Trimethylindium purification device
By designing a trimethyl indium purification device and using a high-purity nitrogen purge process and a purifier, the problem of removing low-content silicon impurities in trimethyl indium products is solved, and the production and yield of high-purity products are improved, which is suitable for the industrial production of trimethyl indium.
Patent Information
- Application Number
- CN202422553358.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-22
- Publication Date
- 2025-08-22
- Estimated Expiration
- 2034-10-22
AI Technical Summary
The prior art is difficult to effectively remove low-content silicon impurities in trimethyl indium products, resulting in product purity not meeting standards and affecting the performance of epitaxial chips. At the same time, repeated purification of conventional distillation processes will lead to a decrease in yield.
A trimethyl indium purification device is designed, using a high-purity nitrogen purge process, combined with a purifier and a buffer tank, and further purification of trimethyl indium products is achieved through a pneumatic shutdown valve and a temperature-controlled heat tracing system, ensuring clean air source and stable flow.
It improves the purity of trimethyl indium products, meets the requirements of high purity, avoids material losses during repeated purification, improves product yield and ensures the performance of epitaxial chips.
Smart Images
Figure CN223248782U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of MO source preparation, in particular to a trimethyl indium purification device. Background Art
[0002] Trimethylindium is a colorless, transparent, sublimable, colorless crystal with a distinctive odor at room temperature and pressure. It has a melting point of 89°C and a boiling point of 135.8°C. High-purity trimethylindium is widely used in the growth of compound semiconductor thin films such as indium gallium phosphide, indium gallium arsenic nitrogen, and indium gallium arsenic. It is an important raw material for growing optoelectronic materials in metal-organic chemical vapor deposition (MOCVD) and chemical beam epitaxy (CBE) processes.
[0003] Trimethylindium products commonly used in MOCVD and chemical beam epitaxy are primarily produced using atmospheric or vacuum distillation processes. Besides requiring a purity of 99.9999% (6N), these products also have extremely high requirements for the impurity content of specific single elements (SI ≤ 0.2ppm, ZN ≤ 0.1ppm). Failure to do so will negatively impact the performance of epitaxial chips and contaminate the epitaxial equipment used for that batch of products. However, conventional distillation processes are less effective at removing low-level silicon impurities (0.2ppm ≤ SI ≤ 0.5ppm) from the product. The lower the silicon impurity content in the product, the less effective the distillation process. Repeatedly repurifying the low-silicon product (with substandard silicon content) after distillation will reduce the distillation yield. Therefore, a purification unit is urgently needed to purify the low-silicon product after the initial distillation. Utility Model Content
[0004] In view of this, the purpose of the present invention is to provide a trimethylindium purification device to solve the problem of removing silicon impurities.
[0005] Based on the above purpose, the utility model provides a trimethyl indium purification device, including a glove box, wherein a plurality of purge cylinders are provided in the glove box, the purge cylinders are connected to a purge pipeline through a bottom pipe, the purge pipeline is connected to a nitrogen cylinder, a pressure reducer, a purifier and a buffer tank in sequence, and the buffer tank is respectively connected to the bottom pipes of the plurality of purge cylinders through a purge branch; the purge cylinders are connected to an emptying pipeline through an air pipe, the emptying pipeline is connected in series with a first tail gas absorption tank and a second tail gas absorption tank and discharges tail gas; a replacement pipeline is connected to one side of the emptying pipeline, the replacement pipeline is connected to a replacement vacuum cold trap and a vacuum pump in sequence, and the other end of the vacuum pump is connected to a pipeline for exhaust gas discharge.
[0006] A further improvement is that a first pneumatic shut-off valve is provided on the pipeline between the pressure reducer and the purifier, a buffer tank pressure gauge is provided on the buffer tank, and the first pneumatic shut-off valve and the buffer tank pressure gauge are interlocked.
[0007] A further improvement is that a cold trap pressure gauge and a fourth pneumatic shut-off valve are sequentially connected to the pipeline between the replacement vacuum cold trap and the vacuum pump, and the fourth pneumatic shut-off valve is interlocked with the vacuum pump.
[0008] A further improvement is that the emptying pipeline, the replacement pipeline and the corresponding connecting hose of the purge cylinder are provided with a temperature control and heating system for controlling the temperature of the pipeline during the purge process, and the temperature control and heating system is interlocked with the first pneumatic shut-off valve.
[0009] A further improvement is that the exhaust pipeline and the replacement pipeline are respectively provided with a second pneumatic shut-off valve, a third pneumatic shut-off valve and a pressure monitoring gauge.
[0010] A further improvement is that the temperature control and heating system is provided with a heating temperature measuring meter.
[0011] A further improvement is that a gas source flow meter is provided on the connecting pipeline between the buffer tank and the purge cylinder, and a regulating needle valve is provided on the purge branch corresponding to the purge cylinder.
[0012] The beneficial effects of this utility model are as follows: 1. This utility model adds a purification and purge process to the existing conventional distillation process, which can further reduce the purity of the low-silicon component product after distillation, avoid material loss during repeated distillation, and indirectly improve product yield. At the same time, the material loss rate of the purification and purge process is extremely low, with a material loss rate of approximately 2% to 3% for the corresponding purge time. This is particularly suitable for new quality improvement measures in the current industrial production of trimethylindium.
[0013] 2. High-purity nitrogen is used as the gas source, and a purifier is set at the back end to purify the impurities (CO, CO2, H2O, O2) in the adsorption gas source to ensure the cleanliness of the purge gas source.
[0014] 3. By setting up an independent buffer tank, and each purge branch independently adjusting the gas source flow through the gas source flow meter and the regulating needle valve, the stability of the gas source pressure and flow of each purge branch is ensured. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only for the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0016] Figure 1 This is a schematic diagram of an embodiment of the present utility model.
[0017] The following are marked in the figure:
[0018] 1. Glove box; 2. Purge cylinder; 3. Nitrogen cylinder; 4. Pressure reducer; 5. Purifier; 6. Buffer tank; 7. First tail gas absorption tank; 8. Second tail gas absorption tank; 9. Replacement vacuum cold trap; 10. Vacuum pump; 11. First pneumatic shut-off valve; 12. Buffer tank pressure gauge; 13. Cold trap pressure gauge; 14. Fourth pneumatic shut-off valve; 15. Temperature control and heating system; 16. Second pneumatic shut-off valve; 17. Third pneumatic shut-off valve; 18. Pressure monitoring gauge; 19. Heating temperature gauge; 20. Gas source flow meter; 21. Adjusting needle valve. DETAILED DESCRIPTION
[0019] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments.
[0020] It should be noted that, unless otherwise defined, the technical or scientific terms used in this utility model should have the usual meanings understood by people with ordinary skills in the field to which this utility model belongs. The "first", "second" and similar words used in this utility model do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative position relationships. When the absolute position of the object being described changes, the relative position relationship may also change accordingly.
[0021] like Figure 1As shown, this embodiment provides a trimethyl indium purification device, including a glove box 1, in which a plurality of purge cylinders 2 are provided, the purge cylinders 2 are connected to the purge pipeline through a bottom tube, and the purge pipeline is sequentially connected to a nitrogen cylinder 3, a pressure reducer 4, a purifier 5 and a buffer tank 6, and the buffer tank 6 is connected to the corresponding purge cylinder 2 bottom tube through a purge branch; the purge cylinder 2 is filled with a low silicon value trimethyl indium product, the nitrogen cylinder 3 is filled with 6N nitrogen, and the pressure of the pressure reducer 4 is set to 0.3 bar; a first pneumatic shut-off valve 11 is provided on the pipeline between the pressure reducer 4 and the purifier 5, and a buffer tank pressure gauge 12 is provided on the buffer tank 6. The first pneumatic shut-off valve 11 and the buffer tank pressure gauge 12 are interlocked, and the interlocking high limit value is 0.4 bar and the low limit value is 0.2 bar; a gas source flow meter 20 is provided on the pipeline connecting the buffer tank 6 and the purge cylinder 2, and a regulating needle valve 21 is provided on the purge branch corresponding to the purge cylinder 2. The gas source in the nitrogen cylinder 3 is first pressure-regulated by the pressure reducer 4 and then further adsorbed and impurities removed through the purifier 5 at the rear end. The purified gas source enters the buffer tank 6 set at the rear end. After the pressure of the gas source is balanced in the buffer tank 6, it enters the purge cylinder 2 on the corresponding purge station of the purge system; the gas source flow meter 20 monitors the gas source flow, and at the same time, the regulating needle valve 21 of each purge branch adjusts the branch gas source flow; the buffer tank pressure gauge 12 monitors the pressure. When the monitored pressure PT-01 is greater than or less than the set pressure of 0.1 bar, the first pneumatic shut-off valve 11 is automatically closed to prevent purge failure.
[0022] The purge cylinder 2 is connected to an exhaust line via an air pipe. The exhaust line is connected in series with the first and second exhaust absorption tanks 7 and 8 to discharge exhaust gas. The first and second exhaust absorption tanks 7 and 8 contain absorbent, which is used to absorb and purify the system exhaust during the purge process. A check valve is installed on the exhaust line corresponding to the connection between the first and second exhaust absorption tanks 7 and 8. The second pneumatic shut-off valve 16 and the check valve prevent exhaust backflow. This series combination of exhaust lines not only meets exhaust absorption requirements but also prevents absorbent from being sucked back into the purge line.
[0023] One side of the emptying pipeline is connected to a replacement pipeline, which is sequentially connected to a replacement vacuum cold trap 9 and a vacuum pump 10. The other end of the vacuum pump 10 is connected to a pipeline for tail gas discharge. The replacement vacuum cold trap 9 is used to replace and absorb the residual trimethyl indium in the pipeline during the disassembly of the semi-finished steel cylinder.
[0024] The pipeline between the replacement vacuum cold trap 9 and the vacuum pump 10 is connected in sequence with a cold trap pressure gauge 13 and a fourth pneumatic shut-off valve 14, and the fourth pneumatic shut-off valve 14 is interlocked with the vacuum pump 10; when the vacuum pump 10 is accidentally powered off, the fourth pneumatic shut-off valve 14 is automatically closed to prevent the disassembly and replacement process from failing.
[0025] The emptying pipeline, the replacement pipeline and the corresponding connecting hose of the purge cylinder 2 are provided with a temperature control heating system 15 for controlling the temperature of the pipeline during the purge process. The temperature control heating system 15 adopts a heating tape, which is a prior art and is not particularly limited here. The temperature control range of the temperature control heating system 15 is 100~120℃; the temperature control heating system 15 is interlocked with the first pneumatic shut-off valve 11, and a heating thermometer 19 is provided on the temperature control heating system 15. The heating set temperature is 110℃, the upper limit is 130℃, and the lower limit is 95℃; when the heating thermometer 19 monitors that the temperature control heating system 15 exceeds the set temperature upper limit, the power supply of the temperature control heating system 15 is automatically cut off, and the first pneumatic shut-off valve 11 is automatically closed; when the monitored temperature continues to be lower than the lower limit, the duration is 10 minutes, and the temperature control heating system 15 issues a low temperature state reminder.
[0026] The exhaust pipeline and the replacement pipeline are respectively provided with a second pneumatic shut-off valve 16, a third pneumatic shut-off valve 17 and a pressure monitoring gauge 18. The exhaust pipeline and the replacement pipeline are opened and closed by the second pneumatic shut-off valve 16 and the third pneumatic shut-off valve 17, and the pressure monitoring gauge 18 monitors the pipeline pressure.
[0027] The silicon and zinc content of trimethylindium products after distillation and purification is tested by ICP analysis as follows: 0.1ppm≤SI≤1ppm, 0.1ppm≤SI≤0.5ppm. Among them, products with SI≥0.2ppm and ZN≥0.1ppm do not meet the COA requirements. If they are repeatedly returned to the distillation line, the product yield will be further reduced. Therefore, in the actual production process, for such products with low silicon and zinc content, they will enter the back-end purge purification line after preliminary packaging and testing. After 3-5 hours of purge treatment and corresponding analysis and testing, the silicon and zinc content can meet the product COA requirements (SI≤0.2ppm, ZN≤0.1ppm).
[0028] The specific working process is as follows: after placing the purge cylinder 2 filled with low silicon value trimethyl indium product into the corresponding purge station in the glove box 1, the bottom tube of the purge cylinder 2 is connected to the nitrogen purge pipeline, and the air pipe of the purge cylinder 2 is connected to the exhaust pipeline. After the connection is completed, the temperature control heating system 15 is turned on, and after the temperature monitored by the heating thermometer 19 reaches the set temperature, the first pneumatic shut-off valve 11 and the second pneumatic shut-off valve 16 and the valve of the nitrogen cylinder 3 are opened. The gas source passes through the pressure reducer 4, the purifier 5, the buffer tank 6 and the purge branch in turn into the corresponding purge cylinder 2. The pressure reducer 4 controls the gas source pressure to 0.3 bar, and the gas source flow rate of each branch is stably adjusted to 60L / h through the regulating needle valve 21 and the gas source flow meter 20 of each purge branch. By maintaining a stable gas source pressure and flow rate for continuous purging, the product in the purge cylinder 2 can be sampled and analyzed during the purging process to ensure the pass rate of the purge purification. The temperature and pressure of the purge pipeline are simultaneously monitored during the purging process to prevent purge failure. After the purging is completed, the valve of the nitrogen cylinder 3, the first pneumatic shut-off valve 11, and the second pneumatic shut-off valve 16 are closed. Once the replacement vacuum cold trap 9 and vacuum pump 10 meet the required usage, the third pneumatic shut-off valve 17 and the fourth shut-off valve are opened to begin the replacement process. During the replacement process, the first pneumatic shut-off valve 11 and the third shut-off valve are controlled to achieve automatic replacement operation.
[0029] Those skilled in the art will understand that the discussion of any of the above embodiments is merely illustrative and is not intended to limit the scope of the present invention to these examples. Within the spirit and principles of the present invention, the technical features of the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and many other variations exist in the various aspects of the present invention described above, which are not provided in detail for the sake of clarity. Any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.
Claims
1. A trimethyl indium purification device, comprising a glove box (1), wherein a plurality of purge cylinders (2) are provided in the glove box (1), characterized in that: The purge cylinder (2) is connected to the purge pipeline through a bottom pipe, and the purge pipeline is connected to the nitrogen cylinder (3), the pressure reducer (4), the purifier (5) and the buffer tank (6) in sequence, and the buffer tank (6) is connected to the corresponding purge cylinder (2) bottom pipe through a purge branch; the purge cylinder (2) is connected to the emptying pipeline through an air pipe, and the emptying pipeline is connected in series with a first tail gas absorption tank (7) and a second tail gas absorption tank (8) for tail gas discharge; one side of the emptying pipeline is connected to a displacement pipeline, and the displacement pipeline is connected to a displacement vacuum cold trap (9) and a vacuum pump (10) in sequence, and the other end of the vacuum pump (10) is connected to the pipeline for tail gas discharge.
2. A trimethyl indium purification device according to claim 1, characterized in that: A first pneumatic shut-off valve (11) is provided on the pipeline between the pressure reducer (4) and the purifier (5), a buffer tank pressure gauge (12) is provided on the buffer tank (6), and the first pneumatic shut-off valve (11) and the buffer tank pressure gauge (12) are interlocked.
3. A trimethyl indium purification device according to claim 1, characterized in that: A cold trap pressure gauge (13) and a fourth pneumatic shut-off valve (14) are sequentially connected to the pipeline between the replacement vacuum cold trap (9) and the vacuum pump (10), and the fourth pneumatic shut-off valve (14) is interlocked with the vacuum pump (10).
4. A trimethyl indium purification device according to claim 1, characterized in that: The connection hoses of the emptying pipeline, the replacement pipeline and the corresponding purge cylinder (2) are provided with a temperature control and heating system (15) for controlling the temperature of the pipeline during the purge process. The temperature control and heating system (15) is interlocked with the first pneumatic shut-off valve (11).
5. A trimethyl indium purification device according to claim 4, characterized in that: The exhaust pipeline and the replacement pipeline are respectively provided with a second pneumatic shut-off valve (16), a third pneumatic shut-off valve (17) and a pressure monitoring gauge (18).
6. A trimethyl indium purification device according to claim 4, characterized in that: The temperature control and heating system (15) is provided with a heating temperature measuring meter (19).
7. A trimethyl indium purification device according to claim 1, characterized in that: A gas source flow meter (20) is provided on the connecting pipeline between the buffer tank (6) and the purge cylinder (2), and a regulating needle valve (21) is provided on the purge branch corresponding to the purge cylinder (2).