A plasma cleaning device for precision electron microscope analysis instruments

Abstract

The present invention discloses a plasma cleaning device for a precision electron microscope analysis instrument, which includes an electron microscope analysis instrument cavity. The electron microscope analysis instrument cavity is respectively connected to a vacuum gauge, an RGA analyzer, a QCM film thickness controller and a vacuum pump. The electron microscope analysis instrument cavity is also connected to a plasma generator. A Langmuir probe is arranged on the connecting pipeline between the output end of the plasma generator and the electron microscope analysis instrument cavity for measuring the plasma parameters generated during the discharge of the plasma generator. A leak valve is arranged at the top of the output end of the plasma generator, and the input end of the plasma generator is connected to a radio frequency source through a radio frequency wire. The plasma cleaning device for the precision electron microscope analysis instrument can select an appropriate discharge power according to the type and size of the cavity to be cleaned, so as to achieve the purpose of cleaning pollutants, and has stronger applicability; the plasma is generated by radio frequency source excitation to clean the inside of the cavity, and the inner wall of the cleaned cavity will not be damaged.

Description

Technical Field

[0001] The present invention belongs to the technical field of plasma cleaning devices, and particularly relates to a plasma cleaning device for precision electron microscopy analysis instruments. Background Art

[0002] In an electron microscopy analysis system, lubricating oil, vacuum grease, high vapor pressure polymers, and photoresist samples may all introduce hydrocarbon contamination into the system. XPS data clearly shows that the surface of a clean sample exposed to air will be contaminated by airborne hydrocarbon materials after only one hour. For a high-resolution SEM system, the high resolution of the system comes from secondary electron imaging, and secondary electrons mainly come from the thin film surface layer of the sample. Therefore, if the surface is contaminated, the electrons mainly come from the contaminated layer rather than the underlying target material. With the continuous progress of scientific research, the requirements for ultra-high vacuum systems are getting higher and higher. Ultra-high vacuum systems are the main part of modern surface analysis and research. Usually, ultra-high vacuum chambers and related pumping pipes are made of stainless steel materials, and knife-edge flanges and copper gaskets are used to seal the connections.

[0003] If the vacuum chamber is severely contaminated with hydrocarbons and the sample is irradiated with a high-dose electron beam for a long time, a black frame will form on the sample surface. This black frame is mainly caused by polymer carbon deposition. The main reason for carbon deposition is that when a high-energy electron beam hits the sample surface, a large number of low-energy secondary electrons will be generated. These secondary electrons, due to their low kinetic energy, will interact with the organic contaminants remaining on the sample surface. The secondary electrons decompose the organic contaminants and at the same time form "carbon deposition" (carbon and hydrocarbon contaminants) around the imaging area. Since hydrocarbon contaminants are poor conductors, unstable charging conditions will be generated inside the electron optical column. As the "carbon deposition" increases, the charge accumulated on the surface will continuously increase. During a long scanning process, the focus and beam position may drift. At the same time, local charging will also increase lens aberration and reduce resolution, resulting in unclear imaging.

[0004] X-rays are used to analyze the composition of materials. A high-dose electron beam irradiates the surface of the sample for a long time. If the vacuum chamber is severely contaminated with hydrocarbons, the carbon deposition will increase and be higher than the actual percentage in the sample material. Two components in electron optics are exposed to high-dose electron irradiation for a long time. The aperture restricts the beam angle and controls the beam current by blocking large-angle electrons, and can also be used as a light attenuator. The scanning electron detector is used to collect the emitted secondary electrons. These two electron-optical components are not in the ultra-high vacuum region, and if the cavity is contaminated, they are easily affected by severe hydrocarbon accumulation. At the same time, during the sample preparation process, inorganic contaminants will inevitably adhere to the surface of the sample and the end of the sample rod. These contaminants will enter the vacuum sample chamber together with the sample, affecting the imaging resolution of the sample and even contaminating the entire sample chamber. Therefore, before performing an electron microscope test on the sample, the sample needs to be cleaned.

[0005] Traditional electron microscope analysis systems are mostly cleaned with organic solvents. On the one hand, organic solvents will remain on the surface of the sample, and on the other hand, they will also cause environmental pollution. Therefore, in response to the above problems, plasma cleaning technology has emerged. Plasma cleaning mainly relies on the "activation effect" of active free radicals generated during the plasma discharge process to remove impurities on the surface of the object. Through gas-phase chemical reactions, organic contaminants and oil stains are converted into gaseous water and carbon dioxide, and these gases can be pumped away by a vacuum pump. Since the plasma generated during the discharge is anisotropic, it can penetrate into the fine pores and recesses of the object to complete the cleaning task. The necessity of using ultra-high vacuum in surface analysis technology: First, the low-energy electron signals to be analyzed are easily scattered by residual gas molecules, resulting in a decrease in the total signal of the spectrum. Only under ultra-high vacuum conditions can low-energy electrons obtain a sufficiently long mean free path without being scattered and lost. Second, the ultra-high vacuum environment is necessary for the surface sensitivity of surface analysis technology itself. At a high vacuum of 1e-6 mbar, about one monolayer of gas will adsorb on the solid surface in about 1 second, which is too short compared to the typical spectrum acquisition time. Obviously, an ultra-high vacuum environment is required during the analysis process to keep the sample surface clean. Finally, surface-sensitive analysis technology has much higher requirements for the cleanliness of the sample surface than other analysis technologies. The preparation and maintenance of a clean surface are very necessary. Surface analysis needs to be carried out in ultra-high vacuum (UHV) to ensure that the surface will not be contaminated during the analysis process.

[0006] To make the system reach the required vacuum degree, it is necessary to ensure the cleanliness of the inner surface of the vacuum pipeline. At present, there are many methods for cleaning the vacuum pipeline, and the common ones are the combination of mechanical wire drawing and polishing and chemical cleaning methods. These methods have their deficiencies. For example, mechanical wire drawing and polishing can easily cause wear on the surface of the object to be cleaned, with a relatively high labor intensity, and the equipment needs to stop working, thus unable to meet the requirements of high cleanliness cleaning. Although the chemical cleaning method can prevent wear on the surface of the object, its disadvantage is that if the chemical cleaning solution is not properly selected, it will cause corrosion damage to the cleaning object and result in losses; moreover, the waste liquid discharged from chemical cleaning is also one of the reasons for environmental pollution, and improper operation and handling of chemical agents will pose hazards to human health and safety.

[0007] In response to the above problems, plasma cleaning technology has emerged. Its greatest feature is that it can be processed regardless of the substrate type of the processing object, and it can handle metals, semiconductors, oxides, and most polymer materials (such as polyethylene, polyvinyl chloride, polytetrafluoroethylene, polyimide, polyester, epoxy resin, etc.) well, and can achieve plasma cleaning of the whole, local, and complex structures. Plasma cleaning mainly relies on the "activation effect" of active free radicals generated during the plasma discharge process to remove impurities on the surface of the object. Through gas-phase chemical reactions, organic pollutants and oil stains are converted into gaseous water and carbon dioxide, and these gases can be pumped away by a vacuum pump. Since the plasma generated during the discharge is anisotropic, it can penetrate into the fine pores and recesses inside the object to complete the cleaning task, so there is no need to consider too much the shape of the wall of the object to be cleaned.

[0008] From the perspective of various current cleaning methods, plasma cleaning is the most thorough stripping cleaning method among all cleaning methods. However, for general discharge plasma cleaning, direct current and low-frequency discharge are generally used to excite the plasma, mainly using physical effects to remove water vapor inside the cavity, with a relatively small power used. The plasma excited in this way is likely to cause damage to the surface of the sample, and at the same time, the operation is complex and not suitable for cleaning precision analytical instruments such as electron microscopes. The present invention aims at the problems existing in the current plasma technology for cleaning precision electron microscope analytical instruments, and invents a plasma cleaning device for precision electron microscope analytical instruments to solve the above problems and better meet the needs of the majority of scientific and technological personnel. Summary of the Invention

[0009] The purpose of the present invention is to provide a plasma cleaning device for precision electron microscope analytical instruments to solve the problems raised in the above background technology.

[0010] To achieve the above object, the present invention provides the following technical solution: A plasma cleaning device for a precision electron microscope analysis instrument, including an electron microscope analysis instrument cavity, the electron microscope analysis instrument cavity is respectively connected to a vacuum gauge, an RGA analyzer, a QCM film thickness controller and a pumping pump, and the electron microscope analysis instrument cavity is also connected to a plasma generator. A Langmuir probe is provided on the connection pipeline between the output end of the plasma generator and the electron microscope analysis instrument cavity for measuring the plasma parameters generated during the discharge of the plasma generator.

[0011] A leak valve is provided at the top of the output end of the plasma generator, and the input end of the plasma generator is connected to a radio frequency integrated source through a radio frequency line.

[0012] Preferably, the radio frequency integrated source includes a housing, heat dissipation holes are provided on the surface of the housing, a base is provided inside the housing, the base is fixedly arranged with the housing, a DC power supply and a radio frequency source are respectively fixed on the upper surface of the base, a power supply port is provided at one end of the DC power supply, and a radio frequency source output port is provided at one end of the radio frequency source. An opening is provided on the surface of the housing for the radio frequency source output port and the power supply port to extend out of the housing.

[0013] In any of the above solutions, preferably, the base includes a bottom plate matching one side of the housing, side plates are vertically arranged around the bottom plate, bolt holes are provided on the surface of the side plates, and the bolt holes of the side plates correspond to the bolt holes on the surface of the housing. The side plates are fixedly connected to the housing through bolts.

[0014] In any of the above solutions, preferably, a fan is provided inside the housing near the radio frequency source. Bolt holes are provided at the four top corners of the fan, and heat dissipation openings are provided on the surface of the housing. Installation holes corresponding to the bolt holes of the fan are provided at the four top corners of the heat dissipation openings for bolted fixed connection with the fan.

[0015] In any of the above solutions, preferably, the plasma generator includes a plasma generator main body. One end of the plasma generator main body is provided with a radio frequency line connection port connected to the radio frequency line. The other end of the plasma generator main body is provided with a mounting seat. A leak valve interface is provided on the surface of the mounting seat for connection with the leak valve. A fastening bolt is provided in the mounting seat corresponding to the upper side of the leak valve interface. The mounting hole at one end of the mounting seat is connected to a sealing flange through a bolt, and the sealing flange connects the mounting seat and the connection pipeline.

[0016] In any of the above solutions, preferably, a heat dissipation channel is provided on the surface of the plasma generator main body.

[0017] In any of the above solutions, preferably, two generating chambers are provided inside the plasma generator main body, and the two generating chambers are separated by a coupler.

[0018] Technical effects and advantages of the present invention: 1. The plasma cleaning device for precision electron microscope analysis instruments can select an appropriate discharge power according to the type and size of the cavity to be cleaned, so as to achieve the purpose of cleaning pollutants, and has stronger applicability;

[0019] 2. The plasma is generated by radio frequency source excitation to clean the inside of the cavity, and the inner wall of the cavity to be cleaned will not be damaged;

[0020] 3. The active free radicals of radio frequency plasma react with organic pollutants to generate volatile CO and CO2 gases (hydrocarbons), and these volatile gases can be pumped away by a vacuum pump, so as to achieve the purpose of cleaning pollutants, with simple operation and convenient use;

[0021] 4. Different discharge gases and electrode materials can be selected according to the type and degree of pollution of the pollutants in the cavity, which can effectively remove pollutants, clean the cavity and samples;

[0022] 5. It can realize the cleaning of ultra-high vacuum precision electron microscope analysis instruments. After the cavity is cleaned by plasma, the time required to reach ultra-high vacuum can be effectively shortened. Description of the Drawings

[0023] Figure 1 It is a schematic structural diagram of the present invention;

[0024] Figure 2 It is a schematic structural diagram of the radio frequency integrated source of the present invention;

[0025] Figure 3 It is a schematic structural diagram of the radio frequency integrated source of the present invention from another perspective;

[0026] Figure 4 It is a schematic internal structure diagram of the radio frequency integrated source of the present invention;

[0027] Figure 5 It is a schematic structural diagram of the plasma generator of the present invention;

[0028] Figure 6 It is a schematic structural diagram of the plasma generator of the present invention from another perspective;

[0029] Figure 7 It is a schematic structural diagram of the mounting seat of the present invention;

[0030] Figure 8 It is a schematic internal structure diagram of the mounting seat of the present invention;

[0031] Figure 9 It is a schematic connection structure diagram of the air leakage valve and the plasma generator of the present invention;

[0032] Figure 10 Schematic diagram of the enlarged structure of part A of the present invention;

[0033] Figure 11 Internal sectional view of the plasma generator of the present invention.

[0034] In the figure: 1. Radio frequency integrated source; 11. Housing; 12. Heat dissipation holes; 13. Power supply port; 14. Radio frequency source output port; 15. Fan; 16. Base; 17. Radio frequency source; 18. DC power supply; 19. Heat dissipation port; 2. Radio frequency cable; 3. Plasma generator; 31. Mounting seat; 32. Sealing flange; 33. Heat dissipation channel; 34. Radio frequency cable connection port; 35. Fastening bolt; 36. Mounting hole; 37. Coupler; 38. Leakage valve interface; 39. Plasma generator main body; 5. Langmuir probe; 6. Electron microscope analysis instrument cavity; 7. Vacuum gauge; 8. RGA analyzer; 9. QCM film thickness controller; 10. Air extraction pump. Specific embodiments

[0035] The following further describes the specific embodiments of the present invention with reference to the accompanying drawings. It should be noted here that the description of these embodiments is for helping to understand the present invention, but does not constitute a limitation to the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0036] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0037] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0038] The present invention provides as Figures 1-11A plasma cleaning device for a precision electron microscope analysis instrument is shown, which includes an electron microscope analysis instrument cavity 6. The electron microscope analysis instrument cavity 6 is respectively connected to a vacuum gauge 7, an RGA analyzer 8, a QCM film thickness controller 9 and a pumping pump 10. The vacuum gauge 7, the RGA analyzer 8, the QCM film thickness controller 9 and the pumping pump 10 are all existing technical equipment, and the vacuum gauge 7, the RGA analyzer 8 and the QCM film thickness controller 9 are all connected to the electron microscope analysis instrument cavity 6 by copper gasket sealed flanges. The vacuum gauge 7 can effectively detect the discharge pressure in the electron microscope analysis instrument cavity 6 during the discharge. The RGA analyzer 8 can effectively analyze the composition change of the residual gas in the electron microscope analysis instrument cavity 6 before and after plasma cleaning. The QCM film thickness controller 9 can effectively monitor the cleaning rate in the electron microscope analysis instrument cavity 6. The electron microscope analysis instrument cavity 6 is also connected to a plasma generator 3. The connecting pipe of the electron microscope analysis instrument cavity 6 is connected to the electron microscope analysis instrument cavity 6 through a sealed flange 32. A Langmuir probe 5 is arranged on the connecting pipe between the output end of the plasma generator 3 and the electron microscope analysis instrument cavity 6 for measuring the plasma parameters generated during the discharge of the plasma generator 3. A leak valve 4 is arranged at the top of the output end of the plasma generator 3. The input end of the plasma generator 3 is connected to a radio frequency integrated source 1 through a radio frequency wire 2. The radio frequency integrated source 1 includes a housing 11. At least two surfaces of the housing 11 are provided with heat dissipation holes 12. A base 16 is arranged inside the housing 11. The base 16 is fixedly arranged with the housing 11. The base 16 includes a bottom plate matching one side of the housing 11. Side plates are vertically arranged around the bottom plate. The side plates and the bottom plate are integrally formed. Bolt holes are opened on the surfaces of two opposite side plates, and the bolt holes correspond to the bolt holes on the surface of the housing 11. The side plates are fixedly connected to the housing 11 through bolts. A DC power supply 18 and a radio frequency source 17 are respectively fixed on the upper surface of the base 16. The fixing methods are bolt connection, gluing and fixing connections other than the two connection methods. One end of the DC power supply 18 is provided with a power supply port 13, and the power supply port 13 is fixed to the housing 11 through bolts. The power supply port 13 is electrically connected to the DC power supply 18 through an electric wire. One end of the radio frequency source 17 is provided with a radio frequency source output port 14. An opening is opened on the surface of the housing 11 for the radio frequency source output port 14 and the power supply port 13 to extend out of the housing 11. A fan 15 is arranged inside the housing 11 near the radio frequency source 17. Bolt holes are arranged at the four top corners of the fan 15. Heat dissipation openings 19 are arranged on the surface of the housing 11, and mounting holes corresponding to the bolt holes of the fan 15 are arranged at the four top corners of the heat dissipation openings 19 for bolt-fixing the fan 15 to the housing 11. Connecting the fan 15 and the housing 11 together by bolts makes it more stable during use and convenient for disassembly.

[0039] Specifically refer to Figures 5-8The plasma generator 3 shown includes a plasma generator main body 39. A heat dissipation channel 33 is provided on the surface of the plasma generator main body 39, and the heat dissipation channel 33 is provided on at least one side. The setting of the heat dissipation channel 33 enables the heat generated by the plasma generator 3 to be dissipated in time during operation, maintaining the use stability and service life. Two generating chambers are provided inside the plasma generator main body 39, and the two generating chambers are separated by a coupler 37. One end of the plasma generator main body 39 is provided with a radio frequency line connection port 34 connected to the radio frequency line 2, and there are no less than 2 radio frequency line connection ports 34. The other end of the plasma generator main body 39 is provided with a mounting seat 31. An air leakage valve interface 38 is opened on the surface of the mounting seat 31 for connecting to the air leakage valve 4. A fastening bolt 35 is provided above the air leakage valve interface 38 inside the mounting seat 31 for fixing the air leakage valve joint 42 of the air leakage valve 4 at the air leakage valve interface 38. The mounting hole 36 at one end of the mounting seat 31 is connected to the sealing flange 32 by a bolt, and the sealing flange 32 connects the mounting seat 31 and the connecting pipe.

[0040] The air leakage valve 4 is used for air leakage. The air leakage valve 4 mainly includes an air leakage valve main body. An air leakage valve joint is provided at one end of the air leakage valve main body. One end of the air leakage valve joint is a tip, which is threadedly fixed to the fastening bolt 35 by a thread. The diameter of the air leakage valve interface 38 is larger than the tip diameter of the air leakage valve joint and not larger than the diameter of the air leakage valve joint, so that the tip of the air leakage valve joint is inserted into the air leakage valve interface 38, and the air leakage valve joint starting from the thread position is located outside the air leakage valve interface 38. Rotating the air leakage valve main body makes the thread of the air leakage valve joint screwed to the inner wall of the fastening bolt 35, so that the connection is tight and stable.

[0041] During the use of the plasma cleaning device for precision electron microscope analysis instruments, first, the vacuum gauge 7, RGA analyzer 8, QCM film thickness controller 9, and air pump 10 are installed on the cavity 6 of the electron microscope analysis instrument, while ensuring airtightness. Then, a plasma generator 3 is connected to the connecting pipe extending from the cavity 6 of the electron microscope analysis instrument, and a Langmuir probe 5 is connected to the connecting pipe. The air leakage valve 4 is fixed on the mounting seat 31 of the plasma generator 3. Then, the plasma generator 3 is connected to the radio frequency integrated source 1 with a radio frequency cable 2. During cleaning, the switch of the radio frequency integrated source 1 is turned on. The radio frequency integrated source 1 acts on the plasma generator 3 to excite the generation of plasma. Then, the plasma reacts with the organic pollutants on the inner wall of the cavity 6 of the electron microscope analysis instrument to produce volatile CO and CO2 gases (hydrocarbons). These volatile gases are pumped away by the air pump 10 to achieve the cleaning of the cavity 6 of the electron microscope analysis instrument. According to the pollutants to be cleaned, different cleaning gases can be selected, such as air, oxygen, nitrogen, argon, etc., but not limited to the above gases. The radio frequency integrated source 1 is also optional. A high-power radio frequency source, using a special radio frequency chip amplifier, is driven by a low voltage of 24V. A discharge frequency of 200 - 500 MHz can be selected, and the discharge power is 100 - 150W, which is proportional to the surface area of the cavity. Increasing the plasma discharge power increases the cleaning speed and intensity by increasing the ion density and ion energy density in the plasma. However, increasing the power too much may be harmful to the pipe cavity and the sample and is also ineffective for the results. Therefore, a suitable discharge power needs to be selected during the cleaning process.

[0042] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limitations of the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A plasma cleaning device for a precision electron microscope analysis instrument, characterized in that: It is composed of an electron microscope analysis instrument cavity (6), a vacuum gauge (7), an RGA analyzer (8), a QCM film thickness controller (9), a pumping pump (10), a plasma generator (3), a Langmuir probe (5), a leak valve (4), a radio frequency line (2), a radio frequency integrated source (1) and a connecting pipe; The electron microscope analysis instrument cavity (6) is respectively connected to the vacuum gauge (7), the RGA analyzer (8), the QCM film thickness controller (9) and the pumping pump (10). The connecting pipe extending from the electron microscope analysis instrument cavity (6) is connected to a plasma generator (3). A Langmuir probe (5) is arranged on the connecting pipe between the output end of the plasma generator (3) and the electron microscope analysis instrument cavity (6). The Langmuir probe (5) is used to measure the plasma parameters generated by the plasma generator (3); A leak valve (4) is arranged at the top of the output end of the plasma generator (3), and the input end of the plasma generator (3) is connected to the radio frequency integrated source (1) through the radio frequency line (2); The plasma generator (3) includes a plasma generator main body (39). At one end of the plasma generator main body (39), at least two radio frequency line connection ports (34) connected to the radio frequency line (2) are arranged. There are two generating chambers inside the plasma generator main body (39), and the two generating chambers are separated by a coupler (37); At the other end of the plasma generator main body (39), a mounting seat (31) is arranged. A leak valve interface (38) is opened on the surface of the mounting seat (31) for connecting to the leak valve (4). A fastening bolt (35) is arranged inside the mounting seat (31) corresponding to the upper part of the leak valve interface (38). The leak valve (4) includes a leak valve main body. One end of the leak valve main body is provided with a leak valve joint. One end of the leak valve joint is a tip, and it is threadedly fixed to the fastening bolt (35) through a thread. The leak valve joint starting from the thread position is located outside the leak valve interface (38). Rotating the leak valve main body makes the thread of the leak valve joint screwed to the inner wall of the fastening bolt (35). The mounting hole (36) at one end of the mounting seat (31) is connected to a sealing flange (32) through a bolt, and the sealing flange (32) connects the mounting seat (31) and the connecting pipe; The discharge frequency of the radio frequency integrated source (1) is 200 - 500 MHz, and the discharge power is 100 - 150 W.

2. The plasma cleaning device for a precision electron microscope analysis instrument according to claim 1, characterized in that: The radio frequency integrated source (1) includes a housing (11). Heat dissipation holes (12) are provided on the surface of the housing (11). A base (16) is provided inside the housing (11), and the base (16) is fixedly arranged with the housing (11). A DC power supply (18) and a radio frequency source (17) are respectively fixed on the upper surface of the base (16). One end of the DC power supply (18) is provided with a power supply port (13), and one end of the radio frequency source (17) is provided with a radio frequency source output port (14). An opening is formed on the surface of the housing (11) for the radio frequency source output port (14) and the power supply port (13) to extend out of the housing (11).

3. The plasma cleaning device for a precision electron microscope analysis instrument according to claim 2, characterized in that: The base (16) includes a bottom plate matching one side of the housing (11). Side plates are vertically arranged around the bottom plate. Bolt holes are provided on the surface of the side plates, and the bolt holes on the side plates correspond to the bolt holes on the surface of the housing (11). The side plates are fixedly connected to the housing (11) by bolts.

4. The plasma cleaning device for a precision electron microscope analysis instrument according to claim 2, characterized in that: A fan (15) is provided inside the housing (11) near the radio frequency source (17). Bolt holes are provided at the four top corners of the fan (15). A heat dissipation port (19) is provided on the surface of the housing (11), and mounting holes corresponding to the bolt holes of the fan (15) are provided at the four top corners of the heat dissipation port (19) for bolted fixed connection with the fan (15).

5. A plasma cleaning device for a precision electron microscope analysis instrument according to claim 1, characterized in that: A heat dissipation channel (33) is provided on the surface of the plasma generator main body (39).

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