A sample stage for scanning electron microscope 3D STEM mode imaging

Abstract

The application discloses a sample stage for scanning electron microscope 3D STEM mode imaging, which comprises a base, a support and a fixer; a clamping groove under the base is embeddedly fixed with a base arranged inside a sample chamber of a scanning electron microscope, the support is fixedly installed on the base through a connecting piece, a plurality of stepped round holes are uniformly arranged on both sides of the support, the fixer is provided with two and rotationally connected with the support, a plurality of annular rings are arranged on each fixer, the number and size of the annular rings are matched with the number and size of the stepped round holes, and the annular rings on the fixer are embedded into the stepped round holes when the fixer is rotated to a horizontal position. The sample stage can effectively fix a circular carrier net and keep it from being deformed, and the number of times of repeatedly loading and changing samples is reduced; the embedded fixer can guarantee that the sample stage is at an optimal working distance and realize scanning electron microscope 3D STEM mode imaging of multiple samples at a time by using limited shooting space.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of scanning electron microscopy, and particularly relates to a sample stage for 3D STEM mode imaging of a scanning electron microscope. BACKGROUND

[0002] The scanning electron microscope is simple to operate and can obtain the microstructure of a material, and has become the most common tool for observing the microstructure and analyzing the composition of a material. The low-voltage imaging mode of the scanning electron microscope is beneficial to imaging of a low-atomic-number sample, and plays an irreplaceable role in imaging of a polymer material and a biological material which are not resistant to electron beam irradiation and need to obtain better imaging contrast.

[0003] The scanning electron microscope can currently be configured with an accessory for shooting a transmission electron detection mode (STEM), and for a sample that has been imaged by a transmission electron microscope, scanning transmission imaging can be realized on the scanning electron microscope without re-preparing the sample. The 3D STEM mode imaging technology is the latest function developed by the scanning electron microscope. The 3D STEM mode shooting imaging generally requires a small working distance of the sample stage, and needs to leave more space for rotation and tilting of the sample stage. The device currently configured by the commercial scanning electron microscope for 3D STEM mode shooting is usually a rectangular sample stage, and this design is more conducive to dynamic rotation and tilting of the sample stage in a tilting angle range of -60°~60° under the condition of ensuring the best working distance, so as to realize collection and imaging of scattered electron signals of the sample. However, the sample stage currently used for 3D STEM mode imaging of the scanning electron microscope is a circular carrier net fixed by a copper sheet tightened by a simple screw, and the rigid contact between the copper sheet and the circular carrier net is very easy to cause the circular carrier net to fall off and deform during the fixing process, especially causing serious loss of a precious sample. At the same time, the fixing copper sheet of the sample stage and the screw for fixing the copper sheet are also very easy to fall off and be lost during use, which limits the sustainable use of the sample stage. In particular, only two circular carrier nets can be installed at a time during sample preparation, which greatly limits the imaging efficiency at a time. Therefore, it is of great significance to develop a sample stage which can effectively fix multiple circular carrier nets without disassembling the fixing assembly and realize dynamic multi-angle shooting of the circular carrier net in a limited shooting space for 3D STEM mode shooting of the scanning electron microscope.

[0004] The Chinese invention patent application with the publication number CN110071029A discloses a scanning electron microscope sample stage, which comprises a base and at least one bearing module detachably connected with the base, and the bearing module is provided with a bearing slope for bearing a sample. The invention can realize the purpose of simultaneously loading multiple samples and simultaneously measuring at multiple angles without the need of relatively complex components such as clamps and rotating shafts, and has the functions of plane and cross-section testing, but the invention is not applicable to the fixation of a circular carrier net for scanning electron microscope 3D STEM mode shooting.

[0005] The Chinese invention patent application with the publication number CN112454291A discloses a novel multifunctional composite variable scanning electron microscope (SEM) sample stage, which comprises a sample stage bottom support and a sample lifting platform. The bottom support is provided with a fixed support connected with an SEM stage at the center of the bottom, the sample lifting platform is screwed into the threaded through hole of the bottom support through an external thread, and the upper part of the sample stage bottom support is provided with a function support. The invention solves the problem that multiple small samples with obvious height difference cannot be observed simultaneously, and solves the problem that multiple small samples are simultaneously at the best working distance of the SEM during comprehensive analysis, but the invention is also not applicable to the fixation of a circular carrier net for scanning electron microscope 3D STEM mode shooting. SUMMARY

[0006] In view of the deficiencies of the prior art, the purpose of the present application is to provide a sample stage for scanning electron microscope 3D STEM mode imaging, which can solve the fixation problem of a circular carrier net and improve the imaging efficiency of scanning electron microscope 3D STEM mode. The sample stage of the present application can effectively fix the circular carrier net and keep it from deforming, and the number of repeated sample loading and unloading is reduced; the embedded fixator avoids the disassembly of the fixing components, which can ensure that the sample stage is at the best working distance and realize the scanning electron microscope 3D STEM mode imaging of multiple samples at a time using limited shooting space.

[0007] The purpose of the present application is achieved by the following technical solutions.

[0008] The present application provides a sample stage for scanning electron microscope 3D STEM mode imaging, which comprises a base, a support and a fixator. A clamping groove is arranged below the base, the clamping groove is embeddedly fixed with a base arranged inside a sample chamber of a scanning electron microscope, the support is fixedly installed on the base through a connecting piece, a plurality of stepped round holes for placing a circular carrier net are uniformly arranged on both sides of the support, the fixator has two and is symmetrically arranged above the support, and a rotating connection is formed between each fixator and the support, respectively. A plurality of annular rings are arranged on each fixator, the number and size of the annular rings are matched with the number and size of the stepped round holes, and when the fixator is rotated to a horizontal position, the annular rings on the fixator are embedded in the stepped round holes.

[0009] In the application, the through holes are arranged on the position of the fixing device and the support close to the rotating connection, the through hole on the support is provided with the combination of the ball, spring and cylinder, the combination is composed of the ball, spring and cylinder which are independent of each other, the spring is located between the ball and the cylinder, the cylinder is arranged away from the fixing device, and the ball is located at the edge of the support close to the fixing device, so that the fixing device is fixed when rotating to the vertical direction through the spring buckle connection.

[0010] In the application, the fixing device and the support are connected through the rotating shaft.

[0011] In the application, the two ends of the support are respectively provided with the ball, the top end of the fixing device is provided with the clamping groove, so that the fixing device is connected with the support when rotating to the horizontal direction, and the ball is connected with the spring fixed on the support.

[0012] In the application, the fixing device is a cuboid frame structure, the support hooks are symmetrically arranged in the inside of the cuboid frame, two round holes are symmetrically arranged on each ring, and the cuboid frame is movably connected with the ring through the support hooks passing through the round holes.

[0013] In the application, the hollow plate is arranged on the fixing device close to the rotating connection of the support, so as to insert the tweezers to guide the 90° rotating movement of the fixing device between the vertical direction and the horizontal direction.

[0014] In the application, two rings are arranged on each fixing device.

[0015] In the application, the support is a rectangle, and the connecting piece is a cylinder.

[0016] Compared with the prior art, the application has the following beneficial effects:

[0017] 1) The application designs the fixing device which can be embedded and integrally connected, so as to ensure the best working distance and effective rotating space of the sample table during the 3D STEM shooting process of the scanning electron microscope.

[0018] 2) The application provides more stable support for the circular support net for 3D STEM imaging of the scanning electron microscope.

[0019] 3) The application uses the fixing device which can be in situ erected or lowered and the ring which can be freely shaken to ensure that the fixed circular support net is not deformed, which has great significance for the precious sample which can be used for transmission electron microscope shooting and 3D STEM imaging of the scanning electron microscope.

[0020] 4) The application can put multiple samples at a time, reduces the number of sample replacement, does not need to disassemble the parts every time the sample is placed, improves the service life of the sample table and the efficiency of the scanning electron microscope shooting. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 This is a schematic diagram of the structure of the device for observing scanned transmission images according to the present invention.

[0022] Figure 2 This is a schematic diagram of the structure of the support frame for the device of the present invention for observing scanned transmission images.

[0023] Figure 3 This is a schematic diagram of the structure of the fixture for observing scanned transmission images according to the present invention.

[0024] Figure 4 This is a schematic diagram of the connection between the fixture and the support in the device for observing scanned transmission images according to the present invention.

[0025] Figure 5 This is a top view schematic diagram of the device for observing scanned transmission images according to the present invention.

[0026] Figure 6 This is a cross-sectional schematic diagram of the device for observing scanned transmission images according to the present invention.

[0027] The following numbers are labeled in the diagram: 1-base, 11-first slot, 2-bracket, 21-stepped hole, 22-shaft hole, 23-combination of ball bearing, spring and cylinder, 231-cylinder, 232-spring, 233-first ball bearing, 24-second ball bearing, 3-fixer, 31-shaft, 32-ring, 33-support hook, 34-second through hole, 35-hollow plate, 36-second slot, 4-connector. Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0029] Example 1

[0030] like Figures 1-6 As shown, the present invention provides a sample stage for 3D STEM mode imaging of a scanning electron microscope, including a base, a base 1, a bracket 2, a fixture 3, a first slot 11, a rotating shaft 31, and a ring 32; the base is disposed inside the sample chamber of the scanning electron microscope, and the first slot 11 is provided below the base 1, and the base 1 and the base are connected and fixed through the first slot 11.

[0031] The bracket 2 is connected and fixed to the base 1 through the connector 4, which is a cylinder; there are two fixtures 3, which are connected to the bracket 2 through the rotating shaft 31, and each fixture 3 has two rings 32 installed inside.

[0032] The support 2 includes two stepped round holes 21 on both sides. In a specific embodiment, the fixed circular grid has a diameter of 3 mm, and the stepped round hole 21 is a first step, which can better bear the circular grid and prevent it from falling off, so that the circular grid can be placed horizontally. The through hole of the stepped round hole 21 is used for scanning transmission imaging of the circular grid by a detector. The edges of the support 2 include an axle hole 22 and a first through hole, and the first through hole is provided with a combination of a ball, a spring and a cylinder 23. In particular, as shown in Figure 4 the combination of the ball, the spring and the cylinder 23, the first ball 233, the spring 232 and the cylinder 231 are independent and non-fixed, the spring 232 is located between the first ball 233 and the cylinder 231, the diameter of the spring 232 is smaller than that of the first ball 233 and the cylinder 231, the cylinder 231 is arranged away from the holder 3 and is used for blocking one end of the first through hole, and the first ball 233 is located inside the edge of the support 2 and is close to the holder 3. The second ball 24 is located at the center of the front end of the support 2 and is fixed to the support 2 by a spring.

[0033] The cuboid assembly of the holder 3 includes a through shaft 31, the through shaft 31 is connected with the axle hole 22 of the edge of the support 2, so that the holder 3 can be raised or lowered by rotating the through shaft 31 around the axle hole 22. The hollow plate 35 at the outer end of the cuboid assembly of the holder 3 can pass through the tweezers to apply force to the holder 3, so that the holder 3 can be raised or lowered. The second through hole 34 of the holder 3 can be connected with the first ball which can be extended and retracted and the second through hole 34 at the edge of the holder 3 to form a buckle connection, so as to keep the holder 3 stable at 90°.

[0034] The holder 3 is fixed to the circular ring 32 by the support hook 33, and the circular ring 32 can freely swing with the holder 3. In particular, when the holder 3 is gradually lowered to a horizontal position, the bottom end of the freely swinging circular ring 32 first contacts the circular grid and generates a relatively small contact force on the circular grid, which reduces the rigid contact between the circular ring 32 and the circular grid and ensures that the circular grid is not deformed. During the horizontal fixing of the holder 3, the edge of the circular ring 32 is aligned above the edge of the circular grid to press and fix the edge of the circular grid. In particular, the hollow hole of the circular ring 32 is aligned with the through hole of the stepped round hole 21, so as to maximize the collection and imaging of the scattered electron signal of the sample of the circular grid by the detector. The second clamping groove 36 at the top end of the outer edge of the holder 3 is connected with the second ball 24 which can be extended and retracted of the support 2 when the holder 3 is lowered, so as to further embed the holder 3 in the support 2 and ensure that the sample stage is fixed when the circular grid is tilted and rotated around the detector.

[0035] In a specific embodiment, the sample of polymer fiber is prepared on a circular carrier with a diameter of 3 mm. After taking the transmission electron microscope, the circular carrier is directly forced upward through the hollow structure of the hollow plate 35 with tweezers, the second through hole 34 of the fixator 3 is connected with the first ball 233 in the combination on the support 2 through the ball buckle connection, and the fixator 3 is kept stable at 90°. The circular carrier is transferred to the stepped circular hole 21 of the sample stage with tweezers, the fixator 3 is forced downward through the hollow structure of the hollow plate 35 with tweezers, the circular ring 32 is lowered to freely shake, the bottom end of the circular ring 32 first contacts the circular carrier and applies a relatively small contact force thereon; further, the fixator 3 is completely horizontally placed, the edge of the circular ring 32 corresponds to the edge of the circular carrier and is fixedly contacted, the hollow hole of the circular ring 32 is directly opposite to the through hole of the stepped circular hole 21, the collection and imaging of the scattered electron signal of the detector to the circular carrier sample are maximally maintained; at the same time, the second clamping groove 36 at the top of the fixator 3 is engaged and fixed with the second ball 24 of the support 2, and the circular carrier is completely pressed and fixed on the sample stage for subsequent scanning electron microscope 3D STEM mode imaging.

Claims

1. A sample stage for scanning electron microscope 3D STEM mode imaging, characterized in that, It includes base, support and fixer; the base is provided with a clamping groove below, the clamping groove is embedded and fixed with a base provided inside a sample chamber of a scanning electron microscope, the support is fixedly installed on the base through a connecting piece, a plurality of stepped round holes for placing a circular support net are uniformly arranged on both sides of the support, the fixer has two, which are symmetrically arranged above the support and respectively form a rotary connection with the support, a plurality of annular rings are arranged on each fixer, the number and size of the annular rings are matched with the number and size of the stepped round holes, when the fixer is rotated to a horizontal position, the annular rings on the fixer are embedded in the stepped round holes; wherein: The fixer is a cuboid frame structure, support hooks are symmetrically arranged inside the cuboid frame, two round holes are symmetrically arranged on each annular ring, the cuboid frame realizes movable connection with the annular ring by passing through the round holes through the support hooks.

2. The sample stage for scanning electron microscope 3D STEM mode imaging of claim 1, wherein, Through holes are correspondingly arranged on the fixer and the support near the rotary connection, a combination of a ball, a spring and a cylinder is built in the through hole on the support, the combination is composed of the ball, the spring and the cylinder which are independent of each other, the spring is located between the ball and the cylinder, the cylinder is arranged away from the fixer, and the ball is located at the edge of the support close to the fixer, so as to realize fixation of the fixer when it is rotated to a vertical direction through snap connection of the spring.

3. The sample stage for scanning electron microscope 3D STEM mode imaging of claim 1, wherein, The fixer and the support are rotatably connected through a rotating shaft.

4. The sample stage for scanning electron microscope 3D STEM mode imaging of claim 1, wherein, Rolling balls are arranged at both ends of the support respectively, a clamping groove is arranged at the top end of the fixer, so that the fixer forms a fixed connection with the support when it is rotated to a horizontal direction; the rolling balls are connected with the springs fixed on the support.

5. The sample stage for scanning electron microscope 3D STEM mode imaging of claim 1, wherein, A hollow plate is arranged on the fixer near the rotary connection with the support, so as to insert forceps to guide 90° rotary movement of the fixer between the vertical and horizontal directions.

6. The sample stage for scanning electron microscope 3D STEM mode imaging of claim 1, wherein, Two annular rings are arranged on each fixer.

7. The sample stage for scanning electron microscope 3D STEM mode imaging of claim 1, wherein, The support is rectangular on both sides, and the connecting piece is a cylinder.

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