Diaphragm adjusting system

Abstract

The invention relates to the technical field of scanning electron microscopes, and discloses a diaphragm adjusting system, which is characterized in that a blind plate is arranged on a through hole of an electron microscope diaphragm chamber in a sealing manner; one end of the diaphragm rod extends into the electron microscope diaphragm chamber through the blind plate via hole; a diaphragm sheet is arranged at one end, located in the electron microscope diaphragm chamber, of the diaphragm rod, and a diaphragm hole is formed in the diaphragm sheet; the bidirectional moving device is connected with the mounting frame; the bidirectional moving device is suitable for driving the mounting rack to translate along the X-axis direction and / or the Y-axis direction; the X-axis direction is perpendicular to the Y-axis direction; one end of the corrugated pipe is hermetically connected to the blind plate, and the interior of the corrugated pipe is communicated with the via hole; the other end of the diaphragm rod penetrates through the inside of the corrugated pipe and then is in sealed connection with the mounting frame, and the corrugated pipe and the electron microscope diaphragm chamber are both in vacuum environment. According to the application, the flexibility of the corrugated pipe is utilized to ensure that the inside of the electron microscope diaphragm chamber and the inside of the corrugated pipe are always in a high-vacuum state in the translation process, and leakage caused by too high movement speed is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of scanning electron microscopes, and in particular to an aperture adjustment system. Background Art

[0002] With the continuous development of science and technology, scanning electron microscope (SEM) is a device for observing the microscopic world, which has the characteristics of high resolution, large depth of field and strong three-dimensional sense. Therefore, SEM is widely used in many fields such as material science, semiconductor, new energy, geology and life science, and plays an important role in the progress of science and technology. SEM scans the surface of the sample with electron beam to observe the microscopic structure at the micro-nano level.

[0003] In the composition of the scanning electron microscope, the aperture assembly is an important part of the scanning electron microscope. The scanning electron microscope also includes: the electron microscope barrel and the electron microscope body. Figure 1 As shown in FIG. 1 , the aperture assembly mainly includes: an aperture piece 1, an aperture rod 2, an adjustment device 3 and a sealing device 4. The electron microscope barrel is provided with an electron microscope aperture chamber 5. When the scanning electron microscope is working, the electron microscope aperture chamber 5 needs to maintain a high vacuum state. The vacuum degree in the electron microscope aperture chamber 5 is generally 1×e -3 Pa or above. The aperture plate 1 and the aperture rod 2 are both located in the aperture chamber 5 of the electron microscope, the aperture plate 1 is arranged at the front end of the aperture rod 2, and the aperture rod 2 is adjustable. A plurality of aperture holes are distributed on the aperture plate 1; the aperture holes have high roundness and the inner surface of the aperture holes is smooth, and the aperture holes are used to limit the scattering range of the electron beam. The adjustment device 3 is used to adjust the position of the aperture rod 2 in the X-axis direction and the Y-axis direction. The X-axis direction is arranged along the longitudinal direction parallel to the aperture rod 2, and the Y-axis direction is arranged along the transverse direction perpendicular to the aperture rod 2. The process of adjusting the aperture hole of the aperture plate 1 on the aperture rod 2 to be located on the axis of the electron optical path of the scanning electron microscope by the adjustment device 3 is called optical path coaxialization. After the optical path coaxialization operation, the near-axial light can be used more effectively, the aberration can be reduced and the imaging quality of the scanning electron microscope can be improved. The existing adjustment device 3 generally includes: a manual adjustment device and an automatic adjustment device. In the existing manual adjustment device, the adjustment handle located outside the electron microscope body is generally used to drive the aperture rod 2 to move as a whole along the X-axis direction through the screw transmission, so as to realize the translation of the aperture hole in the X-axis direction. Specifically, the aperture holes of different apertures can be moved in the X-axis direction by screwing the adjustment handle. The structure adopted by the automatic adjustment device is generally similar to that adopted by the manual adjustment device. The dynamic sealing structure of the adjustment device 3 is sealed with multiple O-rings 6. When the aperture rod 2 moves too fast or translates along the Y-axis direction, the dynamic sealing structure is prone to leakage, and it is difficult to ensure the high vacuum state in the aperture chamber 5 of the electron microscope, resulting in the inability of the scanning electron microscope to work. Summary of the invention

[0004] In view of this, the present invention provides an aperture adjustment system to solve the problem that the dynamic sealing structure adopted by the existing adjustment device mostly adopts O-ring sealing. When the aperture rod moves too fast or translates along the Y-axis direction, the dynamic sealing structure is prone to leakage, making it difficult to ensure the high vacuum state of the electron microscope aperture chamber, resulting in the scanning electron microscope being unable to work.

[0005] The present invention provides an aperture adjustment system, comprising: A blind plate is sealed and arranged on the through hole of the electron microscope aperture chamber; one end of the aperture rod extends into the electron microscope aperture chamber through the through hole provided on the blind plate; an aperture sheet is arranged on one end of the aperture rod located in the electron microscope aperture chamber, and a plurality of aperture holes are arranged on the aperture sheet; Mounting frame; A bidirectional moving device connected to the mounting frame; the bidirectional moving device is suitable for driving the mounting frame to translate along the X-axis direction and / or along the Y-axis direction; the X-axis direction is perpendicular to the Y-axis direction; One end of the bellows is sealed and connected to the blind plate, and the interior of the bellows is connected to the through hole; the other end of the aperture rod passes through the interior of the bellows and is sealed and connected to the mounting frame, and the bellows and the aperture chamber of the electron microscope are both in a vacuum environment. Beneficial effect: The present application adopts the above technical solution and utilizes the flexibility of the bellows to ensure that during the translation along the X-axis direction and the Y-axis direction, the aperture rod and aperture sheet in the aperture chamber of the electron microscope and the bellows can always be in a high vacuum state, and will not leak due to excessive movement speed. In addition, the aperture rod is located in a vacuum environment, and the bellows does not need to occupy the volume of the aperture chamber of the electron microscope. The overall occupied volume is very small, which can meet the application in a small aperture chamber. At the same time, a high vacuum environment can be quickly obtained, the vacuum pumping time can be shortened, and work efficiency can be improved.

[0006] Optionally, a sealing ring is provided between the blind plate and the electron microscope aperture chamber.

[0007] Optionally, the expansion and contraction amount of the bellows along the X-axis direction is greater than the translation distance of the aperture piece along the X-axis direction; the deformation amount of the bellows along the Y-axis direction is greater than the translation distance of the aperture piece along the Y-axis direction. Beneficial effect: The present application adopts the above technical solution to meet the travel requirements of the aperture piece along the X-axis direction and the Y-axis direction.

[0008] Optionally, the bidirectional moving device comprises: First lead screw; A first power structure connected to the first screw, wherein the first power structure is suitable for driving the first screw to rotate; A first guide rail is arranged along the X-axis direction; A first translation slider is threadedly connected to the first lead screw, and the first translation slider is slidably connected to the first guide rail; the first translation slider is suitable for translationally moving along the first guide rail in the X-axis direction as the first lead screw rotates; A second lead screw is disposed on the first translation slider; A second power structure is connected to the second lead screw and is disposed on the first translation slider; the second power structure is suitable for driving the second lead screw to rotate; The second guide rail is arranged along the Y axis direction; The second translation slider is threadedly connected to the second lead screw, and the second translation slider is slidably connected to the second guide rail; the second translation slider is suitable for translation along the second guide rail in the Y-axis direction as the second lead screw rotates; the mounting frame is installed on the second translation slider. Beneficial effect: The application adopts the above technical solution to facilitate the two-way automatic adjustment of the diaphragm. Compared with manual adjustment, the adjustment speed is greatly improved, and the convenience, adjustment efficiency and adjustment accuracy of the diaphragm adjustment are significantly improved.

[0009] Optionally, the first power structure and the second power structure are both motors.

[0010] Optionally, the motor is a stepper motor.

[0011] Optionally, it also includes: A first drive controller, connected to the first power structure signal; the first drive controller is suitable for controlling the rotational movement of the first power structure; The second drive controller is connected to the second power structure signal; the second drive controller is suitable for controlling the rotational movement of the second power structure. Beneficial effect: The present application adopts the above technical solution to realize high-precision control of bidirectional motor operation, nanometer-level resolution adjustment, and ultimately achieve higher-precision motion control than manual aperture adjustment, that is, high-precision automatic adjustment of the aperture.

[0012] Optionally, it also includes: The interactive display module is provided with an interactive interface, and the interactive display module is signal-connected to the first drive controller and the second drive controller; the interactive interface is suitable for displaying the positions of a plurality of apertures relative to the origin, and by clicking on the interactive interface, the designated aperture is moved to the designated position. Beneficial effect: The present application adopts the above technical solution, which can automatically record the positions of different apertures and facilitate accurate adjustment of the positions of the apertures.

[0013] Optionally, first limit switches are respectively provided at both ends of the translation stroke of the first translation slider on the first guide rail; second limit switches are respectively provided at both ends of the translation stroke of the second translation slider on the second guide rail; the first limit switch is connected to the first drive controller signal, and the second limit switch is connected to the second drive controller signal. Beneficial effect: The present application adopts the above technical solution to ensure the movement range of the first translation slider and the second translation slider, and to protect the first translation slider and the second translation slider.

[0014] Optionally, one end of the first screw is connected to the first power structure, and the other end of the first screw is rotatably connected to a bearing provided on the first fixed seat; one end of the second screw is connected to the second power structure, and the other end of the second screw is rotatably connected to a bearing provided on the second fixed seat; the second fixed seat is arranged on the first translation slider. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 It is a schematic diagram of the local arrangement structure of a scanning electron microscope in the prior art; Figure 2 A schematic diagram of a partial three-dimensional structure of an aperture adjustment system provided in an embodiment of the present invention Figure 1 ; Figure 3 A schematic diagram of a partial three-dimensional structure of a bidirectional moving device provided in an embodiment of the present invention Figure 1 ; Figure 4 A schematic diagram of a partial three-dimensional structure of a bidirectional moving device provided in an embodiment of the present invention Figure 2 ; Figure 5 A schematic diagram of a partial three-dimensional structure of a bidirectional moving device provided in an embodiment of the present invention Figure 3 ; Figure 6 A schematic diagram of a partial three-dimensional structure of an aperture adjustment system provided in an embodiment of the present invention Figure 2 ; Figure 7 A schematic diagram of a partial three-dimensional structure of an aperture adjustment system provided in an embodiment of the present invention Figure 3 .

[0017] Description of reference numerals: 1. Aperture plate; 2. Aperture rod; 3. Adjustment device; 4. Sealing device; 5. Electron microscope aperture chamber; 6. O-ring; 7. Blind plate; 8. Mounting bracket; 9. Bellows; 10. Bidirectional moving device; 11. First lead screw; 12. First power structure; 13. First guide rail; 14. First translation slider; 15. Second lead screw; 16. Second power structure; 17. Second guide rail; 18. Second translation slider; 19. First limit switch; 20. Second limit switch. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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 those skilled in the art without creative work are within the scope of protection of the present invention.

[0019] The existing manual aperture adjustment device has a relatively slow manual adjustment speed, which is not suitable for users who are increasingly pursuing efficiency. Due to the above reasons, the present application proposes an aperture adjustment system.

[0020] like Figures 2 to 7 A specific implementation of the aperture adjustment system shown includes: a blind plate 7, a mounting frame 8, a bidirectional moving device 10, a bellows 9, a first drive controller, a second drive controller, a power supply, and an interactive display module. The aperture adjustment system described in the present application is used for a scanning electron microscope. The power supply is used to supply power to the aperture adjustment system.

[0021] like Figure 2 , Figure 6 and Figure 7 As shown, and reference Figure 1, the blind plate 7 is sealed and arranged on the through hole of the electron microscope aperture chamber 5; one end of the aperture rod 2 extends into the electron microscope aperture chamber 5 through the through hole provided on the blind plate 7; an aperture piece 1 is arranged on one end of the aperture rod 2 located in the electron microscope aperture chamber 5, and the aperture piece 1 can be fixed on the aperture rod 2 by screws. A plurality of aperture holes are arranged on the aperture piece 1, and generally four to seven small holes with diameters of tens to hundreds of microns can be arranged on the aperture piece 1 as aperture holes. The bidirectional moving device 10 is connected to the mounting frame 8; the bidirectional moving device 10 is suitable for driving the mounting frame 8 to translate along the X-axis direction and / or along the Y-axis direction; the X-axis direction is perpendicular to the Y-axis direction; the X-axis direction is arranged in a longitudinal direction parallel to the aperture rod 2, and the Y-axis direction is arranged in a transverse direction perpendicular to the aperture rod 2. One end of the bellows 9 is sealed and connected to the blind plate 7, which can be welded and sealed; and the interior of the bellows 9 is connected to the through hole; the other end of the aperture rod 2 passes through the interior of the bellows 9 and is sealed and connected to the mounting frame 8, which can be welded and sealed. The blind plate 7, bellows 9 and mounting frame 8 can be manufactured by integrated design to save installation time and installation process. The bellows 9 and the electron microscope aperture chamber 5 are both vacuum environments, and the vacuum degree range of the vacuum environment is generally: -3Pa to -4Pa. Specifically, a sealing ring is provided between the blind plate 7 and the electron microscope aperture chamber 5, and the sealing ring can be an O-ring 6. The sealing form can be a mirror seal. The expansion and contraction amount of the bellows 9 along the X-axis direction is greater than the translation distance of the aperture piece 1 along the X-axis direction; the deformation amount of the bellows 9 along the Y-axis direction is greater than the translation distance of the aperture piece 1 along the Y-axis direction.

[0022] like Figures 3 to 5As shown, the bidirectional moving device 10 includes: a first lead screw 11, a first power structure 12, a first translation slider 14, a second lead screw 15, a second power structure 16, a second guide rail 17 and a second translation slider 18. Specifically, the first power structure 12 and the second power structure 16 are both motors. The motor may be a stepping motor. The first power structure 12 is connected to the first lead screw 11, and the first power structure 12 is suitable for driving the first lead screw 11 to rotate. The first guide rail 13 is arranged along the X-axis direction. The first translation slider 14 is threadedly connected to the first lead screw 11, and the first translation slider 14 is slidably connected to the first guide rail 13; the first translation slider 14 is suitable for translating along the first guide rail 13 in the X-axis direction as the first lead screw 11 rotates. The second lead screw 15 is arranged on the first translation slider 14. The second power structure 16 is connected to the second lead screw 15, and the second power structure 16 is arranged on the first translation slider 14; the second power structure 16 is suitable for driving the second lead screw 15 to rotate. The second guide rail 17 is arranged along the Y axis direction. The second translation slider 18 is threadedly connected to the second lead screw 15, and the second translation slider 18 is slidably connected to the second guide rail 17; the second translation slider 18 is suitable for translating along the second guide rail 17 in the Y axis direction as the second lead screw 15 rotates; the mounting frame 8 is installed on the second translation slider 18. One end of the first lead screw 11 is connected to the first power structure 12, and the other end of the first lead screw 11 is rotatably connected to the bearing provided on the first fixed seat; one end of the second lead screw 15 is connected to the second power structure 16, and the other end of the second lead screw 15 is rotatably connected to the bearing provided on the second fixed seat; the second fixed seat is arranged on the first translation slider 14. The first translation slider 14 and the second translation slider 18 are both plates, and the number of the first guide rails 13 is three arranged in parallel.

[0023] Furthermore, first limit switches 19 are provided at both ends of the translation stroke of the first translation slider 14 on the first guide rail 13; and second limit switches 20 are provided at both ends of the translation stroke of the second translation slider 18 on the second guide rail 17. The first limit switch 19 and the second limit switch 20 can both be micro switches. After the first translation slider 14 and the second translation slider 18 move left and right, the midpoint can be accurately found through the overall stroke size to achieve precise positioning with an accuracy of within a few microns. Since the translation stroke of the second translation slider 18 is smaller than the translation stroke of the first translation slider 14, the second power structure 16 can use a low-power motor, and the second guide rail 17 uses a short-stroke guide rail to ensure high precision during short-distance movement. The first guide rail 13 and the second guide rail 17 are both high-precision guide rails to ensure vertical accuracy in the X-axis direction and the Y-axis direction.

[0024] The first drive controller is connected to the first power structure 12 by signal; the first drive controller is suitable for controlling the rotational movement of the first power structure 12. The second drive controller is connected to the second power structure 16 by signal; the second drive controller is suitable for controlling the rotational movement of the second power structure 16; the first limit switch 19 is connected to the first drive controller by signal, and the second limit switch 20 is connected to the second drive controller by signal. Both the first drive controller and the second drive controller can be highly integrated circuit boards. Both the first drive controller and the second drive controller include: a pre-drive part and a drive part, the pre-drive part mainly integrates a pre-drive main unit, a micro-step sequence unit, a phase change logic unit, a detection unit and a circuit protection unit; the drive part integrates a pre-drive unit and a power bridge to save peripheral devices, so that the first drive controller and the second drive controller are more miniaturized and meet the modular design. The interactive display module is provided with an interactive interface, and the interactive display module is connected to the first drive controller and the second drive controller by signal; the interactive interface is suitable for displaying the positions of a plurality of apertures relative to the origin, and by clicking on the interactive interface, the specified aperture is moved to the specified position, with an accuracy of not less than 2 microns. The interactive display module cooperates with the first limit switch 19 and the second limit switch 20; the origin can be positioned first. After the origin is defined, the interactive display module cooperates with the memory to store the bidirectional coordinate position of each aperture relative to the origin. By double-clicking on the interactive interface, the end target of the aperture can be read, and the aperture quickly moves to the end target to achieve high-precision repeated positioning of the aperture, and finally achieve rapid switching between the apertures. The first drive controller and the second drive controller can cooperate with the gap compensation module. The gap compensation module can compensate for the error gap caused by mechanical assembly or processing through gap compensation, and finally achieve high-precision positioning; the positioning accuracy can reach several microns, which can meet the precise positioning of the aperture, and finally achieve rapid response and high-precision positioning that cannot be achieved by manual adjustment.

[0025] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. An aperture adjustment system, characterized in that: include: A blind plate (7) is sealingly arranged on the through hole of the electron microscope aperture chamber (5); one end of the aperture rod (2) extends into the electron microscope aperture chamber (5) through the through hole provided in the blind plate (7); an aperture plate (1) is arranged on one end of the aperture rod (2) located in the electron microscope aperture chamber (5), and a plurality of aperture holes are arranged on the aperture plate (1); Mounting frame (8); a bidirectional moving device (10) connected to the mounting frame (8); the bidirectional moving device (10) is suitable for driving the mounting frame (8) to translate along an X-axis direction and / or along a Y-axis direction; the X-axis direction is perpendicular to the Y-axis direction; One end of the bellows (9) is sealed and connected to the blind plate (7), and the interior of the bellows (9) is connected to the through hole; the other end of the aperture rod (2) passes through the interior of the bellows (9) and is sealed and connected to the mounting frame (8), and the bellows (9) and the electron microscope aperture chamber (5) are both in a vacuum environment.

2. The aperture adjustment system according to claim 1, characterized in that: A sealing ring is provided between the blind plate (7) and the electron microscope aperture chamber (5).

3. The aperture adjustment system according to claim 1, characterized in that: The expansion and contraction amount of the bellows (9) along the X-axis direction is greater than the distance that the aperture piece (1) translates along the X-axis direction; the deformation amount of the bellows (9) along the Y-axis direction is greater than the distance that the aperture piece (1) translates along the Y-axis direction.

4. The aperture adjustment system according to any one of claims 1 to 3, characterized in that: The bidirectional moving device (10) comprises: A first lead screw (11); A first power structure (12) connected to the first screw (11), the first power structure (12) being suitable for driving the first screw (11) to rotate; A first guide rail (13) is arranged along the X-axis direction; A first translation slider (14) is threadedly connected to the first lead screw (11), and the first translation slider (14) is slidably connected to the first guide rail (13); the first translation slider (14) is adapted to translate along the first guide rail (13) in the X-axis direction as the first lead screw (11) rotates; A second lead screw (15) is arranged on the first translation slider (14); a second power structure (16) connected to the second lead screw (15), and the second power structure (16) is arranged on the first translation slider (14); the second power structure (16) is suitable for driving the second lead screw (15) to rotate; A second guide rail (17) is arranged along the Y axis direction; The second translation slider (18) is threadedly connected to the second lead screw (15), and the second translation slider (18) is slidably connected to the second guide rail (17); the second translation slider (18) is suitable for translationally moving along the second guide rail (17) in the Y-axis direction as the second lead screw (15) rotates; the mounting frame (8) is mounted on the second translation slider (18).

5. The aperture adjustment system according to claim 4, characterized in that: The first power structure (12) and the second power structure (16) are both motors.

6. The aperture adjustment system according to claim 5, characterized in that: The motor is a stepping motor.

7. The aperture adjustment system according to claim 4, characterized in that: Also includes: A first drive controller, signal-connected to the first power structure (12); The first drive controller is adapted to control the rotational movement of the first power structure (12); A second drive controller, signal-connected to the second power structure (16); The second drive controller is suitable for controlling the rotational movement of the second power structure (16).

8. The aperture adjustment system according to claim 7, characterized in that: Also includes: The interactive display module is provided with an interactive interface, and the interactive display module is signal-connected to the first drive controller and the second drive controller; the interactive interface is suitable for displaying the positions of a plurality of aperture holes relative to the origin, and by clicking on the interactive interface, the designated aperture hole is moved to the designated position.

9. The aperture adjustment system according to claim 7, characterized in that: First limit switches (19) are respectively provided at both ends of the translational travel of the first translational slider (14) on the first guide rail (13); second limit switches (20) are respectively provided at both ends of the translational travel of the second translational slider (18) on the second guide rail (17); the first limit switch (19) is connected to the first drive controller signal, and the second limit switch (20) is connected to the second drive controller signal.

10. The aperture adjustment system according to claim 4, characterized in that: One end of the first lead screw (11) is connected to the first power structure (12), and the other end of the first lead screw (11) is rotatably connected to a bearing provided on the first fixed seat; one end of the second lead screw (15) is connected to the second power structure (16), and the other end of the second lead screw (15) is rotatably connected to a bearing provided on the second fixed seat; the second fixed seat is arranged on the first translation slider (14).

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