Low-temperature sample stage of scanning electron microscope

Abstract

The utility model discloses a low-temperature sample stage of a scanning electron microscope. The low-temperature sample stage comprises a controller, a sample stage body connected with the controller, a driving assembly arranged below the sample stage body, and a low-temperature control assembly arranged in the sample stage body, the sample table body comprises a table body, a plurality of through holes formed in the table body in a circumferential array manner, and sample cabins arranged in the through holes; a supporting plate is arranged at the bottom of the sample cabin; the driving assembly comprises an electric push rod arranged below the supporting base and the supporting base arranged at the bottom of the electric push rod. The low-temperature control assembly comprises a Peltier chip arranged in the sample cabin and a cooling pipeline arranged outside the sample cabin; a liquid inlet and a liquid outlet are respectively formed in two ends of the cooling pipeline. According to the utility model, the controller and the low-temperature control assembly are combined, and direct current is supplied to the Peltier chip and liquid nitrogen is input into the cooling pipeline, so that the temperature in the sample cabin is accurately controlled.

Description

Technical Field

[0001] The utility model relates to the technical field of a scanning electron microscope, in particular to a low-temperature sample stage of the scanning electron microscope. Background Art

[0002] Currently, the scanning electron microscope is a high-resolution microscope that can generate high-quality images of the sample surface by irradiating the sample surface and collecting electrons emitted by the sample. Unlike optical microscopes, scanning electron microscopes use electron beams instead of light beams, which can achieve higher magnifications and higher resolutions than optical microscopes, thereby observing more microscopic details. Scanning electron microscopes use hot cathodes or field emission electron guns to generate high-energy electron beams as probes. These electrons are accelerated to a higher energy level and then focused on the sample observation area and the sample surface, which can easily cause local or even overall heating of the sample.

[0003] Prior art, CN202321838058.4 A low-temperature sample table, comprising: a support seat, the upper side wall of the support seat is embedded with a sample table, the other end of the water inlet pipe is fixedly installed with a first joint, one end of the drain pipe is embedded in the inner cavity of the lower side wall of the support seat, and the other end of the drain pipe is fixedly installed with a second joint. When displaying the sample, the access port of the liquid nitrogen machine is embedded in the first joint, and the liquid nitrogen is introduced into the groove cavity inside the support seat through the water inlet pipe. After the liquid nitrogen is filled into the groove cavity, the temperature of the support seat is reduced, so that the sample table on the support seat is in a low-temperature state. However, the low-temperature sample table of the prior art has the following defects: 1. The refrigeration speed is slow when using liquid nitrogen refrigeration. Liquid nitrogen refrigeration is a gradually stable process, which will cause the sample irradiated with high energy to heat up faster than the liquid nitrogen cooling speed, thereby affecting the efficiency of the experiment; 2. When the liquid nitrogen is discharged and contacts the air, it will quickly gasify, resulting in a sharp expansion of the gas volume, which is easy to cause gas reflux or excessive pressure to cause damage or leakage of the drain pipe.

[0004] Therefore, it is necessary to improve the low-temperature sample stage in the prior art to solve the above problems. Summary of the invention

[0005] The utility model overcomes the shortcomings of the prior art and provides a low-temperature sample stage for a scanning electron microscope, aiming to solve the problem in the prior art that the sample heating speed is higher than the liquid nitrogen cooling speed, and the problem that gas backflow or excessive pressure when liquid nitrogen is discharged causes damage or leakage of the drain pipe.

[0006] To achieve the above-mentioned purpose, the technical solution adopted by the utility model is: a low-temperature sample stage for a scanning electron microscope, comprising: a controller, a sample stage body connected to the controller, a driving component arranged under the sample stage body, and a low-temperature control component arranged in the sample stage body, characterized in that;

[0007] The sample stage body comprises: a stage body, a plurality of through holes arranged in a circumferential array on the stage body, and a sample chamber arranged in the through holes; a support plate is arranged at the bottom of the sample chamber;

[0008] The driving assembly includes: an electric push rod arranged below the support seat, and a support seat arranged at the bottom of the electric push rod;

[0009] The low temperature control component includes: a Peltier chip arranged in the sample chamber, and a cooling pipe arranged outside the sample chamber; liquid nitrogen is arranged in the cooling pipe; and two ends of the cooling pipe are respectively a liquid inlet and a liquid outlet.

[0010] In a preferred embodiment of the present invention, the semiconductor material of the Peltier chip is bismuth boride.

[0011] In a preferred embodiment of the present invention, the Peltier chip is connected to direct current.

[0012] In a preferred embodiment of the utility model, the cooling pipe is a spiral pipe, the liquid inlet is arranged at the bottom of the cooling pipe, the liquid inlet is connected to the liquid inlet pipe, the liquid outlet is arranged at the top of the cooling pipe, and the liquid outlet is connected to the liquid outlet pipe.

[0013] In a preferred embodiment of the utility model, a plurality of limiting columns are arranged in a circumferential array on the support plate, and a plurality of grooves are correspondingly arranged on the inner wall of the through hole, and the grooves are slidably connected to the limiting columns.

[0014] In a preferred embodiment of the utility model, the liquid inlet pipeline is connected to a liquid storage tank, and a first solenoid valve is arranged on the liquid inlet pipeline.

[0015] In a preferred embodiment of the utility model, the liquid outlet pipe is connected to an annular pipe, the annular pipe is connected to an exhaust port, and a second solenoid valve is arranged on the exhaust port.

[0016] In a preferred embodiment of the utility model, a liquid infusion tube is connected to the bottom of the liquid storage tank, and a third solenoid valve is arranged on the liquid infusion tube.

[0017] In a preferred embodiment of the present invention, a temperature sensor is provided in the sample chamber.

[0018] In a preferred embodiment of the present invention, the controller is electrically connected to the first solenoid valve, the second solenoid valve and the third solenoid valve.

[0019] The utility model solves the defects existing in the background technology, and has the following beneficial effects:

[0020] (1) The utility model utilizes the combination of a controller and a cryogenic control component, combines direct current to the Peltier chip with liquid nitrogen input into the cooling pipeline, and achieves precise control of the temperature in the sample chamber, thereby preventing the sample from heating up faster than the speed of cooling with liquid nitrogen alone, which is beneficial for observing and analyzing samples in a low-temperature environment.

[0021] (2) The utility model utilizes the combination of the support plate and the limiting posts and grooves of the circular array to achieve the stability and accuracy of the support plate during movement, which is beneficial to ensure that the sample chamber does not shake during movement and ensure the accuracy of the electron microscope scanning results.

[0022] (3) The utility model realizes rapid heat dissipation and heat transfer by utilizing the spiral design of the cooling pipe and the circulation of liquid nitrogen, which is beneficial to maintaining the low temperature state inside the sample chamber and ensuring stable observation of the sample in a low temperature environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The utility model is further described below in conjunction with the accompanying drawings and embodiments;

[0024] Figure 1 It is a three-dimensional structural diagram of a preferred embodiment of the utility model;

[0025] Figure 2 This is a bottom structural diagram of a platform body of a preferred embodiment of the utility model;

[0026] Figure 3 It is an overall structural diagram of a low temperature control assembly of a preferred embodiment of the utility model;

[0027] Figure 4 It is a structural diagram of a single low temperature control component of a preferred embodiment of the utility model;

[0028] In the figure: 1. controller; 2. table; 3. through hole; 4. sample chamber; 5. support plate; 6. electric push rod; 7. support seat; 8. Peltier chip; 9. cooling pipe; 10. liquid inlet; 11. liquid outlet; 12. liquid inlet pipe; 13. liquid outlet pipe; 14. limit column; 15. groove; 16. liquid storage tank; 17. first solenoid valve; 18. annular pipe; 19. exhaust port; 20. second solenoid valve; 21. infusion tube; 22. third solenoid valve. DETAILED DESCRIPTION

[0029] The present invention will now be further described in detail in conjunction with the accompanying drawings and embodiments. These drawings are simplified schematic diagrams that only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0030] like Figure 1As shown, a low-temperature sample stage for a scanning electron microscope includes: a controller 1, a sample stage body connected to the controller 1, a driving component arranged under the sample stage body, and a low-temperature control component arranged in the sample stage body; the controller 1 is the main control center, responsible for monitoring and adjusting the temperature and position of the sample stage; the sample stage body is a platform for placing samples and observing, providing a stable support for the samples to ensure accurate observation; the driving component is used to control the position and movement of the sample, and adjusting the position of the sample in the scanning electron microscope is very important for focusing, adjusting clarity, and observing samples at different heights, and the low-temperature control component is used to achieve low-temperature control of the sample.

[0031] As Figure 2 and Figure 3 As shown, the sample stage body includes: a stage body 2, a plurality of through holes 3 arranged in a circular array on the stage body 2, and a sample chamber 4 arranged in the through holes 3; a support plate 5 is arranged at the bottom of the sample chamber 4; the stage body 2 has a stable structure and good thermal conductivity to ensure the stability and accuracy of the scanning electron microscope during the observation process; the through holes 3 are used to place the sample chamber 4 to avoid the influence of the external environment on the sample, the sample chamber 4 is used to accommodate and fix the sample, and the support plate 5 is used to support and fix the sample chamber 4 to ensure that the sample can be firmly fixed in the sample chamber 4 without being disturbed by the outside.

[0032] The low temperature control component includes: a Peltier chip 8 arranged in the sample chamber 4, and a cooling pipe 9 arranged outside the sample chamber 4; liquid nitrogen is arranged in the cooling pipe 9; the semiconductor material of the Peltier chip 8 is bismuth boride, and the Peltier chip 8 is connected to direct current. The Peltier chip 8 is a thermoelectric element, and the effect of cooling the inside of the sample chamber 4 and heating the outside of the sample chamber 4 is achieved by applying a direct current between two internal materials with different thermal conductivities; the liquid nitrogen flowing in the cooling pipe 9 is used to dissipate heat and discharge the heat generated inside the sample chamber 4. Through the cooling pipe 9, the heat generated by the refrigeration of the Peltier chip 8 can be transferred to the external environment to maintain the low temperature state inside the sample chamber 4; a temperature sensor is arranged in the sample chamber 4, and the temperature sensor is electrically connected to the controller 1. The controller 1 can display the temperature in the sample chamber 4 in real time. Through the direct current connection, the refrigeration effect and temperature adjustment of the Peltier chip 8 can be controlled to ensure that the sample runs stably in the required low temperature environment;

[0033] like Figure 3 and Figure 4As shown, the cooling pipe 9 is a spiral pipe, and the spiral shape is conducive to increasing the length of the cooling pipe 9, thereby increasing the heat conduction area and improving the heat dissipation efficiency. At the same time, the spiral shape also helps to achieve more efficient heat transfer in a limited space; the two ends of the cooling pipe 9 are respectively a liquid inlet 10 and a liquid outlet 11, the liquid inlet 10 is set at the bottom of the cooling pipe 9, and the liquid nitrogen enters the cooling pipe 9 from the liquid inlet 10, and the liquid inlet 10 is connected to the liquid inlet pipe 12; the liquid outlet 11 is set at the top of the cooling pipe 9, which is used to discharge the liquid nitrogen after absorbing heat, and the liquid outlet 11 is connected to the liquid outlet pipe 13 to maintain the circulation stability inside the cooling pipe 9.

[0034] The liquid inlet pipeline 12 is connected to a liquid storage tank 16, and a first solenoid valve 17 is arranged on the liquid inlet pipeline 12; the liquid storage tank 16 is used to store liquid nitrogen and provide liquid nitrogen for use within a period of time to avoid the cumbersome operation of multiple liquid nitrogen delivery. The first solenoid valve 17 is used to control the input of liquid nitrogen in the sample table; the bottom of the liquid storage tank 16 is connected to an infusion pipe 21, and a third solenoid valve 22 is arranged on the infusion pipe 21. The third solenoid valve 22 is used to control the input of external liquid nitrogen into the liquid storage tank 16; the liquid outlet pipeline 13 is connected to an annular pipeline 18, and the annular pipeline 18 is connected to an exhaust port 19, and a second solenoid valve 20 is arranged on the exhaust port 19; the liquid outlet pipeline 13 is used to discharge the heated liquid nitrogen to maintain the cooling effect, and the second solenoid valve 20 is used to control the discharge and circulation of liquid nitrogen; liquid nitrogen will quickly vaporize when it comes into contact with air, causing the gas volume to expand rapidly. The gas after the liquid nitrogen vaporization can be controlled by the second solenoid valve 20 to control the discharge rate to avoid the rapid expansion of the gas volume, resulting in gas backflow or damage to operators and equipment; the controller 1 is electrically connected to the first solenoid valve 17, the second solenoid valve 20 and the third solenoid valve 22, and the switch states of the three solenoid valves are adjusted by the controller 1 to realize the flow control and circulation logic of the cooling medium in the cooling system.

[0035] The driving assembly includes: an electric push rod 6 arranged below the support seat 7, and a support seat 7 arranged at the bottom of the electric push rod 6; by controlling the movement of the electric push rod 6, the support plate 5 can be pushed, so that the sample chamber 4 moves in the through hole 3, so that the sample reaches a suitable position for easy observation by personnel; there are a number of limit columns 14 in a circular array on the support plate 5, and a number of grooves 15 are correspondingly arranged on the inner wall of the through hole 3, and the grooves 15 are slidably connected to the limit columns 14, and the grooves 15 and the limit columns 14 effectively cooperate to achieve the stability and accuracy of the support plate 5 during the movement, and ensure that the support plate 5 can move according to the predetermined trajectory to avoid shaking and cause inaccurate electron microscope scanning results.

[0036] When the utility model is used, the controller 1 is turned on to monitor the temperature in the sample chamber 4, the sample to be observed is placed in the sample chamber 4, direct current is passed to the Peltier chip 8 to achieve rapid cooling, the first solenoid valve 17 is opened to input liquid nitrogen into the cooling pipe 9, and the electric push rod 6 is started to adjust the position of the sample chamber 4 to ensure that the sample is in a suitable observation position.

[0037] The above is based on the ideal embodiment of the utility model. Through the above description, relevant personnel can make various changes and modifications without deviating from the technical concept of the utility model. The technical scope of this utility model is not limited to the content in the specification, and the technical scope must be determined according to the scope of the claims.

Claims

1. A low temperature sample stage for a scanning electron microscope, comprising: A controller (1), a sample stage body connected to the controller (1), a driving component arranged under the sample stage body, and a low temperature control component arranged in the sample stage body, characterized in that: The sample stage body comprises: a stage body (2), a plurality of through holes (3) arranged in a circumferential array on the stage body (2), and a sample chamber (4) arranged in the through holes (3); a support plate (5) is arranged at the bottom of the sample chamber (4); The driving assembly comprises: an electric push rod (6) arranged below the support plate (5), and a support seat (7) arranged at the bottom of the electric push rod (6); The low temperature control component comprises: a Peltier chip (8) arranged in the sample chamber (4), and a cooling pipe (9) arranged outside the sample chamber (4); liquid nitrogen is arranged in the cooling pipe (9); and two ends of the cooling pipe (9) are respectively a liquid inlet (10) and a liquid outlet (11).

2. The low temperature sample stage for a scanning electron microscope according to claim 1, characterized in that: The semiconductor material of the Peltier chip (8) is bismuth boride.

3. The low temperature sample stage for a scanning electron microscope according to claim 2, characterized in that: The Peltier chip (8) is connected to direct current.

4. The low temperature sample stage for a scanning electron microscope according to claim 1, characterized in that: The cooling pipe (9) is a spiral pipe, the liquid inlet (10) is arranged at the bottom of the cooling pipe (9), the liquid inlet (10) is connected to a liquid inlet pipe (12), the liquid outlet (11) is arranged at the top of the cooling pipe (9), and the liquid outlet (11) is connected to a liquid outlet pipe (13).

5. The low temperature sample stage for a scanning electron microscope according to claim 1, characterized in that: The support plate (5) is provided with a plurality of limiting columns (14) in a circumferential array, and the inner wall of the through hole (3) is correspondingly provided with a plurality of grooves (15), and the grooves (15) are slidably connected to the limiting columns (14).

6. The low temperature sample stage for a scanning electron microscope according to claim 4, characterized in that: The liquid inlet pipeline (12) is connected to a liquid storage tank (16), and a first solenoid valve (17) is provided on the liquid inlet pipeline (12).

7. The low temperature sample stage for a scanning electron microscope according to claim 6, characterized in that: The liquid outlet pipe (13) is connected to an annular pipe (18), the annular pipe (18) is connected to an exhaust port (19), and a second solenoid valve (20) is provided on the exhaust port (19).

8. The low temperature sample stage for a scanning electron microscope according to claim 6, characterized in that: The bottom of the liquid storage tank (16) is connected to a liquid infusion tube (21), and a third solenoid valve (22) is arranged on the liquid infusion tube (21).

9. The low temperature sample stage for a scanning electron microscope according to claim 1, characterized in that: A temperature sensor is arranged in the sample chamber (4).

10. The low temperature sample stage for a scanning electron microscope according to claim 8, characterized in that: The controller (1) is electrically connected to the first solenoid valve (17), the second solenoid valve (20) and the third solenoid valve (22).

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