An aperture adjustment system

Abstract

The application relates to the technical field of scanning electron microscopes, and discloses a diaphragm adjusting system which comprises the following parts: a blind plate is sealed on a through hole of an electron microscope diaphragm chamber; a diaphragm rod extends into the electron microscope diaphragm chamber through a through hole of the blind plate; a diaphragm piece is arranged at one end of the diaphragm rod in the electron microscope diaphragm chamber, and a diaphragm hole is arranged on the diaphragm piece; a bidirectional moving device is connected with a mounting frame; the bidirectional moving device is suitable for driving the mounting frame to translate along an X-axis direction and / or to translate along a Y-axis direction; the X-axis direction is perpendicular to the Y-axis direction; one end of a bellows is sealingly connected with the blind plate, and the inside of the bellows is communicated with the through hole; the other end of the diaphragm rod is sealingly connected with the mounting frame after penetrating through the inside of the bellows; and the bellows and the electron microscope diaphragm chamber are both in vacuum environment. The flexibility of the bellows is utilized to ensure that the electron microscope diaphragm chamber and the bellows are always in high vacuum state during translation, and leakage does not occur due to too high moving speed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of scanning electron microscopy, and particularly relates to a diaphragm adjusting system. BACKGROUND

[0002] With the continuous development of science and technology, a scanning electron microscope, as a device for observing the microcosmic world, has the characteristics of high resolution, large depth of field and strong stereoscopic effect. Therefore, the scanning electron microscope 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. The scanning electron microscope forms an image by scanning the surface of a sample with an electron beam to observe microstructures at the micro-nano level.

[0003] In the composition of the scanning electron microscope, the diaphragm assembly is an important part of the scanning electron microscope. The scanning electron microscope also includes an electron microscope lens barrel and an electron microscope body. As shown in Figure 1 , the diaphragm assembly mainly includes a diaphragm sheet 1, a diaphragm rod 2, an adjusting device 3 and a sealing device 4. The electron microscope lens barrel is provided with an electron microscope diaphragm chamber 5. When the scanning electron microscope is working, the electron microscope diaphragm chamber 5 needs to maintain a high vacuum state, and the vacuum degree in the electron microscope diaphragm chamber 5 is generally 1x10 -3 Pa or more. The diaphragm sheet 1 and the diaphragm rod 2 are located in the electron microscope diaphragm chamber 5, the diaphragm sheet 1 is arranged at the front end of the diaphragm rod 2, and the diaphragm rod 2 can be adjusted. A plurality of diaphragm holes are distributed on the diaphragm sheet 1; the diaphragm holes have high circularity, and the inner surface of the diaphragm holes is smooth, and the diaphragm holes are used to limit the scattering range of the electron beam. The adjusting device 3 is used to adjust the position of the diaphragm rod 2 in the X-axis direction and the Y-axis direction. The X-axis direction is arranged in parallel to the longitudinal direction of the diaphragm rod 2, and the Y-axis direction is arranged in perpendicular to the transverse direction of the diaphragm rod 2. The process of adjusting the diaphragm holes of the diaphragm sheet 1 on the diaphragm rod 2 to be located on the electron optical axis of the scanning electron microscope by the adjusting device 3 is called optical path alignment. After the optical path alignment operation, the paraxial rays can be used more effectively, the aberration is reduced, and the imaging quality of the scanning electron microscope is improved. The existing adjusting device 3 generally includes a manual adjusting device and an automatic adjusting device. In the existing manual adjusting device, an adjusting handle located outside the electron microscope body is generally used to drive the diaphragm rod 2 to move integrally along the X-axis direction through screw transmission, so as to realize the translation of the diaphragm holes in the X-axis direction. Specifically, the diaphragm holes with different apertures can be moved in the X-axis direction by rotating the adjusting handle. The automatic adjusting device is similar in structure to the manual adjusting device. The dynamic sealing structure of the adjusting device 3 adopts a plurality of O-rings 6 for sealing. When the diaphragm 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 maintain the high vacuum state in the electron microscope diaphragm chamber 5, which causes the scanning electron microscope to be unable to work. SUMMARY

[0004] Therefore, the present application provides a diaphragm adjusting system to solve the problem that the dynamic sealing structure of the existing adjusting device adopts O-ring sealing, and the dynamic sealing structure is prone to leakage when the diaphragm rod moves too fast or translates along the Y-axis direction, which is difficult to guarantee the high vacuum state of the electron microscope diaphragm chamber, resulting in the failure of the scanning electron microscope to work.

[0005] The present application provides a diaphragm adjusting system, comprising:

[0006] A blind plate is sealingly arranged on the through hole of the electron microscope diaphragm chamber; one end of the diaphragm rod extends into the electron microscope diaphragm chamber through the through hole provided on the blind plate; a diaphragm sheet is arranged at one end of the diaphragm rod inside the electron microscope diaphragm chamber, and a plurality of diaphragm holes are arranged on the diaphragm sheet;

[0007] A mounting frame;

[0008] A bidirectional moving device is connected with the mounting frame; the bidirectional moving device is adapted to drive 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;

[0009] A bellows is sealingly connected at one end to the blind plate, and the inside of the bellows is in communication with the through hole; the other end of the diaphragm rod is sealingly connected with the mounting frame after penetrating through the inside of the bellows; the bellows and the electron microscope diaphragm chamber are both in vacuum environment. Beneficial effects: The present application uses the flexibility of the bellows to ensure that the diaphragm rod and the diaphragm sheet inside the electron microscope diaphragm chamber and the bellows can always be in a high vacuum state during translation along the X-axis direction and the Y-axis direction, and will not leak due to too fast movement. Moreover, the diaphragm rod is located in a vacuum environment, and the bellows does not need to occupy the volume of the electron microscope diaphragm chamber, so the overall occupied volume is small, which can meet the application in a small diaphragm chamber, and can quickly obtain a high vacuum environment, shorten the vacuum time, and improve the work efficiency.

[0010] Optionally, a sealing ring is arranged between the blind plate and the electron microscope diaphragm chamber.

[0011] Optionally, the extension amount of the bellows along the X-axis direction is greater than the translation distance of the diaphragm sheet along the X-axis direction; and the deformation amount of the bellows along the Y-axis direction is greater than the translation distance of the diaphragm sheet along the Y-axis direction. Beneficial effects: The present application uses the above technical solution to meet the stroke requirements of the diaphragm sheet along the X-axis direction and the Y-axis direction.

[0012] Optionally, the bidirectional moving device comprises:

[0013] A first lead screw;

[0014] A first power structure is connected with the first screw rod, and the first power structure is suitable for driving the first screw rod to rotate;

[0015] A first guide rail is arranged along an X-axis direction;

[0016] A first translation slide is threadedly connected with the first screw rod, and the first translation slide is slidingly connected with the first guide rail; the first translation slide is suitable for translating along the first guide rail in the X-axis direction with the rotation of the first screw rod;

[0017] A second screw rod is arranged on the first translation slide;

[0018] A second power structure is connected with the second screw rod, and the second power structure is arranged on the first translation slide; the second power structure is suitable for driving the second screw rod to rotate;

[0019] A second guide rail is arranged along a Y-axis direction;

[0020] A second translation slide is threadedly connected with the second screw rod, and the second translation slide is slidingly connected with the second guide rail; the second translation slide is suitable for translating along the second guide rail in the Y-axis direction with the rotation of the second screw rod; the mounting frame is mounted on the second translation slide. Advantageous effects: the above technical solution is adopted, and bidirectional automatic adjustment of the diaphragm is conveniently realized; compared with manual adjustment, the adjustment speed is greatly improved, and the convenience, efficiency and precision of diaphragm adjustment are significantly improved.

[0021] Optionally, the first power structure and the second power structure are both motors.

[0022] Optionally, the motor is a stepper motor.

[0023] Optionally, the application further comprises:

[0024] A first drive controller is connected with the first power structure; the first drive controller is suitable for controlling the rotational movement of the first power structure.

[0025] A second drive controller is connected with the second power structure; the second drive controller is suitable for controlling the rotational movement of the second power structure. Advantageous effects: the above technical solution is adopted, and high-precision control of bidirectional motor operation can be realized, nanoscale resolution adjustment can be realized, and finally, higher-precision motion control than manual diaphragm adjustment can be realized, that is, high-precision automatic adjustment of the diaphragm can be realized.

[0026] Optionally, the application further comprises:

[0027] The interactive display module is provided with an interactive interface, and the interactive display module is signal connected with the first drive controller and the second drive controller; the interactive interface is suitable for displaying positions of a plurality of diaphragm holes relative to an origin, and moving a specified diaphragm hole to a specified position by clicking on the interactive interface. Beneficial effects: the application adopts the above technical scheme, can automatically record the positions of different diaphragm holes, and conveniently and accurately adjusts the positions of the diaphragm holes.

[0028] Optionally, first limit switches are arranged at two ends of the first translational sliding block on the first guide rail, and second limit switches are arranged at two ends of the second translational sliding block on the second guide rail; the first limit switches are signal connected with the first drive controller, and the second limit switches are signal connected with the second drive controller. Beneficial effects: the application adopts the above technical scheme, guarantees the moving range of the first translational sliding block and the second translational sliding block, and protects the first translational sliding block and the second translational sliding block.

[0029] Optionally, one end of the first lead screw is connected with the first power structure, and the other end of the first lead screw is rotatably connected to a bearing arranged on the first fixed seat; one end of the second lead screw is connected with the second power structure, and the other end of the second lead screw is rotatably connected to a bearing arranged on the second fixed seat; the second fixed seat is arranged on the first translational sliding block. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the description of the specific embodiments or the prior art. Obviously, the drawings described below are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0031] Figure 1 It is a schematic diagram of the local arrangement structure of the scanning electron microscope in the prior art;

[0032] Figure 2 It is a schematic diagram of the local structure of the diaphragm adjusting system provided in the embodiment of the present application Figure 1 ;

[0033] Figure 3 It is a schematic diagram of the local structure of the bidirectional moving device provided in the embodiment of the present application Figure 1 ;

[0034] Figure 4 It is a schematic diagram of the local structure of the bidirectional moving device provided in the embodiment of the present application Figure 2 ;

[0035] Figure 5Schematic diagram of the partial three-dimensional structure of the bidirectional moving device provided in an embodiment of the present invention Figure 3 ;

[0036] Figure 6 Schematic diagram of the partial three-dimensional structure of the aperture adjustment system provided in an embodiment of the present invention Figure 2 ;

[0037] Figure 7 Schematic diagram of the partial three-dimensional structure of the aperture adjustment system provided in an embodiment of the present invention Figure 3 .

[0038] Description of reference numerals:

[0039] 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

[0040] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying 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 making creative efforts shall fall within the scope of protection of the present invention.

[0041] The existing manual adjustment device for the iris 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 iris adjustment system.

[0042] like Figures 2 to 7 A specific embodiment of the aperture adjustment system shown includes a blind plate 7, a mounting bracket 8, a bidirectional movement 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 herein is used in a scanning electron microscope. The power supply is used to supply power to the aperture adjustment system.

[0043] like Figure 2 、 Figure 6 and Figure 7 As shown, and reference Figure 1The blind plate 7 is sealingly arranged on the through hole of the electron mirror diaphragm chamber 5; one end of the diaphragm rod 2 extends into the electron mirror diaphragm chamber 5 through the through hole provided on the blind plate 7; the diaphragm sheet 1 is arranged on the diaphragm rod 2 at the end inside the electron mirror diaphragm chamber 5, and the diaphragm sheet 1 can be fixed on the diaphragm rod 2 by screws. A plurality of diaphragm holes are provided on the diaphragm sheet 1, and four to seven small holes with a diameter of tens to hundreds of microns can be arranged on the diaphragm sheet 1 as diaphragm holes. The bidirectional moving device 10 is connected with 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 the Y-axis direction; the X-axis direction is perpendicular to the Y-axis direction; the X-axis direction is arranged along the longitudinal direction parallel to the diaphragm rod 2, and the Y-axis direction is arranged along the transverse direction perpendicular to the diaphragm rod 2. One end of the bellows 9 is sealingly connected to the blind plate 7, and the bellows 9 can be sealingly welded to the blind plate 7; the inside of the bellows 9 is in communication with the through hole; the other end of the diaphragm rod 2 penetrates the inside of the bellows 9 and is sealingly connected to the mounting frame 8, and the diaphragm rod 2 can be sealingly welded to the mounting frame 8. The blind plate 7, the bellows 9 and the mounting frame 8 can be integrally designed and manufactured to save installation time and process. The bellows 9 and the electron mirror diaphragm chamber 5 are both in a vacuum environment, and the vacuum degree of the vacuum environment is generally -3Pa to -4Pa. Specifically, a sealing ring is arranged between the blind plate 7 and the electron mirror diaphragm chamber 5, and the sealing ring can be an O-ring 6. The sealing form can be mirror sealing. The extension amount of the bellows 9 along the X-axis direction is greater than the translation distance of the diaphragm sheet 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 diaphragm sheet 1 along the Y-axis direction.

[0044] As Figures 3 to 5As shown, the bidirectional moving device 10 comprises a first screw rod 11, a first power structure 12, a first translation slider 14, a second screw rod 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 can be a stepper motor. The first power structure 12 is connected with the first screw rod 11, and the first power structure 12 is adapted to drive the first screw rod 11 to rotate. The first guide rail 13 is arranged along the X-axis direction. The first translation slider 14 is threadedly connected with the first screw rod 11, and the first translation slider 14 is slidingly connected with 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 with the rotation of the first screw rod 11. The second screw rod 15 is arranged on the first translation slider 14. The second power structure 16 is connected with the second screw rod 15, and the second power structure 16 is arranged on the first translation slider 14; the second power structure 16 is adapted to drive the second screw rod 15 to rotate. The second guide rail 17 is arranged along the Y-axis direction. The second translation slider 18 is threadedly connected with the second screw rod 15, and the second translation slider 18 is slidingly connected with the second guide rail 17; the second translation slider 18 is adapted to translate along the second guide rail 17 in the Y-axis direction with the rotation of the second screw rod 15; the mounting frame 8 is mounted on the second translation slider 18. One end of the first screw rod 11 is connected with the first power structure 12, and the other end of the first screw rod 11 is rotatably connected on a bearing arranged on the first fixed seat; one end of the second screw rod 15 is connected with the second power structure 16, and the other end of the second screw rod 15 is rotatably connected on a bearing arranged 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 plate members, and the number of the first guide rails 13 is three which are arranged in parallel.

[0045] Further, first limit switches 19 are arranged at both ends of the translation stroke of the first translation slider 14 on the first guide rail 13; second limit switches 20 are arranged at both ends of the translation stroke of the second translation slider 18 on the second guide rail 17. The first limit switches 19 and the second limit switches 20 can both be micro switches. After the first translation slider 14 and the second translation slider 18 are moved left and right, the midpoint can be accurately found through the overall stroke size, precise positioning is achieved, and the precision is within a few microns. Since the translation stroke of the second translation slider 18 is smaller than that of the first translation slider 14, a small-power motor can be selected for the second power structure 16, and a short-stroke guide rail is selected for the second guide rail 17, so as 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, which ensure the perpendicular precision in the X-axis direction and the Y-axis direction.

[0046] The first drive controller is signal connected with the first power structure 12; the first drive controller is suitable for controlling the rotary motion of the first power structure 12. The second drive controller is signal connected with the second power structure 16; the second drive controller is suitable for controlling the rotary motion of the second power structure 16; the first limit switch 19 is signal connected with the first drive controller, and the second limit switch 20 is signal connected with the second drive controller. The first drive controller and the second drive controller can both be high-integration circuit boards. The first drive controller and the second drive controller both 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 commutation logic unit, a detection unit and a circuit protection unit; the drive part integrates a pre-drive unit and a power bridge, so as 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; the interactive display module is signal connected with the first drive controller and the second drive controller; the interactive interface is suitable for displaying the positions of a plurality of diaphragm holes relative to the origin, and moving the specified diaphragm hole to the specified position by clicking on the interactive interface, with a precision of no less than 2 microns. The interactive display module cooperates with the first limit switch 19 and the second limit switch 20; the positioning of the origin can be firstly realized, and after the origin is defined, the interactive display module cooperates with the memory to store the bidirectional coordinate positions of the diaphragm holes relative to the origin. The end target of the diaphragm hole can be read through double-clicking on the interactive interface, the diaphragm hole is quickly moved to the end target, the high-precision repositioning of the diaphragm hole is realized, and finally the rapid switching between the diaphragm holes is realized. The first drive controller and the second drive controller can both cooperate with the gap compensation module; the gap compensation module can compensate the error gap caused by mechanical assembly or machining through gap compensation, so as to finally realize high-precision positioning; the positioning precision can reach several microns, so as to meet the accurate positioning of the diaphragm hole, and finally realize the rapid response and high-precision positioning that cannot be realized by manual adjustment.

[0047] Although the embodiments of the present application are described in conjunction with the drawings, various modifications and changes can be made by those skilled in the art without departing from the spirit and scope of the present application, and such modifications and changes fall 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 piece (1) is provided on one end of the aperture rod (2) located in the electron microscope aperture chamber (5), and a plurality of aperture holes are provided on the aperture piece (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 the X-axis direction and / or along the Y-axis direction; the X-axis direction is perpendicular to the Y-axis direction; A bellows (9) is sealedly connected to the blind plate (7) at one end, and the interior of the bellows (9) is communicated with the through hole; the other end of the aperture rod (2) passes through the interior of the bellows (9) and is sealedly connected to the mounting frame (8); the bellows (9) and the electron microscope aperture chamber (5) are both in a vacuum environment; The bidirectional moving device (10) comprises: a first lead screw (11); a first power structure (12) connected to the first screw (11), wherein the first power structure (12) is adapted to drive 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 provided on the first translation slider (14); A 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; A second guide rail (17) is arranged along the Y axis direction; A 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 adapted to translate 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); Also includes: a first drive controller, connected to the first power structure (12) by signal; the first drive controller is adapted to control the rotational movement of the first power structure (12); a second drive controller connected to the second power structure (16) by signal; the second drive controller is adapted to control the rotational movement of the second power structure (16); 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 several aperture holes relative to the origin, and by clicking on the interactive interface, the specified aperture hole is moved to the specified position.

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 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 the aperture piece (1) translates along the Y-axis direction.

4. The aperture adjustment system according to claim 1, characterized in that The first power structure (12) and the second power structure (16) are both motors.

5. The aperture adjustment system according to claim 4, characterized in that: The motor is a stepping motor.

6. The aperture adjustment system according to claim 1, characterized in that A first limit switch (19) is provided at both ends of the translation stroke of the first translation slider (14) on the first guide rail (13); a second limit switch (20) is 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) is connected to the first drive controller signal, and the second limit switch (20) is connected to the second drive controller signal.

7. The aperture adjustment system according to claim 1, characterized in that One end of the first screw (11) is connected to the first power structure (12), and the other end of the first screw (11) is rotatably connected to a bearing provided on the first fixed seat; one end of the second screw (15) is connected to the second power structure (16), and the other end of the second 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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