A method for cleaning a vacuum pump

Abstract

The present invention relates to a cleaning method for a vacuum pump. Aiming at the problem of dead corners in traditional physical cleaning, residual cleaning material of a dry cleaning boat is used to etch sediments deposited in a cavity, a pipe wall and a gap of a vacuum pump, and unreacted cleaning material is reused, thereby improving the utilization rate of the cleaning gas, saving costs and ensuring excellent cleaning effects. Different connection modes of vacuum pumps to be cleaned are adopted and corresponding cleaning processes are matched, so that the method can be applicable to different application scenarios and can achieve effective cleaning of the vacuum pumps to be cleaned.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductor equipment cleaning, and in particular to a vacuum pump cleaning method. Background Art

[0002] During long-term use, vacuum pumps used in plasma enhanced chemical vapor deposition (PECVD) machines for polysilicon deposition and photovoltaic cell silicon nitride deposition will have silicon nitride and silicon oxide dust deposited on the inner cavity wall, air inlet and outlet, rotor gap, etc. The increase in dust thickness will affect the vacuum pump's evacuation effect and service life, and may even cause the rotor to get stuck, resulting in serious problems such as the vacuum pump being unable to operate normally.

[0003] At present, the cleaning and maintenance of vacuum pumps mainly use traditional physical cleaning methods, that is, after the vacuum pump is disassembled, each location where dust is deposited is physically cleaned by sandblasting. On the one hand, physical cleaning can only roughly clean the dust residue on the surface, and it is difficult to effectively clean the complex cavity wall corners and small gaps; on the other hand, during the disassembly and assembly process, the vacuum pump may be physically damaged, thus affecting its performance.

[0004] CN107574422A discloses a semiconductor production equipment and a cleaning method thereof, the cleaning method of the semiconductor production equipment comprising the following steps: rapidly cooling the temperature in the reaction chamber from a first preset temperature to a second preset temperature at a preset cooling rate, so that the thin film deposited on the side wall of the reaction chamber is cracked and peeled off under the action of thermal stress; adjusting the pressure in the reaction chamber to a periodic oscillation below the preset pressure, and using a cleaning substance to clean the reaction chamber under the above pressure conditions to discharge the peeled film particles from the reaction chamber. The invention causes the thin film deposited on the side wall of the reaction chamber to be cracked, peeled off and discharged through rapid cooling and periodic oscillation of the pressure in the chamber, but the cleaning effect of dust deposits at the corners of the chamber wall and small gaps needs to be improved.

[0005] CN109424761A discloses an isolation valve, semiconductor production equipment and a cleaning method thereof, the cleaning method comprising: providing a semiconductor production equipment, the semiconductor production equipment comprising a reaction chamber, a cleaning system, an isolation valve, a throttle valve and a vacuum pump; the cleaning system is connected to the interior of the reaction chamber, and the mounting port in the isolation valve is connected to the interior of the reaction chamber via a gas pipeline. After the deposition process is completed, the cleaning system is used to remove the residual reaction gas in the reaction chamber and the deposits on the inner wall of the reaction chamber, and at the same time, the gas purge system is used to purge the reaction products and cleaning products in the isolation valve. However, this cleaning method requires a multi-step process to clean the deposits, the process is relatively cumbersome, and the production cost is high.

[0006] Therefore, in view of the shortcomings of the prior art, there is an urgent need to provide a method for cleaning deposits in a vacuum pump with excellent effect and low cost. Summary of the invention

[0007] The purpose of the present invention is to provide a cleaning method for a vacuum pump, which effectively solves the problem that the corners and small gaps of the cavity wall of the vacuum pump are difficult to clean.

[0008] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0009] The present invention provides a method for cleaning a vacuum pump, the method comprising the following steps:

[0010] The vacuum pump to be cleaned is connected to the cleaning device, and the cavity of the cleaning device is evacuated by the vacuum pump to be cleaned, and cleaning substances are introduced into the cavity, so that the cleaning substances remaining in the cavity after the boat is washed can clean the vacuum pump to be cleaned.

[0011] The vacuum pump cleaning method provided by the present invention aims at the problem of dead corners in traditional physical cleaning. The residual cleaning material of the dry cleaning boat is used to etch the sediments deposited in the cavity, pipe wall and gap of the vacuum pump to be cleaned. The unreacted cleaning material during the boat cleaning in the cleaning device can also be reused, thereby improving the utilization rate of the cleaning gas, saving costs, and ensuring excellent cleaning effects. The cleaning gas can be NF3, CF4 or C2F6, etc. Before entering the cavity of the cleaning device, the cleaning gas is treated by RPS to generate cleaning substances including fluorine plasma and fluorine groups.

[0012] Preferably, the method of connecting the vacuum pump to be cleaned with the cleaning device includes: replacing the original process pump of the cleaning device with the vacuum pump to be cleaned and connecting it to the main evacuation pipeline of the cleaning device; or, retaining the original process pump and connecting the vacuum pump to be cleaned with the main evacuation pipeline of the cleaning device through a branch pipeline.

[0013] Preferably, when the vacuum pump to be cleaned replaces the original process pump and is connected to the evacuation main pipeline of the cleaning device, the vacuum pump to be cleaned is used to evacuate air from the cavity.

[0014] Preferably, the original process pump is retained, and when the vacuum pump to be cleaned is connected to the evacuation main pipe of the cleaning device through a branch pipe, the original process pump and the vacuum pump to be cleaned, or the vacuum pump to be cleaned, are used to evacuate the cavity; wherein, after the original process pump and the vacuum pump to be cleaned are used to evacuate the cavity, a cleaning substance can be introduced to clean the vacuum pump to be cleaned and the graphite boat in the cavity at the same time.

[0015] Preferably, the cleaning device comprises a dry cleaning station.

[0016] The present invention adopts a method of replacing the original process pump with the vacuum pump to be cleaned, which is suitable for the situation where the vacuum pump to be cleaned is less stuck. The pump to be cleaned needs to retain a certain evacuation capacity. This method does not require additional pipelines, and only requires connecting the pipes and valves of the original process pump to the vacuum pump to be cleaned; after the process is started, the cleaning material in the cavity will be pumped into the vacuum pump to be cleaned along the vacuum pipe and discharged to the exhaust gas treatment device. The original process pump can also be retained, and the vacuum pump to be cleaned can be connected through additional pipes, which is suitable for different application scenarios; in addition, the cleaning process of cleaning the vacuum pump to be cleaned alone or cleaning the vacuum pump to be cleaned and the graphite boat at the same time can be adopted, and different connection methods of the vacuum pump to be cleaned can be matched to achieve effective cleaning of the vacuum pump to be cleaned.

[0017] Preferably, before using the vacuum pump to be cleaned to evacuate the cavity of the cleaning device, the non-process pump of the cleaning device is first used to evacuate the cavity, and then the vacuum pump to be cleaned, or the vacuum pump to be cleaned and the original process pump are used to evacuate the cavity to the target vacuum degree.

[0018] Preferably, the pressure in the cavity after the non-process pump is evacuated is 160-235 torr, for example, it can be 160 torr, 170 torr, 180 torr, 190 torr, 200 torr, 210 torr, 220 torr, 230 torr or 235 torr, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0019] Preferably, the target vacuum degree is 0.01-0.3 torr, for example, 0.01 torr, 0.05 torr, 0.1 torr, 0.15 torr, 0.2 torr, 0.25 torr or 0.3 torr, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0020] When pumping air, depending on the degree of sticking of the vacuum pump to be cleaned, if the sticking degree is light, the vacuum pump to be cleaned will pump air out of the cavity alone; if the sticking degree is heavy, the original process pump and the vacuum pump to be cleaned will pump air out of the cavity at the same time.

[0021] Preferably, when the cleaning material is introduced to clean the vacuum pump to be cleaned, the flow rate of the cleaning material is 2-10SLM, for example, it can be 2SLM, 4SLM, 5SLM, 6SLM, 8SLM or 10SLM, but is not limited to the listed values. Other unlisted values ​​within the numerical range are also applicable, preferably 4-6SLM.

[0022] Preferably, the cavity pressure for cleaning the vacuum pump to be cleaned by introducing the cleaning substance is 500-4000mtorr, for example, it can be 500mtorr, 1000mtorr, 1500mtorr, 2000mtorr, 2500mtorr, 3000mtorr or 4000mtorr, but is not limited to the listed values. Other unlisted values ​​within the numerical range are also applicable, preferably 1500-2500mtorr.

[0023] Preferably, the time for introducing the cleaning substance to clean the vacuum pump to be cleaned is 30-200 minutes, for example, it can be 30 minutes, 60 minutes, 90 minutes, 120 minutes, 150 minutes, 180 minutes or 200 minutes, but is not limited to the listed values. Other unlisted values ​​within the numerical range are also applicable, preferably 60-120 minutes.

[0024] The cleaning material flow rate, pressure and time of the cleaning material for cleaning the vacuum pump to be cleaned are increased or decreased according to the operation time and the degree of pump jam of the vacuum pump to be cleaned. For example, if the operation time is long and the pump jam is serious, the cleaning material flow rate is appropriately reduced, the pressure is appropriately increased, and the cleaning time is appropriately extended.

[0025] Preferably, when the cleaning substance is introduced to clean the vacuum pump and the graphite boat simultaneously, the cleaning parameters are selected according to the type of the graphite boat, and the type of the graphite boat includes a silicon nitride deposition boat or a polysilicon deposition boat.

[0026] Preferably, when the graphite boat is a silicon nitride deposition boat, the flow rate, pressure and time of the cleaning material for simultaneously cleaning the vacuum pump to be cleaned and the graphite boat are the same as the flow rate, pressure and time of the cleaning material for cleaning the vacuum pump to be cleaned.

[0027] Preferably, when the graphite boat is a polysilicon deposition boat, the cleaning material flow rate for simultaneously cleaning the vacuum pump and the graphite boat is 2-10 SLM, the pressure is 500-4000 mtorr, and the time is 20-100 min.

[0028] The cleaning material flow rate is 2-10 SLM, for example, 2 SLM, 4 SLM, 6 SLM, 8 SLM or 10 SLM, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0029] The pressure for simultaneous cleaning is 500-4000 mtorr, for example, 500 mtorr, 1000 mtorr, 1500 mtorr, 2000 mtorr, 2500 mtorr, 3000 mtorr or 4000 mtorr, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0030] The time for simultaneous cleaning is 20-100 min, for example, 20 min, 40 min, 60 min, 80 min or 100 min, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0031] Preferably, the branch pipe comprises a corrugated pipe or an aluminum pipe. The corrugated pipe can be a KF40 corrugated pipe, or a corrugated pipe of a suitable size can be selected according to the requirements. The diameter of the aluminum pipe is 120mm-220mm, for example, it can be 120mm, 130mm, 140mm, 150mm, 160mm, 170mm, 180mm, 190mm, 200mm, 210mm or 220mm, but it is not limited to the listed values, and other values ​​not listed in the numerical range are also applicable.

[0032] Preferably, when the vacuum pump to be cleaned is connected to the evacuation main pipeline through a bellows, the bellows connects the manual valve of the evacuation main pipeline and the flange of the vacuum pump to be cleaned, and the air outlet of the vacuum pump to be cleaned is connected to the tail exhaust pipeline.

[0033] The vacuum pump to be cleaned is connected to the evacuation main pipeline through a bellows, which is suitable for situations where the vacuum pump needs frequent maintenance. By connecting a bellows to the flange of the vacuum pump to be cleaned at the position of the manual valve of the evacuation pipeline, the outlet of the vacuum pump to be cleaned is connected to the tee of the tail exhaust pipeline, thereby completing the suction and exhaust settings.

[0034] Preferably, when the vacuum pump to be cleaned is connected to the evacuation main pipeline through an aluminum pipeline, the aluminum pipeline directly connects the evacuation main pipeline and the flange of the vacuum pump to be cleaned.

[0035] Aluminum pipes are directly used to connect the main evacuation pipe to the flange of the vacuum pump to be cleaned. The advantage is that when necessary, the vacuum pump to be cleaned can be directly switched to carry out the boat washing process. Due to the thicker pipe diameter, the evacuation effect of the process is not affected.

[0036] Preferably, before using the vacuum pump to be cleaned to evacuate the cavity of the cleaning device, the non-process pump and the original vacuum pump of the cleaning device are first used to evacuate the cavity to a target vacuum degree, and then the non-process pump and the original vacuum pump are turned off, the vacuum pump to be cleaned is turned on, and then cleaning material is introduced into the cavity to clean the vacuum pump to be cleaned.

[0037] Preferably, a leak detection step is performed after the non-process pump and the original vacuum pump are evacuated and before the cleaning material is introduced.

[0038] Preferably, after the cleaning, the cleanliness of the air outlet, the air inlet and the pipe wall of the vacuum pump to be cleaned is checked.

[0039] If the cleanliness level is found to be acceptable, replace the next vacuum pump for cleaning.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] The vacuum pump cleaning method provided by the present invention aims to solve the problem of cleaning dead corners in traditional physical cleaning. The residual cleaning material of the dry cleaning boat is used to etch the sediments deposited in the vacuum pump cavity, tube wall and gap, and the unreacted cleaning material is reused, thereby improving the utilization rate of the cleaning gas, saving costs and ensuring excellent cleaning effect. Different connection methods of the vacuum pump to be cleaned are adopted, and corresponding cleaning processes are matched, which can be applicable to different application scenarios and can achieve effective cleaning of the vacuum pump to be cleaned. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a schematic diagram of the connection between the vacuum pump to be cleaned and the dry cleaning machine provided in Example 1 of the present invention;

[0043] Figure 2 is an optical image of the gas outlet of the vacuum pump to be cleaned before cleaning provided in Example 1 of the present invention;

[0044] Figure 3 is an optical image of the pipe wall of the vacuum pump to be cleaned before cleaning provided in Example 1 of the present invention;

[0045] Figure 4 is an optical image of the air outlet of the vacuum pump to be cleaned after cleaning provided in Example 1 of the present invention;

[0046] Figure 5 is an optical image of the pipe wall of the vacuum pump to be cleaned after cleaning provided in Example 1 of the present invention;

[0047] Figure 6 This is a schematic diagram of the connection between the vacuum pump to be cleaned and the dry cleaning machine provided in Example 6 of the present invention;

[0048] Figure 7 It is a schematic diagram of the connection between the vacuum pump to be cleaned and the dry cleaning machine provided in Example 8 of the present invention.

[0049] Among them: 1. Vacuum pump to be cleaned; 2. KF40 bellows; 3. Aluminum pipe. DETAILED DESCRIPTION

[0050] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0051] Example 1

[0052] This embodiment provides a vacuum pump cleaning method, the cleaning method comprising the following steps:

[0053] The vacuum pump 1 to be cleaned is replaced with the original process pump. The connection diagram of the vacuum pump 1 to be cleaned and the dry cleaning machine is as follows: Figure 1 As shown, the non-process pump is used to perform the first evacuation of the cavity until the pressure in the cavity is 200torr, and the vacuum pump 1 to be cleaned is used to perform the second evacuation of the cavity until the target vacuum degree is 0.1torr. After the leak detection, the vacuum pump 1 to be cleaned continues to evacuate, and NF3 gas is introduced to clean the vacuum pump 1 to be cleaned. The flow rate of NF3 gas is 5SLM, the pressure is 2000mtorr, and the time is 100min. The cleanliness of the air outlet, air inlet and pipe wall of the vacuum pump 1 to be cleaned is checked. The optical image of the air outlet before cleaning is as shown in FIG. Figure 2 As shown, the optical image of the tube wall is Figure 3 As shown in the figure, it can be seen that there are a lot of deposits on the outlet and the pipe wall; the optical image of the outlet after cleaning is as follows Figure 4 As shown, the optical image of the tube wall is Figure 5 As shown, it can be seen that the air outlet and the pipe wall have been cleaned and there is no sediment accumulation.

[0054] Example 2

[0055] This embodiment provides a vacuum pump cleaning method, the cleaning method comprising the following steps:

[0056] Replace the original process pump with the vacuum pump to be cleaned, and use the non-process pump to perform the first evacuation of the cavity until the pressure in the cavity reaches 160torr, and use the vacuum pump 1 to be cleaned to perform the second evacuation of the cavity until the target vacuum degree is 0.01torr. After leak detection, the vacuum pump 1 to be cleaned continues to evacuate, and CF4 is introduced and ionized to clean the vacuum pump 1. The flow rate of CF4 is 4SLM, the pressure is 2500mtorr, and the time is 120min. Check that the air outlet, air inlet and pipe wall of the vacuum pump 1 to be cleaned are relatively clean, and there is no sediment accumulation.

[0057] Example 3

[0058] This embodiment provides a vacuum pump cleaning method, the cleaning method comprising the following steps:

[0059] Replace the original process pump with the vacuum pump to be cleaned, and use the non-process pump to perform the first evacuation of the cavity until the pressure in the cavity reaches 235torr, and use the vacuum pump 1 to be cleaned to perform the second evacuation of the cavity until the target vacuum degree is 0.3torr. After leak detection, the vacuum pump 1 to be cleaned continues to evacuate, and C2F6 is introduced to clean the vacuum pump 1 after ionization. The flow rate of C2F6 is 6SLM, the pressure is 1500mtorr, and the time is 60min. Check that the air outlet, air inlet and pipe wall of the vacuum pump 1 to be cleaned are relatively clean without sediment accumulation.

[0060] Example 4

[0061] This embodiment provides a method for cleaning a vacuum pump, which is different from Embodiment 1 in that, except that the flow rate of NF3 is adjusted to 2SLM, the pressure is adjusted to 4000mtorr, and the time is adjusted to 200min, the rest is the same as Embodiment 1.

[0062] Example 5

[0063] This embodiment provides a method for cleaning a vacuum pump, which is different from Embodiment 1 in that, except that the flow rate of NF3 is adjusted to 10 SLM, the pressure is adjusted to 500 mtorr, and the time is adjusted to 30 min, the rest is the same as Embodiment 1.

[0064] Example 6

[0065] This embodiment provides a vacuum pump cleaning method, the cleaning method comprising the following steps:

[0066] Keep the original process pump, connect the vacuum pump 1 to be cleaned to the main evacuation pipeline of the dry cleaning machine through the KF40 bellows 2. The connection diagram of the vacuum pump 1 to be cleaned and the dry cleaning machine is as follows: Figure 6 As shown, the KF40 bellows 2 connects the manual valve of the evacuation main pipeline with the flange of the vacuum pump 1 to be cleaned, and the air outlet of the vacuum pump 1 to be cleaned is connected with a tail exhaust pipeline.

[0067] The non-process pump is used to perform the first evacuation of the cavity until the pressure in the cavity is 200torr, and the original process pump and the vacuum pump 1 to be cleaned are used to perform the second evacuation of the cavity until the target vacuum degree is 0.1torr. After leak detection, the vacuum pump 1 to be cleaned and the original process pump are opened for evacuation, and NF3 is introduced and ionized to clean the vacuum pump 1 to be cleaned and the graphite boat for silicon nitride deposition at the same time. The flow rate of NF3 is 5SLM, the pressure is 2000mtorr, and the time is 100min. Check that the air outlet, air inlet and pipe wall of the vacuum pump 1 to be cleaned are at a high level of cleanliness without sediment accumulation.

[0068] Example 7

[0069] This embodiment provides a vacuum pump cleaning method, the cleaning method comprising the following steps:

[0070] The original process pump is retained, and the vacuum pump 1 to be cleaned is connected to the evacuation main pipeline through the KF40 bellows 2. The KF40 bellows 2 connects the manual valve of the evacuation main pipeline and the flange of the vacuum pump 1 to be cleaned. The air outlet of the vacuum pump 1 to be cleaned is connected to the tail exhaust pipe.

[0071] The non-process pump is used to perform the first evacuation of the cavity until the pressure in the cavity is 200torr, and the original process pump and the vacuum pump 1 to be cleaned are used to perform the second evacuation of the cavity until the target vacuum degree is 0.1torr. After leak detection, the vacuum pump 1 to be cleaned and the original process pump are opened for evacuation, and NF3 is introduced and ionized to clean the vacuum pump 1 to be cleaned and the graphite boat for polysilicon deposition at the same time. The flow rate of NF3 is 5SLM, the pressure is 2000mtorr, and the time is 60min. Check that the air outlet, air inlet and pipe wall of the vacuum pump 1 to be cleaned are at a high level of cleanliness without sediment accumulation.

[0072] Example 8

[0073] This embodiment provides a vacuum pump cleaning method, the cleaning method comprising the following steps:

[0074] The original process pump is retained, and the vacuum pump 1 to be cleaned is connected to the main evacuation pipeline of the dry cleaning machine through the aluminum pipe 3. The connection diagram of the vacuum pump 1 to be cleaned and the dry cleaning machine is as shown in the figure. Figure 7 As shown, the aluminum pipe 3 is directly connected to the evacuation main pipe and the flange of the vacuum pump 1 to be cleaned.

[0075] The non-process pump is used to perform the first evacuation of the cavity until the pressure in the cavity is 200torr, and the original process pump is used to perform the second evacuation of the cavity to the target vacuum degree of 0.1torr. The non-process pump and the original process pump are turned off. Then, the vacuum pump 1 to be cleaned is opened for evacuation, and NF3 is introduced for ionization to clean the vacuum pump 1 to be cleaned. The flow rate of NF3 is 5SLM, the pressure is 2000mtorr, and the time is 100min. Check that the air outlet, air inlet and pipe wall of the vacuum pump 1 to be cleaned are at a high level of cleanliness without sediment accumulation.

[0076] Comparative Example 1

[0077] This comparative example provides a method for cleaning a vacuum pump, the cleaning method comprising: disassembling the vacuum pump to be cleaned, and performing sandblasting cleaning on each location where dust is deposited.

[0078] This comparative example adopts a physical cleaning method to clean the vacuum pump to be cleaned. Inspection shows that the cleanliness level of the air outlet, air inlet and pipe wall of the vacuum pump to be cleaned is low, and some sediments are still accumulated. In addition, during the disassembly and assembly process, physical damage may be caused to the vacuum pump to be cleaned, thereby affecting its performance.

[0079] To sum up, the vacuum pump cleaning method provided by the present invention aims to solve the problem of dead corners in traditional physical cleaning. The residual cleaning material of the dry cleaning boat is used to etch the sediments deposited in the vacuum pump cavity, tube wall and gap, and the unreacted cleaning material is reused, thereby improving the utilization rate of the cleaning gas, saving costs and ensuring excellent cleaning effect. Different connection methods of the vacuum pump to be cleaned are adopted, and the corresponding cleaning processes are matched, which can be suitable for different application scenarios and can achieve effective cleaning of the vacuum pump to be cleaned.

[0080] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for cleaning a vacuum pump, characterized in that: The cleaning method comprises the following steps: The vacuum pump to be cleaned is connected to the cleaning device, and the cavity of the cleaning device is evacuated by the vacuum pump to be cleaned, and cleaning substances are introduced into the cavity, so that the cleaning substances remaining in the cavity after the boat is washed can clean the vacuum pump to be cleaned.

2. The cleaning method according to claim 1, characterized in that: The method for connecting the vacuum pump to be cleaned with the cleaning device includes: replacing the original process pump of the cleaning device with the vacuum pump to be cleaned and connecting it to the main evacuation pipeline of the cleaning device; or, retaining the original process pump and connecting the vacuum pump to be cleaned with the main evacuation pipeline of the cleaning device through a branch pipeline.

3. The cleaning method according to claim 2, characterized in that: When the vacuum pump to be cleaned replaces the original process pump and is connected to the main evacuation pipeline of the cleaning device, the vacuum pump to be cleaned is used to evacuate the air in the cavity; Preferably, the original process pump is retained, and when the vacuum pump to be cleaned is connected to the evacuation main pipe of the cleaning device through a branch pipe, the original process pump and the vacuum pump to be cleaned, or the vacuum pump to be cleaned, are used to evacuate the cavity; wherein, after the original process pump and the vacuum pump to be cleaned are used to evacuate the cavity, a cleaning substance can be introduced to clean the vacuum pump to be cleaned and the graphite boat in the cavity at the same time.

4. The cleaning method according to claim 3, characterized in that: Before using the vacuum pump to be cleaned to evacuate the cavity of the cleaning device, first use the non-process pump of the cleaning device to evacuate the cavity, and then use the vacuum pump to be cleaned, or the vacuum pump to be cleaned and the original process pump to evacuate the cavity to the target vacuum degree; Preferably, the pressure in the cavity after the non-process pump is evacuated is 160-235 torr; Preferably, the target vacuum degree is 0.01-0.3 torr; Preferably, when the cleaning material is extracted by the vacuum pump to be cleaned, the original process pump is turned on; Preferably, when the cleaning substance is introduced to clean the vacuum pump to be cleaned, the flow rate of the cleaning substance is 2-10 SLM, preferably 4-6 SLM; Preferably, the cavity pressure for cleaning the vacuum pump to be cleaned by introducing the cleaning substance is 500-4000mtorr, preferably 1500-2500mtorr; Preferably, the time for introducing the cleaning substance to clean the vacuum pump to be cleaned is 30-200 minutes, preferably 60-120 minutes.

5. The cleaning method according to claim 3, characterized in that: When the cleaning material is introduced to clean the vacuum pump and the graphite boat simultaneously, the cleaning parameters are selected according to the type of the graphite boat, which includes a silicon nitride deposition boat or a polysilicon deposition boat.

6. The cleaning method according to claim 5, characterized in that: When the graphite boat is a polysilicon deposition boat, the cleaning material flow rate for simultaneously cleaning the vacuum pump and the graphite boat is 2-10 SLM, the pressure is 500-4000 mtorr, and the time is 20-100 min.

7. The cleaning method according to claim 3, characterized in that: The branch pipe includes a corrugated pipe or an aluminum pipe.

8. The cleaning method according to claim 7, characterized in that: When the vacuum pump to be cleaned is connected to the evacuation main pipeline through a bellows, the bellows connects the manual valve of the evacuation main pipeline and the flange of the vacuum pump to be cleaned, and the air outlet of the vacuum pump to be cleaned is connected to the tail exhaust pipeline.

9. The cleaning method according to claim 7, characterized in that: When the vacuum pump to be cleaned is connected to the evacuation main pipeline through the aluminum pipeline, the aluminum pipeline directly connects the evacuation main pipeline and the flange of the vacuum pump to be cleaned.

10. The cleaning method according to any one of claims 1 to 3, characterized in that: Before using the vacuum pump to be cleaned to evacuate the cavity of the cleaning device, first use the non-process pump and the original vacuum pump of the cleaning device to evacuate the cavity to a target vacuum degree, then turn off the non-process pump and the original vacuum pump, then turn on the vacuum pump to be cleaned, and then introduce a cleaning substance into the cavity to clean the vacuum pump to be cleaned; Preferably, a leak detection step is performed after the non-process pump and the original vacuum pump are evacuated and before the cleaning material is introduced; Preferably, after the cleaning, the cleanliness of the air outlet, the air inlet and the pipe wall of the vacuum pump to be cleaned is checked.

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