of tubular distributors, the tubular distributors having a plurality of small holes, the adsorption collector including at least 3 adsorption layers, a liquid receiving tray located below the adsorption layers, and a mesh collection pipe threadedly connected to the adsorption layers, the other end of the dual-liquid isolation pump being connected to the adsorption tank outlet via a liquid guide pipe;

[0007] The above scheme, through the design of multi-layer tubular distributor and multi-layer adsorption layer, significantly increases the distribution area and adsorption capacity of the liquid phase. The use of dual-liquid isolation pumps enables independent delivery of different liquids, avoiding cross-contamination. At the same time, the removal system is compactly designed with a reasonable pipeline layout, reducing the complexity of the equipment, lowering the difficulty of installation and maintenance, improving the reliability and stability of the system, and significantly improving the removal efficiency of boron and phosphorus.

[0008] According to one embodiment of the present invention, it further includes a second adsorption tank connected to the outlet pipe via a branch pipe, a trichlorosilane storage tank and a nitrogen heating tank connected to the top of the second adsorption tank via an outlet pipe and a nitrogen pipe, and an inlet and a waste gas treatment system connected to the bottom of the second adsorption tank via an inlet pipe and a desorption gas pipe.

[0009] By adding a second adsorption tank to achieve two adsorption tanks connected in series, the removal efficiency of boron and phosphorus can be further improved. The first adsorption tank initially adsorbs most of the impurities, while the second adsorption tank performs deep adsorption on the remaining impurities, ensuring the high purity of the final product. At the same time, the two adsorption tanks can be used in parallel and alternately, thereby reducing the burden on each adsorption tank, extending the service life of the adsorbent, and reducing the frequency and cost of replacing the adsorbent.

[0010] According to one embodiment of the present invention, the adsorption layer is configured as a two-stage adsorption structure. The two-stage adsorption structure can adsorb boron and phosphorus impurities in the liquid phase in stages. The first-stage adsorption layer mainly removes most of the impurities, and the second-stage adsorption layer further purifies them, which significantly improves the overall removal efficiency and the utilization efficiency of resources.

[0011] According to one embodiment of this utility model, both the inlet and outlet pipes are equipped with sampling ports, thermometers, and pressure gauges. Liquid samples can be collected at any time through the sampling ports for composition and purity analysis, ensuring that the quality of the inlet and outlet liquids meets the process requirements. The real-time monitoring data from the thermometer and pressure gauge helps to monitor changes in the temperature and pressure of the liquid, ensuring the stability and controllability of the process.

[0012] According to one embodiment of this utility model, the liquid inlet is also equipped with a flow meter. The flow meter at the liquid inlet can monitor the liquid flow rate in real time, ensuring precise control of the liquid inlet volume, meeting process requirements, and avoiding production problems caused by excessive or insufficient liquid.

[0013] According to one embodiment of the present invention, both the first adsorption tank and the second adsorption tank are provided with adsorbent outlets. The design of the adsorbent outlets of the first adsorption tank and the second adsorption tank facilitates the periodic or as-needed replacement of the adsorbent, ensuring the adsorption effect and system performance, and extending the service life of the equipment.

[0014] According to one embodiment of this utility model, all pipelines are equipped with electric valves. Through the above scheme, the electric valves can be operated through a remote control system, and the opening degree can be finely adjusted to achieve precise control of fluid flow and pressure, reduce on-site manual intervention, and improve the safety and convenience of operation. It is especially suitable for dangerous or inaccessible environments.

[0015] According to one embodiment of the present invention, the adsorbent in the adsorption layer is a microcrystalline material. The microcrystalline material has a large specific surface area, providing more adsorption sites and significantly improving the adsorption capacity for boron and phosphorus impurities in the liquid phase.

[0016] According to one embodiment of the present invention, the microcrystalline material is an artificially hydrothermally synthesized aluminosilicate crystal. As a microcrystalline material, the artificially hydrothermally synthesized aluminosilicate crystal has the characteristics of high strength, no powder shedding, no pollution to raw materials, high adsorption precision, and low water content. During adsorption, the microcrystalline material can control the feed temperature at 0°C and ensure that the inlet and outlet temperatures remain unchanged, thereby improving the purification effect and thus improving production efficiency.

[0017] According to one embodiment of this utility model, the heating temperature of the nitrogen heating tank is 200℃~250℃, preferably 230℃. Through the above scheme, when the adsorption column reaches saturation, high-temperature nitrogen is used as the regeneration desorption gas to purge and regenerate the saturated adsorption tower, and then transported to the waste gas treatment system. The high-temperature nitrogen can provide sufficient heat to promote the desorption of adsorbed impurities and restore the activity of the adsorbent. In addition, nitrogen is an inert gas and will not chemically react with the adsorbed impurities, ensuring that no new chemical substances are introduced during the regeneration process and maintaining the stability of the system.

[0018] The technical advantages of this application are as follows:

[0019] 1. This patent provides a highly efficient, stable, and low-cost liquid-phase trichlorosilane-boron-phosphorus removal system. Through a compact design and reasonable pipeline layout, it reduces the complexity of the equipment and lowers the difficulty of installation and maintenance.

[0020] 2. By designing a multi-layer tubular distributor and a multi-layer adsorption layer, the distribution area and adsorption capacity of the liquid phase are significantly increased. The use of a dual-liquid isolation pump enables independent delivery of different liquids, avoids cross-contamination, improves the reliability and stability of the system, and significantly improves the removal efficiency of boron and phosphorus.

[0021] 3. Microcrystalline materials are used as adsorbents. Their unique pore structure and surface properties can effectively adsorb boron and phosphorus impurities. Compared with traditional adsorbents, they have higher selectivity and adsorption capacity, thereby improving removal efficiency.

[0022] 4. Add a second adsorption tank, connecting the two adsorption tanks in series to further improve the removal efficiency. The first adsorption tank adsorbs most of the impurities, while the second adsorption tank performs deep adsorption on the remaining impurities, ultimately enabling the product to achieve high purity. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of a liquid-phase trichlorosilane-boron-phosphorus removal system provided by this utility model.

[0024] Figure 2 This is a schematic diagram of the internal structure of the adsorption tank of a liquid-phase trichlorosilane-boron-phosphorus removal system provided by this utility model.

[0025] Figure 3 This is a schematic diagram of the tubular distributor structure of a liquid-phase trichlorosilane-silicon-boron-phosphorus removal system provided by this utility model.

[0026] Explanation of reference numerals in the attached figures:

[0027] 1. Liquid inlet; 2. Flow meter; 3. Sampling port; 4. Thermometer; 5. Pressure gauge; 6. Electric valve; 7. Adsorbent outlet; 8. First adsorption tank; 81. Adsorption tank inlet; 82. Dual-liquid isolation pump; 83. Distributor main pipe; 84. Tubular distributor; 85. Adsorption collector; 86. Liquid guide pipe; 87. Liquid receiving tray; 88. Mesh collection pipe; 89. Adsorption layer; 9. Adsorption tank outlet; 10. Trichlorosilane storage tank; 11. Nitrogen heating tank; 12. Second adsorption tank; 13. Waste gas treatment system; 14. Outlet pipe; 15. Nitrogen pipe; 16. Desorption gas pipe; 17. Branch pipe; 18. Inlet pipe. Detailed Implementation

[0028] The following will be combined with the appendix Figures 1-3 The embodiments of the technical solution of this application are described in detail below. The following embodiments are only used to illustrate the technical solution of this application more clearly, and are therefore only examples and should not be used to limit the scope of protection of this application.

[0029] Example 1

[0030] Reference Figures 1-3This utility model provides a liquid-phase trichlorosilane-boron-phosphorus removal system, comprising: a first adsorption tank 8, an inlet 1 connected to the bottom of the first adsorption tank 8 via an inlet pipe 18, a trichlorosilane storage tank 10 connected to the adsorption tank outlet 9 via an outlet pipe 14, a nitrogen heating tank 11 connected to the adsorption tank outlet 9 via a nitrogen pipe 15, and a waste gas treatment system 13 connected to the inlet 1 via a desorption gas pipe 16; the first adsorption tank 8 includes: an adsorption tank inlet 81 located at the bottom of the first adsorption tank 8, and a dual-liquid isolation pump 82 connected to the adsorption tank inlet 81. The distributor main pipe 83 and the adsorption collector 85 are connected respectively. The distributor main pipe 83 is connected to at least 3 layers of tubular distributors 84. The tubular distributors 84 are provided with several small holes. Each pipe installed on it is connected to the central pipe by a flange, which is easy to disassemble and maintain. The adsorption collector 85 includes at least 3 adsorption layers 89, a liquid receiving tray 87 located below the adsorption layers 89, and a mesh screen collection pipe 88 threadedly connected to the adsorption layers 89. The mesh screen collection pipe 88 can filter crystals and prevent crystals from being carried out. The other end of the dual liquid isolation pump 82 is connected to the adsorption tank outlet 9 through a liquid guide pipe 86.

[0031] Through the above scheme, the design of the multi-layer tubular distributor 84 and the multi-layer adsorption layer 89 significantly increases the distribution area and adsorption capacity of the liquid phase. The dual-liquid isolation pump 82 has two independent pump chambers, each equipped with its own inlet and outlet. The two pump chambers are isolated by the pump body to ensure that the liquids do not mix inside the pump, realizing the independent delivery of different liquids, avoiding cross-contamination, improving the reliability and stability of the system, and significantly improving the removal efficiency of boron and phosphorus.

[0032] The aforementioned removal system also includes a second adsorption tank 12 connected to the outlet pipe 14 via a branch pipe 17. A trichlorosilane storage tank 10 and a nitrogen heating tank 11 are connected to the top of the second adsorption tank 12 via the outlet pipe 14 and a nitrogen pipe 15. An inlet 1 and a waste gas treatment system 13 are connected to the bottom of the second adsorption tank 12 via an inlet pipe 18 and a desorption gas pipe 16. By adding the second adsorption tank 12, two adsorption tanks are connected in series, which can further improve the removal efficiency of boron and phosphorus. The first adsorption tank 8 initially adsorbs most of the impurities, while the second adsorption tank 12 performs deep adsorption on the remaining impurities, ensuring the high purity of the final product. Simultaneously, the two adsorption tanks can be used alternately, thereby reducing the burden on each adsorption tank, extending the service life of the adsorbent, and reducing the frequency and cost of replacing the adsorbent.

[0033] Both the inlet 1 and outlet pipe 14 are equipped with sampling ports 3, thermometers 4, and pressure gauges 5. Sampling ports 3 allow for the collection of liquid samples at any time for composition and purity analysis, ensuring that the quality of the incoming and outgoing liquids meets process requirements. Real-time monitoring data from thermometers 4 and pressure gauges 5 helps monitor changes in liquid temperature and pressure, ensuring the stability and controllability of the process. Inlet 1 is also equipped with a flow meter 2, which allows for real-time monitoring of the liquid flow rate, ensuring precise control of the incoming liquid volume to meet process requirements and avoid production problems caused by over- or under-intake.

[0034] Both the first adsorption tank 8 and the second adsorption tank 12 are equipped with adsorbent outlets 7. The design of the adsorbent outlets 7 of the first adsorption tank 8 and the second adsorption tank 12 facilitates the periodic or as-needed replacement of the adsorbent, ensuring the adsorption effect and system performance, and extending the service life of the equipment.

[0035] All of the above pipelines are equipped with electric valves 6. Through the above scheme, the electric valves 6 can be operated through a remote control system and the opening degree can be finely adjusted to achieve precise control of fluid flow and pressure, reduce on-site manual intervention, and improve the safety and convenience of operation. They are especially suitable for dangerous or inaccessible environments.

[0036] The aforementioned adsorption layer 89 is configured as a two-stage adsorption system. The spacing between the two adsorption layers 89 can be adjusted according to the actual adsorption process. The two-stage adsorption structure can adsorb boron and phosphorus impurities in the liquid phase in stages. The first-stage adsorption layer 89 mainly removes most of the impurities, while the second-stage adsorption layer 89 further purifies the liquid. The adsorbent in the adsorption layer 89 is a microcrystalline material. The microcrystalline material has a large specific surface area, providing more adsorption sites. The microcrystalline material is artificially hydrothermally synthesized aluminosilicate crystals. Each stage of the adsorption tank has a packing volume of approximately 0.35 m³, totaling 0.7 m³. As a microcrystalline material, artificially hydrothermally synthesized aluminosilicate crystals have the characteristics of high strength, no powder shedding, no pollution to raw materials, high adsorption precision, and low moisture content. During adsorption, the microcrystalline material can control the feed temperature at 0℃ and ensure that the inlet and outlet temperatures remain constant, improving the purification effect and thus increasing production efficiency.

[0037] The heating temperature of the nitrogen heating tank 11 is 200℃~250℃, preferably 230℃. Through the above scheme, when the adsorption column reaches saturation, high-temperature nitrogen is used as the regeneration desorption gas to purge and regenerate the saturated adsorption tower, and then transported to the waste gas treatment system 13. High-temperature nitrogen can provide sufficient heat to promote the desorption of adsorbed impurities and restore the activity of the adsorbent. In addition, nitrogen is an inert gas and will not react chemically with the adsorbed impurities, ensuring that no new chemical substances are introduced during the regeneration process and maintaining the stability of the system.

[0038] Working principle:

[0039] Liquid trichlorosilane is introduced from the experimental access point to the inlet 1, and its flow rate is precisely controlled by the flow meter 2 to maintain a suitable material running space velocity. Sampling ports 3 are provided at both the inlet and outlet of the adsorption tank to facilitate detailed analysis and testing of the liquid before and after treatment.

[0040] Liquid trichlorosilane enters one chamber of the dual-liquid isolation pump 82 through the inlet 81 of the adsorption tank. It is then pumped to the distributor manifold 83 and flows out through the small holes distributed on the tubular distributor 84, landing on the first-stage adsorption layer 89. The microcrystalline material in the adsorption tank can effectively adsorb impurities such as phosphine, borohydride, germanide, and arsine. The adsorbed liquid falls onto the second-stage adsorption layer 89, and the deeply adsorbed liquid falls onto the inclined receiving tray 87 and flows into the mesh screen collection pipe 88. Due to gravity, it flows into the other chamber of the dual-liquid isolation pump 82. Through the pump, it is sent to the adsorption tank outlet 9 through the liquid guide pipe 86 and then flows to the trichlorosilane storage tank 10 through the outlet pipe 14.

[0041] To improve the removal efficiency of trichlorosilane boron phosphorus, a second adsorption tank 12 can be connected in parallel with the first adsorption tank 8. Liquid trichlorosilane can be introduced into both the first adsorption tank 8 and the second adsorption tank 12 simultaneously to carry out the adsorption process synchronously, which can significantly improve the removal efficiency.

[0042] To achieve higher purity of the output trichlorosilane, a second adsorption tank 12 is connected in series with the first adsorption tank 8. The trichlorosilane liquid treated in the first adsorption tank 8 is sent to the second adsorption tank 12 through the branch pipe 17. The trichlorosilane liquid output from the second adsorption tank 12 has significantly improved purity, meeting the requirements for higher purity, so that the subsequent silicon extraction can be carried out with higher purity.

[0043] Once the adsorption tank reaches saturation, the adsorption process will be stopped, and 233°C high-temperature nitrogen gas will be used as the regeneration gas to purge and regenerate the saturated adsorption tank. The regenerated gas will then be sent to the waste gas treatment system for further processing.

[0044] During the adsorption process of microcrystalline materials, the feed temperature can be controlled at 0℃, and the inlet and outlet temperatures can be kept constant. A certain amount of heat may be released in the initial stage of adsorption due to the phase change that occurs during capillary condensation. However, under normal operating conditions, the system generates virtually no additional heat.

[0045] Considering the issues of flow rate, air speed control, and data reading during operation, the condition is now changed to production output (8m³). 3 The content was 1 / 80 of that in the table below, which shows the experimental conditions. After boron and phosphorus removal, the content was significantly reduced.

[0046]

[0047] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A liquid-phase trichlorosilane-boron-phosphorus removal system, characterized in that, include: A first adsorption tank (8), an inlet (1) connected to the bottom of the first adsorption tank (8) via an inlet pipe (18), a trichlorosilane storage tank (10) connected to the adsorption tank outlet (9) via an outlet pipe (14), a nitrogen heating tank (11) connected to the adsorption tank outlet (9) via a nitrogen pipe (15), and a waste gas treatment system (13) connected to the inlet (1) via a desorption gas pipe (16). The first adsorption tank (8) includes: an adsorption tank inlet (81) located at the bottom of the first adsorption tank (8), a distributor manifold (83) and an adsorption collector (85) connected to the adsorption tank inlet (81) via a dual-liquid isolation pump (82), the distributor manifold (83) being connected to at least 3 layers of tubular distributors (84), the tubular distributors (84) having a plurality of small holes, the adsorption collector (85) including at least 3 layers of adsorption layers (89), a liquid receiving tray (87) located below the adsorption layers (89), and a mesh screen collection pipe (88) threadedly connected to the adsorption layers (89), the other end of the dual-liquid isolation pump (82) being connected to the adsorption tank outlet (9) via a liquid guide pipe (86).

2. The liquid phase trichlorosilane boron phosphorus removal system of claim 1, wherein, It also includes a second adsorption tank (12) connected to the outlet pipe (14) via a branch pipe (17), a trichlorosilane storage tank (10) connected to the top of the second adsorption tank (12) via the outlet pipe (14) and the nitrogen pipe (15), a liquid inlet (1) connected to the bottom of the second adsorption tank (12) via the inlet pipe (18) and the desorption gas pipe (16), and the waste gas treatment system (13).

3. The liquid phase trichlorosilane boron phosphorus removal system of claim 1, wherein, The adsorption layer (89) is configured for two-stage adsorption.

4. The liquid phase trichlorosilane boron phosphorus removal system of claim 2, wherein, The inlet (1) and the outlet pipe (14) are each equipped with a sampling port (3), a thermometer (4), and a pressure gauge (5).

5. The liquid phase trichlorosilane boron phosphorus removal system of claim 4, wherein, The inlet (1) is also equipped with a flow meter (2).

6. The liquid phase trichlorosilane boron phosphorus removal system of claim 5, wherein, Both the first adsorption tank (8) and the second adsorption tank (12) are equipped with adsorbent outlets (7).

7. The liquid phase trichlorosilane boron phosphorus removal system of claim 6, wherein, All pipelines are equipped with electric valves (6).

8. The liquid phase trichlorosilane boron phosphorus removal system of claim 3, wherein, The adsorbent in the adsorption layer (89) is a microcrystalline material.

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