Electronic grade trichlorosilane automatic filling system and automatic filling method thereof

Abstract

The application discloses an electronic-grade trichlorosilane automatic filling system and an automatic filling method thereof, wherein the system comprises a high-purity buffer tank, a filter, a vacuum pump, an argon purifier, a residual liquid recovery tank, an online analysis cabin, a filling pipeline, a mass flowmeter, a ground scale, a PLC control system, an HCl alarm, an emergency shut-off valve and a remote signal transmission to a DCS control system, and the method comprises the following steps: filling tank pretreatment: performing vacuumizing, 9N argon pressure charging and pressure releasing on the filling tank, and detecting H2O and O2 at the end point, wherein the cycle number is n times, H2O is less than or equal to 10 ppm, and O2 is less than or equal to 10 ppm; two-stage filling: the PLC performs automatic filling according to the set weight and high / low speed rate, the ground scale is real-time returned, the mass flowmeter or the weight is mutually checked at the end point, and the filling valve is immediately closed when the target value is reached; and the application can realize automatic filling, online monitoring, one-key start and stop and remote monitoring, and the electronic-grade trichlorosilane automatic filling system and the automatic filling method thereof are batch traceable.

Description

Technical Field

[0001] This invention belongs to the field of electronic-grade trichlorosilane filling technology, specifically referring to an electronic-grade trichlorosilane automatic filling system and its automatic filling method. Background Technology

[0002] Electronic-grade trichlorosilane (TCS), also known as trichlorosilane, is a key raw material in silicon epitaxial growth and low-temperature chemical vapor deposition (CVD) processes. It is widely used in high-end fields such as semiconductor device fabrication. Its purity directly determines the performance and yield of subsequent semiconductor products. Therefore, the industry has extremely stringent requirements for the purity of electronic-grade trichlorosilane, and it is necessary to strictly control the impurity content and eliminate the introduction of various pollution hazards during the filling process.

[0003] Electronic-grade trichlorosilane has the physical and chemical properties of being easily hydrolyzed, easily oxidized, and easily volatile. It is a colorless and transparent liquid at room temperature and pressure. When it comes into contact with water or water vapor, it will react violently to produce corrosive substances such as hydrogen chloride (HCl). When it comes into contact with oxygen, it will easily undergo an oxidation reaction, which will lead to excessive acid radicals and decreased purity in the product, making it unable to meet the requirements of semiconductor processes. Therefore, its filling process must strictly isolate impurities such as moisture and oxygen, while ensuring the stability and safety of operation.

[0004] Currently, the industrial filling of electronic-grade trichlorosilane still uses traditional methods. While these methods can achieve basic filling functions, they have many significant shortcomings in terms of purity control, operational stability, monitoring and traceability, and safety assurance. They are no longer suitable for the stringent filling requirements of electronic-grade products. Specific shortcomings are as follows: Firstly, the pressure-holding protection measures of the filling tanks are inadequate. Existing solutions generally only use ordinary nitrogen for pressure holding, but the residual moisture (H2O) and oxygen (O2) in ordinary nitrogen cannot be effectively removed. These residual impurities will undergo hydrolysis and oxidation reactions with trichlorosilane during the filling process, directly leading to excessive acid content in the product, damaging the product purity, causing unqualified products, increasing production costs, and at the same time, the hydrogen chloride produced by the hydrolysis reaction will also corrode the filling equipment and shorten the service life of the equipment.

[0005] Secondly, the pressure and flow control accuracy during the filling process is insufficient. Most existing filling systems use diaphragm pumps in conjunction with manual valves for control. The randomness of manual operation and the operating characteristics of diaphragm pumps lead to large fluctuations in pressure and flow during the filling process, making it impossible to achieve stable filling. This can easily result in excessive metering errors, making it difficult to accurately control the filling amount. This not only affects the consistency of product packaging but may also cause product waste or inconvenience due to overfilling or underfilling.

[0006] Third, the filling process lacks an effective online monitoring and traceability mechanism. The existing solution does not have a real-time online detection device during the filling process, so it is impossible to monitor the product purity, impurity content and filling parameters in real time. It is necessary to conduct tests through offline sampling and laboratory testing, and the test feedback cycle exceeds 4 hours. During this period, unqualified batches of products have been mixed into the finished product cans and cannot be detected and intercepted in time. This not only causes batch product contamination, but also makes it difficult to trace the source of unqualified products, making subsequent rectification and accountability difficult and seriously affecting the efficiency of product quality control.

[0007] Fourth, the high reliance on manual operation makes it prone to operational errors. In the existing filling process, key steps such as pressure holding, valve opening and closing, and parameter adjustment all rely on manual operation. The skill level and sense of responsibility of operators vary greatly, which can easily lead to errors such as untimely valve opening and closing, deviations in parameter adjustment, and non-standard pressure holding operations. This not only affects the accuracy of filling, but may also lead to trichlorosilane leakage due to improper operation. Trichlorosilane is toxic, flammable, and reacts easily with moisture. After leakage, it can easily cause fires, personnel poisoning, and other safety accidents, posing a great safety hazard and failing to meet the safety control requirements of industrial production.

[0008] In summary, the aforementioned defects in existing industrial filling solutions for electronic-grade trichlorosilane severely restrict the improvement of product purity control, filling efficiency, operational safety, and quality traceability, and fail to meet the stringent filling requirements of the semiconductor industry for electronic-grade trichlorosilane. Summary of the Invention

[0009] This invention aims to provide an electronic-grade trichlorosilane automatic filling system and its automatic filling method that features automatic filling, online monitoring, one-button start / stop, remote monitoring, and batch traceability.

[0010] To achieve the above objectives, the present invention provides an electronic-grade trichlorosilane automatic filling system, comprising a high-purity buffer tank, a filter, a vacuum pump, an argon purifier, a residual liquid recovery tank, an online analysis cabin, a filling pipeline, a mass flow meter, a weighing scale, a PLC control system, an HCl alarm, an emergency shut-off valve, and a remote signal transmission system to a DCS control system. The high-purity buffer tank is sequentially connected to the filter and the filling pipeline. The filling pipeline is connected to a sampling valve assembly, which is connected to the online analysis cabin. The online analysis cabin is connected to the PLC control system. The PLC control system is interconnected with the DCS control system. The PLC control system is also connected to the emergency shut-off valve. The filling valve assembly is connected, and the PLC control system is also directly connected to the filling valve assembly. The filling pipeline is also connected to the filling valve assembly. The output end of the filling valve assembly is connected to the residual liquid recovery tank and the TCS filling tank, respectively. The unqualified liquid is transported to the residual liquid recovery tank, and the qualified liquid is transported to the TCS filling tank. The unqualified liquid in the TCS filling tank is also transported to the residual liquid recovery tank. The vacuum pump is connected to the vacuum valve assembly and the filling pipeline in sequence. The vacuum valve assembly is also connected to the TCS filling tank. The argon passivator is connected to the argon valve assembly and the filling pipeline in sequence. The argon valve assembly is also connected to the TCS filling tank. The HCl alarm, pressure sensor, mass flow meter, and ground pump are all connected to the PLC control system.

[0011] An automatic filling method for an electronic-grade trichlorosilane automatic filling system includes the following steps: S1, System Startup: DCS issues filling command, PLC self-checks valve group, pressure sensor, and online GC status; S2, Pre-treatment of filling tank: Vacuuming, 9N argon pressurization, and depressurization are performed on the filling tank, with n cycles. The endpoint test results are H2O≤10ppm and O2≤10ppm. S3, Filtration: The high-purity material in the buffer tank is filtered before entering the filling pipeline; S4, two-stage filling: The PLC automatically fills according to the set weight and high / low speed, the weighing scale transmits data in real time, and the mass flow meter or weight is mutually calibrated at the end point. The filling valve is closed immediately when the target value is reached. S5, online monitoring GC samples every 5 minutes, and automatically switches to the residual liquid recovery tank and locks the batch for non-conforming products; S6, End and Report: After filling is completed, high-purity argon gas is used to purify the filling tank connection pipeline. Then, all valves are closed, the filling tank is removed, and the filling tank is moved to the waiting area for shipment, ready for the next filling. The PLC system automatically generates an electronic batch report, which includes a unique batch number, actual net weight, gross weight, tare weight, valve opening and closing sequence, and alarm records, achieving full traceability.

[0012] As a further aspect of the present invention: in step S2, the number of times n≥10, and the endpoint is determined by GC detection of H2O≤10ppm and O2≤10ppm as the pass criteria.

[0013] As a further aspect of the present invention: Step S4 includes the following steps: First, filling is performed at a preset high-speed segment rate. When the real-time weight of the local scale is ≥90% of the set value, the filling is automatically switched to a low-speed segment rate. The filling endpoint is mutually calibrated by weight and cumulative flow. When |ΔW|≤20g and the duration is ≥3s, the filling main valve is immediately closed and the over-rush amount is ≤20g.

[0014] As a further aspect of the present invention: the filling method is implemented by a filling program, which is preset in the PLC control system in advance.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. High filling efficiency: The program is precisely controlled, and the two-stage filling rate not only increases the filling speed but also ensures the accuracy of the filling weight. 2. High purity: Vacuuming and high-purity argon purging and replacement are used to effectively reduce water and oxygen content, ensuring product purity. Online GC is used to reduce the risk of contamination by non-conforming products. 3. High safety: It can be remotely controlled via a DCS system and is equipped with an emergency shut-off valve to ensure safety during the filling process; 4. Automation: PLC automatic program control reduces manual intervention; one-button start allows for fully unmanned operation, reducing costs. Attached Figure Description

[0016] Figure 1 This is a structural block diagram of the electronic-grade trichlorosilane filling system of the present invention.

[0017] Figure 2 This is a flowchart of the automatic filling process of the present invention. Detailed Implementation

[0018] The invention will now be further described with reference to the accompanying drawings.

[0019] like Figure 1As shown, an automatic filling system for electronic-grade trichlorosilane includes a high-purity buffer tank, a filter, a vacuum pump, an argon purifier, a residual liquid recovery tank, an online analysis cabin, a filling pipeline, a mass flow meter, a weighing scale, a PLC control system, an HCl alarm, an emergency shut-off valve, and a remote signal transmission system to a DCS control system. The high-purity buffer tank is connected sequentially to the filter and the filling pipeline. The filling pipeline is connected to a sampling valve assembly, which is connected to the online analysis cabin. The online analysis cabin is connected to the PLC control system, which is interconnected with the DCS control system. The PLC control system is also connected to the emergency shut-off valve, which is connected to the filling valve assembly. The system is connected to the PLC control system, which is also directly connected to the filling valve assembly. The filling pipeline is also connected to the filling valve assembly. The output of the filling valve assembly is connected to the residual liquid recovery tank and the TCS filling tank, respectively. Unqualified liquid is transported to the residual liquid recovery tank, qualified liquid is transported to the TCS filling tank, and unqualified liquid in the TCS filling tank is also transported to the residual liquid recovery tank. The vacuum pump is connected to the vacuum valve assembly and the filling pipeline in sequence, and the vacuum valve assembly is connected to the TCS filling tank. The argon passivator is connected to the argon valve assembly and the filling pipeline in sequence, and the argon valve assembly is also connected to the TCS filling tank. The HCl alarm, pressure sensor, mass flow meter, and ground pump are all connected to the PLC control system.

[0020] The high-purity buffer tank is made of SS316L material, EP grade standard, with an inner surface roughness Ra≤0.25µm. It features strong corrosion resistance, high surface smoothness, no impurity adsorption, and no material residue, making it suitable for high-purity buffering of electronic-grade trichlorosilane.

[0021] Vacuum pumps can evacuate the system under oil-free and pollution-free conditions, effectively removing residual gas, moisture and impurities from the tank and pipelines, meeting the high vacuum and high cleanliness requirements for electronic-grade trichlorosilane filling.

[0022] The argon purifier is a 9N argon purifier.

[0023] The online analysis cabin is a positive-pressure explosion-proof structure, with an integrated online gas chromatograph (online GC) that can perform real-time, online component and purity analysis of electronic-grade trichlorosilane in an explosion-proof and safe environment.

[0024] like Figure 2 As shown, an automatic filling method for an electronic-grade trichlorosilane filling system includes the following steps: the filling program can be operated through a DCS system or on a touch screen operation panel. The following example uses the touch screen operation panel.

[0025] Step 1: Start the filling process. Place the filling tank on the scale. The system will automatically record the weight of the empty tank and tare it. Set the filling weight and two filling rates on the touch screen control panel, and then proceed to the tank pre-treatment stage. If there is residue in the filling tank, manually push the residue back into the residual liquid recovery tank, purge and replace it with high-purity argon gas, and then proceed with the filling process.

[0026] Step 2: Filling tank pretreatment: Connect the filling tank connector to the system. After confirming the connection on the touch screen operation panel, the system starts the vacuum pump to evacuate the filling tank and maintain it for 5 minutes to check for leaks. Then, open the argon valve, pressurize and let it stand for 2 minutes, then depressurize. Repeat this cycle 10 times. The endpoint is determined by two consecutive GC samples: H2O ≤ 10ppm and O2 ≤ 10ppm. Otherwise, an alarm is triggered and the cycle is repeated, up to a maximum of 15 times. If it still fails to meet the requirements, the filling tank is marked as abnormal and the filling process is terminated. If it meets the requirements, proceed to the next filling step.

[0027] Step 3: After the filling tank pretreatment is qualified, the system automatically opens the buffer tank filling valve, allowing the electronic-grade TCS to enter the filling pipeline after passing through the filter, ready for filling. When the pressure difference between the pressure gauges before and after the filter is >0.15MPa, the system prompts to replace the filter element.

[0028] Step 4: Start two-stage filling. First, fill at the preset high-speed speed. When the real-time weight on the scale is ≥90% of the set value, automatically switch to the low-speed speed for filling. At the end of filling, use weight and cumulative flow to mutually calibrate. When |ΔW|≤20g and the duration is ≥3s, immediately close the main filling valve. The overcharge amount is ≤20g. Step 5: During the filling process, the online GC samples every 5 minutes. If the online GC continuously determines that the filling is qualified, the filling ends. If it determines that the filling is unqualified, the system alarms and stops the filling valve, automatically opens the three-way valve to guide the remaining TCS to the residual liquid recovery tank, and automatically locks the "NG" status in the batch report.

[0029] Step Six: After filling is complete, purify the filling tank connection line with high-purity argon gas, then close all valves, remove the filling tank, and move it to the shipping area for the next filling. If the product is qualified, the PLC will automatically generate an electronic batch report, including: unique batch number, actual net weight, gross weight, tare weight, valve opening and closing sequence, and alarm records. If the HCL alarm detects any leakage during the filling process, it will automatically interlock the emergency shut-off valve.

[0030] Example 1:

[0031] The 200L filling tank is placed on the scale, and the filling program begins. The system automatically records the weight of the empty tank and tare it. The filling weight is set to 250kg on the touchscreen control panel, with the filling rate as follows: 6.7kg / min for the first 90% of the weight and 5kg / min for the last 10%. The filling tank interface is connected to the system, and the connection is confirmed on the touchscreen control panel. The system automatically begins vacuuming, pressurizing with 9N argon gas, and depressurizing, repeating this cycle 10 times. Finally, O2 and H2O are <10ppm, and the system begins automatic filling: using a two-stage flow rate, with a filling rate of 6.7kg / min for the first 90% of the weight and 5kg / min for the last 10%. The actual filling weight is 250.01kg, with an error of +0.01kg. The filling time is 38 minutes. The online GC runs continuously, checking every 5 minutes. If there are no unqualified signals, the filling is complete, the batch is qualified, the filling tank connector pipeline is replaced, the filling tank is removed, and it is moved to the waiting area for shipment.

[0032] Example 2 – Remote Monitoring: By enabling PLC communication through the DCS system, operators can view real-time flow and pressure in the DCS control room and remotely lock the filling valve.

Claims

1. An automatic filling system for electronic-grade trichlorosilane, characterized in that, The system includes a high-purity buffer tank, filter, vacuum pump, argon purifier, residual liquid recovery tank, online analysis cabin, filling pipeline, mass flow meter, weighbridge, PLC control system, HCl alarm, emergency shut-off valve, and remote signal transmission to the DCS control system. The high-purity buffer tank is connected sequentially to the filter and filling pipeline. The filling pipeline is connected to the sampling valve assembly, which is then connected to the online analysis cabin. The online analysis cabin is connected to the PLC control system, which is interconnected with the DCS control system. The PLC control system is also connected to the emergency shut-off valve, which is connected to the filling valve assembly. It is also directly connected to the filling valve assembly, and the filling pipeline is also connected to the filling valve assembly. The output end of the filling valve assembly is connected to the residual liquid recovery tank and the TCS filling tank respectively. The unqualified liquid is transported to the residual liquid recovery tank, and the qualified liquid is transported to the TCS filling tank. The unqualified liquid in the TCS filling tank is also transported to the residual liquid recovery tank. The vacuum pump is connected to the vacuum valve assembly and the filling pipeline in sequence. The vacuum valve assembly is also connected to the TCS filling tank. The argon passivator is connected to the argon valve assembly and the filling pipeline in sequence. The argon valve assembly is also connected to the TCS filling tank. The HCl alarm, pressure sensor, mass flow meter, and ground pump are connected to the PLC control system respectively.

2. The automatic filling method of the electronic-grade trichlorosilane automatic filling system according to claim 1, characterized in that, Includes the following steps: S1, System Startup: DCS issues filling command, PLC self-checks valve group, pressure sensor, and online GC status; S2, Pre-treatment of filling tank: Vacuuming, 9N argon pressurization, and depressurization are performed on the filling tank, with n cycles. The endpoint test results are H2O≤10ppm and O2≤10ppm. S3, Filtration: The high-purity material in the buffer tank is filtered before entering the filling pipeline; S4, two-stage filling: The PLC automatically fills according to the set weight and high / low speed, the weighing scale transmits data in real time, and the mass flow meter or weight is mutually calibrated at the end point. The filling valve is closed immediately when the target value is reached. S5, online monitoring GC samples every 5 minutes, and automatically switches to the residual liquid recovery tank and locks the batch for non-conforming products; S6, End and Report: After filling is completed, high-purity argon gas is used to purify the filling tank connection pipeline. Then, all valves are closed, the filling tank is removed, and the filling tank is moved to the waiting area for shipment, ready for the next filling. The PLC system automatically generates an electronic batch report, which includes a unique batch number, actual net weight, gross weight, tare weight, valve opening and closing sequence, and alarm records, achieving full traceability.

3. The automatic filling method according to claim 2, characterized in that, In step S2, the number of times n≥10, and the endpoint is determined by GC detection H2O≤10ppm and O2≤10ppm as qualified criteria.

4. The automatic filling method according to claim 2, characterized in that, In step S4 The process includes the following steps: First, fill the container at the preset high-speed rate. When the real-time weight on the scale is ≥90% of the set value, automatically switch to the low-speed rate for filling. At the end of the filling process, the weight and cumulative flow are mutually checked. When |ΔW|≤20g and the duration is ≥3s, immediately close the main filling valve. The overcharge amount is ≤20g.

5. The automatic filling method according to claim 2, characterized in that, The filling method is implemented through a filling program, which is preset in the PLC control system.

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