Double butterfly valve pressure control system, method and epitaxial furnace

Abstract

The present application relates to the technical field of epitaxial growth, and specifically provides a double butterfly valve pressure control system, method and epitaxial furnace, the system comprising: an exhaust pipe, on which a gate valve, a first pressure collection component, a first butterfly valve and a process pump are sequentially arranged; a pressure regulating pipe, on which a second butterfly valve is arranged; a second pressure collection component; a controller, used to adjust the opening of the first butterfly valve according to a first preset opening range, first pressure information and a first preset pressure, and when the opening change of the first butterfly valve is within the first preset opening range and the difference between the first pressure information and the first preset pressure is within the first preset pressure range, adjust the opening of the second butterfly valve according to the second preset opening range, the second pressure information and the first preset pressure; the system can effectively reduce the number of times the opening of the first butterfly valve is adjusted, thereby effectively extending the service life of the first butterfly valve, and further effectively reducing the maintenance cycle of the epitaxial furnace.

Description

Technical Field

[0001] The present application relates to the field of epitaxial growth technology, and in particular to a double butterfly valve pressure control system, method and epitaxial furnace. Background Art

[0002] The related technology needs to use an exhaust pipeline to discharge the gas in the reaction chamber. The related technology is provided with a butterfly valve on the exhaust pipeline. The related technology adjusts the gas pressure in the reaction chamber by adjusting the opening of the butterfly valve.

[0003] During the epitaxial growth process, the gas pressure in the reaction chamber will fluctuate due to various factors, which may be changes in the type of process gas, changes in the flow rate of process gas, or pipeline switching. Therefore, the relevant technology requires frequent adjustment of the opening of the butterfly valve to stabilize the gas pressure in the reaction chamber at a preset pressure. Since the flow rate of the gas discharged from the reaction chamber is large, the impact force exerted on the butterfly valve will change significantly each time the opening of the butterfly valve is adjusted. That is, the impact force exerted on the butterfly valve changes frequently and significantly during the epitaxial growth process, thereby shortening the service life of the butterfly valve, and further shortening the maintenance cycle of the epitaxial furnace.

[0004] There is no effective technical solution to the above problems. It should be noted that the above information disclosed in this section is only used to understand the background of the present invention, and therefore may contain information that does not constitute prior art. Summary of the invention

[0005] The purpose of the present application is to provide a double butterfly valve pressure control system, method and epitaxial furnace, which can effectively reduce the number of times the opening of the first butterfly valve is adjusted, thereby effectively extending the service life of the first butterfly valve, and further effectively extending the maintenance period of the epitaxial furnace.

[0006] In a first aspect, the present application provides a double butterfly valve pressure control system, which is applied in an epitaxial furnace. The epitaxial furnace includes a reaction chamber. The double butterfly valve pressure control system includes:

[0007] An exhaust pipe is connected to the exhaust port of the reaction chamber, and is provided with a gate valve, a first pressure collection component, a first butterfly valve and a process pump in sequence, wherein the first pressure collection component is used to collect first pressure information;

[0008] A pressure regulating pipe, whose input end and output end are both connected to the exhaust pipe and are respectively located before and after the gate valve, and a second butterfly valve is arranged on it, and the pipe diameter of the pipe section of the pressure regulating pipe located at the output end of the second butterfly valve is smaller than the pipe diameter of the exhaust pipe;

[0009] A second pressure collection component is arranged at the input end of the pressure regulating tube and is used to collect second pressure information;

[0010] A controller is used to open the gate valve before or during the epitaxial growth process, adjust the opening of the first butterfly valve according to a first preset opening range, first pressure information and a first preset pressure, and when the opening change of the first butterfly valve is within the first preset opening range and the difference between the first pressure information and the first preset pressure is within the first preset pressure range, adjust the opening of the second butterfly valve according to a second preset opening range, second pressure information and the first preset pressure.

[0011] The present application provides a double butterfly valve pressure control system, which first roughly adjusts the air pressure in the reaction chamber to near the first preset pressure by adjusting the opening of the first butterfly valve based on the first preset opening range, the first pressure information and the first preset pressure, and then stabilizes the air pressure in the reaction chamber at the first preset pressure by adjusting the opening of the second butterfly valve based on the second preset opening range, the second pressure information and the first preset pressure. After the air pressure in the reaction chamber is roughly adjusted to near the first preset pressure, the present application stabilizes the air pressure in the reaction chamber at the first preset pressure by frequently adjusting the opening of the second butterfly valve, and the flow rate of the gas passing through the first butterfly valve is greater than the flow rate of the gas passing through the second butterfly valve. Even if the opening of the second butterfly valve is frequently adjusted, the service life of the second butterfly valve will not be shortened due to a significant change in the impact force on the second butterfly valve. Therefore, the present application can effectively reduce the number of times the opening of the first butterfly valve is adjusted, thereby effectively extending the service life of the first butterfly valve, and further effectively extending the maintenance cycle of the epitaxial furnace.

[0012] Optionally, the double butterfly valve pressure control system also includes a diaphragm valve, the input and output ends of the diaphragm valve are connected to the pressure regulating pipe and are respectively located before and after the second butterfly valve. The controller is also used to control the gate valve to close when the reaction chamber needs to be vacuumed, and control the process pump and the diaphragm valve to open, and control the first butterfly valve to open at a first preset opening rate, and then when the vacuum degree information of the reaction chamber reaches a preset vacuum degree, control the second butterfly valve to open at a second preset opening rate, and the first preset opening rate is greater than the second preset opening rate.

[0013] After the vacuum degree information of the reaction chamber reaches the preset vacuum degree, the vacuum pumping rate will gradually decrease under the influence of the diameter of the pipe connected to the diaphragm valve. When the vacuum degree information of the reaction chamber reaches the preset vacuum degree, the technical scheme controls the second butterfly valve to open at a second preset opening rate. At this time, the diameter of the vacuum pumping pipe will increase, and the diameter of the vacuum pumping pipe is positively correlated with the vacuum pumping rate. Therefore, this technical scheme is equivalent to increasing the vacuum pumping rate by opening the second butterfly valve after the vacuum degree information of the reaction chamber reaches the preset vacuum degree, thereby effectively improving the vacuum pumping efficiency.

[0014] Optionally, the process of adjusting the opening of the first butterfly valve according to the first preset opening range, the first pressure information and the first preset pressure, and when the opening change of the first butterfly valve is within the first preset opening range and the difference between the first pressure information and the first preset pressure is within the first preset pressure range, adjusting the opening of the second butterfly valve according to the second preset opening range, the second pressure information and the first preset pressure includes:

[0015] A1. adjusting the opening of the first butterfly valve according to the first pressure information and the first preset pressure;

[0016] A2, determining whether the difference between the first pressure information and the first preset pressure is within the first preset pressure range, if so, executing step A3, if not, returning to step A1;

[0017] A3, determining whether the opening change of the first butterfly valve is within the first preset opening range, if so, controlling the first butterfly valve to maintain the current opening, and adjusting the opening of the second butterfly valve according to the second preset opening range, the second pressure information and the first preset pressure, if not, executing step A4;

[0018] A4. Determine whether the accumulated adjustment time of the first butterfly valve reaches the first preset time. If yes, end the adjustment, clear the accumulated adjustment time of the first butterfly valve and generate an alarm message. If no, return to step A1.

[0019] Optionally, the process of adjusting the opening of the second butterfly valve according to the second preset opening range, the second pressure information and the first preset pressure includes:

[0020] B1. adjusting the opening of the second butterfly valve according to the second pressure information and the first preset pressure;

[0021] B2, determining whether the second pressure information is the same as the first preset pressure, if so, executing step B3, if not, returning to step B1;

[0022] B3, judging whether the opening change of the second butterfly valve is within the second preset opening range, if so, starting the epitaxial growth process, if not, executing step B4;

[0023] B4. Determine whether the accumulated adjustment time of the second butterfly valve reaches the second preset time. If so, end the adjustment, clear the accumulated adjustment time of the second butterfly valve and generate an alarm message. If not, return to step B1.

[0024] Optionally, the epitaxial furnace also includes a gas supply assembly, and the controller is also used to control the gas supply assembly to supply carrier gas to the reaction chamber before the epitaxial growth process and when adjusting the opening of the first butterfly valve and the second butterfly valve. The controller is also used to control the gas supply assembly to supply carrier gas and process gas to the reaction chamber when the opening change of the second butterfly valve is within a second preset opening range and the difference between the second pressure information and the first preset pressure is within the second preset pressure range, and control the reaction chamber to start the epitaxial growth process.

[0025] Because before the epitaxial growth process and when adjusting the opening of the first butterfly valve and the second butterfly valve, the gas supply component only supplies carrier gas to the reaction chamber, and only when the opening change of the second butterfly valve is within the second preset opening range and the difference between the second pressure information and the first preset pressure is within the second preset pressure range, the gas supply component will supply process gas to the reaction chamber. Therefore, this technical solution can effectively reduce the usage of process gas.

[0026] Optionally, the controller is also used to control the gate valve to close after the epitaxial growth process is completed, and then adjust the opening of the first butterfly valve according to the first preset opening range, the first pressure information and the second preset pressure; and when the opening change of the first butterfly valve is within the first preset opening range and the difference between the first pressure information and the second preset pressure is within the third preset pressure range, adjust the opening of the second butterfly valve according to the second preset opening range, the second pressure information and the second preset pressure.

[0027] This technical solution is equivalent to using an open second butterfly valve instead of an open gate valve during the pressurization process. Since the opening of the gate valve cannot be adjusted, while the opening of the second butterfly valve is adjustable, this technical solution can adjust the opening of the second butterfly valve to make the gas pressure in the reaction chamber quickly reach the second preset pressure while avoiding the reaction chamber from exploding, thereby effectively shortening the time required to pressurize the reaction chamber and reducing the amount of gas used to pressurize the reaction chamber.

[0028] Optionally, the diameter of the pipe section in the exhaust pipe between the output end of the gate valve and the output end of the pressure regulating pipe is smaller than the diameter of the exhaust pipe in other areas.

[0029] Since the diameter of the pipe section in the exhaust pipe between the output end of the gate valve and the output end of the pressure regulating pipe is smaller than the diameter of the exhaust pipe in other areas, the flow rate of the gas discharged from the reaction chamber will not change significantly before and after the gate valve is opened. Therefore, the present application can effectively avoid the situation where the graphite parts in the reaction chamber are pulled due to a sudden increase in the flow rate of the gas discharged from the reaction chamber after the gate valve is opened.

[0030] Optionally, the double butterfly valve pressure control system also includes a gate valve and a washing tower, the input end of the gate valve is connected to the output end of the first butterfly valve, the output end of the gate valve is connected to the input end of the process pump, and the output end of the process pump is connected to the washing tower.

[0031] In a second aspect, the present application further provides a double butterfly valve pressure control method, which is applied in the double butterfly valve pressure control system provided in the first aspect above. The double butterfly valve pressure control method comprises the following steps:

[0032] S1. adjusting the opening of the first butterfly valve according to a first preset opening range, first pressure information and a first preset pressure;

[0033] S2. When the opening change of the first butterfly valve is within the first preset opening range and the difference between the first pressure information and the first preset pressure is within the first preset pressure range, the opening of the second butterfly valve is adjusted according to the second preset opening range, the second pressure information and the first preset pressure.

[0034] The present application provides a double butterfly valve pressure control method, which first roughly adjusts the air pressure in the reaction chamber to near the first preset pressure by adjusting the opening of the first butterfly valve based on a first preset opening range, first pressure information and the first preset pressure, and then stabilizes the air pressure in the reaction chamber at the first preset pressure by adjusting the opening of the second butterfly valve based on the second preset opening range, the second pressure information and the first preset pressure. After the air pressure in the reaction chamber is roughly adjusted to near the first preset pressure, the present application stabilizes the air pressure in the reaction chamber at the first preset pressure by frequently adjusting the opening of the second butterfly valve, and the flow rate of the gas passing through the first butterfly valve is greater than the flow rate of the gas passing through the second butterfly valve. Even if the opening of the second butterfly valve is frequently adjusted, the service life of the second butterfly valve will not be shortened due to a significant change in the impact force on the second butterfly valve. Therefore, the present application can effectively reduce the number of adjustments to the opening of the first butterfly valve, thereby effectively extending the service life of the first butterfly valve, and further effectively extending the maintenance cycle of the epitaxial furnace.

[0035] In a third aspect, the present application provides an epitaxial furnace, which includes the double butterfly valve pressure control system provided in the first aspect above.

[0036] The present application provides an epitaxial furnace, which first roughly adjusts the air pressure in a reaction chamber to near a first preset pressure by adjusting the opening of a first butterfly valve based on a first preset opening range, first pressure information and the first preset pressure, and then stabilizes the air pressure in the reaction chamber at the first preset pressure by adjusting the opening of a second butterfly valve based on a second preset opening range, second pressure information and the first preset pressure. After the air pressure in the reaction chamber is roughly adjusted to near the first preset pressure, the present application stabilizes the air pressure in the reaction chamber at the first preset pressure by frequently adjusting the opening of the second butterfly valve, and the flow rate of gas passing through the first butterfly valve is greater than the flow rate of gas passing through the second butterfly valve. Even if the opening of the second butterfly valve is frequently adjusted, the service life of the second butterfly valve will not be shortened due to a significant change in the impact force on the second butterfly valve. Therefore, the present application can effectively reduce the number of times the opening of the first butterfly valve is adjusted, thereby effectively extending the service life of the first butterfly valve, and further effectively extending the maintenance cycle of the epitaxial furnace.

[0037] As can be seen from the above, the present application provides a double butterfly valve pressure control system, method and epitaxial furnace, which first roughly adjusts the air pressure in the reaction chamber to near the first preset pressure by adjusting the opening of the first butterfly valve based on the first preset opening range, the first pressure information and the first preset pressure, and then stabilizes the air pressure in the reaction chamber at the first preset pressure by adjusting the opening of the second butterfly valve based on the second preset opening range, the second pressure information and the first preset pressure. After the air pressure in the reaction chamber is roughly adjusted to near the first preset pressure, the present application stabilizes the air pressure in the reaction chamber at the first preset pressure by frequently adjusting the opening of the second butterfly valve, and the flow rate of the gas passing through the first butterfly valve is greater than the flow rate of the gas passing through the second butterfly valve. Even if the opening of the second butterfly valve is frequently adjusted, the service life of the second butterfly valve will not be shortened due to a significant change in the impact force on the second butterfly valve. Therefore, the present application can effectively reduce the number of adjustments to the opening of the first butterfly valve, thereby effectively extending the service life of the first butterfly valve, and further effectively extending the maintenance cycle of the epitaxial furnace. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A schematic diagram of the structure of an epitaxial furnace provided in an embodiment of the present application.

[0039] Figure 2 A control relationship diagram of a double butterfly valve pressure control system provided in an embodiment of the present application.

[0040] Figure 3 A flow chart of a double butterfly valve pressure control method provided in an embodiment of the present application.

[0041] Figure numerals: 1. reaction chamber; 2. exhaust pipe; 3. gate valve; 4. first pressure collection assembly; 5. first butterfly valve; 6. process pump; 7. pressure regulating pipe; 8. second butterfly valve; 9. second pressure collection assembly; 10. controller; 11. diaphragm valve; 12. air supply assembly; 13. gate valve; 14. washing tower; 15. transfer chamber; 16. robot; 17. cache chamber; 18. load chamber; 19. wafer. DETAILED DESCRIPTION

[0042] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0043] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. At the same time, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0044] First, as Figure 1 and Figure 2 As shown, the present application provides a double butterfly valve pressure control system, which is applied in an epitaxial furnace. The epitaxial furnace includes a reaction chamber 1. The double butterfly valve pressure control system includes:

[0045] An exhaust pipe 2 is connected to the exhaust port of the reaction chamber 1, and is provided with a gate valve 3, a first pressure collection component 4, a first butterfly valve 5 and a process pump 6 in sequence, wherein the first pressure collection component 4 is used to collect first pressure information;

[0046] A pressure regulating pipe 7, whose input end and output end are both connected to the exhaust pipe 2 and are respectively located before and after the gate valve 3, and a second butterfly valve 8 is arranged on it. The diameter of the pipe section of the pressure regulating pipe 7 located at the output end of the second butterfly valve 8 is smaller than the diameter of the exhaust pipe 2;

[0047] A second pressure collection component 9, arranged at the input end of the pressure regulating tube 7, for collecting second pressure information;

[0048] The controller 10 is used to open the gate valve 3 before or during the epitaxial growth process, adjust the opening of the first butterfly valve 5 according to the first preset opening range, the first pressure information and the first preset pressure, and when the opening change of the first butterfly valve 5 is within the first preset opening range and the difference between the first pressure information and the first preset pressure is within the first preset pressure range, adjust the opening of the second butterfly valve 8 according to the second preset opening range, the second pressure information and the first preset pressure.

[0049] The double butterfly valve pressure control system provided in this embodiment is applied in an epitaxial furnace. Specifically, the epitaxial furnace of this embodiment includes a reaction chamber 1, a transfer chamber 15, a buffer chamber 17 and a load chamber 18. The load chamber 18 is used to load and unload wafers 19 and cool wafers 19. A manipulator 16 is provided in the transfer chamber 15. The manipulator 16 can move wafers 19 to various chambers. The buffer chamber 17 is used to buffer wafers 19 waiting for epitaxial growth process. The double butterfly valve pressure control system of this embodiment is used to adjust the air pressure in the reaction chamber 1. The exhaust pipe 2 of this embodiment is provided with a gate valve 3, a first pressure collection component 4, a first butterfly valve 5 and a process pump 6 in sequence. The first pressure collection component 4 is preferably a pressure gauge. The first pressure collection component 4 is used to collect first pressure information. The first pressure information is the air pressure at the input end of the first butterfly valve 5. The first pressure information is the same as or close to the air pressure in the reaction chamber 1. This embodiment can use the process pump 6 to drive the gas in the reaction chamber 1 to flow out of the reaction chamber 1. The exhaust pipe 2 of this embodiment is equivalent to the exhaust pipeline of the prior art. The input end and the output end of the pressure regulating pipe 7 of this embodiment are connected to the exhaust pipe 2 and are respectively located before and after the gate valve 3. The second butterfly valve 8 is provided on the pressure regulating pipe 7, that is, the gate valve 3 and the second butterfly valve 8 of this embodiment are in parallel relationship. The pressure regulating pipe 7 can play a diversion role on the exhaust pipe 2. Since the diameter of the pipe section located at the output end of the second butterfly valve 8 in the pressure regulating pipe 7 is smaller than the diameter of the exhaust pipe 2, when the gate valve 3 is opened and the opening degrees of the first butterfly valve 5 and the second butterfly valve 8 are the same, the flow rate of the gas passing through the first butterfly valve 5 is greater than the flow rate of the gas passing through the second butterfly valve 8. It should be understood that the gas discharged from the reaction chamber 1 contains dust particles. When the gate valve 3 is opened and the opening degrees of the first butterfly valve 5 and the second butterfly valve 8 are the same, most of the dust particles pass through the first butterfly valve 5, that is, the amount of dust particles passing through the first butterfly valve 5 is greater than the amount of dust particles passing through the second butterfly valve 8. The second pressure collection component 9 of this embodiment is preferably a pressure gauge, and the second pressure collection component 9 is arranged at the input end of the pressure regulating tube 7, and the second pressure collection component 9 is used to collect second pressure information, which is equivalent to the air pressure in the reaction chamber 1. It should be understood that since the first butterfly valve 5 and the second butterfly valve 8 of this embodiment are both front-end controlled, and the first pressure collection component 4 of this embodiment is located upstream of the first butterfly valve 5, and the second pressure collection component 9 of this embodiment is located upstream of the second butterfly valve 8, that is, this embodiment is equivalent to equipping the first butterfly valve 5 and the second butterfly valve 8 with separate pressure collection components, so this embodiment can effectively improve the adjustment accuracy of the first butterfly valve 5 and the second butterfly valve 8, thereby effectively improving the pressure control accuracy of the reaction chamber 1.

[0050] The controller 10 of this embodiment is electrically connected to the first pressure collection component 4, the first butterfly valve 5, the second butterfly valve 8 and the second pressure collection component 9 respectively. The controller 10 of this embodiment can adjust the opening of the first butterfly valve 5 according to the first preset opening range, the first pressure information and the first preset pressure. Specifically, the first preset pressure of this embodiment is the air pressure that needs to be maintained in the reaction chamber 1 during the epitaxial growth process. The first preset pressure is preferably 100 mbar. If the opening change of the first butterfly valve 5 (the percentage of the change in the opening of the first butterfly valve 5 per unit time to the maximum opening of the first butterfly valve 5) is outside the first preset opening range, the opening of the first butterfly valve 5 is unstable. At this time, The pressure fluctuation range in the reaction chamber 1 is too large and the pressure control accuracy of the reaction chamber 1 is insufficient. The first preset opening range is preferably -1%~1%. If the difference between the first pressure information and the first preset pressure is within the first preset pressure range, it means that the pressure in the reaction chamber 1 is near the first preset pressure. If the opening change of the second butterfly valve 8 (the percentage of the change in the opening of the second butterfly valve 8 per unit time and the maximum opening of the second butterfly valve 8) is outside the second preset opening range, the opening of the second butterfly valve 8 is unstable. At this time, the pressure fluctuation range in the reaction chamber 1 is too large and the pressure control accuracy of the reaction chamber 1 is insufficient. The second preset opening range is preferably -0.5%~0.5%. This embodiment is equivalent to firstly adjusting the pressure in the reaction chamber 1 to the vicinity of the first preset pressure by adjusting the opening of the first butterfly valve 5 based on the first preset opening range, the first pressure information and the first preset pressure, and then stabilizing the pressure in the reaction chamber 1 at the first preset pressure by adjusting the opening of the second butterfly valve 8 based on the second preset opening range, the second pressure information and the first preset pressure. It should be understood that, since the flow rate of gas passing through the first butterfly valve 5 is greater than the flow rate of gas passing through the second butterfly valve 8, when the first butterfly valve 5 and the second butterfly valve 8 are adjusted based on the same change in opening, the change in impact force received by the first butterfly valve 5 (the change in impact force received by the first butterfly valve 5 per unit time) is greater than the change in impact force received by the second butterfly valve 8 (the change in impact force received by the second butterfly valve 8 per unit time), and since the amount of dust particles passing through the first butterfly valve 5 is greater than the amount of dust particles passing through the second butterfly valve 8, when the first butterfly valve 5 and the second butterfly valve 8 are adjusted based on the same change in opening, the amount of dust particles deposited on the first butterfly valve 5 is greater than the amount of dust particles deposited on the second butterfly valve 8, and since in the process of adjusting the butterfly valve opening, the service life of the butterfly valve is negatively correlated with the change in impact force received by it and the amount of dust particles deposited thereon, and this embodiment is equivalent to replacing the frequent adjustment of the first butterfly valve 5 by frequently adjusting the second butterfly valve 8, so this embodiment can effectively extend the service life of the first butterfly valve 5, and frequent adjustment of the second butterfly valve 8 will not cause a significant change in its service life.

[0051] The present application provides a double butterfly valve pressure control system, which first roughly adjusts the air pressure in the reaction chamber 1 to near the first preset pressure by adjusting the opening of the first butterfly valve 5 based on the first preset opening range, the first pressure information and the first preset pressure, and then stabilizes the air pressure in the reaction chamber 1 at the first preset pressure by adjusting the opening of the second butterfly valve 8 based on the second preset opening range, the second pressure information and the first preset pressure. After the air pressure in the reaction chamber 1 is roughly adjusted to near the first preset pressure, the present application stabilizes the air pressure in the reaction chamber 1 at the first preset pressure by frequently adjusting the opening of the second butterfly valve 8, and the flow rate of the gas passing through the first butterfly valve 5 is greater than the flow rate of the gas passing through the second butterfly valve 8. Even if the opening of the second butterfly valve 8 is frequently adjusted, the service life of the second butterfly valve 8 will not be shortened due to a significant change in the impact force on the second butterfly valve 8. Therefore, the present application can effectively reduce the number of adjustments to the opening of the first butterfly valve 5, thereby effectively extending the service life of the first butterfly valve 5, and further effectively extending the maintenance cycle of the epitaxial furnace. In addition, since the present application first uses the first butterfly valve 5 to roughly adjust the air pressure in the reaction chamber 1 and then uses the second butterfly valve 8 to finely adjust the air pressure in the reaction chamber 1, the present application can effectively improve the air pressure regulation accuracy in the reaction chamber 1, and since the diameter of the pipe section at the output end of the second butterfly valve 8 in the pressure regulating pipe 7 is smaller than the diameter of the exhaust pipe 2, the flow rate of the gas discharged from the reaction chamber 1 will not change significantly before and after the second butterfly valve 8 is opened, the present application can effectively avoid the situation in which the graphite parts in the reaction chamber 1 are pulled due to a sudden increase in the flow rate of the gas discharged from the reaction chamber 1 after the second butterfly valve 8 is opened.

[0052] In some preferred embodiments, the double butterfly valve pressure control system further includes a diaphragm valve 11, the input and output ends of the diaphragm valve 11 are connected to the pressure regulating pipe 7 and are respectively located before and after the second butterfly valve 8, and the controller 10 is also used to control the gate valve 3 to close when the reaction chamber 1 needs to be evacuated, and control the process pump 6 and the diaphragm valve 11 to open and control the first butterfly valve 5 to open at a first preset opening rate, and then control the second butterfly valve 8 to open at a second preset opening rate when the vacuum degree information of the reaction chamber reaches the preset vacuum degree, and the first preset opening rate is greater than the second preset opening rate. The diaphragm valve 11, the gate valve 3 and the second butterfly valve 8 of this embodiment are in parallel with each other, and the pipe section in the pressure regulating pipe 7 between the output end of the second butterfly valve 8 and the confluence of the diaphragm valve 11 and the pressure regulating pipe 7 (reference Figure 1The diameter of a) in the embodiment is smaller than the diameter of the exhaust pipe 2. The vacuum degree information of the reaction chamber in this embodiment may be information fed back by the reaction chamber 1. After the vacuum degree information of the reaction chamber reaches the preset vacuum degree, the vacuum pumping rate will gradually decrease under the influence of the diameter of the pipe connected to the diaphragm valve 11. Since the vacuum degree information of the reaction chamber reaches the preset vacuum degree, the embodiment controls the second butterfly valve 8 to open at the second preset opening rate. At this time, the diameter of the vacuum pumping pipe will increase, and the diameter of the vacuum pumping pipe is positively correlated with the vacuum pumping rate. Therefore, this embodiment is equivalent to increasing the vacuum pumping rate by opening the second butterfly valve 8 after the vacuum degree information of the reaction chamber reaches the preset vacuum degree, thereby effectively improving the vacuum pumping efficiency. It should be understood that if the second butterfly valve 8 is opened before the vacuum degree information of the reaction chamber reaches the preset vacuum degree, the graphite parts in the reaction chamber 1 may be pumped due to the excessive airflow generated during the vacuum pumping. That is, this embodiment is equivalent to improving the vacuum pumping efficiency while avoiding the graphite parts in the reaction chamber 1 from being pumped. It should also be understood that the vacuuming of the reaction chamber 1 is performed before adjusting the openings of the first butterfly valve 5 and the second butterfly valve 8, that is, this embodiment is equivalent to first vacuuming the reaction chamber 1, then adjusting the gas pressure in the reaction chamber 1 to the first preset pressure, and then starting the epitaxial growth process.

[0053] In some preferred embodiments, the process of adjusting the opening of the first butterfly valve 5 according to the first preset opening range, the first pressure information and the first preset pressure, and when the opening change of the first butterfly valve 5 is within the first preset opening range and the difference between the first pressure information and the first preset pressure is within the first preset pressure range, adjusting the opening of the second butterfly valve 8 according to the second preset opening range, the second pressure information and the first preset pressure includes:

[0054] A1. adjusting the opening of the first butterfly valve 5 according to the first pressure information and the first preset pressure;

[0055] A2, determining whether the difference between the first pressure information and the first preset pressure is within the first preset pressure range, if so, executing step A3, if not, returning to step A1;

[0056] A3, judging whether the opening change of the first butterfly valve 5 is within the first preset opening range, if so, controlling the first butterfly valve 5 to maintain the current opening, and adjusting the opening of the second butterfly valve 8 according to the second preset opening range, the second pressure information and the first preset pressure, if not, executing step A4;

[0057] A4. Determine whether the accumulated adjustment time of the first butterfly valve 5 reaches the first preset time. If yes, end the adjustment, clear the accumulated adjustment time of the first butterfly valve 5 and generate an alarm message. If no, return to step A1.

[0058] Step A1 can adjust the opening of the first butterfly valve 5 according to the first pressure information and the first preset pressure based on PID control, and step A3 can also adjust the opening of the second butterfly valve 8 according to the second pressure information and the first preset pressure based on PID control. The first preset time of step A4 is preferably 4 minutes. Since this embodiment will end the adjustment when the cumulative adjustment time of the first butterfly valve 5 reaches the first preset time, this embodiment can effectively avoid the situation where the opening of the first butterfly valve 5 is continuously adjusted due to the change in the opening of the first butterfly valve 5 being outside the first preset opening range or the difference between the first pressure information and the first preset pressure being outside the first preset pressure range.

[0059] In some preferred embodiments, the process of adjusting the opening of the second butterfly valve 8 according to the second preset opening range, the second pressure information and the first preset pressure includes:

[0060] B1. adjusting the opening of the second butterfly valve 8 according to the second pressure information and the first preset pressure;

[0061] B2, determining whether the second pressure information is the same as the first preset pressure, if so, executing step B3, if not, returning to step B1;

[0062] B3, judging whether the opening variation of the second butterfly valve 8 is within the second preset opening range, if so, starting the epitaxial growth process, if not, executing step B4;

[0063] B4. Determine whether the accumulated adjustment time of the second butterfly valve 8 reaches the second preset time. If yes, end the adjustment, clear the accumulated adjustment time of the second butterfly valve 8 and generate an alarm message. If no, return to step B1.

[0064] The second preset time of this embodiment is preferably 4 minutes. Since this embodiment will end the adjustment when the cumulative adjustment time of the second butterfly valve 8 reaches the second preset time, this embodiment can effectively avoid the situation where the opening of the second butterfly valve 8 is continuously adjusted because the opening change of the second butterfly valve 8 is outside the second preset opening range or the second pressure information is different from the first preset pressure.

[0065] In some preferred embodiments, the epitaxial furnace also includes a gas supply component 12, and the controller 10 is also used to control the gas supply component 12 to supply carrier gas to the reaction chamber 1 before the epitaxial growth process and when adjusting the opening of the first butterfly valve 5 and the second butterfly valve 8. The controller 10 is also used to control the gas supply component 12 to supply carrier gas and process gas to the reaction chamber 1 when the opening change of the second butterfly valve 8 is within the second preset opening range and the difference between the second pressure information and the first preset pressure is within the second preset pressure range, and control the reaction chamber 1 to start the epitaxial growth process. The gas supply component 12 of this embodiment can be an existing device, and the gas supply component 12 can supply carrier gas and a mixed gas composed of carrier gas and process gas to the reaction chamber 1. Because before the epitaxial growth process and when adjusting the opening of the first butterfly valve 5 and the second butterfly valve 8, the gas supply component 12 only supplies carrier gas to the reaction chamber 1, and only when the opening change of the second butterfly valve 8 is within the second preset opening range and the difference between the second pressure information and the first preset pressure is within the second preset pressure range, the gas supply component 12 will supply process gas to the reaction chamber 1, so this embodiment can effectively reduce the usage of process gas. It should be understood that during the epitaxial growth process, the flow rate of the carrier gas is much greater than the flow rate of the process gas, that is, the supply of process gas to the reaction chamber 1 usually does not cause the gas pressure in the reaction chamber 1 to change, so it is usually unnecessary to adjust the opening of the second butterfly valve 8 before and after the supply of process gas to the reaction chamber 1.

[0066] In some preferred embodiments, the controller 10 is further used to control the gate valve 3 to close after the epitaxial growth process is completed, and then adjust the opening of the first butterfly valve 5 according to the first preset opening range, the first pressure information and the second preset pressure, and when the opening change of the first butterfly valve 5 is within the first preset opening range and the difference between the first pressure information and the second preset pressure is within the third preset pressure range, adjust the opening of the second butterfly valve 8 according to the second preset opening range, the second pressure information and the second preset pressure. Specifically, after the epitaxial growth process is completed, the present application needs to use the manipulator 16 in the transfer chamber 15 to take out the wafer 19 that has completed the epitaxial growth process from the reaction chamber 1. Since the reaction chamber 1 needs to be connected to the transfer chamber 15 when taking out the wafer 19, before opening the gate valve between the reaction chamber 1 and the transfer chamber 15, the embodiment needs to increase the pressure of the reaction chamber 1 so that the pressure of the reaction chamber 1 is the same as the pressure of the transfer chamber 15 (preferably, the embodiment increases the pressure of the reaction chamber 1 from 100 mbar to 1000 mbar, that is, the second preset pressure of the embodiment is preferably 1000 mbar). Since the opening of the second butterfly valve 8 is not 0 during the epitaxial growth process, even if the gate valve 3 is closed in this embodiment, the gas in the reaction chamber 1 can still flow out through the first butterfly valve 5 and the second butterfly valve 8, thereby effectively avoiding the situation where the gas in the reaction chamber 1 cannot flow out due to the need for the gas supply component 12 to supply the atmospheric flow to the reaction chamber 1 during the pressurization process, causing the reaction chamber 1 to be filled and exploded. When the reaction chamber 1 is pressurized, the prior art needs to open the gate valve 3, while this embodiment opens the second butterfly valve 8 and closes the gate valve 3, that is, this embodiment is equivalent to replacing the opened gate valve 3 with the opened second butterfly valve 8 during the pressurization process. Since the opening of the gate valve 3 cannot be adjusted, while the opening of the second butterfly valve 8 is adjustable, this embodiment can quickly make the gas pressure in the reaction chamber 1 reach the second preset pressure by adjusting the opening of the second butterfly valve 8 while avoiding the reaction chamber 1 from being filled and exploded, thereby effectively shortening the time required for pressurizing the reaction chamber 1 and reducing the amount of gas used for pressurizing the reaction chamber 1.

[0067] In some preferred embodiments, the diameter of the pipe section between the output end of the gate valve 3 and the output end of the pressure regulating pipe 7 in the exhaust pipe 2 is smaller than the diameter of the exhaust pipe 2 in other areas. Preferably, the diameter of the pipe section between the output end of the gate valve 3 and the output end of the pressure regulating pipe 7 in the exhaust pipe 2 of this embodiment is one-third of the diameter of the exhaust pipe 2, and the diameter of the pipe section at the output end of the second butterfly valve 8 in the pressure regulating pipe 7 of this embodiment is one-half of the diameter of the pipe section of the exhaust pipe 2 other than the output end of the gate valve 3 and the output end of the pressure regulating pipe 7. Figure 1The diameter of b) is smaller than the diameter of the exhaust pipe 2 in other areas, and the flow rate of the gas discharged from the reaction chamber 1 will not change significantly before and after the gate valve 3 is opened. Therefore, the present application can effectively avoid the situation where the graphite parts in the reaction chamber 1 are pulled due to the sudden increase in the flow rate of the gas discharged from the reaction chamber 1 after the gate valve 3 is opened.

[0068] In some preferred embodiments, the double butterfly valve pressure control system further includes a gate valve 13 and a washing tower 14, the input end of the gate valve 13 is connected to the output end of the first butterfly valve 5, the output end of the gate valve 13 is connected to the input end of the process pump 6, and the output end of the process pump 6 is connected to the washing tower 14. This embodiment can connect or disconnect the process pump 6 and the washing tower 14 with the second butterfly valve 8 by opening or closing the gate valve 13, and this embodiment can use the washing tower 14 to treat the exhaust gas discharged from the reaction chamber 1.

[0069] As can be seen from the above, the double butterfly valve pressure control system provided by the present application first roughly adjusts the air pressure in the reaction chamber 1 to near the first preset pressure by adjusting the opening of the first butterfly valve 5 based on the first preset opening range, the first pressure information and the first preset pressure, and then stabilizes the air pressure in the reaction chamber 1 at the first preset pressure by adjusting the opening of the second butterfly valve 8 based on the second preset opening range, the second pressure information and the first preset pressure. After the air pressure in the reaction chamber 1 is roughly adjusted to near the first preset pressure, the present application stabilizes the air pressure in the reaction chamber 1 at the first preset pressure by frequently adjusting the opening of the second butterfly valve 8, and the flow rate of the gas passing through the first butterfly valve 5 is greater than the flow rate of the gas passing through the second butterfly valve 8. Even if the opening of the second butterfly valve 8 is frequently adjusted, the service life of the second butterfly valve 8 will not be shortened due to a significant change in the impact force on the second butterfly valve 8. Therefore, the present application can effectively reduce the number of adjustments to the opening of the first butterfly valve 5, thereby effectively extending the service life of the first butterfly valve 5, and further effectively extending the maintenance cycle of the epitaxial furnace.

[0070] Second, as Figure 3 As shown, the present application also provides a double butterfly valve pressure control method, which is applied in the double butterfly valve pressure control system provided in the first aspect above. The double butterfly valve pressure control method includes the following steps:

[0071] S1. Before or during the epitaxial growth process, open the gate valve 3, and adjust the opening of the first butterfly valve 5 according to the first preset opening range, the first pressure information and the first preset pressure;

[0072] S2. When the opening change of the first butterfly valve 5 is within the first preset opening range and the difference between the first pressure information and the first preset pressure is within the first preset pressure range, the opening of the second butterfly valve 8 is adjusted according to the second preset opening range, the second pressure information and the first preset pressure.

[0073] An embodiment of the present application provides a double butterfly valve pressure control method, which is applied in a double butterfly valve pressure control system provided in the first aspect above. The principle of the double butterfly valve pressure control method provided by this embodiment is the same as the principle of the double butterfly valve pressure control system provided in the first aspect above, and will not be discussed in detail here.

[0074] As can be seen from the above, the present application provides a double butterfly valve pressure control method, which first roughly adjusts the air pressure in the reaction chamber 1 to near the first preset pressure by adjusting the opening of the first butterfly valve 5 based on the first preset opening range, the first pressure information and the first preset pressure, and then stabilizes the air pressure in the reaction chamber 1 at the first preset pressure by adjusting the opening of the second butterfly valve 8 based on the second preset opening range, the second pressure information and the first preset pressure. After the air pressure in the reaction chamber 1 is roughly adjusted to near the first preset pressure, the present application stabilizes the air pressure in the reaction chamber 1 at the first preset pressure by frequently adjusting the opening of the second butterfly valve 8, and the flow rate of the gas passing through the first butterfly valve 5 is greater than the flow rate of the gas passing through the second butterfly valve 8. Even if the opening of the second butterfly valve 8 is frequently adjusted, the service life of the second butterfly valve 8 will not be shortened due to a significant change in the impact force on the second butterfly valve 8. Therefore, the present application can effectively reduce the number of adjustments to the opening of the first butterfly valve 5, thereby effectively extending the service life of the first butterfly valve 5, and further effectively extending the maintenance cycle of the epitaxial furnace.

[0075] Thirdly, Figure 1 As shown, the present application provides an epitaxial furnace, which includes the double butterfly valve pressure control system provided by the first aspect above.

[0076] An embodiment of the present application provides an epitaxial furnace, which includes the double butterfly valve pressure control system provided in the first aspect above. The principle of the epitaxial furnace provided in the embodiment of the present application is the same as the principle of the double butterfly valve pressure control system provided in the first aspect above, and will not be discussed in detail here.

[0077] As can be seen from the above, the double butterfly valve pressure control system, method and epitaxial furnace provided by the present application first roughly adjust the air pressure in the reaction chamber 1 to near the first preset pressure by adjusting the opening of the first butterfly valve 5 based on the first preset opening range, the first pressure information and the first preset pressure, and then stabilize the air pressure in the reaction chamber 1 at the first preset pressure by adjusting the opening of the second butterfly valve 8 based on the second preset opening range, the second pressure information and the first preset pressure. After the air pressure in the reaction chamber 1 is roughly adjusted to near the first preset pressure, the present application stabilizes the air pressure in the reaction chamber 1 at the first preset pressure by frequently adjusting the opening of the second butterfly valve 8, and the flow rate of the gas passing through the first butterfly valve 5 is greater than the flow rate of the gas passing through the second butterfly valve 8. Even if the opening of the second butterfly valve 8 is frequently adjusted, the service life of the second butterfly valve 8 will not be shortened due to a significant change in the impact force on the second butterfly valve 8. Therefore, the present application can effectively reduce the number of adjustments to the opening of the first butterfly valve 5, thereby effectively extending the service life of the first butterfly valve 5, and further effectively extending the maintenance cycle of the epitaxial furnace.

[0078] In the embodiments provided in the present application, it should be understood that, herein, relational terms such as first and second, etc. are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0079] The above description is only an embodiment of the present application and is not intended to limit the protection scope of the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A double butterfly valve pressure control system, used in an epitaxial furnace, the epitaxial furnace comprising a reaction chamber, characterized in that: The double butterfly valve pressure control system comprises: an exhaust pipe connected to the exhaust port of the reaction chamber, on which a gate valve, a first pressure collection component, a first butterfly valve and a process pump are sequentially arranged, wherein the first pressure collection component is used to collect first pressure information; A pressure regulating pipe, whose input end and output end are both connected to the exhaust pipe and are respectively located before and after the gate valve, and a second butterfly valve is arranged on the pressure regulating pipe, and the pipe diameter of the pipe section of the pressure regulating pipe located at the output end of the second butterfly valve is smaller than the pipe diameter of the exhaust pipe; A second pressure collection component is arranged at the input end of the pressure regulating tube and is used to collect second pressure information; A controller is used to open the gate valve before or during the epitaxial growth process, adjust the opening of the first butterfly valve according to a first preset opening range, the first pressure information and a first preset pressure, and when the opening change of the first butterfly valve is within the first preset opening range and the difference between the first pressure information and the first preset pressure is within the first preset pressure range, adjust the opening of the second butterfly valve according to a second preset opening range, the second pressure information and the first preset pressure.

2. The double butterfly valve pressure control system according to claim 1, characterized in that: The double butterfly valve pressure control system also includes a diaphragm valve, the input and output ends of the diaphragm valve are connected to the pressure regulating pipe and are respectively located before and after the second butterfly valve. The controller is also used to control the gate valve to close when the reaction chamber needs to be evacuated, and control the process pump and the diaphragm valve to open, and control the first butterfly valve to open at a first preset opening rate, and then control the second butterfly valve to open at a second preset opening rate when the vacuum degree information of the reaction chamber reaches a preset vacuum degree, and the first preset opening rate is greater than the second preset opening rate.

3. The double butterfly valve pressure control system according to claim 1, characterized in that: The process of adjusting the opening of the first butterfly valve according to the first preset opening range, the first pressure information and the first preset pressure, and when the opening change of the first butterfly valve is within the first preset opening range and the difference between the first pressure information and the first preset pressure is within the first preset pressure range, adjusting the opening of the second butterfly valve according to the second preset opening range, the second pressure information and the first preset pressure includes: A1. adjusting the opening of the first butterfly valve according to the first pressure information and the first preset pressure; A2, determining whether the difference between the first pressure information and the first preset pressure is within the first preset pressure range, if so, executing step A3, if not, returning to step A1; A3, determining whether the opening change of the first butterfly valve is within a first preset opening range, if so, controlling the first butterfly valve to maintain the current opening, and adjusting the opening of the second butterfly valve according to a second preset opening range, the second pressure information and the first preset pressure, if not, executing step A4; A4. Determine whether the accumulated adjustment time of the first butterfly valve reaches the first preset time. If so, end the adjustment, clear the accumulated adjustment time of the first butterfly valve and generate an alarm message. If not, return to step A1.

4. The double butterfly valve pressure control system according to claim 1, characterized in that: The process of adjusting the opening of the second butterfly valve according to the second preset opening range, the second pressure information and the first preset pressure includes: B1. adjusting the opening of the second butterfly valve according to the second pressure information and the first preset pressure; B2, determining whether the second pressure information is the same as the first preset pressure, if so, executing step B3, if not, returning to step B1; B3, determining whether the opening variation of the second butterfly valve is within a second preset opening range, if so, starting the epitaxial growth process, if not, executing step B4; B4. Determine whether the accumulated adjustment time of the second butterfly valve reaches the second preset time. If yes, end the adjustment, clear the accumulated adjustment time of the second butterfly valve and generate an alarm message. If no, return to step B1.

5. The double butterfly valve pressure control system according to claim 1, characterized in that: The epitaxial furnace also includes a gas supply assembly, and the controller is also used to control the gas supply assembly to supply carrier gas to the reaction chamber before the epitaxial growth process and when adjusting the opening of the first butterfly valve and the second butterfly valve. The controller is also used to control the gas supply assembly to supply carrier gas and process gas to the reaction chamber when the opening change of the second butterfly valve is within a second preset opening range and the difference between the second pressure information and the first preset pressure is within the second preset pressure range, and control the reaction chamber to start the epitaxial growth process.

6. The double butterfly valve pressure control system according to claim 1, characterized in that: The controller is also used to control the gate valve to close after the epitaxial growth process is completed, and then adjust the opening of the first butterfly valve according to a first preset opening range, the first pressure information and the second preset pressure, and when the opening change of the first butterfly valve is within the first preset opening range and the difference between the first pressure information and the second preset pressure is within a third preset pressure range, adjust the opening of the second butterfly valve according to the second preset opening range, the second pressure information and the second preset pressure.

7. The double butterfly valve pressure control system according to claim 1, characterized in that: The diameter of the pipe section in the exhaust pipe between the output end of the gate valve and the output end of the pressure regulating pipe is smaller than the diameter of the exhaust pipe in other areas.

8. The double butterfly valve pressure control system according to claim 1, characterized in that: The double butterfly valve pressure control system also includes a gate valve and a washing tower, the input end of the gate valve is connected to the output end of the first butterfly valve, the output end of the gate valve is connected to the input end of the process pump, and the output end of the process pump is connected to the washing tower.

9. A double butterfly valve pressure control method, characterized in that: Applied in the double butterfly valve pressure control system according to any one of claims 1 to 8, the double butterfly valve pressure control method comprises the following steps: S1. adjusting the opening of the first butterfly valve according to a first preset opening range, the first pressure information and a first preset pressure; S2. When the opening change of the first butterfly valve is within a first preset opening range and the difference between the first pressure information and the first preset pressure is within the first preset pressure range, the opening of the second butterfly valve is adjusted according to a second preset opening range, the second pressure information and the first preset pressure.

10. An epitaxial furnace, characterized in that: The epitaxial furnace comprises the double butterfly valve pressure control system as described in any one of claims 1-8.

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