Circulating type filtering system

Abstract

According to the circulating type filtering system provided by the invention, through the arrangement of the first filter, the second filter, the control valve and the like, switching and back flushing of the first filter and / or the second filter can be conveniently realized under the condition that external air does not need to be additionally introduced, so that the problem of filter blockage is effectively solved, and impurities can be prevented from being introduced into the system.

Description

Technical Field

[0001] The invention belongs to the field of semiconductor manufacturing equipment and relates to a circulating filtering system. Background Art

[0002] In the manufacture of semiconductor devices, the suppression of particulate matter is crucial. For example, in the process of using supercritical fluid to replace residual liquid medicine on the wafer, the suppression of particulate matter in the supercritical fluid is the top priority of the entire process.

[0003] In order to effectively remove particulate matter, in existing semiconductor equipment, high-precision and high-efficiency particle filters are usually installed in pipelines to filter particulate matter. However, as the process time increases, high-precision particle filters are extremely easy to clog. Once the filter is clogged, in order to ensure the filtering effect, the equipment needs to be shut down to reduce the pressure in the pipeline to normal pressure before replacing the filter. During the replacement process, there is a risk of secondary contamination due to the exposure of the pipeline. After the filter is replaced, the pipeline needs to be purged for a certain period of time to reduce the particulate matter to a level that meets production requirements. In addition, the existing filters are often delayed in finding blockages, which may cause a large range of product quality problems.

[0004] Therefore, it is necessary to provide a circulating filtering system. Summary of the invention

[0005] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a circulating filtration system for solving the clogging problem of the drying filter in the prior art.

[0006] To achieve the above-mentioned purpose and other related purposes, the present invention provides a circulating filtration system, which comprises: a first filter, a second filter, a process chamber, an air inlet pipe, an air outlet pipe, a first control valve, a second control valve, a third control valve, a fourth control valve, a fifth control valve, a sixth control valve, a first air inlet shunt pipe, a second air inlet shunt pipe, a first air outlet shunt pipe, a second air outlet shunt pipe, a first backflush shunt pipe, and a second backflush shunt pipe; wherein,

[0007] The first air intake shunt pipe, the second air intake shunt pipe, the first air outlet shunt pipe, the second air outlet shunt pipe, the first back-blowing shunt pipe and the second back-blowing shunt pipe are respectively installed with the first control valve, the second control valve, the third control valve, the fourth control valve, the fifth control valve and the sixth control valve;

[0008] The air inlet pipeline is connected to the first air inlet shunt pipeline and the second air inlet shunt pipeline respectively; the first end of the air outlet pipeline is connected to the first air outlet shunt pipeline and the second air outlet shunt pipeline respectively, and the second end of the air outlet pipeline is connected to the process chamber;

[0009] The first end of the first filter is connected to the first air inlet shunt pipe, and the second end of the first filter is connected to the first air outlet shunt pipe; the first end of the second filter is connected to the second air inlet shunt pipe, and the second end of the second filter is connected to the second air outlet shunt pipe;

[0010] The first backflush shunt pipe is connected to the first air intake shunt pipe, and the interface is located between the first control valve and the first filter. The second backflush shunt pipe is connected to the second air intake shunt pipe, and the interface is located between the second control valve and the second filter.

[0011] Optionally, it also includes a third back-blow shunt pipe, which is connected to the first air outlet shunt pipe, and the interface is located between the first filter and the third control valve, and the third back-blow shunt pipe is connected to the second air outlet shunt pipe, and the interface is located between the second filter and the fourth control valve, and a seventh control valve is installed on the third back-blow shunt pipe.

[0012] Optionally, it also includes a pressure reducing pipeline connected to the third back-blow shunt pipeline and the second air outlet shunt pipeline, and an eighth control valve is also installed on the third back-blow shunt pipeline, the interface between the pressure reducing pipeline and the third back-blow shunt pipeline is located between the seventh control valve and the eighth control valve, the interface between the pressure reducing pipeline and the second air outlet shunt pipeline is located at the end of the fourth control valve away from the second filter, and a pressure reducing valve is installed on the pressure reducing pipeline.

[0013] Optionally, pressure sensors are provided at both ends of the first filter; and / or pressure sensors are provided at both ends of the second filter.

[0014] Optionally, the circulating filtration system further includes one or a combination of a heater, a temperature sensor, a flow restrictor and a pressure relief device.

[0015] Optionally, any control valve among the first control valve, the second control valve, the third control valve, the fourth control valve, the fifth control valve and the sixth control valve comprises a pneumatic valve or a solenoid valve.

[0016] Optionally, the filter in the circulating filtration system includes a filter for filtering supercritical fluid.

[0017] Optionally, the first filter and the second filter have the same structure.

[0018] Optionally, the air outlet pipeline includes a first air outlet pipeline and a second air outlet pipeline arranged in parallel, and a ninth control valve and a tenth control valve are installed on the first air outlet pipeline and the second air outlet pipeline respectively.

[0019] Optionally, the circulating filtration system includes a circulating filtration system applied to wafer surface treatment.

[0020] As described above, the circulating filtration system of the present invention, through the arrangement of the first filter, the second filter and the control valve, etc., can conveniently realize the switching and backflushing of the first filter and / or the second filter without the need to introduce additional external gas, so as to effectively solve the filter clogging problem and avoid introducing impurities into the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It shows a schematic diagram of the structure of the circulating filtration system in the first embodiment of the present invention.

[0022] Figure 2 It shows a schematic diagram of the structure of the circulating filtration system in the second embodiment of the present invention.

[0023] Figure 3 It shows a schematic diagram of the structure of the circulating filtration system in the third embodiment of the present invention.

[0024] Component number description

[0025] 101 Intake duct

[0026] 102 First air intake diversion pipe

[0027] 103 Second air intake diversion pipe

[0028] 104 First gas outlet diversion pipeline

[0029] 105 Second gas outlet diversion pipeline

[0030] 106 First air outlet pipe

[0031] 107 Second air outlet pipe

[0032] 108 First backflush diversion pipeline

[0033] 109 Second backflush diversion pipeline

[0034] 110 Third backflush diversion pipeline

[0035] 111 Pressure Relief Pipe

[0036] 201 First control valve

[0037] 202 Second control valve

[0038] 203 Third control valve

[0039] 204 Fourth control valve

[0040] 205 Fifth control valve

[0041] 206 Sixth control valve

[0042] 207 Seventh control valve

[0043] 208 Eighth control valve

[0044] 209 Ninth control valve

[0045] 210 Tenth control valve

[0046] 301 First Filter

[0047] 302 Second filter

[0048] 400 process chamber

[0049] 501 First pressure sensor

[0050] 502 Second pressure sensor

[0051] 600 Heater

[0052] 701 First current limiter

[0053] 702 Second current limiter

[0054] 703 Third current limiter

[0055] 801 First temperature sensor

[0056] 802 Second temperature sensor

[0057] 803 Third temperature sensor

[0058] 901 First Pressure Relief Device

[0059] 902 Second pressure relief device

[0060] 120 Pressure reducing valve DETAILED DESCRIPTION

[0061] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0062] See also Figure 1 to Figure 3 It should be noted that the illustrations provided in this embodiment are only used to illustrate the basic concept of the present invention in a schematic manner, and the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0063] Embodiment 1

[0064] like Figure 1 The present embodiment provides a circulating filtration system, which includes: a first filter 301, a second filter 302, a process chamber 400, an air inlet pipe 101, an air outlet pipe, a first control valve 201, a second control valve 202, a third control valve 203, a fourth control valve 204, a fifth control valve 205, a sixth control valve 206, a first air inlet diversion pipe 102, a second air inlet diversion pipe 103, a first air outlet diversion pipe 104, a second air outlet diversion pipe 105, a first backflush diversion pipe 108, and a second backflush diversion pipe 109.

[0065] The first air inlet shunt pipe 102, the second air inlet shunt pipe 103, the first air outlet shunt pipe 104, the second air outlet shunt pipe 105, the first back-blowing shunt pipe 108 and the second back-blowing shunt pipe 109 are respectively installed with a first control valve 201, a second control valve 202, a third control valve 203, a fourth control valve 204, a fifth control valve 205 and a sixth control valve 206;

[0066] The inlet pipe 101 is connected to the first inlet branch pipe 102 and the second inlet branch pipe 103 respectively; the first end of the outlet pipe is connected to the first outlet branch pipe 104 and the second outlet branch pipe 105 respectively, and the second end of the outlet pipe is connected to the process chamber 400. Figure 1 The middle A area can be replaced with an outlet pipe; the first end of the first filter 301 is connected to the first air inlet shunt pipe 102, and the second end of the first filter 301 is connected to the first air outlet shunt pipe 104; the first end of the second filter 302 is connected to the second air inlet shunt pipe 103, and the second end of the second filter 302 is connected to the second air outlet shunt pipe 105;

[0067] The first back-blowing shunt pipe 108 is connected to the first air intake shunt pipe 102 , and the interface is located between the first control valve 201 and the first filter 301 . The second back-blowing shunt pipe 109 is connected to the second air intake shunt pipe 103 , and the interface is located between the second control valve 202 and the second filter 302 .

[0068] The circulating filtration system of this embodiment can conveniently realize the switching and backflushing of the first filter 301 and / or the second filter 302 through the arrangement of the first filter 301, the second filter 302 and various control valves without the need to introduce additional external gas, so as to effectively solve the filter clogging problem and avoid introducing impurities into the system.

[0069] As an example, the gas outlet pipeline may include a first gas outlet pipeline 106 and a second gas outlet pipeline 107 which are arranged in parallel, and a ninth control valve 209 and a tenth control valve 210 are installed on the first gas outlet pipeline 106 and the second gas outlet pipeline 107 respectively.

[0070] For details, see Figure 1 In the dotted box A in the dotted box A, in this embodiment, by setting the first gas outlet pipeline 106, the second gas outlet pipeline 107, the ninth control valve 209 and the tenth control valve 210 in the dotted box A, by switching the ninth control valve 209 and the tenth control valve 210, intermittent gas supply to the process chamber 400 can be achieved to meet the process requirements. For example, the circulating filtration system may include a circulating filtration system applied to wafer surface treatment, such as supercritical fluid drying treatment of the surface of the wafer located in the process chamber 400, but it is not limited to this. The process chamber 400 can also be set as a processing chamber with other functions according to needs, which is not overly limited here. By switching the ninth control valve 209 and the tenth control valve 210, intermittent treatment of the wafer in the process chamber 400 can be achieved.

[0071] Of course, in another embodiment, according to needs, only one air outlet pipeline can be used to replace the first air outlet pipeline 106, the second air outlet pipeline 107, the ninth control valve 209 and the tenth control valve 210 in the dotted box A, which will not be elaborated here.

[0072] As an example, the filter in the recirculating filtration system may include a filter for filtering a supercritical fluid.

[0073] Specifically, in this embodiment, the first filter 301 and the second filter 302 are filters for filtering supercritical CO2 fluid, that is, the fluid provided by the intake pipe 101 is supercritical CO2 fluid, but the type of filter 301 is not limited thereto and can be selected as needed to expand the scope of application.

[0074] As an example, the first filter 301 and the second filter 302 may have the same structure, or may be set to different structures as needed. In this embodiment, it is preferred that the first filter 301 and the second filter 302 have the same structure, so that the first filter 301 and / or the second filter 302 can both achieve filtering and backblowing functions.

[0075] As an example, pressure sensors are provided at both ends of the first filter 301 ; and / or pressure sensors are provided at both ends of the second filter 302 .

[0076] Specifically, by setting a pressure sensor, the pressure difference between the two ends of the first filter 301 and / or the second filter 302 can be obtained, so as to determine whether to start the backwash operation of the first filter 301 and / or the second filter 302. Figure 1 In this embodiment, two pressure sensors are provided, namely a first pressure sensor 501 and a second pressure sensor 502. The type, quantity, distribution position, etc. of the pressure sensors can be selected according to needs and are not excessively limited here.

[0077] As an example, each of the control valves mentioned above may include a pneumatic valve or a solenoid valve.

[0078] Specifically, each control valve in this embodiment, such as any of the first control valve 201, the second control valve 202, the third control valve 203, the fourth control valve 204, the fifth control valve 205, and the sixth control valve 206, can preferably be a pneumatic valve to avoid introducing impurities into the system, but the type of each control valve is not limited to this and can be selected according to specific needs.

[0079] As an example, the circulating filtration system may further include one or a combination of a heater 600 , a temperature sensor, a flow restrictor, and a pressure relief device.

[0080] Specifically, Figure 1 In this embodiment, there are provided a heater 600 located on the air intake pipe 101, three temperature sensors, namely, a first temperature sensor 801 located on the air intake pipe 101, a second temperature sensor 802 located on the first air outlet pipe 106, and a third temperature sensor 803 located on the second air outlet pipe 107, two flow restrictors, namely, a first flow restrictor 701 located on the air intake pipe 101 and a second flow restrictor 702 located on the first air outlet pipe 106, and two pressure relief devices, namely, a first pressure relief device 901 located at the end of the air intake pipe 101 and at the connection between the first end of the first air intake diversion pipe 102 and the head end of the second air intake diversion pipe 103, and a second pressure relief device 902 located on the first air outlet diversion pipe 104, but it is not limited thereto, and can be selected and arranged according to needs, and the specific number, type and position are not limited here.

[0081] It can be understood that the circulating filtration system may also include a controller (not shown), and the controller can communicate with the first filter 301, the second filter 302, each control valve, the heater 600, the temperature sensor, the flow limiter and the pressure relief device, so as to realize automatic control of each device through the controller to improve the convenience and accuracy of operation.

[0082] The following combination Figure 1 , the specific application of the circulating filtration system of this embodiment is explained.

[0083] Normal use and backwashing of the first filter 301:

[0084] When the first filter 301 is used normally, the first control valve 201, the third control valve 203, the ninth control valve 209 and the tenth control valve 210 are opened, and the fifth control valve 205, the sixth control valve 206, the second control valve 202 and the fourth control valve 204 are closed, and CO2 flows through the first filter 301 into the process chamber 400.

[0085] After running for a period of time, when the first pressure sensor 501 and the second pressure sensor 502 detect that the pressure difference on both sides of the first filter 301 increases, that is, the difference PS2-PS1 between the pressure PS1 measured by the first pressure sensor 501 and the pressure PS2 measured by the second pressure sensor 502 increases, it means that the first filter 301 is blocked and backblowing can be performed.

[0086] When the first filter 301 is back-flushed, the first control valve 201 is closed, and the second control valve 202 , the fourth control valve 204 and the fifth control valve 205 are opened. At this time, CO2 can back-flush the first filter 301 while flowing into the process chamber 400 through the second filter 302 .

[0087] Furthermore, the backwash pressure can be adjusted by adjusting the inlet pressure of CO 2 at the inlet of the air intake pipe 101 .

[0088] Preferably, the pressure of the process chamber 400 is adjusted when the process is in a process interval to avoid affecting the process.

[0089] Furthermore, the filter can be switched regularly for normal use and backflushing to achieve filter replacement, thereby effectively avoiding filter blockage.

[0090] Normal use and backwashing of the second filter 302:

[0091] When the second filter 302 is in normal use, the second control valve 202, the fourth control valve 204, the ninth control valve 209 and the tenth control valve 210 are opened, and the fifth control valve 205, the sixth control valve 206, the first control valve 201 and the third control valve 203 are closed, and CO2 flows through the second filter 302 into the process chamber 400.

[0092] After running for a period of time, when the first pressure sensor 501 and the second pressure sensor 502 detect that the pressure difference between the two sides of the second filter 302 increases, it means that the second filter 302 is clogged and back-blowing can be performed.

[0093] When the second filter 302 is back-flushed, the second control valve 202 is closed, and the first control valve 201 , the third control valve 203 and the sixth control valve 206 are opened. At this time, CO2 can back-flushed the second filter 302 while flowing into the process chamber 400 through the first filter 301 .

[0094] Similarly, further, the backflush pressure can be adjusted by adjusting the inlet pressure of CO2 at the inlet of the air inlet pipe 101. Preferably, the pressure is adjusted when the process chamber 400 is in a process interval to avoid affecting the process.

[0095] Embodiment 2

[0096] like Figure 2 The present embodiment provides a circulating filtering system, which is different from the first embodiment mainly in that the circulating filtering system in the present embodiment also includes a third back-blowing shunt pipe 110, which is connected to the first air outlet shunt pipe 104, and the interface is located between the first filter 301 and the third control valve 203, and the third back-blowing shunt pipe 110 is connected to the second air outlet shunt pipe 105, and the interface is located between the second filter 302 and the fourth control valve 204, and the third back-blowing shunt pipe 110 is installed with a seventh control valve 207.

[0097] Further, such as Figure 2 A flow restrictor, namely, a third flow restrictor 703, may also be installed on the third back-flushing shunt pipe 110. By adding the third flow restrictor 703, when CO2 back-flushes the filter, the impact of CO2 on the filter can be reduced to avoid damage to the filter.

[0098] The pipelines, control valves, filters, process chambers, pressure sensors, heaters, flow limiters, temperature sensors, pressure relief devices and applications provided on the circulating filtration system can be found in Example 1 and will not be elaborated here. The following only describes the normal use of the first filter 301 in the circulating filtration system of this embodiment and the specific application of backblowing.

[0099] When the first filter 301 is in normal use, the first control valve 201, the third control valve 203, the ninth control valve 209 and the tenth control valve 210 are opened, and the fifth control valve 205, the sixth control valve 206, the seventh control valve 207, the second control valve 202 and the fourth control valve 204 are closed, and CO2 flows through the first filter 301 into the process chamber 400.

[0100] After running for a period of time, when the first pressure sensor 501 and the second pressure sensor 502 detect that the pressure difference on both sides of the first filter 301 increases, it means that the first filter 301 is blocked. The second control valve 202 and the fourth control valve 204 can be opened, and the first control valve 201 and the third control valve 203 can be closed to allow CO2 to flow into the process chamber 400 through the second filter 302.

[0101] When a wafer process is completed, the fourth control valve 204 can be closed to stop supplying gas to the process chamber 400. At this time, the seventh control valve 207 and the fifth control valve 205 are opened, and CO2 is back-blown through the first filter 301 through the seventh control valve 207 and discharged from the fifth control valve 205.

[0102] When the next wafer enters the process chamber 400, the fifth control valve 205 and the seventh control valve 207 are closed to stop backblowing and continue the process.

[0103] When the gas pressure of the gas inlet channel 101 is sufficient, the gas supply to the process chamber 400 may not be stopped during backblowing, that is, the fourth control valve 204 may not be closed during backblowing, which may be selected according to needs.

[0104] Embodiment 3

[0105] like Figure 3 The present embodiment provides a circulating filtering system, which is different from the second embodiment mainly in that the circulating filtering system in the present embodiment also includes a pressure reducing pipe 111 connected to the third back-blowing shunt pipe 110 and the second air outlet shunt pipe 105, and an eighth control valve 208 is also installed on the third back-blowing shunt pipe 110, and the interface between the pressure reducing pipe 111 and the third back-blowing shunt pipe 110 is located between the seventh control valve 207 and the eighth control valve 208, and the interface between the pressure reducing pipe 111 and the second air outlet shunt pipe 105 is located at the end of the fourth control valve 204 away from the second filter 302, and a pressure reducing valve 120 is installed on the pressure reducing pipe 111.

[0106] The pipelines, control valves, filters, process chambers, pressure sensors, heaters, flow limiters, temperature sensors, pressure relief devices and applications provided on the circulating filtration system can be referred to in Example 1 or Example 2 and will not be elaborated here. Only the specific application of backflushing of the first filter 301 in the circulating filtration system of this embodiment will be described below.

[0107] When back-blowing the first filter 301, open the second control valve 202, the fourth control valve 204, the seventh control valve 207, and the fifth control valve 205, and close the first control valve 201, the third control valve 203, the sixth control valve 206, and the eighth control valve 208. CO2 passes through the second filter 302, flows into the first filter 301 through the pressure reducing valve 120 and the seventh control valve 207, and is discharged through the fifth control valve 205.

[0108] Compared with the second embodiment, the present embodiment introduces a pressure reducing valve 120, which can accurately control the purge pressure of a gas, such as CO2, so as to better protect the filter and prevent the filter from being damaged by pressure shock.

[0109] To sum up, the circulating filtration system of the present invention, through the arrangement of the first filter, the second filter and the control valve, etc., can conveniently realize the switching and backblowing of the first filter and / or the second filter without the need to introduce additional external gas, so as to effectively solve the filter clogging problem and avoid introducing impurities into the system.

[0110] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A circulating filtration system, characterized in that: The circulating filtration system comprises: a first filter, a second filter, a process chamber, an air inlet pipe, an air outlet pipe, a first control valve, a second control valve, a third control valve, a fourth control valve, a fifth control valve, a sixth control valve, a first air inlet diversion pipe, a second air inlet diversion pipe, a first air outlet diversion pipe, a second air outlet diversion pipe, a first backflush diversion pipe, and a second backflush diversion pipe; wherein, The first air intake shunt pipe, the second air intake shunt pipe, the first air outlet shunt pipe, the second air outlet shunt pipe, the first back-blowing shunt pipe and the second back-blowing shunt pipe are respectively installed with the first control valve, the second control valve, the third control valve, the fourth control valve, the fifth control valve and the sixth control valve; The air inlet pipeline is connected to the first air inlet shunt pipeline and the second air inlet shunt pipeline respectively; the first end of the air outlet pipeline is connected to the first air outlet shunt pipeline and the second air outlet shunt pipeline respectively, and the second end of the air outlet pipeline is connected to the process chamber; The first end of the first filter is connected to the first air inlet shunt pipe, and the second end of the first filter is connected to the first air outlet shunt pipe; the first end of the second filter is connected to the second air inlet shunt pipe, and the second end of the second filter is connected to the second air outlet shunt pipe; The first backflush shunt pipe is connected to the first air intake shunt pipe, and the interface is located between the first control valve and the first filter. The second backflush shunt pipe is connected to the second air intake shunt pipe, and the interface is located between the second control valve and the second filter.

2. The circulating filtration system according to claim 1, characterized in that: It also includes a third back-blow shunt pipe, which is connected to the first air outlet shunt pipe, and the interface is located between the first filter and the third control valve, and the third back-blow shunt pipe is connected to the second air outlet shunt pipe, and the interface is located between the second filter and the fourth control valve, and a seventh control valve is installed on the third back-blow shunt pipe.

3. The circulating filtration system according to claim 2, characterized in that: It also includes a pressure reducing pipeline connected to the third back-blow shunt pipeline and the second air outlet shunt pipeline, and an eighth control valve is also installed on the third back-blow shunt pipeline, the interface between the pressure reducing pipeline and the third back-blow shunt pipeline is located between the seventh control valve and the eighth control valve, the interface between the pressure reducing pipeline and the second air outlet shunt pipeline is located at the end of the fourth control valve away from the second filter, and a pressure reducing valve is installed on the pressure reducing pipeline.

4. The circulating filtration system according to claim 1, characterized in that: It also includes arranging pressure sensors at both ends of the first filter; and / or arranging pressure sensors at both ends of the second filter.

5. The circulating filtration system according to claim 1, characterized in that: The circulating filtering system further includes one or a combination of a heater, a temperature sensor, a flow restrictor and a pressure relief device.

6. The circulating filtration system according to claim 1, characterized in that: Any control valve among the first control valve, the second control valve, the third control valve, the fourth control valve, the fifth control valve and the sixth control valve includes a pneumatic valve or a solenoid valve.

7. The circulating filtration system according to claim 1, characterized in that: The filter in the circulating filtration system includes a filter for filtering supercritical fluid.

8. The circulating filtration system according to claim 1, characterized in that: The first filter and the second filter have the same structure.

9. The circulating filtration system according to any one of claims 1 to 8, characterized in that: The air outlet pipeline includes a first air outlet pipeline and a second air outlet pipeline which are arranged in parallel, and a ninth control valve and a tenth control valve are installed on the first air outlet pipeline and the second air outlet pipeline respectively.

10. The circulating filtration system according to claim 9, characterized in that: The circulating filtration system includes a circulating filtration system applied to wafer surface treatment.

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