Vacuum system and operation method thereof

Abstract

The invention provides a vacuum system and a method for operating the vacuum system, the vacuum system comprises an outer cavity and a plurality of inner cavities, the plurality of inner cavities are located in the outer cavity, the plurality of inner cavities comprise a first inner cavity and a second inner cavity, the first inner cavity and the second inner cavity are communicated through a first hole, and the second inner cavity is located in the outer cavity. A second hole capable of being opened and closed is formed in the second inner cavity, and the second inner cavity is communicated with the outer cavity through the second hole; the first vacuum pump is used for vacuumizing the outer cavity; the second vacuum pump is used for vacuumizing the first inner cavity; and the third vacuum pump is used for vacuumizing the second inner cavity. The vacuum system provided by the invention can improve the process integration level and the vacuum stability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vacuum systems, in particular to a vacuum system and an operating method thereof. BACKGROUND

[0002] In the semiconductor industry, some experiments or processes need to be carried out in a multi-stage differential vacuum environment. The vacuum cavity provided by the prior art is maintained by a single-stage differential pipe, without vacuum transition, and is prone to high-vacuum cavity vacuum failure under high pressure difference due to permeation and other reasons, and does not have high-vacuum stability. SUMMARY

[0003] The present application provides a vacuum system and an operating method thereof, which can complete multi-nested vacuum differential through a group of vacuum cavities, improve process integration and vacuum stability.

[0004] In a first aspect, a vacuum system is provided, comprising: an outer cavity and a plurality of inner cavities, the plurality of inner cavities being located inside the outer cavity, the plurality of inner cavities comprising a first inner cavity and a second inner cavity, the first inner cavity and the second inner cavity being in communication through a first hole, the second inner cavity being provided with an openable and closable second hole, the second inner cavity being in communication with the outer cavity through the second hole; a first vacuum pump for performing vacuum pumping operation on the outer cavity; a second vacuum pump for performing vacuum pumping operation on the first inner cavity; and a third vacuum pump for performing vacuum pumping operation on the second inner cavity.

[0005] The present application provides a vacuum system, a plurality of inner cavities can form a multi-stage differential vacuum environment, and the plurality of inner cavities are located inside the outer cavity. Since the outer cavity is also a vacuum environment, even if the vacuum of a certain inner cavity is destroyed, it will not have too much impact on other inner cavities, improving the vacuum stability. At the same time, the present application can complete multi-nested vacuum differential through a group of vacuum cavities, improving the process integration and saving the hardware cost.

[0006] In some possible application scenarios, the first hole and the second hole can also be referred to as an aperture, a small hole, a slit or a differential hole, which essentially is a hole with a size less than a certain threshold, and the specific name should not be understood as a limitation on the present application.

[0007] Optionally, the plurality of inner cavities can further comprise at least one third inner cavity in communication with the first inner cavity and the second inner cavity through a hole, and the vacuum system can further comprise at least one vacuum pump corresponding to the at least one third inner cavity for performing vacuum pumping operation on the third inner cavity.

[0008] Optionally, the outer cavity can comprise a plurality of inner cavity groups, and each inner cavity group can comprise the plurality of inner cavities.

[0009] Exemplarily, the openable and closable second hole can be implemented by a vacuum gate valve, or can be implemented by a movable cover plate and a lock, and the specific implementation mode should not be understood as a limitation to the present application.

[0010] The types of the first vacuum pump, the second vacuum pump and the third vacuum pump can be the same or different. Exemplarily, the first vacuum pump, the second vacuum pump and the third vacuum pump can be a molecular pump, an ion pump or a cryogenic pump, etc.

[0011] In some possible application scenarios, when the vacuum of the outer cavity is destroyed, the second hole can be closed to avoid the vacuum of the inner cavity being destroyed. When the inner cavity is subjected to a vacuumizing operation, the second hole can also be closed to improve the vacuumizing efficiency of the inner cavity. When some experimental or detection scenarios require an electron beam to pass through the second hole, the second hole can be opened to allow the electron beam to pass through.

[0012] With reference to the first aspect, in some implementations of the first aspect, the second inner cavity is provided with a vacuum gate valve, and the vacuum gate valve is configured to open and close the second hole.

[0013] The present application provides a vacuum system, and the second hole can be implemented by a vacuum gate valve, which is flexible in opening and closing and has good air-tightness.

[0014] With reference to the first aspect, in some implementations of the first aspect, the vacuum gate valve is driven by a piezoelectric ceramic motor.

[0015] The present application provides a vacuum system, and the vacuum gate valve can be driven by a piezoelectric ceramic motor, which does not involve air compression or motor lubrication and can operate in a high-vacuum environment.

[0016] With reference to the first aspect, in some implementations of the first aspect, a fourth vacuum pump is further included, which is connected to the first inner cavity and the second inner cavity and is configured to simultaneously perform a vacuumizing operation on the first inner cavity and the second inner cavity.

[0017] In some possible application scenarios, the fourth vacuum pump can simultaneously perform a pre-evacuation on the first inner cavity and the second inner cavity. Exemplarily, the fourth vacuum pump is configured to reduce the air pressure of the first inner cavity and the second inner cavity from normal atmospheric pressure to 10E -1 Pa, and the second vacuum pump and the third vacuum pump can maintain the vacuum degree of the first inner cavity and the second inner cavity at 10E -8 Pa to 10E -1 Pa.

[0018] In some possible application scenarios, the vacuum system can include multiple fourth vacuum pumps, for example, one fourth vacuum pump is a dry pump and one fourth vacuum pump is a molecular pump.

[0019] The application provides a vacuum system, which can simultaneously pre-evacuate the first inner cavity and the second inner cavity through the fourth vacuum pump, and improves the vacuum efficiency of the vacuum system.

[0020] In some implementations of the first aspect, the first vacuum pump is connected to the outer cavity through a first pipe, the second vacuum pump is connected to the first inner cavity through a second pipe, and the third vacuum pump is connected to the second inner cavity through a third pipe.

[0021] In some implementations of the first aspect, at least one valve is arranged on the first pipe, the second pipe, or the third pipe.

[0022] The application provides a vacuum system, in which a valve is arranged on the pipe connecting the vacuum pump and the inner cavity or the outer cavity, so that the air tightness of the inner cavity and the outer cavity is ensured.

[0023] In some implementations of the first aspect, the vacuum system further comprises a vacuum gauge connected to the first inner cavity and / or the second inner cavity, and used for measuring the vacuum degree of the first inner cavity and / or the second inner cavity.

[0024] In some implementations of the first aspect, a baking unit is arranged on the cavity wall of the outer cavity and / or any one of the plurality of inner cavities, and the baking unit is used for heating the outer cavity and / or the any one of the inner cavities.

[0025] The application provides a vacuum system, in which a baking unit can be used to heat the outer cavity and / or any one of the inner cavities during the vacuum operation, so that the exhaust speed is accelerated and the vacuum efficiency is improved.

[0026] In some implementations of the first aspect, the vacuum system can be applied to an electron beam device, the electron beam device comprising a filament and a displacement table, the filament being located in the first inner cavity, and the displacement table being located in the outer cavity, the filament being used for emitting an electron beam, and the electron beam passing through the first hole and the second hole to reach the displacement table.

[0027] In some possible application scenarios, the electron beam device can comprise an electron beam detection device, an electron beam etching device, or the like. The electron beam device can comprise various types of electron sources, such as a hot ion cathode electron source, a Schottky electron source, or a cold field emission electron source, or the like. The electron source comprises a filament, and the filament is used for emitting an electron beam. The displacement table is used for placing an object to be detected or an object to be etched. For the object to be detected, the object to be detected can be scanned by using the electron beam, so that the image of the secondary electron imaging of the object to be detected can be obtained, and the abnormal points in the image can be found out by using a computer vision technology. The electron beam can also be used for etching the object to be etched.

[0028] In some possible application scenarios, the first hole, the second hole and the displacement table can be located on the same straight line.

[0029] In some possible application scenarios, the vacuum degree of the first inner cavity is higher than or equal to the vacuum degree of the second inner cavity, and the vacuum degree of the second inner cavity is higher than or equal to the vacuum degree of the outer cavity.

[0030] The application provides a vacuum system, which can be applied to an electron beam detection device. A plurality of inner cavities are located inside an outer cavity. Since the outer cavity is also a vacuum environment, even if the vacuum of a certain inner cavity is destroyed, other inner cavities will not be excessively affected, the vacuum stability is improved, and the working environment of the electron beam detection device is ensured.

[0031] In a second aspect, an operation method of a vacuum system is provided. The vacuum system includes an outer cavity, a plurality of inner cavities, a first vacuum pump, a second vacuum pump and a third vacuum pump. The plurality of inner cavities are located inside the outer cavity. The plurality of inner cavities include a first inner cavity and a second inner cavity. The first inner cavity and the second inner cavity are in communication through a first hole. The second inner cavity is provided with an openable and closable second hole. The second inner cavity is in communication with the outer cavity through the second hole. The first vacuum pump is used for performing a vacuumizing operation on the outer cavity. The second vacuum pump is used for performing a vacuumizing operation on the first inner cavity. The third vacuum pump is used for performing a vacuumizing operation on the second inner cavity. The method includes: closing the second hole; and starting the first vacuum pump, the second vacuum pump and the third vacuum pump.

[0032] Optionally, the first vacuum pump, the second vacuum pump and the third vacuum pump can be started simultaneously or not simultaneously. The application does not limit the starting order of the first vacuum pump, the second vacuum pump and the third vacuum pump.

[0033] The application provides an operation method of a vacuum system. A plurality of inner cavities can form a plurality of differential vacuum environments, and the plurality of inner cavities are located inside an outer cavity. Since the outer cavity is also a vacuum environment, even if the vacuum of a certain inner cavity is destroyed, other inner cavities will not be excessively affected, the vacuum stability is improved. Meanwhile, the application can complete multi-nested vacuum differential through a group of vacuum cavities, improve the process integration, and save the hardware cost.

[0034] In combination with the second aspect, in some implementations of the second aspect, the second inner cavity is provided with a vacuum gate valve, the vacuum gate valve is used for opening and closing the second hole, and the closing of the second hole includes: closing the second hole by driving the vacuum gate valve through a piezoelectric ceramic motor.

[0035] The application provides an operation method of a vacuum system. The vacuum gate valve can be driven by a piezoelectric ceramic motor, air compression or motor lubrication is not involved, and the vacuum gate valve can operate in a high-vacuum environment.

[0036] With reference to the second aspect, in some implementations of the second aspect, the first vacuum pump is connected to the outer cavity through a first pipe, the second vacuum pump is connected to the first inner cavity through a second pipe, and the third vacuum pump is connected to the second inner cavity through a third pipe, and at least one valve is arranged on the first pipe, the second pipe, and the third pipe, and the starting of the first vacuum pump, the second vacuum pump, and the third vacuum pump comprises starting the at least one valve on the first pipe, the second pipe, and the third pipe, and simultaneously starting the first vacuum pump, the second vacuum pump, and the third vacuum pump.

[0037] With reference to the second aspect, in some implementations of the second aspect, the vacuum system further comprises a fourth vacuum pump connected to the first inner cavity and the second inner cavity, and before the starting of the first vacuum pump, the second vacuum pump, and the third vacuum pump, the method further comprises starting the fourth vacuum pump.

[0038] In some possible application scenarios, the fourth vacuum pump can simultaneously pre-evacuate the first inner cavity and the second inner cavity. For example, the fourth vacuum pump is used to reduce the air pressure of the first inner cavity and the second inner cavity from normal atmospheric pressure to 10E -1 Pa, and the second vacuum pump and the third vacuum pump can maintain the vacuum degree of the first inner cavity and the second inner cavity between 10E -8 Pa and 10E -1 Pa.

[0039] In some possible application scenarios, the vacuum system can comprise a plurality of fourth vacuum pumps, for example, one fourth vacuum pump is a dry pump, and one fourth vacuum pump is a molecular pump.

[0040] The present application provides an operation method of a vacuum system, which can simultaneously pre-evacuate the first inner cavity and the second inner cavity through the fourth vacuum pump, thereby improving the process integration of the vacuum system.

[0041] With reference to the second aspect, in some implementations of the second aspect, the fourth vacuum pump is connected to the second pipe and the third pipe through a fourth pipe, and a first valve is arranged on the fourth pipe, and after the starting of the fourth vacuum pump, before the starting of the first vacuum pump, the second vacuum pump, and the third vacuum pump, the method further comprises closing the fourth vacuum pump, and closing the first valve to make the second pipe and the third pipe not connected to each other.

[0042] The application provides an operating method of a vacuum system, a first valve is arranged on a fourth pipeline, when the first valve is opened, pre-evacuation can be simultaneously performed on a first inner cavity and a second inner cavity through a fourth vacuum pump, when the first valve is closed, the first inner cavity and the second inner cavity form a differential vacuum environment through different vacuum pumps.

[0043] With reference to the second aspect, in some implementations of the second aspect, a baking unit is arranged on a cavity wall of the outer cavity and / or any one of the plurality of inner cavities, the baking unit is used for heating the outer cavity and / or the any one of the inner cavities, and the method further comprises: starting the baking unit.

[0044] The application provides an operating method of a vacuum system, when vacuumizing operation is performed, a baking unit can be used for heating the outer cavity and / or any one of the inner cavities, so that the exhaust speed is accelerated, and the vacuumizing efficiency is improved. BRIEF DESCRIPTION OF DRAWINGS

[0045] Figure 1 is a schematic diagram of a vacuum system applied to an electron beam detection device according to an embodiment of the application.

[0046] Figure 2 is a schematic structural diagram of a vacuum system according to an embodiment of the application.

[0047] Figure 3 is a schematic structural diagram of another vacuum system according to an embodiment of the application.

[0048] Figure 4 is a schematic structural diagram of another vacuum system according to an embodiment of the application.

[0049] Figure 5 is an example flowchart of an operating method of a vacuum system according to an embodiment of the application.

[0050] Figure 6 is a schematic structural diagram of another vacuum system according to an embodiment of the application.

[0051] Figure 7 is an example flowchart of an operating method of another vacuum system according to an embodiment of the application.

[0052] Figure 8 is a schematic structural diagram of another vacuum system according to an embodiment of the application.

[0053] Figure 9 is a schematic structural diagram of another vacuum system according to an embodiment of the application.

[0054] Figure 10 is a schematic structural diagram of another vacuum system according to an embodiment of the application.

[0055] Figure 11 FIG. 14 is a schematic diagram of a simulation result of a vacuum system according to an embodiment of the present application. DETAILED DESCRIPTION

[0056] With reference to the accompanying drawings, the technical solutions in the embodiments of the present application will be described below. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of the present application.

[0057] In the present application, the words "example" and "for example" are used to mean serving as an instance, illustration, or demonstration. Any embodiment or design presented as an "example" in the present application should not be interpreted as being more preferable or advantageous than other embodiments or designs. In fact, the word "example" is used to present concepts in a concrete manner.

[0058] The business scenarios described in the embodiments of the present application are used to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation to the technical solutions provided by the embodiments of the present application. Those skilled in the art can know that, as new business scenarios appear, the technical solutions provided by the embodiments of the present application are also applicable to similar technical problems.

[0059] In the present specification, the reference "one embodiment" or "some embodiments" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present application. Therefore, the statements "in one embodiment", "in some embodiments", "in other embodiments", "in additional embodiments", etc. appearing in various places in the present specification are not necessarily all referring to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically stated. The terms "comprise", "include", "have", and their conjugates mean "including but not limited to", unless otherwise specifically stated.

[0060] In this application, "at least one" means one or more, and "multiple" means two or more. The association relationship of "and / or" describing the associated objects indicates that there can be three kinds of relationships, for example, A and / or B can represent the following three cases: A exists alone, A and B exist together, and B exists alone, where A and B can be singular or plural. The character " / " generally represents an "or" relationship between the front and rear associated objects. "At least one of the following" or similar expressions means any combination of these items, including any combination of single or multiple items. For example, at least one of a, b, or c can represent a, b, c, a-b, a-c, b-c, or a-b-c, where a, b, and c can be single or multiple.

[0061] To facilitate understanding of the embodiments of the present application, first, some definitions involved in the present application are briefly explained.

[0062] 1. Flange connection: two pipes, fittings or equipment are fixed on a flange plate respectively, and flange gaskets are added between the two flange plates, which are fastened together with bolts to complete the connection. Some fittings and equipment have flange plates, which also belong to flange connection.

[0063] 2. Vacuum gauge: an instrument used to measure and monitor the degree of vacuum. It is a pressure measuring device specifically designed to measure the pressure of gas in a very low pressure or vacuum state.

[0064] 3. Vacuum gate valve: a mechanical device used in vacuum systems to control the flow of gas into and out of a vacuum chamber. It consists of a sliding door or plate that can be moved to block or allow passage through the vacuum valve body, effectively isolating the chamber from the external environment, and can also be used to control airflow.

[0065] 4. Degree of vacuum: refers to the thinness of gas in a vacuum state.

[0066] In the semiconductor industry, some experiments or processes need to be carried out at different degrees of vacuum. For example, the filament and displacement table of a metrology machine and an electron beam etching machine need to work at different degrees of vacuum. The vacuum chamber provided by the prior art maintains the vacuum difference by a single-stage differential tube without vacuum transition, and under high pressure difference conditions, high vacuum chamber vacuum failure is easily caused by permeation and other reasons, and it does not have high vacuum stability.

[0067] The present application provides a vacuum system, multiple inner cavities can form a multi-stage differential vacuum environment, and the multiple inner cavities are located inside the outer cavity. Since the outer cavity is also a vacuum environment, even if the vacuum of a certain inner cavity is destroyed, it will not have much impact on other inner cavities, improving the vacuum stability. At the same time, the present application can complete multi-nested vacuum difference through a group of vacuum cavities, improving the process integration and saving hardware costs.

[0068] The vacuum system provided by the embodiments of the present application can be applied to an electron beam device. The electron beam device can include an electron beam detection device, an electron beam etching device, etc. The electron beam device can include various types of electron sources, such as a hot cathode electron source, a Schottky electron source, or a cold field emission (CFE) electron source, etc. The electron source includes a filament for emitting an electron beam, and a displacement table for placing an object to be detected or an object to be etched. For the object to be detected, the object to be detected is scanned by an electron beam, and an image of secondary electron imaging of the object to be detected can be obtained, and an abnormal point in the image can be found out by computer vision technology. The electron beam can also etch the object to be etched. The vacuum system provided by the embodiments of the present application can meet the multi-vacuum gradient scenarios of the filament and the displacement table by making multi-level differences inside the vacuum system.

[0069] Figure 1 FIG. 1 is a schematic diagram of a vacuum system provided by an embodiment of the present application applied to an electron beam detection device.

[0070] The electron beam detection device is mainly used for detecting the performance and defects of a wafer or a photomask in a semiconductor manufacturing process. The detection method of the electron beam detection device is to scan a wafer or a photomask to be detected by an electron beam, obtain an image of secondary electron imaging of the wafer or the photomask, and find out an abnormal point in the image by computer vision technology.

[0071] The electron beam detection device can include various types of electron sources, such as a hot cathode electron source, a Schottky electron source, or a cold field emission (CFE) electron source, etc. The filament 110 of the electron source is located in a first vacuum chamber 130, and is used for emitting an electron beam. The electron beam passes through an aperture 120 and a second vacuum chamber 140, and is emitted onto a wafer or a photomask to be detected, which is placed on a displacement table 150.

[0072] Figure 2 FIG. 2 is a schematic structural diagram of a vacuum system provided by an embodiment of the present application.

[0073] The vacuum system includes an outer chamber 210 and a plurality of inner chambers, and the plurality of inner chambers are located inside the outer chamber 210. The plurality of inner chambers include a first inner chamber 221 and a second inner chamber 222, that is, the first inner chamber 221 and the second inner chamber 222 can both be referred to as inner chambers. The first inner chamber 221 and the second inner chamber 222 are communicated through a first hole 230, and the second inner chamber is provided with an openable and closable second hole 240. The second inner chamber 222 is communicated with the outer chamber 210 through the second hole 240.

[0074] The first vacuum pump P1 is configured to perform vacuumizing operation on the outer cavity 210, the second vacuum pump P2 is configured to perform vacuumizing operation on the first inner cavity 221, and the third vacuum pump P3 is configured to perform vacuumizing operation on the second inner cavity 222.

[0075] In some possible application scenarios, the first hole 230 and the second hole 240 can also be referred to as an aperture, a pinhole, a slit, or a differential hole, which essentially refers to a hole with a size less than a certain threshold, and the specific name should not be construed as a limitation to the present application.

[0076] Exemplarily, the openable and closable second hole 240 can be implemented by a vacuum gate valve, or can be implemented by a movable cover plate and a lock, and the specific implementation manner should not be construed as a limitation to the present application.

[0077] The types of the first vacuum pump P1, the second vacuum pump P2, and the third vacuum pump P3 can be the same or different. Exemplarily, the first vacuum pump P1, the second vacuum pump P2, and the third vacuum pump P3 can be a molecular pump, an ion pump, or a cryogenic pump, etc.

[0078] In some possible application scenarios, when the vacuum of the outer cavity 210 is destroyed, the second hole 240 can be closed to avoid the vacuum of the inner cavity being destroyed. When performing vacuumizing operation on the inner cavity, the second hole 240 can also be closed to improve the vacuumizing efficiency of the inner cavity. When the electron beam needs to pass through the second hole 240 in some experimental or detection scenarios, the second hole 240 can be opened to allow the electron beam to pass through.

[0079] Figure 3 is a schematic structural diagram of another vacuum system provided by an embodiment of the present application. Figure 3 Similarly, Figure 2 Similarly, the plurality of inner cavities can also include at least one third inner cavity 223 in addition to the first inner cavity 221 and the second inner cavity 222, and the third inner cavity 223 is in communication with other inner cavities through a hole. It should be understood that the specific number of inner cavities can be set according to requirements, and the diagram should not be construed as a limitation to the present application. Other structures can be referred to the description in Figure 2 , and the present application will not be repeated here.

[0080] Figure 4 is a schematic structural diagram of another vacuum system provided by an embodiment of the present application. Figure 4 Similarly, Figure 2 , Figure 3Similarly, the outer cavity 210 can include a plurality of inner cavity groups, each of which includes a plurality of inner cavities. For example, a first inner cavity group includes a first inner cavity 221, a second inner cavity 222, and a third inner cavity 223, and a second inner cavity group includes a first inner cavity 224 and a second inner cavity 225. A vacuum pump P21 is used to perform a vacuumizing operation on the first inner cavity 224, and a vacuum pump P31 is used to perform a vacuumizing operation on the second inner cavity 225. Other structures can be described in Figure 2 and Figure 3 , which will not be repeated here.

[0081] Figure 5 is an exemplary flowchart of an operating method of a vacuum system provided by an embodiment of the present application. Figure 5 The operating method of Figure 2 , the vacuum system shown in Figure 3 , and the operating method of the vacuum system shown in Figure 4 are similar to Figure 5 , which will not be repeated here.

[0082] 510, close the second hole.

[0083] In some possible implementations, the second inner cavity 222 is provided with a vacuum gate valve for opening and closing the second hole 240. The vacuum gate valve can be driven to close the second hole 240 by a piezoelectric ceramic motor in an embodiment of the present application.

[0084] 520, open P1, P2, and P3.

[0085] Optionally, the first vacuum pump P1, the second vacuum pump P2, and the third vacuum pump P3 can be opened simultaneously or not simultaneously, and the order of opening the first vacuum pump P1, the second vacuum pump P2, and the third vacuum pump P3 is not limited in an embodiment of the present application.

[0086] Continuously opening the first vacuum pump P1 can keep the vacuum degree of the outer cavity 210 within a certain range, continuously opening the second vacuum pump P2 can keep the vacuum degree of the first inner cavity 221 within a certain range, and continuously opening the third vacuum pump P3 can keep the vacuum degree of the second inner cavity 222 within a certain range.

[0087] In some possible application scenarios, the vacuum degree of the first inner cavity 221 is higher than or equal to the vacuum degree of the second inner cavity 222, and the vacuum degree of the second inner cavity 222 is higher than or equal to the vacuum degree of the outer cavity 210.

[0088] Figure 6 is another schematic structural diagram of a vacuum system provided by an embodiment of the present application.

[0089] The vacuum system includes an outer chamber 210, a first inner chamber 221, a second inner chamber 222, vacuum pumps P1-P5, a vacuum gate valve 280, a vacuum gauge G1, and valves V1-V7.

[0090] The first inner chamber 221 and the second inner chamber 222 are in communication through a first hole 230. The filament 110 is disposed in the first inner chamber 221. The first inner chamber 221 and the second inner chamber 222 can be collectively referred to as an inner chamber. The first inner chamber 221 and the second inner chamber 222 are located inside the outer chamber 210. A baking unit can be disposed on the chamber wall of the first inner chamber 221, the second inner chamber 222, and / or the outer chamber 210 to improve the vacuuming efficiency.

[0091] The second inner chamber 222 is provided with a second hole 240 and a vacuum gate valve 280. The vacuum gate valve 280 is used to open and close the second hole 240 to communicate or isolate the inner chamber and the outer chamber 210. For example, the vacuum gate valve 280 can open the second hole 240 when the electron beam needs to pass through, and close the second hole 240 when the inner chamber needs to be vacuumed. In one possible implementation, the vacuum gate valve 280 can be driven by a piezoelectric ceramic motor, without involving air compression or motor lubrication, and can operate in a high-vacuum environment.

[0092] The vacuum pump P1 is in communication with the outer chamber 210 through a pipe 1, and is used to perform a vacuuming operation on the outer chamber 210. At least one valve can be disposed on the pipe 1, for example, a valve V1 can be disposed. The valve V1 can control the gas flow between the vacuum pump P1 and the outer chamber 210. When the valve V1 is opened, the vacuum pump P1 can extract the gas in the outer chamber 210, thereby improving the vacuum degree in the outer chamber 210. When the valve V1 is closed, the outer chamber 210 is sealed to prevent gas from entering or leaving the outer chamber 210.

[0093] The vacuum pump P2 is connected to the first inner cavity 221 through a pipe 2 for vacuumizing the first inner cavity 221. At least one valve, for example, valve V2 and / or valve V3, can be provided on the pipe 2. The valve V2 is close to the vacuum pump P2, and the valve V3 is close to the first inner cavity 221. The valves V2 and V3 can control the gas flow between the vacuum pump P2 and the first inner cavity 221. When the valves V2 and V3 are opened, the vacuum pump P2 can extract the gas in the first inner cavity 221, thereby increasing the vacuum degree in the first inner cavity 221. When the valves V2 and V3 are closed, the first inner cavity 221 is sealed to prevent the gas from entering or leaving the first inner cavity 221 (as the first hole 230 is very small, the gas in the second inner cavity 222 can be ignored). In a possible implementation, the pipe 2 can be connected to the outer cavity 210 and the first inner cavity 221 through flange connection. CF23 is a flange interface of the pipe 2 connected to the outer cavity 210, and CF32 is a flange interface of the pipe 2 connected to the first inner cavity 221. It should be understood that the above flange connection is only one possible implementation, and the pipe 2 can also be connected to the outer cavity 210 and the first inner cavity 221 through other connection modes, for example, threaded rubber ring connection, welding connection, etc. The specific connection mode should not be understood as a limitation to the present application.

[0094] The vacuum pump P3 is connected to the second inner cavity 222 through a pipe 3 for vacuumizing the second inner cavity 222. At least one valve, for example, valve V4 and / or valve V5, can be provided on the pipe 3. The valve V4 is close to the vacuum pump P3, and the valve V5 is close to the second inner cavity 222. The valves V4 and V5 can control the gas flow between the vacuum pump P3 and the second inner cavity 222. When the valves V4 and V5 are opened, the vacuum pump P3 can extract the gas in the second inner cavity 222, thereby increasing the vacuum degree in the second inner cavity 222. When the valves V4 and V5 are closed, the second inner cavity 222 is sealed to prevent the gas from entering or leaving the second inner cavity 222 (as the first hole 230 is very small, the gas in the first inner cavity 221 can be ignored). In a possible implementation, the pipe 3 can be connected to the outer cavity 210 and the second inner cavity 222 through flange connection. CF45 is a flange interface of the pipe 3 connected to the outer cavity 210, and CF54 is a flange interface of the pipe 3 connected to the second inner cavity 222. It should be understood that the above flange connection is only one possible implementation, and the pipe 3 can also be connected to the outer cavity 210 and the second inner cavity 222 through other connection modes, for example, threaded connection, welding connection, bolt connection, etc. The specific connection mode should not be understood as a limitation to the present application.

[0095] A pipe 4 is connected to the pipe 2 and the pipe 3. The pipe 4 is connected to the pipe 2 through a connection point D1, and the pipe 4 is connected to the pipe 3 through a connection point D2. A valve V6 can be arranged between the connection points D1 and D2 of the pipe 4. The valve V6 can control the gas flow between the pipe 2 and the pipe 3. When the valve V6 is opened, the gas between the pipe 2 and the pipe 3 is connected to each other through the pipe 4. When the valve V6 is closed, the pipe 4 and the pipe 5 are not connected to each other.

[0096] A vacuum pump P4 and a vacuum pump P5 are connected to the pipe 4 through a pipe 5. The vacuum pump P4 and the vacuum pump P5 are used to pre-evacuate the inner cavity. For example, the vacuum pump P5 can be a dry pump, and the vacuum pump P4 can be a molecular pump. The vacuum pump P5 can reduce the gas pressure in the inner cavity from the normal atmospheric pressure to 10E -1 Pa, and the vacuum pump P4 can maintain the vacuum degree of the inner cavity between 10E -8 Pa and 10E -1 Pa. A valve V7 can be arranged on the pipe 5. The valve V7 can control the gas flow between the pipe 5 and the pipe 4. When the valve V7 is opened, the pipe 5 and the pipe 4 are connected to each other. When the valve V7 is closed, the pipe 4 and the pipe 5 are not connected to each other.

[0097] Optionally, the pipe 4 can also be connected to a vacuum gauge G1, which is used to measure and monitor the vacuum degree of the first inner cavity 221 and / or the second inner cavity 222.

[0098] The valves V1-V7 include, but are not limited to, gate valves, angle valves, plug valves, etc. The vacuum pumps P2 and P3 include, but are not limited to, molecular pumps, ion pumps, cryogenic pumps, etc. The ion pump can maintain the vacuum degree of the inner cavity between 10E -10 Pa and 10E -8 Pa.

[0099] When the vacuum system is applied to an electron beam device, a filament 110 of the electron beam device can be arranged in the first inner cavity 221, and a displacement table 150 can be arranged in the outer cavity 210. The filament 110 is used to emit an electron beam, and the displacement table 150 is used to place an object to be detected or an object to be etched. The electron beam is shot on the object to be detected or the object to be etched of the displacement table through the first hole 230 and the second hole 240. For the object to be detected, the object to be detected can be scanned by the electron beam to obtain the image of the secondary electron imaging of the object to be detected, and the abnormal points in the image can be found out by computer vision technology. The electron beam can also etch the object to be etched.

[0100] Figure 7 is an exemplary flowchart of another operation method of a vacuum system provided by an embodiment of the present application. Figure 7 The operation method of corresponds to the vacuum system shown in Figure 6 .

[0101] 710, P1, P4, P5 pre-exhaust.

[0102] Open valves V1, V3, V5, V6 and V7, and close valves V2 and V4. Start vacuum pumps P1, P4 and P5, and stop vacuum pumps P2 and P3.

[0103] Vacuum pump P1 performs vacuumizing operation on outer cavity 210, and vacuum pumps P4 and P5 perform pre-vacuumizing operation on first inner cavity 221 and second inner cavity 222. When the vacuum degrees of first inner cavity 221 and second inner cavity 222 respectively reach preset threshold values, step 720 is performed. Exemplarily, whether the vacuum degrees of first inner cavity 221 and second inner cavity 222 reach preset threshold values can be observed by vacuum gauge G1.

[0104] Optionally, during the pre-exhaust process of inner cavities and outer cavity 210 by vacuum pumps P1, P4 and P5, an oven unit can be used to bake the inner cavities and outer cavity, so as to improve the vacuumizing efficiency. In a possible implementation, the oven unit can be arranged on the cavity walls of first inner cavity 221, second inner cavity 222 and outer cavity 210.

[0105] Exemplarily, the inner cavities and outer cavity can be baked to above 100℃, for example, the outer cavity is baked to 180℃, and the inner cavities are baked to 150℃. After maintaining the temperature for a period of time, for example, 48 hours, the vacuum degrees of first inner cavity 221, second inner cavity 222 and outer cavity 210 respectively reach preset threshold values, and then the temperature is lowered until the temperature of the inner cavities and outer cavity 210 drops to room temperature.

[0106] 720, P2, P3 vacuumizing.

[0107] Close valves V6 and V7, and open valves V2, V3, V4 and V5. Stop vacuum pumps P4 and P5, and start vacuum pumps P2 and P3. Optionally, vacuum pump P1 and valve V1 can be started or stopped.

[0108] In some possible implementations, the vacuum degree of first inner cavity 221 can be maintained at 10E -8 Pa to 10E -6 Pa by setting the pumping speed of vacuum pump P2. The vacuum degree of second inner cavity 222 can be maintained at 10E -6 Pa to 10E -5 Pa by setting the pumping speed of vacuum pump P3.

[0109] Figure 8 is a schematic structural diagram of another vacuum system provided by an embodiment of the present application. Figure 8 and Figure 6Similarly, the difference is that the vacuum pumps P41, P51, P42 and P52 are used to replace the vacuum pumps P4 and P5 in Figure 6 . The vacuum pumps P41 and P51 are connected with the pipeline 2 for pre-evacuating the first inner cavity 221. The vacuum pumps P42 and P52 are connected with the pipeline 3 for pre-evacuating the second inner cavity 222. Other structures can be referred to the description in Figure 6 , which will not be repeated here.

[0110] Figure 9 is a schematic structural diagram of another vacuum system provided by an embodiment of the present application. Figure 9 is similar to Figure 6 , the difference is that the vacuum system includes N inner cavities, N is a positive integer greater than 1, and the N inner cavities are connected through holes. The vacuum gate valve can be used to open and close part of the holes. In some possible application scenarios, the holes can also be referred to as apertures, pinholes, slits or differential holes, which are essentially holes with a size less than a certain threshold, and the specific name should not be understood as a limitation of the present application. Different inner cavities can be evacuated by the same vacuum pump or by different vacuum pumps, which is not limited by the present application, and those skilled in the art can design according to the needs. Other structures can be referred to the description in Figure 6 , which will not be repeated here.

[0111] Figure 10 is a schematic structural diagram of another vacuum system provided by an embodiment of the present application. Figure 10 is similar to Figure 6 , Figure 9 , the outer cavity 210 can include a plurality of inner cavity groups, and each inner cavity group includes a plurality of inner cavities. For example, the first inner cavity group includes the first inner cavity 221 and the second inner cavity 222, and the second inner cavity group includes the first inner cavity 224 and the second inner cavity 225. Other structures can be referred to the description in Figure 6 and Figure 9 , which will not be repeated here.

[0112] Figure 11 is a simulation result schematic diagram of a vacuum system provided by an embodiment of the present application. After a specific vacuum obtaining process, a vacuum gradient of 10 -8 Pa~10 -5 Pa can be achieved, and the first inner cavity 221 can be in an ultrahigh vacuum. The vacuum stability of the entire vacuum system is high, and the change is less than or equal to 10% per 24 hours.

[0113] The vacuum system provided by the application can complete multi-nested vacuum differential through a group of vacuum cavities, has small size, high integration efficiency, saves the cost of multiple vacuum systems, saves the project cost, and improves the vacuum efficiency of the whole vacuum system. Moreover, when a certain chamber is exposed to the atmosphere or has a sharp vacuum change, other vacuum chambers can maintain independent vacuum, thereby improving the vacuum stability.

[0114] The above is only a specific embodiment of the application, but the protection scope of the application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the application, which should be covered within the protection scope of the application. Therefore, the protection scope of the application should be subject to the protection scope of the claims.

Claims

1. A vacuum system, characterized in that, include: An outer cavity and multiple inner cavities, wherein the multiple inner cavities are located inside the outer cavity, the multiple inner cavities include a first inner cavity and a second inner cavity, the first inner cavity and the second inner cavity are connected through a first hole, the second inner cavity is provided with an openable and closable second hole, and the second inner cavity is connected to the outer cavity through the second hole; The first vacuum pump is used to perform a vacuuming operation on the outer cavity; The second vacuum pump is used to perform a vacuuming operation on the first inner cavity; The third vacuum pump is used to perform a vacuuming operation on the second inner cavity.

2. The vacuum system according to claim 1, characterized in that, The second inner cavity is provided with a vacuum gate valve, which is used to open and close the second hole.

3. The vacuum system according to claim 2, characterized in that, The vacuum gate valve is driven by a piezoelectric ceramic motor.

4. The vacuum system according to any one of claims 1 to 3, characterized in that, It also includes a fourth vacuum pump, which connects the first inner cavity and the second inner cavity, and is used to simultaneously perform vacuuming operations on the first inner cavity and the second inner cavity.

5. The vacuum system according to any one of claims 1 to 4, characterized in that, The first vacuum pump is connected to the outer cavity through a first pipe, the second vacuum pump is connected to the first inner cavity through a second pipe, and the third vacuum pump is connected to the second inner cavity through a third pipe.

6. The vacuum system according to claim 5, characterized in that, At least one valve is installed on the first pipe, the second pipe, and the third pipe.

7. The vacuum system according to any one of claims 1 to 6, characterized in that, It also includes a vacuum gauge, connected to the first inner cavity and / or the second inner cavity, for measuring the vacuum level of the first inner cavity and / or the second inner cavity.

8. The vacuum system according to any one of claims 1 to 7, characterized in that, A baking unit is provided on the cavity wall of the outer cavity and / or any one of the plurality of inner cavities, and the baking unit is used to heat the outer cavity and / or any one of the inner cavities.

9. The vacuum system according to any one of claims 1 to 8, characterized in that, This invention is applied to an electron beam device, which includes a filament and a displacement stage. The filament is located in a first inner cavity, and the displacement stage is located in the outer cavity. The filament is used to emit an electron beam, which passes through a first aperture and a second aperture to reach the displacement stage.

10. A method for operating a vacuum system, characterized in that, The vacuum system includes an outer cavity, multiple inner cavities, a first vacuum pump, a second vacuum pump, and a third vacuum pump. The multiple inner cavities are located inside the outer cavity. Each inner cavity includes a first inner cavity and a second inner cavity, which are connected by a first hole. The second inner cavity has an openable second hole and is connected to the outer cavity through the second hole. The first vacuum pump is used to evacuate the outer cavity, the second vacuum pump is used to evacuate the first inner cavity, and the third vacuum pump is used to evacuate the second inner cavity. The method includes: Close the second hole; Turn on the first vacuum pump, the second vacuum pump, and the third vacuum pump.

11. The method according to claim 10, characterized in that, The second inner cavity is provided with a vacuum gate valve, which is used to open and close the second orifice. Closing the second hole includes: The vacuum gate valve is driven by a piezoelectric ceramic motor to close the second hole.

12. The method according to claim 10 or 11, characterized in that, The first vacuum pump is connected to the outer cavity via a first pipe, the second vacuum pump is connected to the first inner cavity via a second pipe, and the third vacuum pump is connected to the second inner cavity via a third pipe. At least one valve is installed on each of the first, second, and third pipes. The step of activating the first vacuum pump, the second vacuum pump, and the third vacuum pump includes: Open at least one valve on the first pipe, the second pipe, and the third pipe, and simultaneously turn on the first vacuum pump, the second vacuum pump, and the third vacuum pump.

13. The method according to claim 12, characterized in that, The vacuum system also includes a fourth vacuum pump, which connects the first inner cavity and the second inner cavity. Before activating the first vacuum pump, the second vacuum pump, and the third vacuum pump, the method further includes: Turn on the fourth vacuum pump.

14. The method according to claim 13, characterized in that, The fourth vacuum pump is connected to the second and third pipes via a fourth pipe, and a first valve is installed on the fourth pipe. After the fourth vacuum pump is turned on and before the first, second, and third vacuum pumps are turned on, the method further includes: Turn off the fourth vacuum pump; Close the first valve to prevent the second and third pipes from connecting to each other.

15. The method according to any one of claims 10 to 14, characterized in that, A baking unit is provided on the cavity wall of the outer cavity and / or any one of the plurality of inner cavities, the baking unit being used to heat the outer cavity and / or any one of the inner cavities, the method further comprising: Start the baking unit.

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