A dual beam scanning electron microscope vacuum cryo-transfer device

Abstract

The present application relates to a kind of double-beam scanning electron microscope vacuum frozen transmission device, including vacuum sample chamber door, sample transmission pipe, frozen sample transmission rod and angle adjusting device.Vacuum sample chamber door is sealingly connected at the opening of vacuum sample chamber, and is equipped with sample transmission window, sample transmission pipe is sealingly connected in sample transmission window position, and is communicated with vacuum sample chamber.Frozen sample transmission rod is arranged in sample transmission pipe, and outer periphery is dynamically sealed with sample transmission pipe, for delivering frozen sample to vacuum sample chamber, and the end of frozen sample transmission rod can be clamped with sample transmission pipe and / or unclamped.Angle adjusting device is arranged on vacuum sample chamber door, and is connected with sample transmission pipe, when frozen sample transmission rod is clamped with sample transmission pipe, angle adjusting device is suitable for driving sample transmission pipe and frozen sample transmission rod synchronous rotation, adjusts the inclination angle of frozen sample, meets the demand of ion beam processing and scanning electron microscope imaging of frozen sample.

Description

Technical Field

[0001] This invention relates to the field of microscopic imaging technology, and more particularly to a vacuum cryogenic transport device for a dual-beam scanning electron microscope. Background Technology

[0002] Cryo-electron microscopy (cryo-EM) uses rapid freezing or autoclaving to freeze biological samples to a near-physiological state, preserving their high-resolution structure. Another important technique in cryo-EM is electron tomography (ETM), which allows for the sequential imaging of frozen samples, reconstructing their high-resolution three-dimensional structure. Since cellular and tissue samples are typically a few micrometers to tens of micrometers or even larger, far exceeding the thickness that transmission electron microscopes (TEM) can penetrate (hundreds of nanometers), cryo-focused ion beam (CFFE) is a highly effective technique for thinning these samples. This technique can reduce samples to approximately 200 nanometers without deformation or wrinkling.

[0003] One of the current problems affecting the application of this technology is the technique of sample cryogenic transport. During transport, frozen samples are prone to ice crystal contamination, breakage or even loss of sample sections, and rotation of the sample position. These problems result in the partial loss of carefully prepared frozen sections in cryogenic dual-beam scanning electron microscopy, significantly impacting the success rate of experiments and becoming one of the current bottlenecks in this technology. Summary of the Invention

[0004] (a) Technical problems to be solved

[0005] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a dual-beam scanning electron microscope vacuum cryogenic transport device for transporting frozen samples in cryogenic sample cutting and thinning experiments using a dual-beam scanning electron microscope, as well as for transporting frozen samples between a dual-beam scanning electron microscope and a cryogenic transmission electron microscope or a cryogenic fluorescence microscope. This device solves the problem of low success rate in the prior art of frozen sample transport technology, greatly reduces ice crystal contamination and sample sheet breakage, improves the sample transfer success rate, and is easy to operate.

[0006] (II) Technical Solution

[0007] To achieve the above objectives, the present invention provides a vacuum cryogenic transport device, the specific technical solution of which is as follows:

[0008] A vacuum cryogenic transfer device, comprising:

[0009] The vacuum sample chamber door is sealed to the opening of the vacuum sample chamber, and a sample transfer window is provided on the vacuum sample chamber door;

[0010] The sample transfer tube is sealed and connected to the sample transfer window and communicates with the vacuum sample chamber.

[0011] A frozen sample transfer rod is inserted into the sample transfer tube and its outer circumference is dynamically sealed to the inner wall of the sample transfer tube. It is used to transport frozen samples to the vacuum sample chamber.

[0012] The end of the frozen sample transfer rod away from the frozen sample can be engaged with and / or disengaged from the sample transfer tube;

[0013] An angle adjustment device is located on the vacuum sample chamber door and connected to the sample transfer tube;

[0014] When the frozen sample transfer rod is engaged with the sample transfer tube, the angle adjustment device is adapted to drive the sample transfer tube and the frozen sample transfer rod to rotate synchronously, so as to adjust the tilt angle of the frozen sample.

[0015] Furthermore, it also includes a three-dimensional translation stage;

[0016] The sample transfer tube is connected to the sample transfer window via a corrugated pipe;

[0017] The three-dimensional translation stage is connected to the sample transfer tube and is mounted on the translation stage support, which is connected to the angle adjustment device.

[0018] When the frozen sample transfer rod is engaged with the sample transfer tube, the three-dimensional translation stage can drive the sample transfer tube and the frozen sample transfer rod to move synchronously to adjust the position of the frozen sample.

[0019] Furthermore, the angle adjustment device includes:

[0020] The bushing vacuum plate valve housing assembly is sealed at one end to the refrigeration transfer window and sealed at the other end to the bellows.

[0021] The worm gear is mounted on the shaft disk, which is rotatably fitted around the outer periphery of the shaft sleeve vacuum plate valve housing assembly and is fixedly connected to the translation stage bracket.

[0022] The worm gear is rotatably connected to the worm gear support, which is in turn connected to the vacuum sample chamber door.

[0023] One end of the worm gear is connected to the motor and meshes with the worm wheel. When the motor works, it can drive the worm wheel meshing with the worm gear to rotate, which in turn drives the shaft disk, translation stage support, three-dimensional translation stage, sample transfer tube and frozen sample transfer rod to rotate synchronously.

[0024] Furthermore, the angle adjustment device also includes a synchronization sleeve;

[0025] The synchronous sleeve is fitted around the outer periphery of the bellows, with one end fixedly connected to the end of the bellows and the other end connected to the translation stage support.

[0026] The synchronizing sleeve is located inside the housing assembly of the bushing vacuum plate valve, and its outer periphery is dynamically sealed to the inner wall of the housing assembly of the bushing vacuum plate valve.

[0027] Furthermore, it also includes a vacuum plate valve;

[0028] The vacuum plate valve is sealed to the side opening of the vacuum plate valve housing of the bushing vacuum plate valve housing assembly, and can form a sealed channel between the frozen sample transfer rod, the sample transfer tube, the bellows, the bushing vacuum plate valve housing assembly and the vacuum plate valve. The vacuum plate valve is used to control the connection and / or closure of the sealed channel with the vacuum sample chamber.

[0029] When the sealed channel is connected to the vacuum sample chamber, the frozen sample transfer rod, under manual control and negative pressure, sends the end containing the frozen sample into the vacuum sample chamber.

[0030] Furthermore, it also includes a pre-vacuum valve;

[0031] The pre-vacuum valve is sealed to the sample transfer tube and communicates with the sealed channel, and is used to pre-vacuum the sealed channel.

[0032] Furthermore, it also includes a positioning sleeve;

[0033] The positioning sleeve is located inside the sample transfer tube, and is axially and radially positioned to the sample transfer tube, and is located on the side of the sample transfer tube near the vacuum sample chamber door.

[0034] The positioning sleeve is equipped with a Z-shaped groove, and the frozen sample transfer rod is equipped with a limit pin;

[0035] The frozen sample transfer rod is inserted into the positioning sleeve, and the limiting pin can slide into and / or slide out of the Z-shaped groove.

[0036] When the limiting pin slides into the Z-shaped groove and is located at the turning point of the Z-shaped groove, it limits the pre-insertion position of the frozen sample transfer rod.

[0037] Furthermore, a locking pin is provided on the side of the sample transfer tube away from the vacuum sample chamber door, and a locking groove is provided on the end of the frozen sample transfer rod away from the frozen sample.

[0038] The SIM card ejector tool can be inserted into and / or removed from the SIM card slot;

[0039] When the pin is inserted into the slot, the frozen sample transfer rod engages with the sample transfer tube.

[0040] When the caliper pin is pulled out of the caliper slot, the frozen sample transfer rod is released from the sample transfer tube.

[0041] Furthermore, a Dewar flask is provided at the end of the frozen sample transfer rod away from the frozen sample. The Dewar flask is used to provide a cold source for the frozen sample placed on the frozen sample transfer rod.

[0042] Furthermore, it also includes a controller;

[0043] The controller is communicatively connected to the angle adjustment device, the three-dimensional translation stage, the vacuum plate valve, and the pre-vacuum valve, and is used to control the start and stop of the above-mentioned equipment.

[0044] (III) Beneficial Effects

[0045] The dual-beam scanning electron microscope vacuum cryogenic transport device provided by the present invention has the following beneficial effects.

[0046] In this invention, an angle adjustment device is provided and connected to the sample transfer tube. A cryogenic sample transfer rod passes through the sample transfer tube and can slide along it to transfer the cryogenic sample to the vacuum sample chamber. The end of the cryogenic sample transfer rod furthest from the cryogenic sample can be engaged or disengaged from the sample transfer tube. When engaged, the angle adjustment device is activated, causing the cryogenic sample transfer rod engaged with the sample transfer tube to rotate, thereby adjusting the tilt angle of the cryogenic sample and meeting the requirements for cryogenic focused ion beam cutting and imaging of the cryogenic sample.

[0047] In this invention, frozen samples are transported to the vacuum sample chamber via a frozen sample transfer rod. The frozen sample transfer rod serves as both a transfer device and a stage. During the transfer of frozen samples into the vacuum sample chamber of a dual-beam scanning electron microscope (DEM) and from the DEM to a cryo-transmission electron microscope (CREM) or other equipment, the frozen samples do not need to be transferred. This effectively avoids deformation, ice contamination, breakage, and movement or rotation of the frozen samples during handling, greatly improving the success rate of experiments. Attached Figure Description

[0048] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments of this application and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0049] Figure 1 This is a schematic diagram of the structure of the dual-beam scanning electron microscope and the dual-beam scanning electron microscope vacuum cryogenic transport device in a specific embodiment;

[0050] Figure 2 This is a partial structural diagram of the dual-beam scanning electron microscope vacuum cryogenic transport device in a specific embodiment;

[0051] Figure 3 This is an exploded view of the sample transfer tube and the frozen sample transfer rod in a specific embodiment;

[0052] Figure 4 This is a schematic diagram of the angle adjustment device in a specific implementation embodiment;

[0053] Figure 5 for Figure 4 AA section view in the middle;

[0054] Figure 6 for Figure 3 BB section view;

[0055] Figure 7 This is a schematic diagram of the structure of the vacuum sample chamber door in a specific implementation embodiment;

[0056] Figure 8 This is a schematic diagram of the positioning sleeve in a specific implementation embodiment;

[0057] Figure 9 This is a schematic diagram of the sample transfer tube in a specific implementation method.

[0058] [Explanation of Labels in the Attached Image]

[0059] 1. Vacuum sample chamber door; 110. Vacuum sample chamber door flange; 120. Sample transfer window;

[0060] 2. Vacuum sample chamber;

[0061] 3. Frozen sample transfer rod; 310. Limiting pin; 320. Slot; 330. Indicator line; 340. Dewar flask;

[0062] 4. Sample transfer tube; 410. Pick pin; 420. Stop; 430. Protrusion;

[0063] 5. Three-dimensional translation stage;

[0064] 6. Angle adjustment device; 610. Bushing vacuum plate valve housing assembly; 620. Shaft disc; 630. Worm gear; 640. Worm support; 650. Worm; 660. Motor; 670. Synchronizing sleeve; 680. Bearing;

[0065] 7. Pre-vacuum valve; 8. Vacuum plate valve; 9. Ion beam system; 10. Electron beam system; 11. Controller; 12. Bellows; 14. Threaded sleeve;

[0066] 15. Positioning sleeve; 151. Z-shaped groove; 152. Through hole; 153. Positioning flange;

[0067] 16. Translation stage support; 17. Frozen sample. Detailed Implementation

[0068] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be described in more detail below with reference to the accompanying drawings of the preferred embodiments. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are some, but not all, embodiments of the present invention. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0069] In the description of this embodiment, it should be understood that the terms "center", "longitudinal", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this embodiment and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this embodiment.

[0070] See Figures 1 to 9 This embodiment provides a cryogenic dual-beam scanning electron microscope vacuum cryogenic transport device for transporting a frozen sample 17 to a vacuum sample chamber 2, including a vacuum sample chamber door 1, a cryogenic sample transport rod 3, a sample transport tube 4, and an angle adjustment device 6.

[0071] Specifically, the vacuum sample chamber door 1 is sealed to the opening of the vacuum sample chamber 2, and a sample transfer window 120 is provided on the vacuum sample chamber door 1. The vacuum sample chamber door 1 has a concave structure, with a vacuum sample chamber door flange 110 on its edge. The concave structure is placed inside the vacuum sample chamber 2, and the vacuum sample chamber door flange 110 is bolted to the opening of the vacuum sample chamber 2. A sealing strip is provided at the contact position between the vacuum sample chamber door flange 110 and the vacuum sample chamber 2 to ensure the required vacuum level of the vacuum sample chamber 2. An angle adjustment device 6 is provided on the vacuum sample chamber door 1 and connected to the sample transfer tube 4. The angle adjustment device 6 is adapted to drive the sample transfer tube 4 to rotate. The sample transfer tube 4 is sealed to the sample transfer window 120 and communicates with the vacuum sample chamber 2. One end of the cryogenic sample transfer rod 3 is used to fix the cryogenic sample 17, and the other end is provided with a Dewar flask 340. The Dewar flask 340 is used to provide a cold source for the cryogenic sample 17 placed on the cryogenic sample transfer rod 3. Furthermore, the fixed end of the frozen sample 17 of the frozen sample transfer rod 3 passes through the sample transfer tube 4. Under the push of an external force, it can slide along the sample transfer tube 4 and pass through the sample transfer window 120 to transport the frozen sample 17 into the vacuum sample chamber 2. Furthermore, a slot 320 is provided on the frozen sample transfer rod 3 on the side where the Dewar flask 340 is located, and a corresponding locking pin 410 is provided on the sample transfer tube 4. When the frozen sample transfer rod 3 slides towards the vacuum sample chamber 2, when it reaches the designated position, the locking pin 410 engages in the slot 320, and the frozen sample transfer rod 3 stops sliding, thus limiting the position of the frozen sample 17 within the vacuum sample chamber 2. When it is necessary to remove the frozen sample transfer rod 3, it is pulled away from the vacuum chamber 2, and the locking pin 410 is pulled out of the slot 320, releasing the engagement between the frozen sample transfer rod 3 and the sample transfer tube 4.

[0072] In practical use, the frozen sample 17 is pre-fixed onto the frozen sample transfer rod 3, and the fixed end of the frozen sample 17 is inserted into the sample transfer tube 4. External force pushes the frozen sample transfer rod 3 to transfer the frozen sample 17 into the vacuum sample chamber 2, and the frozen sample transfer rod 3 is engaged with the sample transfer tube 4. According to the required cutting angle of the frozen sample 17 using the focused ion beam, the angle adjustment device 6 is activated, driving the sample transfer tube 4 and the frozen sample transfer rod 3 to rotate synchronously, adjusting the tilt angle of the frozen sample 17, thereby meeting the angle requirements when the frozen sample 17 is cut by the focused ion beam. In this embodiment, the frozen sample transfer rod 3 is used to transport the frozen sample 17 on one hand, and on the other hand, it can be used as a cold stage to support the frozen sample 17. When the frozen sample 17 is introduced into the dual-beam scanning electron microscope and when the sample is transferred from the dual-beam scanning electron microscope to the cryo-transmission electron microscope, there is no need to transfer the sample between different stages, which can effectively avoid deformation, ice contamination, and displacement of the frozen sample 17 during the handling and transfer process, greatly improving the success rate of the experiment.

[0073] Further, see Figure 1 and Figure 2 The vacuum cryogenic transport device in this embodiment also includes a three-dimensional translation stage 5, which is mounted on a translation stage support 16 and connected to the sample transport tube 4. The translation stage support 16 is fixedly connected to the angle adjustment device 6 by bolts. Correspondingly, the sample transport tube 4 is flexibly connected to the vacuum sample chamber door 1 via a bellows 12, which has telescopic functions in the length, horizontal, and vertical directions. The three-dimensional translation stage 16 is suitable for position adjustment in the X, Y, and Z directions. When the three-dimensional translation stage 16 is working, it can drive one end of the bellows 12 connected to the sample transport tube 4 to move accordingly. The position of the sample transport tube 4 relative to the vacuum sample chamber 2 changes, and the insertion length of the cryogenic sample transport rod 3 also changes accordingly. This allows for precise adjustment of the position of the cryogenic sample 17 within the vacuum sample chamber 2 relative to the ion beam system 9 or the electron beam system 10, to meet the requirements for adjusting the focused ion beam cutting position and the scanning electron microscope imaging position of the cryogenic sample 17 within the vacuum sample chamber 2.

[0074] Specifically, see Figure 4In this embodiment, the angle adjustment device 6 includes a bushing vacuum plate valve housing assembly 610, a shaft disk 620, a worm gear 630, a worm 650, and a motor 660. One end of the bushing vacuum plate valve housing assembly 610 is sealed to the vacuum sample chamber door 1, and the other end is dynamically sealed to the bellows 12. The worm gear 630 is bolted to the shaft disk 620, which is rotatably fitted onto the outer periphery of the bushing vacuum plate valve housing assembly 610 via a turntable bearing 680 and fixedly connected to the translation stage bracket 16 by bolts. Both ends of the worm 650 are rotatably connected to a worm bracket 640 via bearings, and the worm bracket 640 is bolted to the vacuum sample chamber door 1. The worm 650 meshes with the worm gear 630, and its end is connected to the motor 660. The operation of the motor 660 drives the worm 650 and worm gear 630 in meshing transmission. Furthermore, the angle adjustment device 6 also includes a synchronization sleeve 670, which is fitted around the outer periphery of the bellows 12. One end of the synchronization sleeve 670 is fixedly connected to the end of the bellows 12 by welding, and the other end is detachably connected to the translation stage bracket 16 by bolts. The synchronization sleeve 670 is located inside the bushing vacuum plate valve housing assembly 610, and its outer periphery is dynamically sealed to the bushing vacuum plate valve housing assembly 610. When angle adjustment is required, the frozen sample transfer rod 3 is confirmed to be engaged with the sample transfer tube 4, and the control motor 660 is started. The motor 660 drives the worm gear 650 and worm wheel 630 to mesh and transmit power, thereby driving the shaft disk 620, translation stage bracket 16, sample transfer tube 4, bellows 12, synchronization sleeve 670, frozen sample transfer rod 3, and frozen sample 17 to rotate synchronously, so as to meet the needs of tilt imaging or ion beam processing of frozen sample 17. In this embodiment, a synchronization sleeve 670 is provided. Both the synchronization sleeve 670 and the shaft disk 620 are connected to the translation stage support 16. When the shaft disk 620 rotates, the synchronization sleeve 670 and the bellows 12 rotate synchronously through the translation stage support 16.

[0075] Further, see Figure 2The vacuum cryogenic transfer device in this embodiment also includes a vacuum delivery system, which drives the cryogenic sample transfer rod 3 to slide along the sample transfer tube 4 using a negative pressure working principle. Specifically, the vacuum delivery system includes a vacuum plate valve 8 and a pre-vacuum valve 7. The vacuum plate valve 8 is sealed to the bushing vacuum plate valve housing assembly 610 to form a sealed channel between the cryogenic sample transfer rod 3, the sample transfer tube 4, the bellows 12, the bushing vacuum plate valve housing assembly 610, and the vacuum plate valve 8. The vacuum plate valve 8 is used to control the connection and closure of the sealed channel with the vacuum sample chamber 2. The pre-vacuum valve 7 is sealed to the sample transfer tube 4 and communicates with the sealed channel to evacuate the sealed channel to a low vacuum. In practical use, the vacuum plate valve 8 is closed, the frozen sample transfer rod 3 is inserted into the sample transfer tube 4, and then the pre-vacuum valve 7 is opened. A vacuum pump is used to begin evacuating the sealed channel to a low vacuum. When the set value is reached, the pre-vacuum valve 7 is closed and the vacuum plate valve 8 is opened. Because the vacuum level in the vacuum sample chamber 2 is much lower than the external atmospheric pressure, the frozen sample transfer rod 3 slides along the sample transfer tube 4 under manual control and negative pressure to transport the frozen sample 17 into the vacuum sample chamber 2. In this embodiment, the transfer process of the frozen sample 17 is simple, convenient, and quick.

[0076] Further, see Figure 3 , Figure 6 , Figure 8 and Figure 9The vacuum freezing transfer device also includes a positioning sleeve 15, used to define the pre-insertion position of the frozen sample transfer rod 3. Specifically, the positioning sleeve 15 is disposed inside the sample transfer tube 4 and located on the side near the bellows 12. A stop 420 is provided inside the sample transfer tube 4, and a protrusion 430 is provided on the stop 420, extending towards the bellows 12. A positioning flange 153 is correspondingly provided on the positioning sleeve 15. The positioning sleeve 15 is disposed inside the sample transfer tube 4, and the positioning flange 153 abuts against the stop 420. The threaded sleeve 14 is screwed into the sample transfer tube 4, and its end abuts against the positioning flange 153, limiting the axial movement of the positioning sleeve 15 to prevent axial sliding of the positioning sleeve 15. Furthermore, the positioning sleeve 15 is also provided with a through hole 152, through which the pre-vacuum valve 7 communicates with the sealing channel. The positioning sleeve 15 is also provided with a Z-shaped groove 151. A protrusion 430 is placed in the Z-shaped groove 151 and located on the side close to the positioning flange 153. The protrusion 430 is flush with the inner surface of the positioning sleeve 15, which limits the circumferential movement of the positioning sleeve 15 to prevent it from rotating. The frozen sample transfer rod 3 is provided with a limiting pin 310. The frozen sample transfer rod 3 passes through the positioning sleeve 15. The limiting pin 310 can slide into or out of the Z-shaped groove 151. When the limiting pin 310 is located at the turning part of the Z-shaped groove 151, this is the pre-insertion position of the frozen sample transfer rod 3, ensuring that the pre-insertion position of the frozen sample transfer rod 3 is consistent each time a sample is loaded.

[0077] In practical use, the frozen sample transfer rod 3 is inserted into the sample transfer tube 4. The limiting pin 310 is slidably connected to the Z-shaped groove 151 and located at the turning point of the Z-shaped groove 151, limiting the frozen sample transfer rod 3 to the pre-insertion position. The vacuum pre-evacuation system is started to evacuate the sealed channel. When the pre-evacuation reaches the set value, the pre-evacuation valve 7 is closed and the vacuum plate valve 8 is opened. The frozen sample transfer rod 3 is manually rotated. Under the action of negative pressure, the frozen sample transfer rod 3 slides along the sample transfer tube 4. The limiting pin 310 slides along the Z-shaped groove 151 and slides out of the Z-shaped groove 151. The frozen sample transfer rod 3 continues to slide along the sample transfer tube 4 until the locking pin 410 is engaged in the locking groove 320, completing the transfer of the frozen sample 17.

[0078] See Figure 8In this embodiment, the angle between the side of the Z-shaped groove 151 away from the vacuum sample chamber 2 and the vertical direction is 30° to 40°. The cryogenic sample transfer rod 3 needs to be rotated by a certain angle when inserted. To ensure that the limiting pin 310 quickly and accurately aligns with the Z-shaped groove 151 and slides in when the cryogenic sample transfer rod 3 is inserted, an indicator line 330 is provided on the side where the slot 320 of the cryogenic sample transfer rod 3 is located. The angle between the indicator line 330 and the center line of the slot 320 is 30° to 40°. When inserting, rotate the cryogenic sample transfer rod 3 so that the position of the indicator line 330 corresponds to the position of the pin 410, and then insert it. When pulling out, keep the cryogenic sample transfer rod 3 vertically pulled out, and the limiting pin 310 can accurately slide into the Z-shaped groove 151, which is convenient and quick.

[0079] Furthermore, a controller 11 is also included. The controller 11 is communicatively connected to the three-dimensional translation stage 5 and is used to control the start and stop of the three-dimensional translation stage 5, as well as the adjustment of the movement distance. The controller 11 is also communicatively connected to the angle adjustment device 6 and is used to control the start and stop of the angle adjustment device, as well as the angle adjustment. The controller 11 is also communicatively connected to the pre-vacuum valve 7 and the vacuum plate valve 8 and is used to control the opening and closing of the pre-vacuum valve 7 and the vacuum plate valve 8 to control the connection and closure of the sealed channel and the vacuum sample chamber 2, thereby realizing the vacuum transfer of the frozen sample 17. This embodiment, by adding the controller 11 to control the above-mentioned equipment, improves the automation control of the dual-beam scanning electron microscope vacuum cryogenic transfer device, making it convenient and fast.

[0080] Based on the aforementioned dual-beam scanning electron microscope vacuum cryogenic transport device, the transport, imaging, and processing of the frozen sample 17 include the following steps:

[0081] 1) Evacuate the vacuum sample chamber 2 to a high vacuum:

[0082] Control the vacuum plate valve 8 and the pre-vacuum valve 7 to close, and start controlling the dual-beam scanning electron microscope vacuum system to evacuate the vacuum sample chamber 2 to a high vacuum until it is better than the vacuum set value;

[0083] 2) Fill the Dewar flask 340 of the frozen sample transfer rod 3 with liquid nitrogen and pre-cool the frozen sample 17 to the liquid nitrogen temperature;

[0084] 3) Fix the frozen sample 17 to the end of the frozen sample transfer rod 3;

[0085] 4) Evacuate a low vacuum in the sealed channel:

[0086] Insert the frozen sample transfer rod 3 containing the frozen sample 17 into the sample transfer tube 4, control the pre-vacuum valve 7 to open, and the vacuum pump to start drawing a low vacuum in the sealed channel. When the vacuum level reaches the set value (e.g., 10 Pa), control the pre-vacuum valve 7 to close, the vacuum plate valve 8 to open, and manually control the frozen sample transfer rod 3 to slowly insert it into the vacuum sample chamber 2 under negative pressure.

[0087] 5) Control the three-dimensional translation stage 5 to precisely adjust the horizontal position and height of the frozen sample transfer rod 3 so that the frozen sample 17 is located at the intersection of the ion beam system 9 and the electron beam system 10;

[0088] 6) Adjusting the tilt angle of frozen sample 17:

[0089] The angle adjustment device 6 is activated, which drives the frozen sample 17 to rotate to meet the needs of the focused ion beam processing or imaging of the ion beam system 9.

[0090] 7) Control the three-dimensional translation stage 5 to precisely adjust the position of the frozen sample transfer rod 3, and select a suitable sample position for focused ion beam processing or imaging.

[0091] 8) After the focused ion beam processing or imaging is completed, the frozen sample transmission rod 3 is pulled out of the vacuum sample chamber 2 by the opposite operation to the insertion of the frozen sample transmission rod 3 into the vacuum sample chamber 2.

[0092] 9) The frozen sample transfer rod 3 is inserted into the cryo-transmission electron microscope for cryo-transmission electron microscopy imaging, followed by electron tomography imaging to collect a series of tilt images, and then reconstruct the three-dimensional high-resolution structure of the sample.

[0093] The above describes the specific structure and usage of the vacuum cryogenic transport device provided in this embodiment. It can be widely applied in cryogenic dual-beam scanning electron microscopy (CEM) and scanning electron microscopy (SEM) imaging technologies, enabling high-resolution imaging of frozen samples 17 after cutting or imaging under a dual-beam SEM and then transferring them to a transmission electron microscope (TEM). This facilitates sample transfer between different devices. By changing the shape and size of the vacuum sample chamber door 1 and equipping it with different models of cryogenic sample transport rods 3, it can be used for sample transfer between dual-beam SEMs, SEMs, and TEMs from different manufacturers. Simultaneously, it can be used in conjunction with other types of sample transport rods to achieve various operation modes such as room temperature, freezing, variable temperature, and liquid sample observation, suitable for ion beam microfabrication or scanning electron microscopy imaging, component analysis, etc., under different conditions. The vacuum cryogenic transport device transports the frozen sample 17 to the vacuum sample chamber 2 for imaging or processing via vacuum transport, achieving in-situ processing and imaging. Then, the frozen sample is directly transferred to the TEM for high-resolution imaging, eliminating the need for direct handling and transfer of the frozen sample 17, thus avoiding sample damage and contamination during the transfer process.

[0094] In summary, the vacuum cryogenic transport device for cryogenic dual-beam scanning electron microscope systems provided by the present invention is only a preferred embodiment of the present invention. However, the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, are covered within the scope of protection of the present invention.

Claims

1. A vacuum cryogenic transport device for a dual-beam scanning electron microscope, characterized in that, include: A vacuum sample chamber door (1) is sealed and connected to the opening of the vacuum sample chamber (2), and a sample transfer window (120) is provided on the vacuum sample chamber door (1); The sample transfer tube (4) is sealed and connected to the sample transfer window (120) and communicates with the vacuum sample chamber (2); A frozen sample transfer rod (3) is inserted into the sample transfer tube (4) and its outer periphery is dynamically sealed to the inner wall of the sample transfer tube (4) for transporting frozen sample (17) into the vacuum sample chamber (2). The end of the frozen sample transfer rod (3) away from the frozen sample (17) can be engaged with and / or disengaged from the sample transfer tube (4); A three-dimensional translation stage (5) is connected to the sample transfer tube (4) and is mounted on a translation stage support (16), which is connected to an angle adjustment device (6). The sample transfer tube (4) is connected to the sample transfer window (120) via a corrugated pipe (12); When the frozen sample transfer rod (3) is engaged with the sample transfer tube (4), the three-dimensional translation stage (5) can drive the sample transfer tube (4) and the frozen sample transfer rod (3) to move synchronously to adjust the position of the frozen sample (17); The angle adjustment device (6) is located on the vacuum sample chamber door (1) and connected to the sample transfer tube (4); The angle adjustment device (6) includes: The bushing vacuum plate valve housing assembly (610) is sealed at one end to the sample transfer window (120) and sealed at the other end to the bellows (12); A worm gear (630) is mounted on a shaft disk (620), which is rotatably fitted around the outer periphery of the shaft sleeve vacuum plate valve housing assembly (610) and is fixedly connected to the translation stage bracket (16). A worm gear (650) is rotatably connected to a worm gear support (640), which is connected to the vacuum sample chamber door (1). One end of the worm (650) is connected to the motor (660) and meshes with the worm wheel (630). The operation of the motor (660) can drive the worm wheel (630) meshing with the worm (650) to rotate, thereby driving the three-dimensional translation stage (5), the translation stage support (16), the shaft disk (620), the sample transfer tube (4) and the frozen sample transfer rod (3) to rotate synchronously. When the frozen sample transfer rod (3) is engaged with the sample transfer tube (4), the angle adjustment device (6) is adapted to drive the sample transfer tube (4) and the frozen sample transfer rod (3) to rotate synchronously, so as to adjust the tilt angle of the frozen sample (17).

2. The dual-beam scanning electron microscope vacuum cryogenic transport device according to claim 1, characterized in that, The angle adjustment device (6) also includes a synchronization sleeve (670); The synchronization sleeve (670) is sleeved on the outer periphery of the corrugated pipe, with one end fixedly connected to the end of the corrugated pipe and the other end connected to the translation stage support (16). The synchronizing sleeve (670) is located inside the bushing vacuum plate valve housing assembly (610), and its outer periphery is dynamically sealed to the inner wall of the bushing vacuum plate valve housing assembly (610).

3. The dual-beam scanning electron microscope vacuum cryogenic transport device according to claim 2, characterized in that, It also includes a vacuum plate valve (8); The vacuum plate valve (8) is sealed to the side opening of the vacuum plate valve housing of the bushing vacuum plate valve housing assembly (610), and can form a sealed channel between the frozen sample transfer rod (3), the sample transfer tube (4), the bellows (12), the bushing vacuum plate valve housing assembly (610) and the vacuum plate valve (8). The vacuum plate valve (8) is used to control the connection and / or closure of the sealed channel with the vacuum sample chamber (2). When the sealed channel is connected to the vacuum sample chamber (2), the frozen sample transfer rod (3) sends one end containing the frozen sample (17) into the vacuum sample chamber (2) under manual control and negative pressure.

4. The dual-beam scanning electron microscope vacuum cryogenic transport device according to claim 3, characterized in that, It also includes a pre-vacuum valve (7); The pre-vacuum valve (7) is sealed and connected to the sample transfer tube (4) and communicates with the sealed channel for pre-vacuuming the sealed channel.

5. The dual-beam scanning electron microscope vacuum cryogenic transport device according to claim 1, characterized in that, It also includes a positioning sleeve (15); The positioning sleeve (15) is located inside the sample transfer tube (4), and is axially and circumferentially positioned and connected to the sample transfer tube (4), and is located on the side of the sample transfer tube (4) near the vacuum sample chamber door (1). The positioning sleeve (15) is provided with a Z-shaped groove (151), and the frozen sample transfer rod (3) is provided with a limiting pin (310); The frozen sample transfer rod (3) is inserted into the positioning sleeve (15), and the limiting pin (310) can slide into and / or slide out of the Z-shaped groove (151); When the limiting pin (310) slides into the Z-shaped groove (151) and is located at the turning point of the Z-shaped groove (151), it limits the pre-insertion position of the frozen sample transfer rod (3).

6. The dual-beam scanning electron microscope vacuum cryogenic transport device according to claim 1, characterized in that, A jack (410) is provided on the side of the sample transfer tube (4) away from the vacuum sample chamber door (1), and a slot (320) is provided on the end of the frozen sample transfer rod (3) away from the frozen sample (17). The pin (410) can be inserted into and / or removed from the slot (320); When the caliper pin (410) is inserted into the caliper slot (320), the frozen sample transfer rod (3) engages with the sample transfer tube (4); When the pin (410) is pulled out of the slot (320), the frozen sample transfer rod (3) is released from the sample transfer tube (4).

7. The dual-beam scanning electron microscope vacuum cryogenic transport device according to claim 1, characterized in that, A Dewar flask (340) is provided at one end of the frozen sample transfer rod (3) away from the frozen sample (17), and the Dewar flask (340) is used to provide a cold source for the frozen sample (17) placed on the frozen sample transfer rod (3).

8. The dual-beam scanning electron microscope vacuum cryogenic transport device according to claim 4, characterized in that, It also includes the controller (11); The controller (11) is communicatively connected to the angle adjustment device (6), the three-dimensional translation stage (5), the vacuum plate valve (8), and the pre-vacuum valve (7), and is used to control the start and stop of the above-mentioned equipment.

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