Vacuum sample holder with adjustable grid voltage

Abstract

The invention discloses a grid voltage adjustable vacuum sample holder, which comprises a top connecting piece, a middle ceramic piece, a first electrode, a second electrode and a third electrode, and is characterized in that the top connecting piece is fixed at the middle position of the top end of the middle ceramic piece through a first bolt, and the first electrode, the second electrode and the third electrode are uniformly distributed around the top connecting piece; a first electrical interface, a second electrical interface and a third electrical interface are respectively fixed at the bottom end of the middle ceramic piece. The third electrode and the top connecting piece are designed into a whole, the top connecting piece and the middle ceramic piece are jointly fixed through the two second bolts above the third electrode and the first bolt below the middle ceramic piece, and the stability of the structure is remarkably improved. By means of the design, axial rotation between the top connecting piece and the middle ceramic piece is avoided, and connection is firmer.

Description

Technical Field

[0001] The invention relates to the technical field of preparation of high-quality two-dimensional thin film materials, and in particular to a vacuum sample holder with adjustable grid voltage. Background Art

[0002] In the field of preparation and characterization of high-quality two-dimensional thin film materials, a vacuum environment is required because the atmosphere will affect the preparation quality and physical properties of thin film materials. Generally speaking, the higher the vacuum degree, the higher the quality of material preparation, and the less likely the properties of the material will be changed. Equipment for preparing thin film materials include molecular beam epitaxy (MBE), pulsed laser deposition (PLD), etc., and characterization equipment includes scanning tunneling microscopy (STM), angle-resolved photoelectron spectroscopy (ARPES), etc.

[0003] The preparation of materials requires a substrate, which is then transferred into the material growth equipment for material growth, to prepare a sample, which is then transferred into the material characterization equipment for material property measurement and characterization. However, researchers cannot reach into the vacuum system to transfer and manipulate samples, so a sample holder (a small device that can hold substrates or samples) and a sample transfer mechanism (a method for transferring and manipulating the sample holder in a vacuum) are needed to replace the researchers' hands to move and control samples in a vacuum.

[0004] At present, there are several relatively universal and general sample holder structures in ultra-high vacuum systems (especially molecular beam epitaxy, scanning tunneling microscope, angle-resolved photoelectron spectroscopy and other equipment). The sample holders in the prior art are prone to screw loosening during variable temperature measurement, and the variable temperature stability is poor, thus affecting precision electronic measurements (such as scanning tunneling microscope measurements, etc.). This patent application upgrades and transforms one of the structures, which can greatly improve its variable temperature stability. Summary of the invention

[0005] In order to solve the problems mentioned in the above background technology, the present invention provides a vacuum sample holder with adjustable grid voltage.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A vacuum sample holder with adjustable grid voltage comprises a top connecting piece and an intermediate ceramic piece, a first electrode, a second electrode and a third electrode, wherein the top connecting piece is fixed to the middle position of the top of the intermediate ceramic piece by a first bolt, the first electrode, the second electrode and the third electrode are evenly distributed around the top connecting piece and are fixed to the intermediate ceramic piece, the bottom end of the intermediate ceramic piece is respectively fixed with a first electrical interface, a second electrical interface and a third electrical interface, the first electrical interface is located directly below the first electrode and is electrically connected to the first electrode, the second electrical interface is located directly below the second electrode and is electrically connected to the second electrode, the third electrical interface is located directly below the third electrode and is electrically connected to the third electrode, the first electrode, the second electrode and the third electrode are insulated from each other, the third electrode is fixed to the top connecting piece, a sample is fixed to the bottom end of the intermediate ceramic piece, and both the first electrical interface and the second electrical interface are in contact with the sample.

[0008] Preferably, the first electrode, the second electrode and the third electrode are all fixed to the middle ceramic part by two second bolts, and the first electrical interface, the second electrical interface and the third electrical interface are also connected to the middle ceramic part by second bolts, and the second bolts serve as electrical connections.

[0009] Preferably, an isolation convex ring is fixed to the top end of the intermediate ceramic member, which is located outside the top connecting member, and the isolation convex ring separates the first electrode and the second electrode from the top connecting member.

[0010] Preferably, a groove corresponding to the isolation convex ring is formed at the bottom end of the third electrode, and the isolation convex ring is stuck in the groove.

[0011] Preferably, the top connecting piece is a cylindrical structure, a grabbing round rod is fixed on the top connecting piece, the grabbing round rod horizontally penetrates the top connecting piece, and both ends of the grabbing round rod extend to the outside of the top connecting piece.

[0012] Preferably, a positioning hole is provided at the top end of the top connecting member, a first locking threaded hole is provided at the middle position of the grabbing round rod, a third bolt is installed in the positioning hole, and the bottom end of the third bolt extends into the first locking threaded hole.

[0013] Preferably, a positioning protrusion is fixed on one side of the first electrode, the second electrode and the third electrode away from the top connecting member.

[0014] Preferably, the bottom ends of the first electrical interface and the second electrical interface are both fixed with pressing plates by fourth bolts, and the two pressing plates press and fix the sample to the bottom ends of the first electrical interface and the second electrical interface from both sides of the bottom end of the sample respectively.

[0015] Preferably, a second locking threaded hole is provided at the top of the top connecting piece, the grabbing round rod passes through the top connecting piece through the second locking threaded hole, and the outside of the grabbing round rod is provided with an external thread corresponding to the second locking threaded hole.

[0016] Preferably, the thickness of the third electrical interface is lower than the thickness of the first electrical interface and the second electrical interface, a support member is fixed to the bottom end of the first bolt, the bottom end of the third electrical interface is flush with the bottom of the support member, and a support plate is fixed between the third electrical interface and the bottom end of the support member by a fourth bolt, a gold foil is provided on the side of the support plate close to the sample, a layer of indium is coated on the side of the sample close to the support plate, the sample and the support plate are connected by a platinum wire, the support plate is a 0.5 mm thick molybdenum plate, and the thickness of the gold foil is 0.1 mm.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. By designing the third electrode and the top connector as a whole, and using the two second bolts above the third electrode and the first bolt below the middle ceramic part to fix the top connector and the middle ceramic part together, the stability of the structure is significantly improved. This design avoids axial rotation between the top connector and the middle ceramic part, making the connection more secure.

[0019] 2. In the prior art, the top connecting piece and the middle ceramic piece are fixed only by the fifth bolt installed at the bottom of the middle ceramic piece. If only one screw is used, axial rotation will occur, resulting in the top connecting piece and the middle ceramic piece being unable to be fixed to each other. Therefore, the existing design uses three fifth bolts, but due to limited space, only M1.2 ones can be placed. In this solution, a larger screw (such as M1.6 or larger) is used at the bottom of the middle ceramic piece, which enhances the bite stability of the screw thread and reduces the risk of thread slippage.

[0020] 3. The isolation convex ring is stuck in the groove of the third electrode, achieving three-sided contact and increasing friction, so that the structure can maintain stable engagement during the heating and cooling process, further improving the stability of the overall structure.

[0021] 4. Taking into account the differences in thermal expansion and contraction of different materials (such as molybdenum, ceramics, and titanium) during temperature changes, this design overcomes this difference by pressing three screws on two planes toward the middle, making the structure more stable during temperature changes.

[0022] 5. The sample can be connected to the third electrical interface through the indium, platinum wire and gold foil on its surface. The third electrode can be used to apply back-gate voltage regulation to the sample, which can expand the measurement function of the instrument. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 An exploded view of the present invention;

[0025] Figure 2 It is a front view of the present invention;

[0026] Figure 3 It is a cross-sectional view from the main perspective of the present invention;

[0027] Figure 4 A top view of the present invention;

[0028] Figure 5 A bottom view of the present invention;

[0029] Figure 6 It is a bottom view of the present invention (with sample removed);

[0030] Figure 7 A three-dimensional diagram of the present invention

[0031] Figure 8 It is a bottom view of the prior art;

[0032] Fig. 9 It is a top view of the prior art;

[0033] Fig.10 The sample holder has a stable structure and a low noise spectrum (full frequency noise is less than 100fm / sqrt(Hz));

[0034] Fig.11 The screws of the sample holder are loose, causing the low-frequency noise to increase (the noise within 100Hz is higher than 250fm / sqrt(Hz), and the looser the screws, the greater the noise);

[0035] Fig.12 It is a cross-sectional view of Example 5 and Example 6 of the present invention;

[0036] Fig.13 It is a stereogram of Example 5 and Example 6 of the present invention;

[0037] In the figure: 1 top connecting part, 2 first electrode, 201 second electrode, 202 third electrode, 203 positioning protrusion, 204 second bolt, 205 groove, 3 grab round rod, 301 first locking threaded hole, 302 third bolt, 303 positioning hole, 304 external thread, 305 second locking threaded hole, 4 middle ceramic part, 401 isolation protrusion ring, 402 first bolt, 403 support part, 404 support plate, 405 fourth bolt, 5 third electrical interface, 501 first electrical interface, 502 second electrical interface, 6 sample, 7 electrode A, 701 electrode B, 702 electrode C. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] Example 1

[0040] Reference Figure 1-9 A vacuum sample holder with adjustable grid voltage, comprising a top connecting member 1 and an intermediate ceramic member 4, a first electrode 2, a second electrode 201 and a third electrode 202, wherein the top connecting member 1 is fixed to the middle position of the top of the intermediate ceramic member 4 by a first bolt 402, the first electrode 2, the second electrode 201 and the third electrode 202 are evenly distributed around the top connecting member 1 and fixed to the intermediate ceramic member 4, and the bottom end of the intermediate ceramic member 4 is respectively fixed with a first electrical interface 501, a second electrical interface 502 and a third electrical interface 5, wherein the first electrical interface 501 is located at the first electrode 2 The second electrical interface 502 is located directly below the second electrode 201 and is electrically connected to the second electrode 201. The third electrical interface 502 is located directly below the third electrode 202 and is electrically connected to the third electrode 202. The first electrode 2, the second electrode 201 and the third electrode 202 are insulated from each other. The third electrode 202 is fixed to the top connector 1. The third electrode 202 is fixed to the top connector 1. The sample 6 is fixed to the bottom end of the intermediate ceramic member 4, and both the first electrical interface 501 and the second electrical interface 502 are in contact with the sample 6.

[0041] The first electrode 2, the second electrode 201 and the third electrode 202 are all fixed to the middle ceramic part 4 by two second bolts 204, and the first electrical interface 501, the second electrical interface 502 and the third electrical interface 5 are also connected to the middle ceramic part 4 by the second bolts 204, and the second bolts 204 play the role of electrical connection.

[0042] The first electrode 2, the second electrode 201 and the third electrode 202 can transmit the sample signal in the sample 6 to the external circuit, or lead the external current to the sample through the electrodes to realize the heating function. Since the first electrical interface 501 and the second electrical interface 502 are in contact with the sample 6, the electrical connection between the sample 6 and the first electrode 2 and the second electrode 201 is realized. The third electrode 202 is used as a spare electrode. The middle ceramic part 4 is used to isolate the electrical connection between the upper and lower parts, and at the same time, all the parts are assembled into a whole.

[0043] The third electrode 202 and the top connector 1 are connected as a whole and can still be used as a spare electrode. Fig. 9 ) in the bracket, the three electrodes: electrode A 7, electrode B 701 and electrode C 702 are all independent and not connected to the middle top connector 1. The overall stability of the bracket is poor. Since the top connector 1 and the middle ceramic part 4 are only fixed by the fifth bolt 6 installed at the bottom of the middle ceramic part 4 in the prior art, if only one screw is used, axial rotation will occur, resulting in the top connector 1 and the middle ceramic part 4 being unable to be fixed to each other. Therefore, the existing design uses three fifth bolts 6, but the space is limited and only M1.2 can be placed. In this solution, because the top connector 1 and the third electrode 202 form a part, the two second bolts 204 above the third electrode 202 and the first bolt 402 below the middle ceramic part 4, the three bolts can jointly play the role of fixing the top connector 1 and the middle ceramic part 4. Since the third electrode 202 is fixed to the middle ceramic part 4 by the second bolt 204, the top connector 1 and the middle ceramic part 4 will no longer produce axial rotation, and the first bolt 402 can be selected to be M1.6 or larger (sufficient space).

[0044] In the prior art, the fifth bolt 6 is made of molybdenum, the middle ceramic part 4 is made of ceramic, and the top connecting part 1 is generally made of titanium. There are differences in thermal expansion and contraction during the temperature change process, and repeated temperature changes will cause the screws to loosen.

[0045] Compared with the prior art, it has two advantages: 1. The larger the screw, the more stable the engagement of the thread. M1.2 screws cannot be tightened with force, and tightening with force will cause thread stripping; 2. In the prior art, the three fifth bolts 6 in a plane are screwed in one direction, while in this solution, the three screws in two planes are pressed toward the middle, which can better overcome the differences in thermal expansion and contraction between different materials, and the structure is more stable and will be more stable during temperature changes.

[0046] The top connection piece 1 is used as the part for the manipulator to grasp when transferring the sample in vacuum;

[0047] Example 2

[0048] Reference Figure 1-9The difference between this embodiment and the embodiment 1 is that the top end of the intermediate ceramic member 4 is located outside the top connector 1 and is fixed with an isolating convex ring 401, the isolating convex ring 401 separates the first electrode 2 and the second electrode 201 from the top connector 1, and the bottom end of the third electrode 202 is provided with a groove 205 corresponding to the isolating convex ring 401, and the isolating convex ring 401 is stuck in the groove 205;

[0049] The isolation convex ring 401 can prevent electrical interference. Fig. 9 ) The isolation convex ring 401 can only prevent electrical interference. The top connecting piece 1 is in contact with the isolation convex ring 401 on only one side and is easy to slide. In this solution, since the isolation convex ring 401 is stuck in the groove 205, the groove 205 and the isolation convex ring 401 are in contact on three sides, the friction is greater, and it is easier to bite regardless of heating or cooling, thereby further improving its structural stability.

[0050] Example 3

[0051] Reference Figure 1-9 The top connecting member 1 is a cylindrical structure, a grabbing round rod 3 is fixed on the top connecting member 1, the grabbing round rod 3 horizontally penetrates the top connecting member 1, and both ends of the grabbing round rod 3 extend to the outside of the top connecting member 1, a positioning hole 303 is opened at the top of the top connecting member 1, a first locking threaded hole 301 is opened in the middle of the grabbing round rod 3, a third bolt 302 is installed in the positioning hole 303, and the bottom end of the third bolt 302 extends into the first locking threaded hole 301;

[0052] When transferring samples, the manipulator is provided with a sleeve corresponding to the top connecting piece 1, and the sleeve is provided with a hanging groove for hanging and grabbing the round rod 3. The first electrode 2, the second electrode 201 and the third electrode 202 are fixed with positioning protrusions 203 on the side away from the top connecting piece 1. The manipulator is provided with a pressing piece corresponding to the positioning protrusion 203. The positioning protrusion 203 can be respectively clamped to the three pressing pieces to achieve overall fixation and electrically connected to the outside world.

[0053] Example 4

[0054] Reference Figure 1-9 The bottom ends of the first electrical interface 501 and the second electrical interface 502 are both fixed with a pressing sheet 601 through a fourth bolt 602, and the two pressing sheets 601 respectively press and fix the sample 6 to the bottom ends of the first electrical interface 501 and the second electrical interface 502 from both sides of the bottom end of the sample 6;

[0055] It can ensure the stability of the sample during the test and can easily disassemble and install the sample 6. During the sample measurement process, the sample holder structure must maintain high mechanical strength and stability, otherwise obvious noise signals will appear during the test, affecting the measurement structure.

[0056] Example 5

[0057] Reference Fig.12 and 13 The difference between this embodiment and embodiment 3 is that a second locking threaded hole 305 is provided at the top of the top connecting member 1, and the grabbing round rod 3 passes through the top connecting member 1 through the second locking threaded hole 305, and the outside of the grabbing round rod 3 is provided with an external thread 304 corresponding to the second locking threaded hole 305. In embodiment 3, the grabbing round rod 3 is fixed by a third bolt 302, and the contact surface is very small and very easy to loosen. In this embodiment, the grabbing round rod 3 is directly screwed onto the top connecting member 1, and there is a larger contact surface between the grabbing round rod 3 and the top connecting member 1, and the structure is more stable.

[0058] Example 6

[0059] Reference Fig.12 and 13 , the difference between this embodiment and embodiment 1 is that the thickness of the third electrical interface 5 is lower than the thickness of the first electrical interface 501 and the second electrical interface 502, the bottom end of the first bolt 402 is fixed with a support member 403, the bottom end of the third electrical interface 5 is flush with the bottom of the support member 403, and a support plate 404 is fixed between the third electrical interface 5 and the bottom end of the support member 403 by a fourth bolt 405, a gold foil is provided on the side of the support plate 404 close to the sample 6, a layer of indium is coated on the side of the sample 6 close to the support plate 404, the sample 6 is connected to the support plate 404 by a platinum wire, and the support plate 404 is connected to the sample 6 by a platinum wire. 04 is a 0.5mm thick molybdenum plate, and the thickness of the gold foil is 0.1mm. The sample 6 can be connected to the third electrical interface 5 through the indium, platinum wire and gold foil on its surface. The third electrode 202 can be used to apply back gate voltage regulation to the sample 6, which can expand the measurement function of the instrument. Although indium melts at around 160°C, it does not affect the contact of the platinum wire. However, when the temperature exceeds 500°C, its own vapor pressure (thermal evaporation) will affect the material growth. Therefore, the sample heating temperature in this design will be limited to a certain extent (the temperature must not exceed 500°C), but it can still meet the growth needs of more thin film materials.

[0060] Molecular beam epitaxy is a technique for preparing high-quality two-dimensional thin film materials in an ultra-high vacuum environment.

[0061] Scanning tunneling microscopy is a characterization technology for measuring thin film materials prepared by molecular beam epitaxy in an ultra-high vacuum environment. It is usually directly connected to the molecular beam epitaxy equipment and is in the same ultra-high vacuum environment. The sample does not come into contact with the atmosphere from preparation to measurement, and the transfer of samples between different systems requires a sample holder.

[0062] In molecular beam epitaxy equipment, samples need to be heated at high temperatures, and in scanning tunneling microscope systems, samples need to be cooled and measured at low temperatures. During repeated heating and cooling processes, loosening of the screws on the sample holder will have a great impact on the measurements of precision characterization equipment such as scanning tunneling microscopes.

[0063] The gate voltage can be applied to the back of the insulating substrate (the front of the substrate is used to grow thin film materials). The gate voltage can be used to control the chemical potential, carrier concentration, quantum transport properties, etc. of the thin film material. It is extremely important for material research. However, gate voltage control is currently mostly used for non-in-situ measurements outside of vacuum. It is still a major challenge to control the gate voltage of external samples in ultra-high vacuum.

[0064] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0065] In the present invention, unless otherwise clearly specified and limited, the terms "set", "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0066] The control method of the present invention is automatic control through a controller. The control circuit of the controller can be implemented by simple programming by technicians in this field. The provision of power is also common knowledge in this field. The present invention is mainly used to protect mechanical devices, so the present invention will no longer explain the control method and circuit connection in detail.

[0067] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A vacuum sample holder with adjustable grid voltage, comprising a top connecting piece (1), an intermediate ceramic piece (4), a first electrode (2), a second electrode (201) and a third electrode (202), characterized in that: The top connecting member (1) is fixed to the middle position of the top of the middle ceramic member (4) by means of a first bolt (402); the first electrode (2), the second electrode (201) and the third electrode (202) are evenly distributed around the top connecting member (1) and fixed to the middle ceramic member (4); the bottom end of the middle ceramic member (4) is respectively fixed with a first electrical interface (501), a second electrical interface (502) and a third electrical interface (5); the first electrical interface (501) is located directly below the first electrode (2) and is electrically connected to the first electrode (2); the second electrical interface (502) is located directly below the first electrode (2) and is electrically connected to the first electrode (2); and the third electrical interface (5) is located directly below the first electrode (2) and is electrically connected to the first electrode (2). The electrical interface (502) is located directly below the second electrode (201) and is electrically connected to the second electrode (201); the third electrical interface (5) is located directly below the third electrode (202) and is electrically connected to the third electrode (202); the first electrode (2), the second electrode (201) and the third electrode (202) are insulated from each other; the third electrode (202) is fixed to the top connecting piece (1); a sample (6) is fixed to the bottom end of the middle ceramic piece (4); and both the first electrical interface (501) and the second electrical interface (502) are in contact with the sample (6).

2. The vacuum sample holder with adjustable grid voltage according to claim 1, characterized in that: The first electrode (2), the second electrode (201) and the third electrode (202) are all fixed to the middle ceramic part (4) via two second bolts (204), and the first electrical interface (501), the second electrical interface (502) and the third electrical interface (5) are also connected to the middle ceramic part (4) via the second bolts (204), and the second bolts (204) play a role in electrical connection.

3. The vacuum sample holder with adjustable grid voltage according to claim 1, characterized in that: The top end of the intermediate ceramic component (4) is located outside the top connecting component (1) and is fixed with an isolating convex ring (401), and the isolating convex ring (401) separates the first electrode (2) and the second electrode (201) from the top connecting component (1).

4. The vacuum sample holder with adjustable grid voltage according to claim 3, characterized in that: The bottom end of the third electrode (202) is provided with a groove (205) corresponding to the isolation convex ring (401), and the isolation convex ring (401) is stuck in the groove (205).

5. The vacuum sample holder with adjustable grid voltage according to claim 1, characterized in that: The top connecting piece (1) is a cylindrical structure, and a grabbing round rod (3) is fixed on the top connecting piece (1). The grabbing round rod (3) passes through the top connecting piece (1) horizontally, and both ends of the grabbing round rod (3) extend to the outside of the top connecting piece (1).

6. The vacuum sample holder with adjustable grid voltage according to claim 5, characterized in that: A positioning hole (303) is provided at the top end of the top connecting member (1), a first locking threaded hole (301) is provided at the middle position of the grabbing round rod (3), a third bolt (302) is installed in the positioning hole (303), and the bottom end of the third bolt (302) extends into the first locking threaded hole (301).

7. The vacuum sample holder with adjustable grid voltage according to claim 5, characterized in that: A positioning protrusion (203) is fixed on one side of the first electrode (2), the second electrode (201) and the third electrode (202) away from the top connecting member (1).

8. The vacuum sample holder with adjustable grid voltage according to claim 5, characterized in that: The bottom ends of the first electrical interface (501) and the second electrical interface (502) are both fixed with a pressing plate (601) via a fourth bolt (602), and the two pressing plates (601) respectively press and fix the sample (6) to the bottom ends of the first electrical interface (501) and the second electrical interface (502) from both sides of the bottom end of the sample (6).

9. The vacuum sample holder with adjustable grid voltage according to claim 5, characterized in that: A second locking threaded hole (305) is provided at the top end of the top connecting piece (1), and the grabbing round rod (3) passes through the top connecting piece (1) through the second locking threaded hole (305), and an external thread (304) corresponding to the second locking threaded hole (305) is provided on the outside of the grabbing round rod (3).

10. The vacuum sample holder with adjustable grid voltage according to claim 1, characterized in that: The thickness of the third electrical interface (5) is lower than that of the first electrical interface (501) and the second electrical interface (502); a support member (403) is fixed to the bottom end of the first bolt (402); the bottom end of the third electrical interface (5) is flush with the bottom of the support member (403); a support plate (404) is fixed between the third electrical interface (5) and the bottom end of the support member (403) via a fourth bolt (405); a gold foil is provided on a side of the support plate (404) close to the sample (6); a layer of indium is coated on a side of the sample (6) close to the support plate (404); and the sample (6) and the support plate (404) are connected via a platinum wire.

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