Vacuum extraction system and vacuum extraction method for electron microscope

Abstract

The present invention belongs to the technical field of electron microscopes, and discloses a vacuum extraction system and a vacuum extraction method for an electron microscope. The vacuum extraction system of the electron microscope includes: a detection part for detecting the air pressure value in the electron microscope; a controller, which is in communication with the detection part; and a vacuum extraction mechanism, which is in communication with the electron microscope. The vacuum extraction mechanism includes a pre-extraction component, a first-level exhaust component, and a second-level exhaust component, all of which are in communication with the controller. The controller is configured to control the start-up of the pre-extraction component, the first-level exhaust component, and the second-level exhaust component in sequence according to the gradual decrease in the air pressure value. In this way, the exhaust in the electron microscope is completed by starting the pre-extraction component, the first-level exhaust component, and the second-level exhaust component in sequence. Not only can the gas be quickly extracted to obtain a vacuum degree that meets the requirements, but the startup process is completely controlled by the controller. The overall degree of automation is high, which can effectively improve the efficiency of equipment use.

Description

Technical Field

[0001] The present invention relates to the technical field of electron microscopes, and in particular to a vacuum extraction system and a vacuum extraction method for an electron microscope. Background Art

[0002] An electron microscope is a microscope with a resolution of up to 0.2 nanometers. It generally consists of three parts: a tube, a vacuum device, and a power cabinet. It mainly uses the fact that electrons will not be absorbed or deflected in a vacuum state to observe samples. Therefore, the vacuum degree in the electron microscope will have a great impact on the observation of the sample.

[0003] In the prior art, when a vacuum environment is formed in an electron microscope, a mechanical pump, a valve group and an exhaust pipe are used to achieve it. The exhaust pipe is connected to the lens barrel, the valve group is set on the exhaust pipe, and the mechanical pump is connected to the exhaust pipe. The gas in the lens barrel can be extracted through the mechanical pump.

[0004] However, in the above process, although the mechanical pump can extract the gas in the lens barrel, as the gas in the lens barrel decreases, the air pressure will decrease and the vacuum degree will gradually increase. The mechanical pump has its own working range. When the air pressure drops to a certain level, even if the mechanical pump continues to run, the air pressure in the lens barrel will not change greatly, and the vacuum degree will remain unchanged. At this time, if the vacuum degree needs to be further reduced, the mechanical pump needs to be run for a long time or replaced with a mechanical pump within another working range, which makes the overall vacuum extraction process very time-consuming. Summary of the Invention

[0005] The object of the present invention is to provide a vacuum extraction system and a vacuum extraction method for an electron microscope.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] A vacuum extraction system for an electron microscope comprises: a detection part for detecting an air pressure value inside the electron microscope; a controller communicatively connected to the detection part to obtain the air pressure value; a vacuum pumping mechanism connected to the electron microscope to extract the gas inside the electron microscope to form a vacuum, the vacuum pumping mechanism comprising a pre-pumping component, a first-stage exhaust component and a second-stage exhaust component, all of which are communicatively connected to the controller, the controller being configured to sequentially control the start-up of the pre-pumping component, the first-stage exhaust component and the second-stage exhaust component according to a gradual decrease in the air pressure value.

[0008] Optionally, the pre-pumping component includes: a first pre-pumping pump, which is communicatively connected to the controller; a first exhaust valve group, which is respectively connected to the first pre-pumping pump and the electron microscope, and the first pre-pump is configured to pre-pump the gas in the electron microscope and adjust the air pressure at the exhaust end of the first-level exhaust component; a second pre-pumping pump, which is communicatively connected to the controller; and an exhaust valve, which is respectively connected to the second pre-pumping pump and the exhaust end of the first-level exhaust component, and the second pre-pump is configured to adjust the air pressure at the exhaust end of the first-level exhaust component; wherein, when the air pressure at the exhaust end and the exhaust end of the first-level exhaust component meet the preset conditions, the controller controls the first-level exhaust component to start.

[0009] With the above technical solution, during air extraction, the first pre-extraction pump and the second pre-extraction pump are first activated. The first pre-extraction pump can pre-extract the gas within the electron microscope to adjust the air pressure within the electron microscope. The exhaust end of the first-stage exhaust assembly is connected to the electron microscope, which means that the air pressure at the exhaust end of the first-stage exhaust assembly is adjusted. The second pre-extraction pump can extract gas from the exhaust end of the first-stage exhaust assembly to adjust the air pressure. When the air pressure at both ends of the first-stage exhaust assembly is adjusted to meet the preset conditions, the controller will then activate the first-stage exhaust assembly to extract air.

[0010] Optionally, the above-mentioned first-level vacuum assembly includes: a first-level vacuum pump, which is communicatively connected to the above-mentioned controller, and the exhaust end of the above-mentioned first-level vacuum pump is connected to the above-mentioned vacuum valve; a first-level control valve group, which is respectively connected to the vacuum end of the above-mentioned first-level vacuum pump, the above-mentioned first vacuum valve group and the above-mentioned electron microscope.

[0011] Through the above technical solution, when the first-level vacuum assembly is started, the first-level vacuum pump is started. The first-level vacuum pump can continue to vacuum the electron microscope that has completed pre-vacuuming through the first-level control valve group to improve the vacuum degree inside the electron microscope.

[0012] Optionally, the vacuum extraction system of the electron microscope further includes: an air cylinder, which is respectively connected to the extraction end of the second pre-extraction pump and the exhaust end of the first-stage exhaust pump; wherein the air pressure in the air cylinder meets the starting air pressure of the exhaust end of the first-stage exhaust pump.

[0013] Through the above technical solution, when observing the sample chamber through an electron microscope, in order to prevent shaking, the second pre-pump can be turned off first, and the air pressure at the exhaust end of the first-stage air pump can be maintained through the air storage cylinder to ensure that the first-stage air pump can continue to operate.

[0014] Optionally, the secondary exhaust assembly includes: a secondary exhaust pump, which is arranged near the electron gun chamber of the electron microscope and connected to the controller and the electron gun chamber of the electron microscope.

[0015] Through the above technical solution, the secondary vacuum pump is arranged close to the electron gun chamber. When the gas in the electron gun chamber needs to be extracted, the primary vacuum pump can complete the extraction more effectively to ensure the vacuum degree in the electron gun chamber.

[0016] Optionally, the air pumping end of the secondary air pump is connected to the air pumping end of the primary air pumping component to adjust the air pressure at the air pumping end of the secondary air pump.

[0017] Through the above technical solution, before the secondary vacuum pump is started, the air pressure of the secondary vacuum pump is first adjusted to an appropriate range using the primary vacuum pump, and then the secondary vacuum pump is started to continue to evacuate the electron gun chamber in the electron microscope, so as to realize the step-by-step start-up of the primary vacuum component and the secondary vacuum component to ensure the vacuum degree in the electron microscope.

[0018] Optionally, the vacuum extraction system of the electron microscope further includes: a conversion valve connected to the electron gun chamber of the electron microscope for filling or exhausting insulating gas.

[0019] With the above technical solution, corresponding insulating gas can be filled into or discharged from the electron gun chamber through the conversion valve, so as to facilitate the inspection or maintenance of the electron gun chamber.

[0020] A vacuum extraction method for an electron microscope is applied to a vacuum extraction system of an electron microscope as described in any of the above items. The vacuum extraction method for the electron microscope includes: starting the pre-extraction component to pre-extract the gas in the electron microscope and obtaining a first air pressure value in the electron microscope; when the first air pressure value is less than a first air pressure preset value and greater than a second air pressure preset value, starting the first-level exhaust component to perform a first-level exhaust in the electron microscope; when the first air pressure value is less than the second air pressure preset value, starting the second-level exhaust component to perform a second-level exhaust in the electron microscope.

[0021] Optionally, before the above-mentioned first-level vacuum pumping component is started, the vacuum extraction method of the above-mentioned electron microscope also includes: obtaining the first-level air pressure value of the above-mentioned first-level vacuum pumping component, and when the above-mentioned first-level air pressure value meets the above-mentioned starting value, controlling the above-mentioned first-level vacuum pumping component to start; when the above-mentioned first-level air pressure value does not meet the starting value, controlling the above-mentioned pre-vacuum component to adjust the above-mentioned first-level air pressure value.

[0022] Through the above technical solution, when starting the first-level vacuum component, it is possible to first detect whether the first-level air pressure value meets the starting value. If it does not meet the requirements, the electron microscope can be pre-evacuated through the pre-evacuation component to adjust the air pressure values ​​at the vacuum end and the exhaust end of the first-level vacuum component. After the first-level air pressure value meets the starting value, the first-level vacuum component can be started, thereby using the first-level vacuum component to continue to further extract the gas in the electron microscope, and extracting the gas in the electron microscope step by step in turn, which is conducive to obtaining a higher vacuum degree.

[0023] Optionally, before the above-mentioned secondary vacuum pumping component is started, the vacuum extraction method of the above-mentioned electron microscope includes: obtaining the secondary air pressure value of the vacuum end of the above-mentioned secondary vacuum pumping component, and when the above-mentioned secondary air pressure value does not meet the set value, controlling the above-mentioned first-level vacuum pumping component to adjust the above-mentioned secondary air pressure value; when the above-mentioned secondary air pressure value meets the set value, controlling the above-mentioned second-level vacuum pumping component to start.

[0024] Through the above technical solution, before the secondary vacuum assembly is operated, the first-level vacuum assembly is first used to extract the gas from the air inlet end of the secondary vacuum assembly, so that the secondary air pressure value meets the set value, and then the secondary vacuum assembly is controlled to start. At this time, the secondary vacuum assembly can continue to further pump air into the electron microscope, thereby gradually improving the vacuum degree inside the electron microscope.

[0025] Beneficial effects of the present invention:

[0026] 1. When using this system to extract the gas inside the electron microscope, the detection component is first used to measure the air pressure value inside the electron microscope in real time, and the air pressure value is transmitted to the controller. According to the gradual change of the air pressure value, the controller controls the pre-extraction component, the first-level exhaust component, and the second-level exhaust component to start in sequence, thereby forming three levels of gradual exhaust of the electron microscope, so that the vacuum degree inside the electron microscope gradually increases until it meets the vacuum degree requirements. In this way, the exhaust of the electron microscope is completed by starting the pre-extraction component, the first-level exhaust component, and the second-level exhaust component in sequence. Not only can the gas be quickly extracted and the vacuum degree that meets the requirements be obtained, but the startup process is completely controlled by the controller. Its overall degree of automation is high, which can effectively improve the efficiency of equipment use.

[0027] 2. When using this method to extract gas from an electron microscope, the pre-extraction component is first activated to perform pre-extraction to extract the gas from the lens barrel. The first air pressure value is gradually reduced to obtain the first air pressure value inside the electron microscope. When the first air pressure value is greater than the first air pressure preset value, pre-extraction is continued through the pre-extraction component. When the first air pressure value is between the first air pressure preset value and the second air pressure preset value, the first-stage exhaust component is activated to perform further exhaust. When the first air pressure value is less than the second air pressure preset value, the second-stage exhaust component is activated to perform exhaust. In this way, three-stage exhaust of the electron microscope components can be achieved to obtain a vacuum degree that meets the requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Shown is a schematic diagram of a vacuum extraction system for an electron microscope in some embodiments of the present application.

[0029] Figure 2 Shown is a schematic flow chart of a vacuum extraction method for an electron microscope in some embodiments of the present application.

[0030] Figure 3 Shown is a schematic diagram of the process of starting the first-stage exhaust component of the electron microscope in some embodiments of the present application.

[0031] Figure 4 Shown is a schematic diagram of the process of starting the secondary exhaust assembly of the electron microscope in some embodiments of the present application.

[0032] In the picture:

[0033] 100, lens barrel; 101, isolation valve; 110, electron gun chamber; 111, conversion valve; 120, sample chamber; 130, observation chamber; 140, inflation valve; 200, detection element; 400, pre-extraction assembly; 410, first pre-extraction pump; 421, observation chamber pre-extraction valve; 422, sample chamber pre-extraction valve; 423, electron gun chamber pre-extraction valve; 430, second pre-extraction pump; 440, exhaust valve; 500, first-stage exhaust assembly; 510, first-stage exhaust pump; 521, main valve; 522, electron gun chamber exhaust valve ; 524, observation room exhaust valve; 600, secondary exhaust assembly; 700, pre-exhaust pipeline; 710, pre-exhaust main pipeline; 711, pre-exhaust main valve; 720, observation room pre-exhaust branch; 730, sample room pre-exhaust branch; 740, electron gun room pre-exhaust branch; 750, conversion branch; 760, exhaust end pre-exhaust branch; 761, gas cylinder; 800, first-level exhaust pipeline; 810, first-level exhaust main pipeline; 820, sample room exhaust branch; 830, observation room exhaust branch; 900, second-level exhaust pipeline. DETAILED DESCRIPTION

[0034] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It will be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all structures.

[0035] In the description of the present invention, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific circumstances.

[0036] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0037] In the description of this embodiment, the terms "upper," "lower," "right," and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely for ease of description and simplified operation. They do not indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meanings.

[0038] An electron microscope is a high-precision microscope consisting primarily of three components: a tube, a vacuum system, and a power supply cabinet. The vacuum system is used to extract gas from the tube, creating a vacuum environment within the tube, enabling the formation of a uniform electron beam. As electrons move, gas molecules attract them, deflecting or even absorbing them. Therefore, the degree of vacuum within the tube directly affects the quality of the electron beam, significantly impacting the performance of the electron microscope.

[0039] In the prior art, the vacuum device primarily consists of a vacuum pump, a valve block, and an exhaust pipeline. The vacuum pump utilizes the suction force generated by the vacuum pump to extract the gas within the lens barrel through the exhaust pipeline and valve block, thereby creating a vacuum within the lens barrel. However, the vacuum pump itself has a limited operating range. Once the air pressure within the lens barrel drops to a certain level, the efficiency of achieving a vacuum by relying solely on the vacuum pump to extract gas will be significantly reduced. This results in a significant time-consuming process to achieve the required vacuum level within the lens barrel, reducing the overall utilization rate of the equipment.

[0040] The present application provides a vacuum extraction system and method for an electron microscope. When operated using this method, the system can form a three-stage vacuum extraction system using a pre-vacuum assembly, a primary vacuum assembly, and a secondary vacuum assembly. The three stages of vacuum extraction are automatically activated sequentially under the control of a controller to gradually extract the gas within the electron microscope.

[0041] Simply put, the gas inside the electron microscope is first extracted through the pre-extraction component. As the air pressure inside the electron microscope gradually drops to a certain level, the first-level exhaust component and the second-level exhaust component are started in sequence to ensure that the gas inside the electron microscope can be quickly extracted, so that the required vacuum degree can be quickly formed inside the electron microscope.

[0042] Moreover, the pre-vacuum component, the first-stage vacuum component and the second-stage vacuum component are all automatically started or shut down by controllers, which can improve the automation level of the entire equipment. At the same time, during the vacuuming process, the molecular pump and the ion pump are mainly used as the power source, so that the entire system does not use or uses less oil, thereby effectively avoiding oil pollution during the operation of the entire system.

[0043] Figure 1 The figure shows the principle diagram of the vacuum extraction system of the electron microscope in some embodiments of the present application. Figure 1 As shown, the electron microscope barrel 100 includes an electron gun chamber 110, a sample chamber 120, and an observation chamber 130. The three can be assembled from top to bottom to form a column. The electron gun chamber 110 is used to generate an electron beam, a sample rack is provided in the sample chamber 120 to receive the sample, and the observation chamber 130 is used to observe the sample in the sample chamber 120. Isolation valves 101 can be provided between the electron gun chamber 110 and the sample chamber 120, as well as between the sample chamber 120 and the observation chamber 130 for sealing and isolation. It should be understood that the electron microscope barrel 100 can also have other structures or shapes, such as being tiltable as a whole, and can be specifically designed according to the actual application scenario, which is not specifically limited in this application.

[0044] Reference Figure 1 As shown, an inflation valve 140 is provided on the electron gun chamber 110 , the sample chamber 120 and the observation chamber 130 . The inflation valve 140 is connected to an inflation device for delivering macromolecular inert gas, such as nitrogen or helium, to the electron gun chamber 110 , the sample chamber 120 and the observation chamber 130 .

[0045] Reference Figure 1 As shown, the vacuum extraction system of the electron microscope includes a detection member 200, a controller, and a vacuum pumping mechanism. The detection member 200 is disposed on the lens barrel 100 and is used to detect the air pressure value within the lens barrel 100. The controller is in communication with the detection member 200 to obtain the air pressure value. The vacuum pumping mechanism is connected to the lens barrel 100 of the electron microscope to extract the gas within the lens barrel 100.

[0046] The vacuum pumping mechanism includes a pre-vacuum assembly 400, a first-stage vacuum assembly 500, and a second-stage vacuum assembly 600. The pre-vacuum assembly 400, the first-stage vacuum assembly 500, and the second-stage vacuum assembly 600 are all connected to the controller in communication, and the controller is configured to control the activation of the three in sequence according to the air pressure value.

[0047] Specifically, the detection member 200 can adopt a Pirani gauge, which is also called a resistance vacuum gauge. The principle of the Pirani gauge is that the change in the number of molecules in the gas will cause the resistivity of the heated resistance wire to change, thereby changing the resistance. In this way, the voltage drop of the current across the resistance wire will be different. The corresponding air pressure value, that is, the vacuum degree, can be converted based on the change in the voltage drop. The number of detection members 200 can be multiple, for example, three, and the three detection members 200 are respectively used to detect the air pressure values ​​in the electron gun chamber 110, the sample chamber 120, and the observation chamber 130. The specific installation location of the detection member 200 can be the connection between the vacuum pumping mechanism and the lens barrel 100, or it can be other locations, which are not limited by the present invention.

[0048] The controller can be a PLC, and a corresponding computer program is set in the PLC to realize automatic control of this component, the first-stage exhaust component 500, and the second-stage exhaust component 600. The controller can also be of other types, as long as it can start the three-stage exhaust according to the program, and this application does not make specific restrictions.

[0049] The vacuum pumping mechanism may further include a plurality of exhaust pipelines, namely a pre-exhaust pipeline 700, a primary exhaust pipeline 800, and a secondary exhaust pipeline 900. The pre-exhaust assembly 400 is disposed on the pre-exhaust pipeline 700, and the pre-exhaust pipeline 700 can be respectively connected to the electron gun chamber 110, the sample chamber 120, the observation chamber 130, and the primary exhaust pipeline 800. The primary exhaust assembly 500 is disposed on the primary exhaust pipeline 800, and the primary exhaust pipeline 800 can be respectively connected to the observation chamber 130, the sample chamber 120, the electron gun chamber 110, and the secondary exhaust pipeline 900. The secondary exhaust assembly 600 is disposed on the secondary exhaust pipeline 900, and the secondary exhaust assembly 600 can be connected to the electron gun chamber 110.

[0050] When utilizing this system to carry out vacuum acquisition to electron microscope, earlier gas filling valve 140 is connected with gas filling device, open gas filling valve 140, utilize gas filling device that inert gas is filled in electron gun chamber 110, sample chamber 120 and observation chamber 130.After guaranteeing that in the lens barrel 100, be full of inert gas, close gas filling valve 140 and gas filling device again, start detection member 200 and controller.Detection member 200 just can detect the air pressure value in the lens barrel 100, and air pressure value is passed to controller, after controller obtains air pressure value, just can control pre-extraction assembly 400, one-level exhaust assembly 500 and two-level exhaust assembly 600 to start successively.Pre-extraction assembly 400 can pre-extract lens barrel 100, and the air pressure in the lens barrel 100 is reduced to a certain amplitude, such as being reduced to below 5Pa.

[0051] When the air pressure drops to a certain level, the controller starts the first-stage exhaust assembly 500 according to the air pressure value, and uses the first-stage exhaust assembly 500 to continue to exhaust the lens barrel 100, so that the air pressure in the lens barrel 100 is further reduced, for example, to below 10E-4Pa. The controller then starts the second-stage exhaust assembly 600 according to the air pressure value. The second-stage exhaust assembly 600 and the first-stage exhaust assembly 500 run simultaneously to continue exhausting, so that the air pressure in the lens barrel 100 continues to drop to within the required range, for example, to below 10E-5Pa. In this way, by starting the three-stage exhaust in sequence, the air pressure in the lens barrel 100 can be quickly reduced, thereby quickly obtaining the required vacuum degree and improving the efficiency of the equipment. Moreover, the entire exhaust process is also automatically completed by the controller, and the degree of automation in the exhaust process is relatively high, reducing the participation of the operator.

[0052] In some embodiments of the present application, the pre-pump assembly 400 includes a first pre-pump 410, a first air extraction valve assembly, a second pre-pump 430, and an air extraction valve 440. The first pre-pump 410 is connected to the first air extraction valve assembly, which in turn is connected to the electron gun chamber 110, the sample chamber 120, the observation chamber 130, and the air inlet of the first-stage air extraction assembly 500. The second pre-pump 430 is connected to the air extraction valve 440, which is connected to the air exhaust end of the first-stage air extraction assembly 500. The first pre-pump 410 is configured to regulate the air pressure at the air extraction end of the first-stage air extraction assembly 500 and pre-pump the gas within the lens barrel 100. The second pre-pump 430 is configured to regulate the air pressure at the air exhaust end of the first-stage air extraction assembly 500. When the air pressure at the air extraction and exhaust ends of the first-stage air extraction assembly 500 meets preset conditions, the controller controls the first-stage air extraction assembly 500 to start.

[0053] Specifically, the first pre-pump 410 and the second pre-pump 430 can both be mechanical pumps as the pre-pumping power components. The first air extraction valve group and the air extraction valve 440 can each include multiple valves, and the specific valve type and number can be adaptively designed according to the actual air extraction system and are not specifically limited in this application.

[0054] For example, the first pre-pump 410, the second pre-pump 430, the first air extraction valve group, and the air extraction valve 440 are all disposed on a pre-pump line 700, and the pre-pump line 700 may include a pre-pump main line 710 and a plurality of pre-pump branches connected to the pre-pump main line 710. A pre-pump main valve 711 may be disposed on the pre-pump main line 710, and the pre-pump main valve 711 is disposed near the air extraction end of the first pre-pump 410.

[0055] One end of the pre-pumping main line 710 is connected to the first pre-pumping pump 410, and the other end is connected to the first-stage exhaust line 800, and the connection position is set near the electron gun chamber 110. Multiple pre-pumping branches are used to connect the pre-pumping main line 710 and the lens barrel 100, and are also used to connect the second pre-pumping pump 430 and the exhaust end of the first-stage exhaust assembly 500. And a valve of the first exhaust valve group or an exhaust valve 440 can be set on each pre-pumping branch, and a Pirani gauge can also be set as a detection part 200. The connection and quantity of the specific pre-pumping branch, the first exhaust valve group and the Pirani gauge can be set according to the actual scenario, and this application does not limit it. The valve of the first exhaust valve group and the exhaust valve 440 can both use solenoid valves and be connected to the controller for communication, so as to use the controller to directly control the opening or closing of multiple valves.

[0056] In an embodiment of the present invention, the plurality of pre-extraction branches may include an observation chamber pre-extraction branch 720, a sample chamber pre-extraction branch 730, and an electron gun chamber pre-extraction branch 740, one end of each of which is connected to the pre-extraction main line 710, while the other end of the observation chamber pre-extraction branch 720 is connected to a side of the primary exhaust pipe 800 close to the observation chamber 130, the other end of the sample chamber pre-extraction branch 730 is connected to the sample chamber 120, and the other end of the electron gun chamber 110 pre-extraction branch is connected to an end of the primary exhaust pipe 800 close to the electron gun chamber 110. The first exhaust valve group may include an observation chamber pre-extraction valve 421, a sample chamber pre-extraction valve 422, and an electron gun chamber pre-extraction valve 423. The observation chamber pre-extraction valve 421 is provided on the observation chamber pre-extraction branch 720, the sample chamber 120 pre-extraction valve is provided on the sample chamber pre-extraction branch 730, and the electron gun chamber pre-extraction valve 423 is provided on the electron gun chamber pre-extraction branch 740.

[0057] The multiple pre-extraction branches also include a conversion branch 750, one end of which is connected to the pre-extraction main line 710. The electron gun chamber 110 is also provided with a conversion valve 111, which has an inlet, a connection port, an exhaust port, and a pressure relief port. The inlet port is used to connect to an inflator, the connection port communicates with the high-pressure chamber within the electron gun chamber 110, and the exhaust port can be connected to the other end of the conversion branch 750. The conversion valve 111 allows the high-pressure chamber of the electron gun chamber 110 to be filled with or exhausted with insulating gas, facilitating inspection and maintenance of the electron gun chamber 110.

[0058] The plurality of pre-pumping branches further include an exhaust end pre-pumping branch 760 . One end of the exhaust end pre-pumping branch 760 is connected to the exhaust end of the second pre-pumping pump 430 , and the other end is connected to the exhaust end of the first-stage exhaust assembly 500 . The exhaust valve 440 is disposed on the exhaust end pre-pumping branch 760 .

[0059] During gas extraction, by activating the first pre-extraction pump 410, the gas within the electron gun chamber 110, the sample chamber 120, and the observation chamber 130 can be extracted through the pre-extraction pipeline 700, thereby smoothly reducing the pressure within the lens barrel 100. For example, the pressure within the lens barrel 100 can be reduced to 5 Pa, thereby quickly completing the pre-extraction. Simultaneously, the switching valve 111 can also discharge the insulating gas through the switching branch 750 and the pre-extraction main pipeline 710.

[0060] The first-stage exhaust assembly 500 needs to be activated after completing the pre-extraction. Therefore, when the first-stage exhaust assembly 500 is activated, the exhaust end of the first-stage exhaust assembly 500 needs to be consistent with the air pressure in the lens barrel 100, and the air pressure at the exhaust end cannot differ too much from the exhaust end. Therefore, it is necessary to adjust the air pressure at both ends of the first-stage exhaust assembly 500 before the first-stage exhaust assembly 500 is activated. When the first pre-extraction pump 410 is in operation, the gas at the exhaust end of the first-stage exhaust assembly 500 is extracted through the observation chamber pre-extraction branch 720 and the pre-extraction main line 710 to adjust the air pressure at the exhaust end of the first-stage exhaust assembly 500. When the second pre-extraction pump 430 is in operation, the air pressure at the exhaust end of the first-stage exhaust assembly 500 can be adjusted through the exhaust end pre-extraction branch 760 and the exhaust valve 440. When the air pressure at both ends of the first-stage exhaust assembly 500 meets the preset conditions, the controller will automatically control the first-stage exhaust assembly 500 to start to continue extracting the gas in the lens barrel 100.

[0061] In some embodiments of the present application, the primary air extraction assembly 500 includes a primary air extraction pump 510 and a primary control valve group. The primary air extraction pump 510 is communicatively connected to the controller, and its exhaust end is connected to the air extraction valve 440. One end of the primary control valve group is connected to the exhaust end of the primary air extraction pump 510, and the other end of the primary control valve group is connected to the lens barrel 100.

[0062] The first stage air pump 510 is a molecular pump, which is used as the air extraction power of the first stage air extraction assembly 500. Two first stage air pumps 510 can be provided, wherein one of them is provided near the observation chamber 130, and the other is provided near the sample chamber 120. It should be understood that the type and location of the first stage air pump 510 can be designed according to the shape and installation position of the actual lens barrel 100, and this application is not specifically limited thereto. The first stage control valve group includes a plurality of valves, which correspond to the different chambers in the lens barrel 100 respectively. The valves can all be electromagnetic valves and be connected to the controller for communication, so as to utilize the controller to directly control the opening or closing of the plurality of valves.

[0063] For example, the primary air pump 510 and the primary control valve group are both arranged on the primary air extraction pipeline 800. The primary air extraction pipeline 800 further includes a primary air extraction main line 810 and multiple primary air extraction branches each connected to the primary air extraction main line 810. One end of the primary air extraction main line 810 is connected to the primary air extraction pump 510, and the other end can be directly connected to the electron gun chamber 110. The primary air extraction branch is used to connect the air extraction end of the primary air extraction pump 510 to the sample chamber 120 and the observation chamber 130. The multiple valves of the primary control valve group can be respectively arranged on the primary air extraction main line 810 or on different primary air extraction branches.

[0064] In an embodiment of the present invention, the primary exhaust main line 810 is connected to the pre-exhaust main line 710 and the electron gun chamber pre-exhaust branch line 740, and the connection port of the pre-exhaust main line 710 is arranged near the primary exhaust pump 510 to smoothly adjust the air pressure of the primary exhaust pump 510. The primary exhaust pump 510 is one of the two primary exhaust pumps 510 arranged near the sample chamber 120. The primary control valve group may include a main valve 521 and an electron gun chamber exhaust valve 522. The main valve 521 is located at one end of the primary exhaust main line 810 near the primary exhaust pump 510, and the electron gun chamber exhaust valve 522 is located on the side of the primary exhaust main line 810 near the electron gun chamber 110.

[0065] The plurality of primary exhaust branches may include a sample chamber exhaust branch 820 and an observation chamber exhaust branch 830. One end of the sample chamber exhaust branch 820 is connected to the primary exhaust main line 810, and the other end is connected to the sample chamber 120. One end of the observation chamber exhaust branch 830 is connected to the exhaust end of the primary exhaust pump 510, which is the one of the two primary exhaust pumps 510 closer to the observation chamber 130. The primary control valve group may further include an observation chamber exhaust valve 524, which is arranged on the observation chamber exhaust branch 830. At the same time, the end of the observation chamber pre-exhaust branch 720 away from the pre-exhaust main line 710 is connected to the observation chamber exhaust branch 830, and the connection point may be arranged close to one side of the observation chamber 130.

[0066] After the pre-pumping is completed, the air pressure at the suction end and the exhaust end of the first-stage air pump 510 is adjusted through the first pre-pumping pump 410, the pre-pumping main line 710, the observation chamber pre-pumping branch 720, the second pre-pumping pump 430 and the exhaust end pre-pumping branch 760. When the air pressure at both ends of the two first-stage air pumps 510 meets the preset conditions, the controller starts the two first-stage air pumps 510 and controls the first-stage control valve group to open, and then the electron gun chamber 110, the sample chamber 120 and the observation chamber 130 can be further pumped through the first-stage air pumping main line 810 and the corresponding first-stage air pumping branch to quickly reduce the air pressure in the lens barrel 100 to below 10E-4Pa.

[0067] Reference Figure 1 As shown, in some embodiments of the present application, the system further includes an air reservoir 761. The air reservoir 761 is disposed on the exhaust-end pre-pumping branch 760, with one end connected to the air extraction end of the second pre-pumping pump 430 and the other end connected to the exhaust end of the primary air extraction pump 510. The air pressure in the air reservoir 761 can be kept consistent with the operating air pressure at the exhaust end of the primary air extraction pump 510.

[0068] Specifically, three air extraction valves 440 can be provided, two corresponding to the two primary air extraction pumps 510, and one located at one end of the exhaust pre-extraction branch 760 near the second pre-extraction pump 430. The air reservoir 761 is located between the three air extraction valves 440. The air pressure within the air reservoir 761 can be consistent with the preset conditions at the exhaust end of the primary air extraction pump 510. A Pirani gauge can also be provided on the air reservoir 761 as a vacuum detection component 200 to detect the air pressure within the air reservoir 761.

[0069] By providing the air reservoir 761, the second pre-pump 430 can be temporarily shut down. The air pressure at the exhaust port of the primary pre-pump can be temporarily adjusted by the air reservoir 761, preventing the primary air pump 510 from shutting down immediately. This allows the second pre-pump 430 to be temporarily stopped while observing through the observation window, thereby reducing vibration of the entire device and facilitating observation by the operator.

[0070] In some embodiments of the present application, the secondary exhaust assembly 600 includes a secondary exhaust pump disposed near the electron gun chamber 110 and in communication with the controller, with an exhaust port of the secondary exhaust pump communicating with the electron gun chamber 110 .

[0071] Specifically, the secondary air pump can be an ion pump, which is provided on the secondary air pumping line 900. One end of the secondary air pumping line 900 is connected to the air extraction port of the secondary air pump, and the other end of the secondary air pumping line 900 is connected to the primary air extraction main line 810. The connection point is located between the electron gun chamber air extraction valve 522 and the electron gun chamber 110, thereby adjusting the air pressure at the air extraction end of the secondary air pump.

[0072] Since the two first-stage vacuum pumps 510 are far away from the electron gun chamber 110, the suction force in the electron gun chamber 110 is relatively small. By separately setting an ion pump outside the electron gun chamber 110, and adjusting the air pressure at the suction end of the pump to a start-up state in advance through the first-stage vacuum pump 510, and then starting the second-stage vacuum pump through the controller, the second-stage vacuum pump can further pump air from the electron gun chamber 110, while maintaining the continuous operation of the first-stage vacuum assembly 500, thereby quickly reducing the air pressure in the lens barrel 100 to below 10E-5Pa to obtain a vacuum degree that meets the requirements.

[0073] The present application also provides a vacuum extraction method for an electron microscope, which is applied to the vacuum extraction system of the electron microscope in any of the above embodiments. Through this method, the system can quickly increase the vacuum level in the lens barrel 100 and improve the overall equipment utilization efficiency.

[0074] Figure 2 The figure shows a schematic flow chart of a vacuum extraction method for an electron microscope in some embodiments of the present application. Figure 2 As shown, the method includes:

[0075] S100: Start the pre-evacuation component 400 to pre-evacuate the gas in the electron microscope and obtain a first gas pressure value in the electron microscope.

[0076] The initial value of the first air pressure value refers to the air pressure value within the lens barrel 100 before vacuuming begins. Before vacuuming, the lens barrel 100 is filled with an inert gas, such as nitrogen, using the inflation device and inflation valve 140 to expel the existing air and impurities within the lens barrel 100. The first air pressure value can be obtained directly using the detection component 200 in the system, or it can be measured separately.

[0077] When starting to vacuum, first start the pre-vacuum component 400, and the gas in the lens barrel 100 is extracted through the pre-vacuum component 400. The first air pressure value will also change in real time. The first air pressure value is compared with the first air pressure preset value in real time. As long as the first air pressure value is greater than the first air pressure preset value, the pre-vacuum component 400 is maintained in operation. When the first air pressure value is less than the first air pressure preset value, the vacuuming efficiency of the pre-vacuum component 400 will be greatly reduced. Therefore, the first-level vacuuming component 500 is started to increase the vacuuming force to ensure the vacuuming efficiency.

[0078] S200: When the first air pressure value is less than the first air pressure preset value and greater than the second air pressure preset value, the first-stage exhaust component 500 is started to perform first-stage exhaust in the electron microscope.

[0079] The first air pressure preset value refers to the starting condition of the first-level exhaust component 500. In order to ensure that the first-level exhaust component 500 can improve the efficiency of vacuuming, the working upper limit or starting condition of the first-level exhaust component 500 must meet the first air pressure preset value. For example, the starting air pressure of the exhaust end of the first-level exhaust component 500 can be set to 5Pa. At this time, only when the first air pressure value is less than 5Pa can the first-level exhaust component 500 be started to continue to exhaust, thereby ensuring the overall exhaust efficiency. At this time, the part of the structure of the pre-extraction component 400 that exhausts the inside of the lens barrel 100 can stop running. The second air pressure preset value is a judgment standard for a relatively high vacuum degree. Between the first air pressure preset value and the second air pressure preset value, it can be quickly reached using only the first-level exhaust component 500. When the first air pressure value is lower than the second air pressure preset value, the second-level exhaust component 600 is started so that the second-level exhaust and the first-level exhaust are operated simultaneously to continue exhausting.

[0080] S300: When the first air pressure value is less than the second air pressure preset value, the secondary air pumping component 600 is started to perform secondary air pumping in the electron microscope.

[0081] The second air pressure preset value can be set to 10E-4Pa. At this time, the vacuum degree is relatively high. If the first-level vacuum is relied on alone, its efficiency will also be reduced. Therefore, the second-level vacuum component 600 is started through the controller, and the second-level vacuum and the first-level vacuum are maintained to run at the same time, thereby improving the overall vacuum efficiency.

[0082] Through the above steps S100, S200 and S300, when the electron microscope is vacuum-extracted, the gas in the lens barrel 100 is first pre-extracted through the pre-extraction component 400, so that the first air pressure value is gradually reduced. When the first air pressure value is less than the first air pressure preset value, the first-level exhaust component 500 is started to perform first-level exhaust. When the first air pressure value is less than the second air pressure preset value, the second-level exhaust component 600 is started to perform second-level exhaust. The second-level exhaust and the first-level exhaust are operated simultaneously to quickly increase the vacuum degree in the lens barrel 100, so that the vacuum degree in the lens barrel 100 can meet the requirements in a shorter time, which is beneficial to improving the utilization efficiency of the electron microscope.

[0083] Figure 3 The figure shows a flow chart of starting the first-stage vacuum assembly of an electron microscope in some embodiments of the present application. Before starting the first-stage vacuum assembly 500, the method further includes:

[0084] S400: Obtain the first-level air pressure value of the first-level air extraction component 500. When the first-level air pressure value does not meet the starting value, control the pre-extraction component 400 to adjust the first-level air pressure value.

[0085] The primary air pressure value refers to the air pressure at the suction end and exhaust end of the primary air pump 510 in the primary air extraction assembly 500, and the startup value refers to the startup air pressure at both ends of the primary air pump 510. The size of the startup value can be designed based on the actual application scenario and the vacuum degree formed by the pre-evacuation in the lens barrel 100, and this application does not limit it. In an embodiment of the present invention, the startup air pressure at the suction end of the primary air pump 510 can be equal to the first preset air pressure value, while the startup air pressure at the exhaust end can be greater than the first preset air pressure value.

[0086] Because the air pressure in the lens barrel 100 is relatively negative before the first-stage exhaust component 500 is started, and the exhaust end of the first-stage exhaust component 500 is connected to the lens barrel 100 through the corresponding valve group, in order to ensure the smooth start-up of the first-stage exhaust pump 510, it is necessary to pre-exhaust the gas at the exhaust end of the first-stage exhaust pump 510 through the first pre-exhaust pump 410 in the pre-exhaust component 400, and the gas at the corresponding exhaust end is also adjusted through the second pre-exhaust pump 430, so that the air pressure at both ends of the first-stage exhaust pump 510 can meet the startup requirements.

[0087] S410: When the first-level air pressure value meets the starting value, the first-level air extraction component 500 is controlled to start.

[0088] When the first-level air pressure value meets the starting value, it means that the air pressure at the exhaust end and the air inlet end of the first-level air pump 510 both meet the starting conditions. At this time, the first-level air pump 510 can be restarted to continue to extract the gas in the lens barrel 100 directly at an air pressure lower than the first air pressure preset value.

[0089] Through the above steps S400 and S410, the pre-extraction and the first-stage exhaust of the gas can be started in sequence, so that when the pre-extraction efficiency decreases, it is replaced with the more efficient first-stage exhaust to ensure the overall vacuum extraction efficiency, so that the required vacuum degree can be quickly obtained.

[0090] Figure 4 The figure shows a schematic diagram of the process of starting the secondary exhaust assembly of the electron microscope in some embodiments of the present application. Figure 4 As shown, in some embodiments of the present application, before the secondary air extraction assembly 600 is started, the method further includes:

[0091] S500: Obtain the secondary air pressure value of the air extraction end of the secondary air extraction component 600. When the secondary air pressure value does not meet the set value, control the primary air extraction component 500 to adjust the secondary air pressure value.

[0092] The secondary air pressure value represents the air pressure at the exhaust end of the secondary exhaust component 600, and the set value is an air pressure value used to judge the relative size of the secondary air pressure value. Its specific value can be set according to the actual application scenario, and this application does not make specific limitations.

[0093] In an embodiment of the present invention, the secondary air pumping component 600 is an ion pump. When the secondary air pump is started, the air pressure at the connection point of the air pumping end is already relatively low. Therefore, in order to ensure the normal start-up of the ion pump, the air pumping end of the secondary air pumping component 600 can be connected to the air pumping end of the primary air pumping component 500 so that the primary air pressure value is consistent with the secondary air pressure value. When the secondary air pressure value does not meet the set value, the primary air pressure value also does not meet the set value, and the secondary air pumping component 600 cannot be started. The set value can be equal to the second air pressure preset value.

[0094] S510: When the secondary air pressure value meets the set value, the secondary air extraction component 600 is controlled to start.

[0095] When the secondary air pressure value meets the set value, it means that the air pressure in the lens barrel 100 is relatively low and the vacuum degree is relatively high. At this time, the secondary exhaust assembly 600 is started again to perform secondary exhaust on the electron gun chamber 110 in the lens barrel 100 to ensure the efficiency of vacuuming and quickly obtain the required vacuum degree in the electron gun chamber 110.

[0096] Through the above steps S500 and S510, after the first-level vacuum assembly 500 has been running for a period of time, the vacuum degree in the lens barrel 100 will gradually increase. When the air pressure in the lens barrel 100 is lower than a certain value, such as 10E-4Pa, the second-level vacuum can be started. The second-level vacuum and the first-level vacuum are run simultaneously to continue vacuum extraction, so as to realize the sequential start-up of the first-level vacuum and the second-level vacuum, thereby ensuring the overall vacuum extraction efficiency.

[0097] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the embodiments of the present invention. A person skilled in the art would be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A vacuum extraction system for an electron microscope, characterized in that: The vacuum extraction system of the electron microscope comprises: A detection member (200) is used to detect the air pressure value in the electron microscope; A controller (300) is connected to the detection element (200) for obtaining the air pressure value; a vacuum pumping mechanism, connected to the electron microscope, for pumping out gas from the electron microscope to form a vacuum, the vacuum pumping mechanism comprising a pre-pumping component (400), a first-stage pumping component (500), and a second-stage pumping component (600), all of which are communicatively connected to the controller (300), the controller (300) being configured to sequentially control the pre-pumping component (400), the first-stage pumping component (500), and the second-stage pumping component (600) to start according to a gradual decrease in the air pressure value, and to keep the first-stage pumping component (500) in continuous operation; The secondary air extraction assembly (600) comprises: A secondary air pump is arranged near the electron gun chamber (110) of the electron microscope and is connected to the controller (300) and the electron gun chamber (110) of the electron microscope. The air pumping end of the secondary air pump is communicated with the air pumping end of the primary air pumping component (500) to adjust the air pressure at the air pumping end of the secondary air pump.

2. The vacuum extraction system for an electron microscope according to claim 1, characterized in that: The pre-extraction component (400) comprises: a first pre-pump (410) in communication with the controller (300); a first air extraction valve assembly connected to the first pre-extraction pump (410) and the electron microscope, respectively, wherein the first pre-extraction pump (410) is configured to pre-extract gas from the electron microscope and adjust the gas pressure at the extraction end of the first-stage air extraction component (500); a second pre-pump (430) in communication with the controller (300); and an air extraction valve (440) connected to the second pre-extraction pump (430) and the exhaust end of the first-stage air extraction component (500), respectively, wherein the second pre-extraction pump (430) is configured to adjust the air pressure at the exhaust end of the first-stage air extraction component (500); When the air pressure at the air extraction end and the air exhaust end of the first-stage air extraction component (500) meets a preset condition, the controller (300) controls the first-stage air extraction component (500) to start.

3. The vacuum extraction system for an electron microscope according to claim 2, wherein: The first-stage air extraction component (500) comprises: A first-stage air extraction pump (510) is communicatively connected to the controller (300), and an exhaust end of the first-stage air extraction pump (510) is in communication with the air extraction valve (440); The primary control valve group is connected to the air extraction end of the primary air extraction pump (510), the first air extraction valve group and the electron microscope respectively.

4. The vacuum extraction system for an electron microscope according to any one of claims 1 to 3, characterized in that: The vacuum extraction system of the electron microscope also includes: A conversion valve (111) is communicated with the electron gun chamber (110) of the electron microscope and is used for filling or exhausting insulating gas.

5. A vacuum extraction method for an electron microscope, characterized in that: A vacuum extraction system for an electron microscope according to any one of claims 1 to 4, wherein the vacuum extraction method for the electron microscope comprises: Starting the pre-extraction component (400) to pre-extract gas in the electron microscope and obtaining a first gas pressure value in the electron microscope; When the first air pressure value is less than a first air pressure preset value and greater than a second air pressure preset value, the first-stage air extraction component (500) is activated to perform first-stage air extraction in the electron microscope; When the first air pressure value is less than a second air pressure preset value, the secondary air extraction component (600) is activated to perform secondary air extraction in the electron microscope.

6. The vacuum extraction method for an electron microscope according to claim 5, characterized in that: Before the first-stage vacuuming component (500) is activated, the vacuum extraction method of the electron microscope further comprises: Acquiring a first-level air pressure value of the first-level air extraction component (500), and when the first-level air pressure value meets a start-up value, controlling the first-level air extraction component (500) to start; When the first-level air pressure value does not meet the starting value, the pre-evacuation component (400) is controlled to adjust the first-level air pressure value.

7. The vacuum extraction method for an electron microscope according to claim 5, characterized in that: Before the secondary vacuuming component (600) is activated, the vacuum extraction method of the electron microscope includes: Obtaining a secondary air pressure value at the air extraction end of the secondary air extraction component (600), and when the secondary air pressure value does not meet a set value, controlling the primary air extraction component (500) to adjust the secondary air pressure value; When the secondary air pressure value meets the set value, the secondary air extraction component (600) is controlled to start.

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