Electron beam shutter device

Abstract

The utility model relates to scanning electron microscope technical field especially, it relates to a kind of electron beam beam gate device, including pedestal and ground cover, four groups of positioning block and four groups of deflection electrode plate are evenly arranged in the bottom of pedestal, deflection electrode plate and positioning block position correspond, and it is connected by bolt A and positioning block, ground cover is provided in the bottom of deflection electrode plate, ground cover is connected by grounding bolt and positioning block, four groups of deflection electrode plate and pedestal and ground cover between evenly arranged are all equipped with insulating washer, the upper side of pedestal is equipped with end cap, end cap is fixedly connected with pedestal by multiple groups of bolt B.The utility model in the four deflection electrode plate circumferential even distribution, four evenly distributed deflection electrode plate between form symmetrical electric field, realize axial electric field uniformity, can promote deflection efficiency, ensure that electron beam is completely switched off.

Description

Technical Field

[0001] This utility model relates to the field of scanning electron microscopy technology, and more specifically, to an electron beam gate device. Background Technology

[0002] Scanning electron microscopy (SEM) uses a finely focused electron beam to bombard the sample surface. The secondary electrons and backscattered electrons generated by the interaction between electrons and the sample are used to observe and analyze the surface or fracture morphology of the sample. SEM is widely used in materials science, metallurgy, mineralogy, and biology. The electron beam gate, a key component controlling the on / off state of the electron beam, directly affects the detection accuracy and equipment safety of SEM. Its working principle involves placing a pair of parallel plates symmetrically at appropriate positions along the electron beam axis. When a certain DC voltage is applied to the parallel plates, the electron beam deflects due to the electric field, typically being blocked by the intermediate aperture, thus "turning off" the electron beam.

[0003] Existing electron beam gags mostly employ electromagnetic deflection devices, which use electric or magnetic fields to deflect the electron beam off the optical axis to achieve shutdown. However, they have the following drawbacks: 1. The installation location is close to the electron emission source, the electron beam is not fully focused, the beam flow is large, resulting in incomplete shutdown; 2. Close proximity can easily cause contamination of the electron emission source, affecting the equipment's lifespan; 3. The electrode layout is unreasonable, the electric field distribution is uneven, and the deflection efficiency is low.

[0004] In view of this, this application proposes an electron beam gantry device. Utility Model Content

[0005] (I) Purpose of the utility model To address the shortcomings of existing technologies, this invention provides an electron beam gate device that offers thorough shutdown, high security, and optimized layout, thereby solving the problems mentioned in the background section.

[0006] (II) Technical Solution To achieve the above objectives, the technical solution adopted by this utility model is as follows: An electron beam gating device includes a base and a grounding cover. Four sets of positioning blocks and four sets of deflection electrode plates are evenly distributed around the bottom of the base. The deflection electrode plates are positioned corresponding to the positioning blocks and are connected to the positioning blocks by bolts A. A grounding cover is provided at the bottom of the deflection electrode plates and is connected to the positioning blocks by grounding bolts. Insulating washers are provided between the four sets of deflection electrode plates, the base, and the grounding cover.

[0007] Furthermore, the deflection electrode plate is composed of a head and a root, and the whole is an L-shaped structure. The root is a triangular structure, on which a long strip-shaped head is fixed.

[0008] Furthermore, cable fixing holes are provided on both outer end faces of the root of the deflection electrode plate. Set screws are installed at the bottom of the cable fixing holes. The cable fixing holes of two adjacent sets of deflection electrode plates in three directions are short-circuited by vacuum high-voltage cables. The vacuum high-voltage cables are fixed in the cable fixing holes by set screws. The cable fixing holes of two adjacent sets of deflection electrode plates in the remaining direction are connected to power cables. One set of cable fixing holes is the voltage input terminal, and the other set is the voltage output terminal.

[0009] Furthermore, the four sets of deflection electrode plates are spaced at the same distance, with a channel left between the inner sides of the heads, and a through hole is provided at the center of the base, through which the heads of the four sets of deflection electrode plates extend.

[0010] Furthermore, the insulating gasket is made of non-metallic insulating material, and all structural components are made of non-magnetic material.

[0011] Furthermore, the deflection electrode plate and the base are separated by an insulating partition.

[0012] Furthermore, the base is provided with several sets of connecting bolts for connecting with external equipment. The device is installed at the focal point of the second-stage condenser of the scanning electron microscope via the connecting bolts, located between the first-stage condenser and the objective lens.

[0013] Furthermore, the grounding cover plate has an optical aperture inside for the electron beam to pass through, and the optical aperture is coaxial with the through hole.

[0014] (III) Beneficial Effects Compared with the prior art, the present invention has the following beneficial effects: 1. In this utility model, four deflection electrode plates are evenly distributed circumferentially, and a symmetrical electric field is formed between the four evenly distributed deflection electrode plates to achieve axial electric field uniformity, which can improve deflection efficiency, enhance the deflection force of the electric field on the electron beam, and ensure that the electron beam is completely turned off. 2. The device is installed at the focal point of the second-stage condenser lens, far away from the electron emission source, reducing the risk of contamination, extending the equipment life, and this position can achieve the most effective and rapid shutdown of the electron beam; 3. All structural components in the device are made of non-magnetic materials, and the insulating gaskets are made of non-metallic insulating materials. The use of non-magnetic materials and insulation design can avoid magnetic field interference, ensuring that the device as a whole does not have magnetic field interference on the electron beam and ensuring the stability of the electron beam. 4. By connecting the high-voltage grounding wire of the external liner to any grounding bolt, the device achieves the same potential between the grounding cover plate and the base and the liner voltage, which can reduce the influence of stray electric fields and improve detection accuracy. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0016] Figure 2 This is a schematic diagram of the bottom structure of this utility model.

[0017] Figure 3 This is a front view of the present invention.

[0018] Figure 4 This is a front sectional view of the present invention.

[0019] Figure 5 This is a schematic diagram showing the distribution of the four sets of deflection electrode plates in this utility model.

[0020] Figure 6 This is a schematic diagram of the disassembled structure of this utility model.

[0021] Figure 7 This is a schematic diagram of the deflection electrode plate in this utility model.

[0022] Figure 8 This is a schematic diagram of the bottom structure of the deflection electrode plate in this utility model.

[0023] In the diagram: 1. Connecting cable; 2. Base; 3. Connecting bolt; 4. Grounding cover; 5. Deflection electrode plate; 51. Head; 52. Root; 53. Cable fixing hole; 54. Set screw; 6. Through hole; 7. Grounding bolt; 8. Positioning block; 9. Fixing bolt; 10. Insulating washer; 11. Optical hole. Detailed Implementation

[0024] The technical solutions of this utility model will be clearly and completely described below with reference to the embodiments of this utility model. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this utility model.

[0025] Example: like Figures 1 to 8As shown, an electron beam gating device includes a base 2 and a grounding cover plate 4. Four sets of positioning blocks 8 and four sets of deflection electrode plates 5 are evenly distributed circumferentially on the bottom of the base 2. The deflection electrode plates 5 correspond to the positions of the positioning blocks 8 and are connected to the positioning blocks 8 by bolts A. The positioning blocks 8 achieve precise positioning and fixation of the deflection electrode plates 5, ensuring that the four sets of deflection electrode plates 5 have the same spacing and a uniform electric field distribution. A grounding cover plate 4 is provided at the bottom of the deflection electrode plates 5. The grounding cover plate 4 is connected to the positioning blocks 8 by grounding bolts 7. The grounding cover plate 4 and the base 2 are connected at the same potential by the grounding bolts 7. Combined with the high-voltage grounding wire of the external liner, stray electric field interference can be eliminated, improving the electron beam detection accuracy. Insulating washers 10 are provided between the four evenly distributed sets of deflection electrode plates 5, the base 2, and the grounding cover plate 4 to achieve electrical insulation. This design solves the problems of existing electron beam gates being installed close to the electron emission source, resulting in insufficient electron beam convergence, large beam current, incomplete shut-off, easy contamination of the electron emission source at close range, affecting equipment lifespan, unreasonable electrode layout, uneven electric field distribution, and low deflection efficiency.

[0026] In this embodiment, the deflection electrode plate 5 is composed of a head 51 and a root 52, and has an overall L-shaped structure. The root 52 has a triangular structure, on which the elongated head 51 is fixed. The triangular design of the root 52 of the deflection electrode plate 5 reduces charge accumulation, and the elongated structure of the head 51 extends the electric field's effective area, thereby improving deflection efficiency.

[0027] In this embodiment, cable fixing holes 53 are provided on both outer end faces of the root 52 of the deflection electrode plate 5. Set screws 54 are installed at the bottom of the cable fixing holes 53. The cable fixing holes 53 of two adjacent sets of deflection electrode plates 5 in three directions are short-circuited by vacuum high-voltage cables. The vacuum high-voltage cables are fixed in the cable fixing holes 53 by the set screws 54. The cable fixing holes 53 of the remaining two adjacent sets of deflection electrode plates 5 in one direction are connected to the power cable 1. One set of cable fixing holes 53 is the voltage input terminal, and the other set is the voltage output terminal.

[0028] It should be noted that, in actual wiring, the high-voltage grounding wire of the external liner can be connected to any grounding bolt 7, thereby achieving the same potential between the grounding cover plate 4 and the base 2 and the liner voltage, which can reduce the influence of stray electric fields and improve detection accuracy.

[0029] In this embodiment, the four sets of deflection electrode plates 5 are spaced at the same distance, with a channel between the inner sides of the heads 51. A through hole 6 is provided at the center of the base 2, and the heads 51 of the four sets of deflection electrode plates 5 extend through the through hole 6. The channels on the four sets of deflection electrode plates 5, together with the through hole 6, form an electron beam channel, ensuring that the electron beam passes through without obstruction.

[0030] It should be noted that the grounding cover plate 4 has an optical hole 11 for the electron beam to pass through. The optical hole 11 is coaxial with the through hole 6. The optical hole 11 and the through hole 6 on the base 2 form an electron beam channel for the electron beam to pass through.

[0031] In this embodiment, the insulating gasket 10 is made of non-metallic insulating material to achieve electrical insulation, and all structural components are made of non-magnetic material to ensure that the device as a whole does not interfere with the electron beam by a magnetic field.

[0032] In this embodiment, the deflection electrode plate 5 and the base 2 are separated by an insulating partition to further enhance electrical isolation, ensure electrical insulation, and improve the reliability of the device.

[0033] In this embodiment, the base 2 is provided with several sets of connecting bolts 3 for connecting with external equipment. The device is installed at the focal point of the second-stage condenser of the scanning electron microscope through the connecting bolts 3, located between the first-stage condenser and the objective lens. This position can achieve the most effective and rapid shutdown of the electron beam. At the same time, since it is far away from the top electron beam emission source, it can effectively avoid contamination of the electron beam source.

[0034] It should be noted that the control method of this electron beam gantler device is that the overall voltage is kept consistent with the voltage of the inner liner tube of the outer electron gun. When electron beam deflection is required, an additional deflection voltage is added to achieve electron beam deflection.

[0035] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating this utility model, and are not intended to limit the implementation of this utility model. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. Any obvious variations or modifications derived from the technical solutions of this utility model are still within the protection scope of this utility model.

Claims

1. An electron beam gate device, characterized in that: Includes a base (2) and a grounding cover plate (4). The base (2) has four sets of positioning blocks (8) and four sets of deflection electrode plates (5) evenly distributed around its bottom. The deflection electrode plates (5) correspond to the positioning blocks (8) and are connected to the positioning blocks (8) by bolts A. The bottom of the deflection electrode plates (5) is provided with a grounding cover plate (4). The grounding cover plate (4) is connected to the positioning blocks (8) by grounding bolts (7). Insulating washers (10) are provided between the four sets of deflection electrode plates (5) evenly distributed and the base (2) and the grounding cover plate (4).

2. The electron beam gating device according to claim 1, characterized in that: The deflection electrode plate (5) is composed of a head (51) and a root (52), and the whole is an L-shaped structure. The root (52) is a triangular structure, on which the head (51) with a long strip structure is fixed.

3. The electron beam gate device according to claim 2, characterized in that: Cable fixing holes (53) are provided on both outer end faces of the root (52) of the deflection electrode plate (5). Set screws (54) are installed at the bottom of the cable fixing holes (53). The cable fixing holes (53) of two adjacent sets of deflection electrode plates (5) in three directions are short-circuited by vacuum high-voltage cables. The vacuum high-voltage cables are fixed in the cable fixing holes (53) by set screws (54). The cable fixing holes (53) of the remaining two adjacent sets of deflection electrode plates (5) in one direction are connected to power cables (1). One set of cable fixing holes (53) is the voltage input terminal, and the other set is the voltage output terminal.

4. The electron beam gating device according to claim 3, characterized in that: The four sets of deflection electrode plates (5) are spaced at the same distance, with a channel left between the inner sides of the head (51). A through hole (6) is provided at the center of the base (2), and the head (51) of the four sets of deflection electrode plates (5) extends through the through hole (6).

5. The electron beam gating device according to claim 1, characterized in that: The insulating gasket (10) is made of non-metallic insulating material, and all structural components are made of non-magnetic material.

6. The electron beam gating device according to claim 1, characterized in that: The deflection electrode plate (5) and the base (2) are separated by an insulating partition.

7. The electron beam gating device according to claim 1, characterized in that: The base (2) is provided with several sets of connecting bolts (3) for connecting with external equipment. The device is installed at the focal point of the second-stage condenser of the scanning electron microscope through the connecting bolts (3), and is located between the first-stage condenser and the objective lens.

8. The electron beam gating device according to claim 4, characterized in that: The grounding cover plate (4) has an optical hole (11) for the electron beam to pass through, and the optical hole (11) is coaxial with the through hole (6).

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