Preparation method of high-abundance silane isotope
The high-abundance silane-28 was prepared by a single-reactor batch feeding method, which solved the problems of complex equipment and low purity in the existing technology, and achieved the preparation of silane-28 with high yield and high purity, meeting the needs of quantum computing and semiconductor fields.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-25
- Publication Date
- 2026-03-13
AI Technical Summary
China has not yet made a breakthrough in the preparation technology of high-abundance silane isotopes. Existing technologies and equipment are complex and processes are cumbersome, making it difficult to meet the high-purity requirements of quantum computing and semiconductor fields. Moreover, it mainly relies on imports, which are costly.
A one-step batch feeding method with a single reactor was adopted. By controlling the pressure and temperature of the reactor, high-abundance silane-28 was prepared by reacting sodium aluminum hydride with silicon tetrafluoride-28. Nitrogen protection and negative pressure collection were used to reduce process steps and improve product yield and purity.
It achieves high yield (≥90%) and high purity (≥95%) of high-abundance silane-28, reduces the abundance variation of silicon-28 by ≤1%, meets the requirements of quantum computing and semiconductor fields, and solves the problems of domestic preparation gap and equipment complexity.
Smart Images
Figure CN121651371A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of isotope technology, and in particular to a method for preparing high-abundance silane isotopes. Background Technology
[0002] High-abundance silicon isotope materials are one of the key materials in the fields of quantum computing and semiconductors. Among them, high-abundance silicon-28 isotope (Si-28 abundance ≥ 99%) has zero nuclear spin characteristics and extremely low impurity content, which can reduce the influence of electronic noise and low thermal noise, reduce the decoherence effect of qubits, and help improve the stability and lifespan of quantum technology devices.
[0003] The "Three-Year Action Plan for High-Quality Development of the Nuclear Technology Application Industry (2024-2026)" points out the need to coordinate the research and production of commonly used or strategically urgently needed stable isotopes such as silicon-28. Currently, China has not yet achieved a breakthrough in the preparation technology of high-abundance silicon isotopes, and related products are mainly imported from Russia, which are expensive and have long delivery times.
[0004] Currently, there is no domestic research on the preparation of silane isotope products. Most of the domestic production technologies for preparing silanes from natural silicon tetrafluoride are derived from foreign countries and are produced on a large scale without miniaturized equipment. Furthermore, because the process does not require a specific abundance of silane and does not need to control the influence of natural silicon abundance, the amount of raw materials added per batch is large, the supporting equipment structure is complex, and there are many process steps. The preparation technology uses two-stage large reactors, which is not suitable for high-abundance silicon isotope silanes with small batch feed amounts, miniaturized preparation equipment, and processes that must eliminate the influence of natural silicon to avoid reducing the abundance of high-abundance silane isotopes, resulting in significant losses. This does not meet the requirements for high-abundance silane isotopes in the fields of quantum computing and semiconductors. Summary of the Invention
[0005] The purpose of this invention is to address the technical deficiencies in the existing technology by providing a method for preparing high-abundance silane isotopes, which uses a one-step method with batch feeding in a single reactor to prepare high-abundance silane-28.
[0006] The technical solution adopted to achieve the purpose of this invention is: A method for preparing a high-abundance silane isotope includes the following steps: Step 1: Under the protection of a protective gas, take sodium aluminum hydride powder, dissolve sodium aluminum hydride in a solvent, load the dissolved sodium aluminum hydride solution into the reaction vessel, assemble the reaction vessel, and maintain a protective gas atmosphere inside the reaction vessel. Step 2: Connect the gas inlet of the reactor in Step 1 to a container containing silicon tetrafluoride-28 gas, and connect the gas outlet of the reactor to a silane collector. Maintain the temperature of the silane collector below the liquefaction temperature of the silane-28 gas, and evacuate the reactor and the silane collector to a pressure of -0.1~-0.05MPa. Step 3: First, close the gas outlet and control the silicon tetrafluoride-28 gas to enter the reactor through the gas inlet at a fixed flow rate. The reactor is stirred and reacted. When the reactor pressure increases to 0.1~0.5MPa, close the gas inlet and open the gas outlet. The silane-28 gas generated in the reactor is collected in the silane collector, completing one batch reaction. Step 4: Repeat the operation of step 3 until the molar ratio of silicon tetrafluoride-28 added to sodium aluminum hydride in step 1 is 0.5~1. After completing the above operation, collect the silane-28 isotope product.
[0007] In the above technical solution, the protective gas in step 1 is nitrogen.
[0008] In the above technical solution, in step 1, the mass concentration of sodium aluminum hydride in the solvent is 7%~10%.
[0009] In the above technical solution, in step 1, the solvent is ethylene glycol dimethyl ether (DME) or tetrahydrofuran (THF).
[0010] In the above technical solution, in step 2, the container containing silicon tetrafluoride-28 gas is a steel cylinder.
[0011] In the above technical solution, in step 2, a liquid nitrogen cold trap is used to maintain the temperature of the silane collector.
[0012] In the above technical solution, in step 3, the fixed flow rate is 0.2~0.8g / min.
[0013] In the above technical solution, in step 3, the fixed flow rate is controlled by a pressure reducing meter and a flow meter.
[0014] In the above technical solution, in step 3, the stirring speed of the reaction vessel is 100~200 rpm.
[0015] In the above technical solution, the temperature of the reactor in step 3 is 10~70℃.
[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention addresses the shortcomings of existing domestic and international technologies for preparing silanes using silicon tetrafluoride as a raw material. It provides a one-step method for preparing silanes using a single-reactor intermittent feeding process. This method overcomes the risks associated with numerous equipment and complex processes in domestic and international conversion methods, which can affect the abundance of natural silicon. Furthermore, it proposes a novel method for preparing silane-28 isotopes, filling a gap in domestic research on silane-28 isotope preparation. The entire process utilizes a single reactor, resulting in fewer process steps, higher product yield, and higher product purity. Nitrogen protection is used in the early stages of the preparation process, while negative pressure protection is employed in the later stages of reaction and collection to isolate air and reduce the risk of silicon-28 abundance variations. This method meets the requirements of quantum computing and semiconductor fields for high-abundance silane isotopes.
[0017] 2. The present invention employs a one-step method for preparing high-abundance silane-28 using a single reactor with intermittent feeding. By controlling the timing of collecting the generated silane-28 (collecting silane-28 when the reactor pressure increases to 0.1~0.5MPa), the yield reaches over 90%, the product purity is ≥95%, and the change in silane-28 abundance before and after preparation is ≤1%. Attached Figure Description
[0018] Figure 1 A process flow diagram for preparing silane-28 isotopes from silicon tetrafluoride-28. Detailed Implementation
[0019] The present invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
[0020] The chemical reaction equation of this invention is as follows: SiF4+NaAlH4→NaAlF4+SiH4········(1) Example 1 like Figure 1 As shown, a method for preparing a high-abundance silane isotope includes the following steps: Weigh 36g of sodium aluminum hydride (NaAlH4) into a polytetrafluoroethylene beaker inside a glove box. Then weigh 414g of dimethyl ethylene glycol (DME) into the polytetrafluoroethylene beaker containing the sodium aluminum hydride and stir for 3-5 minutes. Then pour the prepared sodium aluminum hydride solution into a 1L reactor. Assemble the reactor inside the glove box and maintain nitrogen protection inside the reactor.
[0021] Connect the silicon tetrafluoride-28 cylinder to the inlet of the reactor and evacuate the pipeline. Connect the outlet of the reactor to the collector. Evacuate the reactor through the evacuation port on the pipeline connecting the outlet and the receiver, and observe the pressure gauge reading. When the pressure reaches -0.05 MPa, stop evacuation, completing the evacuation of the reactor and the collection pipeline. Simultaneously, place the pre-evacuated collector into a cold trap filled with liquid nitrogen, completing the connection of the reaction apparatus. Start the stirring in the reactor at 150 rpm. Open the valve of the silicon tetrafluoride-28 cylinder and adjust the inlet flow rate to 0.6 g / min. Observe the pressure inside the reactor. When the pressure rises from negative pressure to 0.2 MPa, close the inlet valve and open the outlet valve. Observe the pressure gauge. When the pressure drops from 0.2 MPa to -0.05 MPa, it indicates that the generated silane-28 gas has entered the collector. Close the outlet valve to complete one collection cycle, open the inlet valve, and begin the next batch reaction.
[0022] Repeat the above steps, maintaining the reaction temperature between 20℃ and 60℃. When the amount of silicon tetrafluoride-28 added is 36g, the addition of silicon tetrafluoride-28 is complete. Weigh the gain in the collector, calculate the yield to be 92.1%, and detect the gas in the collector. The abundance of silicon-28 changes by 0.072%, and the gas purity is 96.8%.
[0023] Example 2 The difference between Example 2 and Example 1 is that the molar ratio of silicon tetrafluoride-28 to sodium aluminum hydride is different. In Example 2, the molar ratio of silicon tetrafluoride-28 to sodium aluminum hydride is increased from 0.519 in Example 1 to 0.81. Appropriately increasing the amount of silicon tetrafluoride-28 can increase the single batch capacity without affecting the final yield and purity of the product.
[0024] Weigh 36g of sodium aluminum hydride (NaAlH4) into a polytetrafluoroethylene beaker inside a glove box. Then weigh 414g of dimethyl ethylene glycol (DME) into the polytetrafluoroethylene beaker containing the sodium aluminum hydride and stir for 3-5 minutes. Then pour the prepared sodium aluminum hydride solution into a 1L reactor. Assemble the reactor inside the glove box and maintain nitrogen protection inside the reactor.
[0025] Connect the silicon tetrafluoride-28 cylinder to the inlet of the reactor and evacuate the pipeline. Connect the outlet of the reactor to the collector. Evacuate the reactor through the evacuation port on the pipeline connecting the outlet and the receiver, and observe the pressure gauge reading. When the pressure reaches -0.05 MPa, stop evacuation, completing the evacuation of the reactor and the collection pipeline. Simultaneously, place the pre-evacuated collector into a cold trap filled with liquid nitrogen, completing the connection of the reaction apparatus. Start the stirring in the reactor at 150 rpm. Open the valve of the silicon tetrafluoride-28 cylinder and adjust the inlet flow rate to 0.6 g / min. Observe the pressure inside the reactor. When the pressure rises from negative pressure to 0.2 MPa, close the inlet valve and open the outlet valve. Observe the pressure gauge. When the pressure drops from 0.2 MPa to -0.05 MPa, it indicates that the generated silane-28 gas has entered the collector. Close the outlet valve to complete one collection cycle, open the inlet valve, and begin the next batch reaction.
[0026] Repeat the above steps, maintaining the reaction temperature between 20℃ and 60℃. When the amount of silicon tetrafluoride-28 added is 56g, the addition of silicon tetrafluoride-28 is complete. Weigh the gain in the collector, calculate the yield as 90.7%, and detect the gas in the collector. The abundance of silicon-28 changes by 0.075%, and the gas purity is 95.2%.
[0027] In both embodiments of the present invention, the yield of silane-28 isotope products is above 90%, and the change in silicon-28 abundance before and after preparation is ≤1%, and the gas purity is ≥95%.
[0028] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that when silicon tetrafluoride-28 reacts with sodium aluminum hydride + ethylene glycol dimethyl ether solution, the pressure in the reaction vessel is less than 0.1 MPa, and the resulting silane is collected. The final yield and purity of the product are both reduced.
[0029] The specific experimental data are as follows: Weigh 36g of sodium aluminum hydride (NaAlH4) into a polytetrafluoroethylene beaker inside a glove box. Then weigh 414g of dimethyl ethylene glycol (DME) into the polytetrafluoroethylene beaker containing the sodium aluminum hydride and stir for 3-5 minutes. Then pour the prepared sodium aluminum hydride solution into a 1L reactor. Assemble the reactor inside the glove box and maintain nitrogen protection inside the reactor.
[0030] Connect the silicon tetrafluoride-28 steel cylinder to the gas inlet of the reactor and evacuate the pipeline. Connect the gas outlet of the reactor to the collector. Evacuate the reactor through the evacuation port on the pipeline between the gas outlet and the receiver. Observe the pressure gauge reading of the reactor. When the pressure value is -0.05MPa, stop evacuation. The evacuation of the reactor and the collection pipeline is completed. At the same time, put the pre-evacuated collector into the cold trap filled with liquid nitrogen to complete the connection of the reaction device. Start the stirring in the reactor, set the stirring speed to 150 rpm, open the valve of the silicon tetrafluoride-28 cylinder, adjust the gas inlet flow rate to 0.6 g / min, observe the pressure value inside the reactor, when the pressure rises from negative pressure to 0.08 MPa, close the gas inlet valve, open the gas outlet valve, observe the pressure gauge of the reactor, when the pressure gauge drops from 0.08 MPa to between -0.05 MPa, it indicates that the generated silane-28 gas has entered the collector, close the gas outlet valve to complete one collection, open the gas inlet valve, and start the next batch reaction.
[0031] Repeat the above steps, maintaining the reaction temperature between 20℃ and 60℃. When the amount of silicon tetrafluoride-28 added is 36g, the addition of silicon tetrafluoride-28 is complete. Weigh the gain in the collector, calculate the yield to be 89.4%, and detect the gas in the collector. The abundance of silicon-28 changes by 0.074%, and the gas purity is 88.9%.
[0032] The decrease in the yield and purity of silane products is mainly due to two reasons: first, the pressure in the reactor is too low, and the small pressure difference between the reactor and the collector is not conducive to the collection of silane gas; second, the low pressure in the reactor means that the reaction time is short, and the silicon tetrafluoride-28 gas is absorbed into the collector under negative pressure before it reacts completely.
[0033] Comparative Example 2 The difference between this comparative example and Example 1 is that the pressure in the reactor during the reaction of silicon tetrafluoride-28 with sodium aluminum hydride + ethylene glycol dimethyl ether solution was greater than 0.5 MPa, and the resulting silane was collected under these conditions, which reduced the final yield and purity of the product.
[0034] The specific experimental data are as follows: Weigh 36g of sodium aluminum hydride (NaAlH4) into a polytetrafluoroethylene beaker inside a glove box. Then weigh 414g of dimethyl ethylene glycol (DME) into the polytetrafluoroethylene beaker containing the sodium aluminum hydride and stir for 3-5 minutes. Then pour the prepared sodium aluminum hydride solution into a 1L reactor. Assemble the reactor inside the glove box and maintain nitrogen protection inside the reactor.
[0035] Connect the silicon tetrafluoride-28 steel cylinder to the gas inlet of the reactor and evacuate the pipeline. Connect the gas outlet of the reactor to the collector. Evacuate the reactor through the evacuation port on the pipeline between the gas outlet and the receiver. Observe the pressure gauge reading of the reactor. When the pressure value is -0.05MPa, stop evacuation. The evacuation of the reactor and the collection pipeline is completed. At the same time, put the pre-evacuated collector into the cold trap filled with liquid nitrogen to complete the connection of the reaction device. Start the stirring in the reactor, set the stirring speed to 150 rpm, open the valve of the silicon tetrafluoride-28 cylinder, adjust the gas inlet flow rate to 0.6 g / min, observe the pressure value inside the reactor, when the pressure rises from negative pressure to 0.55 MPa, close the gas inlet valve, open the gas outlet valve, observe the pressure gauge of the reactor, when the pressure gauge drops from 0.55 MPa to -0.05 MPa again, it indicates that the generated silane-28 gas has entered the collector, close the gas outlet valve to complete one collection, open the gas inlet valve, and start the next batch reaction.
[0036] Repeat the above steps, maintaining the reaction temperature between 20℃ and 60℃. When the amount of silicon tetrafluoride-28 added is 36g, the addition of silicon tetrafluoride-28 is complete. Weigh the gain in the collector and calculate the yield to be 85.9%. Detect the gas in the collector; the abundance of silicon-28 changes by 0.072%, and the gas purity is 84.7%.
[0037] The main reason for the reduced yield and purity of silane products is that when the pressure in the reactor is high and then negative pressure collection is performed, the silanes stay in the reactor for a longer time, and some of the silanes produced dissolve in ethylene glycol dimethyl ether, resulting in silane loss and low yield. At the same time, since ethylene glycol dimethyl ether is a highly volatile organic solvent, the volatile ethylene glycol dimethyl ether will be collected during negative pressure collection, which will reduce the purity of the silane products.
[0038] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that the molar ratio of silicon tetrafluoride-28 to sodium aluminum hydride is different. In Comparative Example 3, the molar ratio of silicon tetrafluoride-28 to sodium aluminum hydride is 0.4, and the purity of the product is significantly reduced.
[0039] The specific experimental data are as follows: Weigh 36g of sodium aluminum hydride (NaAlH4) into a polytetrafluoroethylene beaker inside a glove box. Then weigh 414g of dimethyl ethylene glycol (DME) into the polytetrafluoroethylene beaker containing the sodium aluminum hydride and stir for 3-5 minutes. Then pour the prepared sodium aluminum hydride solution into a 1L reactor. Assemble the reactor inside the glove box and maintain nitrogen protection inside the reactor.
[0040] Connect the silicon tetrafluoride-28 cylinder to the inlet of the reactor and evacuate the pipeline. Connect the outlet of the reactor to the collector. Evacuate the reactor through the evacuation port on the pipeline connecting the outlet and the receiver, and observe the pressure gauge reading. When the pressure reaches -0.05 MPa, stop evacuation, completing the evacuation of the reactor and the collection pipeline. Simultaneously, place the pre-evacuated collector into a cold trap filled with liquid nitrogen, completing the connection of the reaction apparatus. Start the stirring in the reactor at 150 rpm. Open the valve of the silicon tetrafluoride-28 cylinder and adjust the inlet flow rate to 0.6 g / min. Observe the pressure inside the reactor. When the pressure rises from negative pressure to 0.2 MPa, close the inlet valve and open the outlet valve. Observe the pressure gauge. When the pressure drops from 0.2 MPa to -0.05 MPa, it indicates that the generated silane-28 gas has entered the collector. Close the outlet valve to complete one collection cycle, open the inlet valve, and begin the next batch reaction.
[0041] Repeat the above steps, maintaining the reaction temperature between 20℃ and 60℃. When the amount of silicon tetrafluoride-28 added is 27.73g, the silicon tetrafluoride-28 feeding is complete. Weigh the gain in the collector, calculate the yield as 91.24%, and detect the gas in the collector. The abundance of silicon-28 changes by 0.072%, and the gas purity is 72.9%.
[0042] The significant decrease in silane product purity is primarily due to the reduction in the molar ratio of silicon tetrafluoride-28, while the mass of ethylene glycol dimethyl ether remained unchanged. Under the same conditions, the amount of ethylene glycol dimethyl ether volatilized from the collected reaction gas remained constant, but the mass of silane-28 produced relative to the volatilized ethylene glycol dimethyl ether decreased by 23%, resulting in a significant reduction in the purity of silane in the collected gas. Furthermore, the reduced molar ratio of silicon tetrafluoride-28 decreases the utilization rate of raw materials, leading to a large amount of unreacted sodium aluminum hydride in the post-reaction system, resulting in cost losses and increased safety risks during subsequent wastewater treatment.
[0043] Comparative Example 4 The difference between Comparative Example 4 and Example 1 is that the molar ratio of silicon tetrafluoride-28 to sodium aluminum hydride is different. In Comparative Example 4, the molar ratio of silicon tetrafluoride-28 to sodium aluminum hydride is 1.2, and the final yield and purity of the product are reduced.
[0044] The specific experimental data are as follows: Weigh 36g of sodium aluminum hydride (NaAlH4) into a polytetrafluoroethylene beaker inside a glove box. Then weigh 414g of dimethyl ethylene glycol (DME) into the polytetrafluoroethylene beaker containing the sodium aluminum hydride and stir for 3-5 minutes. Then pour the prepared sodium aluminum hydride solution into a 1L reactor. Assemble the reactor inside the glove box and maintain nitrogen protection inside the reactor.
[0045] Connect the silicon tetrafluoride-28 cylinder to the inlet of the reactor and evacuate the pipeline. Connect the outlet of the reactor to the collector. Evacuate the reactor through the evacuation port on the pipeline connecting the outlet and the receiver, and observe the pressure gauge reading. When the pressure reaches -0.05 MPa, stop evacuation, completing the evacuation of the reactor and the collection pipeline. Simultaneously, place the pre-evacuated collector into a cold trap filled with liquid nitrogen, completing the connection of the reaction apparatus. Start the stirring in the reactor at 150 rpm. Open the valve of the silicon tetrafluoride-28 cylinder and adjust the inlet flow rate to 0.6 g / min. Observe the pressure inside the reactor. When the pressure rises from negative pressure to 0.2 MPa, close the inlet valve and open the outlet valve. Observe the pressure gauge. When the pressure drops from 0.2 MPa to -0.05 MPa, it indicates that the generated silane-28 gas has entered the collector. Close the outlet valve to complete one collection cycle, open the inlet valve, and begin the next batch reaction.
[0046] Repeat the above steps, maintaining the reaction temperature between 20℃ and 60℃. When the amount of silicon tetrafluoride-28 added is 83.2g, the silicon tetrafluoride-28 feeding is complete. Weigh the gain in the collector, calculate the yield to be 79.24%, and detect the gas in the collector. The abundance of silicon-28 changes by 0.073%, and the gas purity is 76.7%.
[0047] The yield and purity of silane products decreased significantly for two main reasons: First, when the molar ratio of silicon tetrafluoride-28 to sodium aluminum hydride exceeded 1, silicon tetrafluoride-28 was in significant excess, resulting in a large amount of unreacted silicon tetrafluoride in the collected gas, which significantly reduced the purity of silane-28 in the gas. Second, the excess silicon tetrafluoride-28 resulted in unreacted silicon tetrafluoride remaining in the gas phase of the reactor, inhibiting the forward reaction and reducing the silane yield. Furthermore, the use of excess silicon tetrafluoride-28 increased the loss of isotope products per batch, significantly increasing the synthesis cost.
[0048] The above description is only a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A method for preparing a high-abundance silane isotope, characterized in that, Includes the following steps: Step 1: Under the protection of a protective gas, take sodium aluminum hydride powder, dissolve sodium aluminum hydride in a solvent, load the dissolved sodium aluminum hydride solution into the reaction vessel, assemble the reaction vessel, and maintain a protective gas atmosphere inside the reaction vessel. Step 2: Connect the gas inlet of the reactor in Step 1 to a container containing silicon tetrafluoride-28 gas, and connect the gas outlet of the reactor to a silane collector. Maintain the temperature of the silane collector below the liquefaction temperature of the silane-28 gas, and evacuate the reactor and the silane collector to a pressure of -0.1 to -0.05 MPa. Step 3: First, close the gas outlet and control the silicon tetrafluoride-28 gas to enter the reactor through the gas inlet at a fixed flow rate. The reactor is stirred and reacted. When the reactor pressure increases to 0.1~0.5MPa, close the gas inlet and open the gas outlet. The silane-28 gas generated in the reactor is collected in the silane collector, completing one batch reaction. Step 4: Repeat the operation of step 3 until the molar ratio of silicon tetrafluoride-28 added to sodium aluminum hydride in step 1 is 0.5~1. After completing the above operation, collect the silane-28 isotope product.
2. The method for preparing high-abundance silane isotopes as described in claim 1, characterized in that, In step 1, the protective gas is nitrogen.
3. The method for preparing high-abundance silane isotopes as described in claim 1, characterized in that, In step 1, the mass concentration of sodium aluminum hydride in the solvent is 7%~10%.
4. The method for preparing high-abundance silane isotopes as described in claim 1, characterized in that, In step 1, the solvent is ethylene glycol dimethyl ether or tetrahydrofuran.
5. The method for preparing high-abundance silane isotopes as described in claim 1, characterized in that, In step 2, the container holding silicon tetrafluoride-28 gas is a steel cylinder.
6. The method for preparing high-abundance silane isotopes as described in claim 1, characterized in that, In step 2, the temperature of the silane collector is maintained using a liquid nitrogen cold trap.
7. The method for preparing high-abundance silane isotopes as described in claim 1, characterized in that, In step 3, the fixed flow rate is 0.2~0.8 g / min.
8. The method for preparing high-abundance silane isotopes as described in claim 1, characterized in that, In step 3, the fixed flow rate is controlled by a pressure reducing meter and a flow meter.
9. The method for preparing high-abundance silane isotopes as described in claim 1, characterized in that, In step 3, the stirring speed of the reactor is 100~200 rpm.
10. The method for preparing high-abundance silane isotopes as described in claim 1, characterized in that, In step 3, the temperature of the reactor is 10~70℃.