TW509829B - Method and system for preventing the transmission pipeline of a process from backfill - Google Patents

Abstract

The present invention provides a method for preventing the transmission pipeline of a process from backfill, wherein a plurality of pipelines for transferring liquid are gathered and connected to a chamber, so as to supply different liquids required by the chamber of the process to perform reactions. The method determines the flow direction of the liquid in flow meters (MFC) respectively arranged on the plurality of pipelines, so as to control the pipelines to be on or off. The present invention provides a control board to detect the flow direction of the liquid in the corresponding flow meter. When the control board detects that the flow direction of the liquid in the flow meter is changed, a command is transferred to drive a control valve to turn off an upstream valve and/or a downstream valve of the pipeline where the flow meter is positioned.

Description

509829

Field of the Invention: The present invention relates to a method and system for avoiding total & backfill of a process reaction chamber, especially a flow meter (MFC Method and system for controlling the flow direction of the pipeline and closing or opening the pipeline Background of the invention: In some related technical fields, such as chemical vapor deposition (CVD), plasma etching (PE) or other The process of manufacturing columns and manufacturing products such as flat panei displays and hard disk drives often uses mass flow controllers (MFCs) to control one of the fluids required in a particular process. Specific flow. $ The flow meter can sense the flow (f 1 ow) flowing through the flow meter and change or control the flow as needed to achieve the purpose of controlling the amount of the fluid delivered to the particular process. The response to this flow is a function of the type of fluid used by the household and the physical effects (phys i ca 1 effects) used to sense the flow. There are many types of physical effects used to sense the mass flow. For example, absolute and / or differential pressure changes, temperature differential, and light absorption can be used.

509829 V. Description of the invention (2) (light absorption) or momentum change (momentum change) to measure. As shown in Figure 1, a typical physical action used to sense the flow (mass fl0w) is the measurement 5: the thermal induction through which the fluid flow (thef 1 uidf 1 ow) flows is a coil (ther in a 1 sensorcoi 1 s), the temperature difference Δ τ between the upstream coil Ru and the lower private coil Rd, and the measurement value V0 obtained by the sensor of the flow meter will generate a corresponding flow control signal (flow control signal ) To control the flow rate of the fluid. As far as the semiconductor integrated circuit manufacturing process is concerned, the purity and flow rate of the gases used in the fabrication of integrated circuits have become very important in the context of increasing wafer size and process complexity. Therefore, a flow meter is inserted in a pipeline (pipe, ne) that supplies a reaction gas required by the process equipment in order to control the flow rate of the reaction gas in the process steps. Now use Figure 1 (a partial schematic diagram of the gas delivery pipeline connected to a process reaction chamber) to illustrate the backflow of gas that the process reaction chamber encounters when entering the required reaction gas or performing flowmeter calibration. The problem. As shown in FIG. 1, the reaction chamber 10 includes Δ, B, c, D, and E: five gas sources (gaS trays) are collected through a corresponding line a, b, c, and d, respectively, to a connection. The line f to the reaction chamber 10 has-

509829 V. Description of the invention (3) Final valve 7, and the gas from the gas source is controlled to enter the reaction chamber 10 by the final valve 7. A manual valve al, bl, cl, dl, and el, and a pressure regulator a2, b2, and c2 are sequentially provided on the pipelines a, b, c, d, and e, respectively. D2 and e2, a filter a3, b3, c3, d3 and e3, an upstream valve (UpStream valve) a4, b4, c4, d4 and e4, a flow meter (MFC) a5, b5, c5, d5 and e5 and a downstream valve (a6, b6, c6, d6, and e6) The gas pressures of the five gas sources A, B, C, D, and E are different depending on the process requirements and / Or the same, for example, the gas pressures of the A and b gas sources are 15 pSi, the gas pressures of the C, d, and E gas sources are all 35 psi °, and the reaction control machine (not shown) of the process sends a signal When the C gas is turned into the reaction chamber (assuming that the pipelines of other gas sources are closed at this time), the C gas flows through the pipeline c, passes the manual valve cl, the pressure regulator c2, and the filter Device C3, the upstream valve C4, the flow meter c, 5 = and the downstream valve c6, and enter the pipeline f to reach the final valve 7. Under normal circumstances, the final valve 7 will also receive a signal of ♦ positive opening from the reaction control machine, so that the C gas can be smoothly input into the reaction chamber (or ^ is zero).田 $ ^ 力 But sometimes, the final valve 7 is actuated due to a difference in electronic signal transmission or mechanical

Page 6 509829 V. Description of the invention (4) Defective, such as when the trachea is ruptured or not plugged in but not opened, the C gas at a pressure of 3 5 psi will be stagnated at the downstream valve c 6 and the final Between valve 7. Under unknown circumstances, if at this time the A gas with a pressure of 15 psi in the pipeline 3 is passed to the reaction chamber 10 or the flow meter a5 in the pipeline a is calibrated, it will stagnate in the Ding You The higher pressure of the c gas between the valve c6 and the final valve 7 will be backfilled to the lower pressure line a, causing the line a to be contaminated with another gas (ie, the C gas). When the pipeline has a problem of backflow and gas backflow, not only will it take a lot of extra time and cost to clean up and restore the original state of the pipeline, but it may also be because it is too late to find that other gases have been backflowed to the gas source of the pipeline. 'Cause the relevant pipelines of other reaction chambers that also supply the required gas through the gas source are also contaminated, which affects the purity of the reaction gases in other reaction chambers. Therefore, how to prevent and control the problem of pipeline transportation has become an important issue in the current process. See above 31. Summary of the invention: The main purpose of the present invention is to provide a flow meter (MFC) by judging the flow direction of a flow meter (MFC) installed on a pipeline in Shi Cheng equipment. Close or open the control method to avoid the backfill problem of the rotary pipeline in the manufacturing process.

509829

5. Description of the invention (5) Another object of the present invention is to provide a flow meter control panel (MFC c ο ntr ο 1 b 〇ard) and a solenoid valve (s 〇 1 en 〇 土 己 va 1 ve) transmission line system 'to prevent other gases in another line from flowing back. The present invention discloses a method for avoiding the backflow of the transportation pipeline of a reaction chamber in a process, in which 'a plurality of pipelines for transporting fluids are collected ^ and connected to the reaction chamber' to supply the reaction chamber with the difference required for the process The method is to control the closing or opening of the pipelines by judging the flow direction of the fluid in a flow meter (MFC) provided on the plurality of pipelines. In one embodiment of the method of the present invention, a control board is provided to detect the flow direction of the fluid in the flow meter corresponding to the control board. When the control panel detects a change in the fluid flow direction in the flowmeter, it transmits a command to drive a control valve to close an upstream valve and / or a downstream valve of the pipeline where the flowmeter is located. In a preferred embodiment of the present invention, the control valve is a solenoid valve (s ο 1 e η ω d v a 1 v e), and the flow meter is composed of a thermal sensor. Therefore, when the fluid flow direction in the thermal sensor flowmeter changes, the reading of the thermal sensor flowmeter is a negative value, and the control panel can set a specific negative voltage value (which can be set according to Need to make adjustments and changes) as the control reference point, when the control panel detects the thermal

Page 509829 V. Description of the invention (6) ---------- When the reading of the reactor flow meter is not greater than or less than the specific negative voltage value, a solenoid valve is driven to close the upstream of the pipeline. The valve, or the downstream valve, is one that drives two solenoid valves to close the upstream valve and the downstream valve, respectively. In addition, the present invention also discloses a system for avoiding backflow of the pipelines in the process chamber. The pipelines are respectively provided with a flow meter (MFC). The system includes a flow meter control panel (MFc control). board) and a control valve. The MFC control panel is used to detect the corresponding change in the fluid flow direction in the flowmeter, and transmits a closing instruction. The control valve receives the closing instruction sent by the MFC control panel, and closes the flow. An upstream valve and / or a two-way valve of the pipeline are considered. 〆 In a preferred embodiment of the system of the present invention, the control valve is a solenoid valve, and the flow meter is constituted by a thermal sensor. When the flow direction of the fluid in the thermal sensor flowmeter changes, the reading of the thermal sensor flowmeter is a negative value, and the control '' panel can set a specific negative voltage value (which can be set according to (Need to make adjustment and change) as the control reference point. When the control panel detects that the reading of the thermal sensing flowmeter is not greater than or less than the specific negative voltage value, it drives a solenoid valve to close the pipeline. The upstream valve or the downstream valve, or the two solenoid valves are driven to close the upstream valve and the downstream valve respectively. Detailed description of the invention:

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V. Description of the invention (7) The method of the present invention will be exemplified by the schematic diagram of the thermal sensor flowmeter shown in the figure / shown above and the gas transmission pipeline shown in figure 2. ; Please refer to FIG. 3, which is a partial schematic diagram of a gas transmission pipeline connected to a process reaction chamber of the present invention, except for MFC control board a8, b8, c8, d8, and e8 and solenoid Valves (solenoid valve) a91, a92, b91, b92, c9l, C92, d91, d92, e91 and e92, the rest of the components are the same as those shown in Figure 2, so the same reference numerals. First, as shown in Figure 3, when the reaction control machine (not shown) of the process sends a signal to input the C gas into the reaction chamber (assuming that the pipelines of other gas sources are closed at this time), The C gas flows through the pipeline. , Through the manual valve cl, the pressure regulator c2, the filter c3, the upstream valve C4: the flowmeter c5 and the downstream valve c6, and reach the π 幡-, Gu Yuedou, ς 'work panel c8 The voltage measurement value ν〇 of this flow meter (a thermal induction flow meter) will be measured, a value greater than zero, indicating that the flow of the gas is from one to one. Under normal circumstances, the most: main; downstream wide direction flow number, and let the C gas smoothly turn into the anti-cutting will receive the open machine. Eighty-five Hai reaction chamber 10 (at that time the pressure is zero, but if the final valve 7 is not opened due to electronic or mechanical factors)

509829 5. In the description of the invention (8), the [gas with a force of 35 psi of the C gas stagnates between the downstream valve c6 and the final valve 7. On this day, the MFC control panel will detect that The voltage measurement value V0 of the flow meter C5 is a value equal to zero, showing that the movement of the gas is a stagnant state. Under unknown circumstances, the A gas with a pressure of 15 psi flowing through the pipeline a is then executed. To the reaction chamber 10, or to calibrate the flow meter a5 of the pipeline a, the relatively high pressure C gas that is stagnated between the downstream valve c6 and the final valve 7 starts to go to a lower pressure and open. The pipeline a backflow backfill (backf i 11), first passes through the downstream valve a6 of the pipeline a, then flows through the flow meter a5, and will then continue to backflow to the upstream valve a4. When the returning gas flows through C In the flow meter a5, since the gas flow direction is from a downstream valve to an upstream valve at this time, the MFC control panel a8 will detect the voltage measurement value (f 1 〇w) sent by the flow meter a5. output) V0 is a value less than zero. Therefore, the MFC control panel a8 will A signal is transmitted to drive the solenoid valves a 9 1 and a 9 2 to close the upstream valve a 4 and the downstream valve a 6 of the pipeline a, respectively, to prevent the C gas from continuing in a direction above the upstream valve a 4 In this way, the serious consequence of the pipeline a being contaminated by other gas (ie, the C gas) is effectively controlled and prevented. As for the upstream valve a4 and the downstream which are blocked in the pipeline a The contaminated C gas between the valves a6 can be removed only after a slight purge. Moreover, the MFC control panel a8 receives the voltage measurement value sent by the flow meter a5.

509829 V. Description of the invention (9) V0 'Reuse the solenoid valve to close the upstream valve a4 and the downstream valve a6, because the signal is not directly or indirectly transmitted to the flow meter & 5, so it is not Will cause interference to the flow meter a5. Figure 4 shows a schematic diagram of the communication operation circuit of the MFC control panel a8 and the solenoid valves a9 1 and a92. Among them, the MFC control panel & 8 can set a specific negative voltage value as the reading of the MFC a5. The control reference point 'uses the adjustable resistors R1 and R2 shown in Figure 4 to adjust the setting. When the MFC control panel a8 reads the reading sent by the flow meter a5 (that is, the voltage measurement value V0), compares it, and determines that the value of v0 is not greater than the specific negative voltage value of the MFC control panel a8 (Or it can be set to be less than the 2 negative voltage values), the liver C control panel a8 immediately transmits a signal through the circuit 'makes a relay r (1 ay) to actuate to drive the solenoid valves a91, = 92 opens the DC voltage of the upstream valve a4 and the downstream valve a6 of the pipeline a to form an open circuit. In this way, the upstream valve a4 and the downstream valve a6 are closed ', so as to prevent other gases from continuing to flow back and back. If the MFC control panel a8 reads that the V0 value is greater than the specific negative voltage value, the MFC control panel a8 will not command the relay R to operate. In this way, the direct voltage of 2 4 V is still the path to drive such. The solenoid valves a 9 j and a 9 2 respectively open the upstream valve a4 and the downstream valve a6 of the pipeline a to make the pipeline a unblocked. 509829

509829 Brief description of the drawings The above-mentioned technical content and many advantages of the present invention can be easily understood through the following detailed description combined with the attached drawings, of which: Figure 1 is a schematic diagram of a typical thermal sensor coil Figure 2 is a partial schematic view of a conventional technology for a gas delivery pipeline connected to a process reaction chamber;

Figure 3 is a schematic diagram of a part of a gas delivery pipeline connected to a process reaction chamber according to the present invention; and Figure 4 is a schematic diagram of a communication operation circuit of an MFC control panel and a solenoid valve. Figure number description:

Ru upstream coil Rd downstream coil

AT Temperature difference V 0 Voltage measurement value of flow meter 10 Reaction chamber A, B, C, D, E Gas source a, b, c, d, e, f Line 7 Final valve a 1, b 1, c 1, d 1, e 1 manual valve R relays a2, b2, c2, d2, e2 pressure regulators a3, b3, c3, d3, e3 filters R1 and R2 adjustable resistance

Page 14 509829 The diagram briefly explains a4, b4, c4, d4, e4 upstream valve a 5, b 5, c 5, d 5, e 5 flow meter a6, b6, c6, d6, e6 downstream valve a8, b8, c8, d8, e8 MFC control panel a91, a92, b91, b92, c91, c92, d91, d92, e91, e92 solenoid valve

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Claims (1)

Patent application scope (bae method for avoiding backflow of the transfer line of a process chamber 1 1 1), wherein a plurality of pipelines for conveying fluid are passed through: connected to the reaction chamber to supply the reaction chamber The same machine body is required to carry out the process. The method is to close or open the pipelines by judging the flow direction of the fluids in the flow meters (MFCs) provided in the plurality of above and above. control. ★ The method described in claim 1 of the patent scope, wherein the method includes: ^ providing a control panel (c 0 ntr 〇1 b 〇ard) to determine the fluid flow direction corresponding to the flow meter; When the control panel detects that the fluid flow direction in the flowmeter is changed, it transmits a command to drive a control valve to close an upstream valve (up str eam va 1 ve) and / or a downstream valve ( downstream valve). 3. The method according to item 2 of the scope of patent application, wherein the control valve is a solenoid valve (s ο 1 e η ω i d v a 1 v e). 4. The method according to item 2 of the scope of patent application, wherein the flow meter is composed of a thermal sensor, and when the fluid flow direction in the flow meter is changed, the reading of the flow meter is A negative value. 5 · The method as described in item 4 of the scope of patent application, wherein the control panel can set a specific negative electrical calendar value as needed, when the reading of the flow meter is not large Page 16 509829 6. Scope of patent application When the specific negative voltage value is reached, the control valve is driven to close the upstream valve and / or the downstream valve of the pipeline. 6 · A system for preventing backf i 1 1 from flowing back in the conveying pipelines of a process chamber, wherein each of these pipelines is provided with a flow meter (MFC). The system includes: a first-class meter control panel (MFC c ο ntr ο 1 b 〇ard), which is used to detect the change of the fluid flow direction in the corresponding flow meter, and transmits a closing command; and a control valve, which is received by the MFC control panel. The closing instruction sent out and closing an upstream valve and / or a downstream valve of the pipeline where the flowmeter is located ° 7 The system according to item 6 of the scope of patent application, wherein: The control valve is a solenoid valve. 8. The system according to item 6 of the scope of patent application, wherein the flow meter is composed of a thermal sensor, and when the flow direction of the fluid in the meter is changed, the reading of the flow meter (reading ) Is a negative value. 9 The system according to item 8 of the scope of patent application, wherein the control panel 509829 6. The scope of patent application is to set a specific negative voltage value as required. When the reading of the flow meter is not greater than the specific negative voltage value, the control valve is driven to close the upstream valve and / or the downstream of the pipeline. valve. 10. A method for avoiding gas backflow (backfi 11) in a gas flow conduit, including the following steps: (1) providing at least one valve (valve) in the gas conveying line; (2) providing a gas flow The monitoring circuit (agasf 1 〇wm ο nit 〇rcir cu it) is in contact with the gas transmission line for air flow measurement, so as to detect the normal air flow in the gas transmission line and the gas return, (3) Electrical connection A valve control circuit to the airflow monitoring circuit, the valve control circuit has a primary current path and a secondary current path; (4) plane connection The valve control circuit to the at least one valve so as to open and close the at least one valve; Page 509829 6. Application scope and (6) When the gas flow monitoring circuit detects the gas return in the gas transmission pipeline, the current from the gas flow monitoring circuit is transmitted through the secondary current path, and Close the at least one valve. Page 19