A cleaning tool, device and method for scanning electron microscope aperture and sample

Abstract

The present invention discloses a cleaning tool, device and method for the diaphragm and sample of a scanning electron microscope, and relates to the technical field of scanning electron microscopes. The cleaning tool comprises a cleaning cavity, which is provided with a cleaning chamber and a first interface, a second interface and a third interface respectively connected to the cleaning chamber; the first interface is used for inserting an object to be cleaned; the second interface is used for connecting a plasma cleaning instrument; the third interface is used for connecting a vacuum pump group. The present invention provides a cleaning tool, a cleaning device and a cleaning method, which can be used to clean objects such as the diaphragm and samples of a scanning electron microscope, and can directly clean the diaphragm without removing the diaphragm sheet, thereby solving the problem of local deformation of the diaphragm caused by high-temperature cleaning and grinding cleaning, and effectively reducing the impact on the imaging quality of the scanning electron microscope.

Description

Technical Field

[0001] The present invention relates to the technical field of cleaning devices, and in particular to a cleaning tool, a cleaning device and a cleaning method thereof. Background Art

[0002] Scanning electron microscope (SEM) is a large precision instrument used for high-resolution micro-area morphology analysis. It uses a narrowly focused high-energy electron beam to scan the sample surface, and generates various signal electrons through the interaction between the electron beam and the sample to characterize the microscopic morphology of the material. Due to its large depth of field, high resolution, intuitive imaging, strong three-dimensional sense, wide magnification range, and the ability to rotate and tilt the sample to be tested in three-dimensional space, scanning electron microscopes are widely used in chemical engineering, material analysis, biomedicine, teaching and scientific research, and other fields.

[0003] In the process of high-energy electron beam moving to the sample surface, the electron beam will inevitably bombard the diaphragm, causing the diaphragm to be contaminated. This contaminant is formed by the polymer formed by hydrocarbons in the vacuum system slowly deposited on the surface of the diaphragm. Once the diaphragm of the scanning electron microscope is contaminated, the edge of the diaphragm hole will be accumulated by contaminants, making the aperture smaller and the edge irregular, resulting in increased astigmatism, decreased signal-to-noise ratio and poor resolution. Usually, the diaphragm in the scanning electron microscope is made of high-purity molybdenum with a thickness between 0.02-0.1mm, and the roundness error is required to be less than 0.002mm. The processing accuracy of this molybdenum is very high, and the material and processing costs are very expensive. At the same time, the diaphragm is easily contaminated, so it is often cleaned to achieve reuse, thereby reducing costs.

[0004] At present, the commonly used cleaning methods for diaphragms are high-temperature heating cleaning and grinding cleaning. However, the high-temperature heating and grinding methods may cause local deformation of the diaphragm during the fixing and cleaning process, thereby affecting its imaging performance. Summary of the invention

[0005] The main purpose of the present invention is to provide a cleaning tool, a cleaning device and a cleaning method thereof, aiming to avoid local deformation of the diaphragm to be cleaned object due to cleaning, so as to reduce the impact on the imaging quality of the electron microscope.

[0006] To achieve the above object, the present invention provides a cleaning tool, which comprises:

[0007] A cleaning cavity body, comprising a cleaning chamber and a first interface, a second interface and a third interface respectively connected with the cleaning chamber;

[0008] The first interface is used for inserting the object to be cleaned;

[0009] The second interface is used to connect to a plasma cleaning instrument;

[0010] The third interface is used to connect to a vacuum pump group.

[0011] Optionally, the first interface is a flange interface embedded in the cleaning cavity, or the first interface is a disc-shaped socket opened on the cavity wall of the cleaning cavity.

[0012] Optionally, the cleaning tool further includes a vacuum gauge, which is connected to the cleaning chamber to monitor the vacuum degree of the cleaning chamber.

[0013] Optionally, a fourth interface is further provided on the cleaning cavity, and the vacuum gauge is connected to the cleaning cavity via the fourth interface.

[0014] Optionally, the second interface, the third interface and the fourth interface are all flange interfaces.

[0015] Optionally, sealing rings are provided at the connections between the second interface, the third interface, the fourth interface and the cleaning cavity.

[0016] Optionally, the cleaning chamber is provided with a fifth interface, the fifth interface is connected to a window flange, a sealing ring is provided at the connection between the fifth interface and the window flange, and glass is installed in the window flange for observing the cleaning condition in the cleaning chamber.

[0017] Optionally, the cleaning tool further includes a support platform, and the cleaning cavity is arranged on the support platform.

[0018] To achieve the above object, the present invention provides a cleaning device, which includes a plasma cleaning instrument, a vacuum pump group and the cleaning tool as described above, wherein the plasma cleaning instrument is connected to the second interface of the cleaning tool, and the vacuum pump group is connected to the third interface of the cleaning tool;

[0019] The cleaning tool comprises:

[0020] A cleaning cavity body, comprising a cleaning chamber and a first interface, a second interface and a third interface respectively connected with the cleaning chamber;

[0021] The first interface is used for inserting the object to be cleaned;

[0022] The second interface is used to connect to a plasma cleaning instrument;

[0023] The third interface is used to connect to a vacuum pump group.

[0024] To achieve the above object, the present invention further provides a cleaning method for a cleaning device. Based on the above cleaning device, the cleaning method comprises the following steps:

[0025] After the object to be cleaned is loaded into the cleaning chamber, the vacuum pump group is turned on to make the cleaning chamber reach a vacuum environment;

[0026] detecting the vacuum degree of the cleaning chamber;

[0027] When the vacuum degree is lower than a preset vacuum value, controlling the plasma cleaning instrument to work;

[0028] After the cleaning time reaches a preset time, photographing the object to be cleaned in the cleaning chamber and generating an image signal, and outputting the image signal to a host computer;

[0029] judging whether the object to be cleaned is in a clean state according to the image signal;

[0030] When the object to be cleaned is in the clean state, the plasma cleaning apparatus and the vacuum pump group are stopped.

[0031] In the technical solution of the present invention, the cleaning tool includes a cleaning cavity, which is provided with a cleaning chamber and a first interface, a second interface and a third interface respectively connected to the cleaning chamber; the first interface is used for inserting the object to be cleaned; the second interface is used to connect the plasma cleaning instrument; the third interface is used to connect the vacuum pump group. In this way, plasma cleaning of objects such as diaphragms and samples is achieved, which can remove surface contaminants without damaging the diaphragms and samples, and will not cause deformation. Therefore, it can meet the cleaning requirements of the two main easily contaminated parts in the scanning electron microscope, and effectively reduce the impact on the imaging quality of the scanning electron microscope. In addition, the cleaning device can also solve the cleaning problem of the beam gate assembly of the electron beam exposure machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0033] Figure 1 It is a structural schematic diagram of an embodiment of a cleaning tool of the present invention;

[0034] Figure 2 It is a front view of an embodiment of a cleaning tool of the present invention;

[0035] Figure 3 for Figure 2 Sectional view at AA in the middle;

[0036] Figure 4 The figure is a schematic flow chart of a cleaning method for a cleaning device according to an embodiment of the present invention.

[0037] Description of Figure Numbers:

[0038] 10. Cleaning cavity; 101. Cleaning chamber; 21. First interface; 22. Second interface; 23. Third interface; 24. Fourth interface; 31. Sealing ring; 41. Window flange; 51. Support platform.

[0039] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0042] In addition, the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the meaning of "and / or" appearing in the full text is to include three parallel solutions. Taking "A and / or B" as an example, it includes solution A, or solution B, or a solution that satisfies both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0043] The present invention provides a cleaning tool, which is formed with a plasma cleaning chamber for accommodating and fixing an aperture, a test sample or other objects that can be cleaned by plasma cleaning, but the scope of the invention is not limited thereto.

[0044] Reference Figures 1 to 3In one embodiment of the present invention, the cleaning tool includes a cleaning chamber 10, which is provided with a cleaning chamber 101 and a first interface 21, a second interface 22 and a third interface 23 respectively connected to the cleaning chamber 101; the first interface 21 is used for inserting the object to be cleaned; the second interface 22 is used for connecting a plasma cleaning instrument; the third interface 23 is used for connecting a vacuum pump group.

[0045] In this embodiment, the cleaning chamber 10 may be a closed structure, and an O-ring 31 may be provided at each interface to improve the sealing performance, so as to ensure that the cleaning chamber 101 can reach a vacuum state, thereby improving the plasma cleaning effect.

[0046] The first interface 21 can adopt a structure that matches the shape of the object to be cleaned. When the object to be cleaned is an aperture, the first interface 21 can be a flange interface embedded in the cleaning chamber 10, or the first interface 21 can be a disc-shaped socket opened on the wall of the cleaning chamber 10; in this case, the aperture can be inserted into the flange interface or the disc-shaped socket. When the object to be cleaned is a test sample, the sample can be placed in the cleaning chamber 101, and the first interface 21 can be sealed with a blind plate. When cleaning the beam gate assembly of the electron beam exposure machine, the beam gate assembly needs to be connected to the first interface 21.

[0047] The second interface 22 and the third interface 23 can be flange interfaces or pipe joints that are convenient for connecting pipelines, which is not limited here.

[0048] It can be understood that the present invention, by adopting the above-mentioned cleaning tool, realizes plasma cleaning of objects such as apertures and samples, can remove surface contaminants without damaging the apertures and samples, and will not cause deformation, so it can meet the cleaning requirements of the two main easily contaminated parts in the scanning electron microscope, and effectively reduce the impact on the imaging quality of the scanning electron microscope. In addition, the cleaning device can also solve the cleaning problem of the beam gate assembly of the electron beam exposure machine.

[0049] In order to achieve a better vacuum state in the cleaning chamber 101 and further improve the plasma cleaning effect, refer to Figures 1 to 3 In one embodiment, the cleaning tool may further include a vacuum gauge (not shown), which is connected to the cleaning chamber 10 to monitor the vacuum degree of the cleaning chamber 101 .

[0050] Furthermore, the main reference Figure 1 The cleaning chamber 10 is also provided with a fourth interface 24, and the vacuum gauge is connected to the cleaning chamber 10 via the fourth interface 24. In this embodiment, the second interface 22, the third interface 23 and the fourth interface 24 can all be preferably flange interfaces.

[0051] In this embodiment, sealing rings 31 may be provided at the connection points between the second interface 22 , the third interface 23 , and the fourth interface 24 and the cleaning chamber 10 . The sealing ring 31 may be made of O-type rubber or the like, which is not limited here.

[0052] The present invention provides a sealing ring 31 for sealing connection without welding interfaces, and the device is easy to process, which can shorten the processing cycle, reduce costs, and facilitate maintenance.

[0053] In order to observe the cleaning state in the cleaning chamber 101 in real time, refer to Figures 1 to 3 In one embodiment, the cleaning chamber 10 is provided with a fifth interface, which is connected to the window flange 41. A sealing ring 31 may also be provided at the connection between the fifth interface and the window flange 41. A transparent member may be installed in the window flange 41 for observing the cleaning status in the cleaning chamber 101. In addition, an optical detection mechanism such as a CCD camera may be provided outside the transparent member to capture image information of the object to be cleaned and feed it back to the computer for automatic judgment of whether the aperture is cleaned, which is conducive to realizing fully automatic plasma cleaning.

[0054] In this embodiment, the transparent member may be made of glass, quartz, sapphire, acrylic or other materials, which are not limited here.

[0055] In addition, in some embodiments, reference Figures 1 to 3 In order to facilitate the direct insertion of the diaphragm into the first interface 21, the cleaning tool may further include a support platform 51, on which the cleaning chamber 10 is disposed, and the height of the support platform 51 may be slightly lower than the height of the diaphragm, so that the first interface 21 can be aligned with the diaphragm, and the diaphragm can be avoided from being disassembled. In addition, the support platform 51 has support legs, on which universal wheels may be mounted for easy operation and movement.

[0056] In summary, the cleaning tool of the present invention has a wide range of uses. The cleaning tool can be used to clean easily contaminated parts in scanning electron microscopes, and can also be used to clean easily contaminated parts of equipment related to high-energy electron beams, such as electron beam exposure machines and transmission electron microscopes. The cleaning tool is small in size, and the design size of the cleaning chamber 101 can be consistent with the valve body of the scanning electron microscope, so it can be well compatible with the aperture assembly interface; in addition, its small size helps to reduce the exhaust time and save space. The cleaning tool is easy to maintain, and the cleaning chamber 101 has a simple structure and can be connected by screws, which is easy to maintain and convenient for cleaning inside the chamber. The cleaning tool is observable and can observe the gas discharge effect. A window flange is installed above the cleaning chamber 101, so that the cleaning process can be observed in real time.

[0057] The present invention proposes a cleaning device, which includes a cleaning tool. The specific structure of the cleaning tool refers to the above-mentioned embodiment. Since the cleaning device proposed by the present invention includes all schemes of all embodiments of the above-mentioned cleaning tool, it has at least the same technical effect as the above-mentioned cleaning tool, which will not be elaborated here one by one.

[0058] Reference Figures 1 to 3 In one embodiment of the present invention, the cleaning device also includes a plasma cleaning device for generating plasma and a vacuum pump group for maintaining a low vacuum in the cleaning chamber 101. The plasma cleaning device is connected to the second interface 22 of the cleaning tool, and the vacuum pump group is connected to the third interface 23 of the cleaning tool.

[0059] The cleaning device can realize automatic cleaning control. A gas fine-tuning valve can be set on the plasma cleaning instrument to adjust the working gas pressure according to the internal gas pressure of the cleaning cavity 10. When the vacuum degree of the cleaning cavity 10 is detected to be up to standard, cleaning can be automatically started. At the same time, it has cleaning time control and does not require manual supervision. Cleaning will automatically end when the time is reached to avoid aperture loss caused by too long cleaning time.

[0060] The present invention also provides a cleaning method for a cleaning device, based on the above-mentioned cleaning device, referring to Figures 1 to 4 In one embodiment of the present invention, the cleaning method comprises the following steps:

[0061] S10, after the object to be cleaned is loaded into the cleaning chamber 101, the vacuum pump group is turned on to make the cleaning chamber 101 reach a vacuum environment;

[0062] In this embodiment, when working, the aperture assembly can be first inserted into the first interface 21 of the cleaning chamber 10, and a sealing ring 31 can be set at the connection to ensure sealing. Then, the plasma cleaning instrument, vacuum gauge and vacuum pump group can be connected to the corresponding flange interface respectively using fasteners such as clamps. After confirming that each interface is connected in place, the vacuum pump group is started to exhaust and vacuumize the cleaning chamber 101.

[0063] S20, detecting the vacuum degree of the cleaning chamber 101;

[0064] During the vacuuming process, the vacuum degree of the cleaning chamber 101 is monitored in real time to ensure that the vacuum degree of the cleaning chamber 101 meets the requirements before the plasma cleaning apparatus is turned on.

[0065] S30, when the vacuum degree is lower than the preset vacuum value, controlling the plasma cleaning instrument to work;

[0066] In this embodiment, the preset vacuum value can be 1Pa. When the vacuum gauge shows that the vacuum degree is better than 1Pa, the gas fine-tuning valve of the plasma cleaning instrument is started, and the gas fine-tuning valve adjusts the intake volume according to the vacuum degree of the cleaning chamber 10 to reach the working pressure, and plasma can be generated at this time. Subsequently, the plasma in the cleaning chamber 10 will remove the contamination on the surface of the object to be cleaned at the aperture, thereby achieving a cleaning effect.

[0067] S40, after the cleaning time reaches a preset time, photograph the object to be cleaned in the cleaning chamber 101 and generate an image signal, and output the image signal to the host computer;

[0068] In this embodiment, an optical detection mechanism such as a CCD camera may be disposed above the window flange 41 to photograph the object to be cleaned during the cleaning process, generate an image signal, and then transmit it to a host computer such as a computer.

[0069] S50, judging whether the object to be cleaned is in a clean state according to the image signal;

[0070] In this embodiment, after receiving the image signal, the host computer determines whether there is any dirt left on the surface of the object through comparative analysis, and determines whether the object is cleaned. In addition, it can also determine whether the aperture is damaged based on the image signal.

[0071] S60, when the object to be cleaned is in a clean state, stopping the plasma cleaning apparatus and the vacuum pump group.

[0072] When the host computer determines that the object is clean, it immediately issues a shutdown command, automatically shutting down the plasma cleaner and vacuum pump group in turn. After confirming that each device is shut down, the pipeline is removed and finally the cleaned object is taken out.

[0073] Of course, in some other embodiments, the cleaning time of the plasma cleaning instrument may also be set, and the plasma cleaning instrument will automatically stop working after the working time reaches the set time.

[0074] The above descriptions are only optional embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, or directly / indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A scanning electron microscope diaphragm cleaning device, characterized in that: It includes a plasma cleaning instrument, a vacuum pump set and a cleaning tool, and the cleaning tool includes: A cleaning cavity body, comprising a cleaning chamber and a first interface, a second interface, a third interface, a fourth interface and a fifth interface respectively connected to the cleaning chamber; a vacuum gauge, the vacuum gauge being connected to the cleaning chamber through the fourth interface to monitor the vacuum degree of the cleaning chamber; The first interface is used for inserting the diaphragm of the scanning electron microscope; The second interface is connected to the plasma cleaning instrument; The third interface is connected to the vacuum pump group; The fifth interface is connected to the window flange, and sealing rings are provided at the connection between the second interface and the cleaning chamber, the connection between the third interface and the cleaning chamber, the connection between the fourth interface and the cleaning chamber, and the connection between the fifth interface and the window flange. Glass is installed in the window flange for observing the cleaning status in the cleaning chamber; A support platform, the cleaning chamber is arranged on the support platform, and the height of the support platform is suitable to be lower than the height of the scanning electron microscope diaphragm, so that the first interface is aligned with the scanning electron microscope diaphragm to avoid disassembly of the scanning electron microscope diaphragm; The cleaning device performs cleaning according to the following steps when working: After the scanning electron microscope aperture is loaded into the cleaning chamber, the vacuum pump group is turned on to make the cleaning chamber reach a vacuum environment; detecting the vacuum degree of the cleaning chamber; When the vacuum degree is lower than a preset vacuum value, controlling the plasma cleaning instrument to operate; After the cleaning time reaches a preset time, photographing the scanning electron microscope aperture in the cleaning chamber and generating an image signal, and outputting the image signal to a host computer; judging whether the scanning electron microscope diaphragm is in a clean state according to the image signal; When the scanning electron microscope aperture is in the clean state, the plasma cleaning instrument and the vacuum pump group are stopped.

2. The scanning electron microscope aperture cleaning device according to claim 1, characterized in that: The first interface is a flange interface embedded in the cleaning cavity, or the first interface is a disc-shaped socket opened on the cavity wall of the cleaning cavity.

3. The scanning electron microscope aperture cleaning device according to claim 1, characterized in that: The second interface, the third interface and the fourth interface are all flange interfaces.

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