Ultra-vacuum ultralow-temperature atomic force microscope device

Abstract

The invention provides an ultra-vacuum ultra-low temperature atomic force microscope device which comprises a vacuum cavity used for wrapping all parts in the vacuum cavity, vacuum can be formed in the vacuum cavity in cooperation with negative pressure equipment, an operation hole is formed in the side face of the vacuum cavity, and a flange connecting end face is arranged on the periphery of the operation hole; the bottom of the damping suspension structure is connected with a supporting frame, and the top of the damping suspension structure is connected with the top of the vacuum cavity inner shell; a laser detection module, a probe frame module and a scanning module are arranged in the supporting frame, and the supporting frame is used for solving the problem that at present, domestic atomic force microscope manufacturers do not have vacuum environment type atomic force microscopes; in the prior art, only a few of foreign mainstream atomic force microscope manufacturers, such as Oxford instruments, Hitachi and RHK, develop ultra-vacuum ultra-low temperature environment control type atomic force microscopes, but mass production is not formed, the price is very high, millions of microscopes are needed, and the cost is relatively high.

Description

Technical Field

[0001] The invention mainly relates to the technical field of atomic force microscopes, and in particular to an ultra-vacuum and ultra-low temperature atomic force microscope device. Background Art

[0002] Atomic force microscopy (AFM) is an analytical instrument that can be used to study the surface microstructure of solid materials, including insulators. It studies the surface structure and properties of materials by detecting the extremely weak atomic interaction force between the surface of the sample to be tested and a miniature force sensitive element. A pair of micro-cantilevers that are extremely sensitive to weak forces are fixed at one end, and the tiny needle tip at the other end is close to the sample. At this time, it will interact with it, and the force will cause the micro-cantilever to deform or change its motion state. In order to obtain information about the sample surface, laser detection is generally used. The laser beam hits the back of the probe cantilever and then reflects to the position detector. During scanning, due to the atomic interaction force between the sample and the probe tip, the probe cantilever will bend and fluctuate with the surface morphology of the sample, and the reflected light beam will also shift accordingly. By detecting the change in the position of the light spot on the position detector, the surface morphology information of the sample to be tested can be obtained. The atomic force microscope is currently the world's highest resolution surface three-dimensional profile measurement instrument and is an indispensable detection equipment in the field of material science research and nano-detection. The atomic force microscope has been widely used for its high resolution, wide range of applications, simple sample preparation, and ability to perform micro-nano detection in various environments.

[0003] We know that the interaction force between atoms is very small. When AFM is working, in order to maintain the interaction force between the two, the distance between the probe and the sample is very close, usually only a few nanometers or tens of nanometers, which places very high requirements on the environment around the instrument. At present, the atomic force microscopes on the market are all operated in ordinary air environments. However, due to the active presence of various gas molecules in the air, various mechanical vibrations and electromagnetic interference, it is still difficult to obtain extremely high resolution. In order to use the atomic force microscope to truly obtain atomic-level resolution, it is still necessary to work in ultra-vacuum and ultra-low temperature environments. Most of the scanning tunneling microscopes (STMs), similar products of the atomic force microscope, work in ultra-vacuum and ultra-low temperature environments. However, unlike the atomic force microscope, the scanning tunneling microscope is based on the tunneling effect principle in quantum mechanics. It detects the tunneling current on the surface of the sample to distinguish the surface morphology of the sample, and does not require a laser detection device. Its signal detection device is relatively simple, and it is mainly used to measure conductive samples. It is very suitable and easy to work in ultra-vacuum and ultra-low temperature environments. In contrast, the atomic force microscope requires a laser detection device, requires frequent replacement of the probe and adjustment of the spot position, and has a much more complex structure. There are many limitations when working in a vacuum environment. At present, domestic atomic force microscope manufacturers do not have vacuum environment atomic force microscopes and such products, and there are only a few mainstream atomic force microscope manufacturers abroad. For example, Oxford Instruments, Hitachi, RHK, etc. have developed ultra-vacuum and ultra-low temperature environment controlled atomic force microscopes, but they have not been mass-produced and are very expensive, costing millions, which is very costly.

[0004] In order to ensure higher resolution and better imaging quality, current atomic force microscopes generally use large high-precision shock-absorbing platforms to place the atomic force microscopes on them to obtain better shock-absorbing effects. However, this large high-precision shock-absorbing platform needs to be tested at a special location, and the high-precision shock-absorbing platform is expensive and should not be easily carried outside for operation.

[0005] It should be noted that the above contents belong to the technical cognition scope of the inventor. Since the technical contents in this field are vast and too complicated, the above contents of this application do not necessarily constitute prior art. Summary of the invention

[0006] 1. Technical problems to be solved by the invention: The present invention provides an ultra-vacuum and ultra-low temperature atomic force microscope device to solve the technical problems existing in the above-mentioned background technology.

[0007] 2. Technical solution: To achieve the above object, the present invention provides a technical solution: an ultra-vacuum ultra-low temperature atomic force microscope device, comprising A vacuum cavity is used to wrap all the parts inside. A vacuum can be formed inside by cooperating with a negative pressure device. An operation hole is opened on the side of the vacuum cavity, and a flange connection end face is arranged outside the operation hole; A shock-absorbing suspension structure, wherein the bottom of the shock-absorbing suspension structure is connected to the support frame, and the top of the shock-absorbing suspension structure is connected to the top of the inner shell of the vacuum chamber; The support frame is internally provided with a laser detection module, a probe frame module and a scanning module.

[0008] When the device is working, the sample to be tested is placed on the scanning module through the operating hole, and the vacuum extraction device is connected through the flange to form a vacuum inside, and the internal temperature is lowered so that the test begins in an ultra-vacuum and ultra-low temperature environment. In addition, the internal shock-absorbing suspension mechanism can ensure internal stability and improve test accuracy.

[0009] Furthermore, the shock-absorbing suspension structure includes a spring, and a damper is arranged inside the spring.

[0010] Furthermore, the laser detection module includes a two-dimensional manual translation stage, which is arranged on one side of the top of the support frame, and a laser emitter is connected to the two-dimensional manual translation stage. A first reflector is arranged on the opposite side of the laser emitter, and a semi-transparent reflector is arranged at the bottom of the first reflector. The scanning module is arranged at the bottom of the semi-transparent reflector, and the probe frame module is arranged on the top of the scanning module. A second reflector is arranged obliquely above the probe frame module, and the second reflector is fixed on a flat-plate adjustment frame. A four-quadrant detector is arranged on the opposite side of the second reflector.

[0011] Furthermore, a CCD sensor is disposed on the side of the semi-transparent reflector.

[0012] Furthermore, the probe rack module includes a probe seat, and the side of the probe seat is connected to the detection probe.

[0013] Furthermore, the scanning module includes a sample stage, and an X piezoelectric displacement stage, a Y piezoelectric displacement stage, a Z piezoelectric scanner and a Z-axis displacement stage are respectively provided at the bottom of the sample stage.

[0014] Furthermore, the bottom of the sample stage is connected to a low-temperature sealed chamber.

[0015] 3. Beneficial effects: Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects: The present invention is reasonably designed. The vacuum cavity is combined with a shock-absorbing suspension structure to enable the atomic force microscope to work in an ultra-vacuum and ultra-low temperature environment, so as to overcome the fact that the existing air environment type atomic force microscope is easily affected by the flow of air gas molecules, mechanical vibration and electromagnetic interference, thereby more accurately obtaining the characteristic parameters of the sample, which is helpful for scientific research, and the overall manufacturing cost is low, which is suitable for the current domestic development situation; and by setting up a shock-absorbing suspension structure, the entire device can achieve shock-absorbing operations in different locations without relying on a precision shock-absorbing platform, thereby improving the adaptability of the device, and all structures inside the device are in a vacuum environment, without worrying about the influence of the external environment, further improving the detection accuracy.

[0016] It should be noted that the structures not introduced in the present invention are the same as the prior art or can be implemented by using the prior art, and are not described in detail here because they do not involve the design points and improvement directions of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the internal structure of the present invention; Figure 2 It is a schematic diagram of the local structure of the present invention; Figure 3 It is a schematic diagram of the internal optical path of the present invention; Figure 4 It is a schematic diagram of other angles of the present invention.

[0018] Reference numerals: 1. Vacuum chamber; 2. Flange; 3. Shock-absorbing suspension structure; 31. Spring; 32. Damper; 4. Support frame; 5. First reflector; 6. Four-quadrant detector; 7. CCD sensor; 8. Probe seat; 9. Sample stage; 10. Z piezoelectric scanner; 11. X piezoelectric displacement stage; 12. Y piezoelectric displacement stage; 13. Z-axis displacement stage; 14. Detection probe; 15. Semi-transparent reflector; 16. Second reflector; 17. Flat-plate adjustment frame; 18. Two-dimensional manual displacement stage; 19. Laser transmitter; 20. Sample; 21. Low-temperature sealed chamber. DETAILED DESCRIPTION

[0019] To facilitate understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. Several embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0020] 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", "page", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicating orientations or positional relationships are 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.

[0021] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0022] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed", "provided with", "provided on" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. Example

[0023] See attached Figure 1-4 , an ultra-vacuum ultra-low temperature atomic force microscope device, comprising The vacuum chamber 1 is used to wrap all the parts inside, and can form a vacuum inside with the help of negative pressure equipment. An operation hole is opened on the side of the vacuum chamber 1, and a flange 2 is provided outside the operation hole to connect the end surface; A shock-absorbing suspension structure 3, wherein the bottom of the shock-absorbing suspension structure 3 is connected to the support frame 4, and the top of the shock-absorbing suspension structure 3 is connected to the top of the inner shell of the vacuum chamber 1; The support frame 4 is internally provided with a laser detection module, a probe frame module and a scanning module.

[0024] The laser detection module, the probe frame module and the scanning module can be connected to the inside of the support frame 4 through supporting structures such as screws or mounting frames, which will not be described in detail here.

[0025] When the device is working, the sample 20 to be tested is placed on the scanning module through the operating hole, and the vacuum extraction device is connected through the flange 2 to form a vacuum inside. Since a shock-absorbing suspension mechanism is provided inside, internal stability can be ensured to improve the detection accuracy.

[0026] The shock-absorbing suspension structure 3 includes a spring 31 , and a damper 32 is arranged inside the spring 31 . The damper 32 cooperates with the spring 31 to achieve a good shock-absorbing effect on the internal support frame 4 .

[0027] The laser detection module includes a two-dimensional manual displacement stage 18, which is arranged on one side of the top of the support frame 4. A laser emitter 19 is connected to the two-dimensional manual displacement stage 18. A first reflector 5 is arranged on the opposite side of the laser emitter 19. A semi-transparent reflector 15 is arranged at the bottom of the first reflector 5. The scanning module is arranged at the bottom of the semi-transparent reflector 15. The probe rack module is arranged on the top of the scanning module. A second reflector 16 is arranged obliquely above the probe rack module. The second reflector 16 is fixed on a flat-plate adjustment frame 17. A four-quadrant detector 6 is arranged on the opposite side of the second reflector 16. The laser detection module can cooperate with the probe rack module to detect the surface information of the sample 20. When working, the laser emitter 19 emits a detection light path, and the detection light path moves downward along the first reflector 5 on the opposite side. Then the detection light path passes through the semi-transparent reflector 15 and irradiates the probe rack module. Then the probe rack module reflects it to the second reflector 16, and then it is shot into the four-quadrant detector 6 along the second reflector 16 to complete the detection operation.

[0028] It should be noted that the semi-transparent reflector 15 is also a semi-transmissive mirror, which in the art refers to a reflector that reflects half of the incident light energy and transmits the other half.

[0029] A CCD sensor 7 is disposed on the side of the semi-transparent reflector 15 , and the semi-transparent reflector 15 reflects the image information of the bottom sample 20 to the CCD sensor 7 , thereby obtaining the image information of the sample 20 .

[0030] The probe rack module includes a probe seat 8 , the side of the probe seat 8 is connected to a detection probe 14 , the bottom of the detection probe 14 is a scanning module, on which a sample 20 to be detected is placed, and the top can reflect the detection light path to the second reflector 16 .

[0031] The scanning module includes a sample stage 9, and an X piezoelectric displacement stage 11, a Y piezoelectric displacement stage 12, a Z piezoelectric scanner 10 and a Z-axis displacement stage 13 are respectively arranged at the bottom of the sample stage 9. A sample 20 to be inspected can be placed on the sample stage 9. When working, the displacement stage can drive the sample 20 to move in a three-dimensional direction, thereby performing surface inspection on products of different thicknesses.

[0032] The bottom of the sample stage 9 is connected to a low-temperature sealed chamber 21. When performing special precision testing, liquid nitrogen can be injected into the low-temperature sealed chamber 21 to cool the sample stage 9 and the sample 20 to keep them in a low-temperature state.

[0033] In summary, when the instrument is working, first install the detection probe 14 on the probe seat 8, place the sample 20 on the sample stage 9, then close the vacuum chamber 1, extract the air in the vacuum chamber 1, and inject liquid nitrogen into the low-temperature sealed chamber 21 in advance to cool the sample 20 as needed. Then turn on the AFM control system and software system, adjust the AFM laser detection light path, and adjust the optical imaging system. The laser emitted by the laser transmitter 19 hits the first reflector 5, and after being reflected by the first reflector 5, it passes through the semi-transparent reflector 15, and the laser finally hits the detection probe 14. After being reflected by the detection probe 14, one path of reflected light hits the second reflector 16, and after being reflected by the second reflector 16, it hits the four-quadrant detector 6. The spot signal received by the four-quadrant detector 6 is transmitted to the AFM controller for processing; the other path of reflected light is reflected along the original path to the semi-transparent reflector 15, and after being reflected by the semi-transparent reflector 15, it hits the CCD sensor 7 for imaging.

[0034] The scanning working mode is selected through the AFM software system, and the Z-axis displacement stage 13 is controlled to drive the sample 20 along the Z-axis direction to the working area of ​​the detection probe 14, and then the basic scanning parameters are set, and the X piezoelectric displacement stage, Y piezoelectric displacement stage and Z piezoelectric scanner start scanning, and the four-quadrant detector 6 starts to collect the received signal. After a scan is completed, the software will automatically save the scanned image and source data. The image analysis software can be used to perform various analyses on the surface data of the sample 20, such as roughness analysis, depth measurement, distance measurement, mechanical property analysis, etc.

[0035] The above-described embodiments only express a certain implementation mode of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the patent scope of the present invention. It should be pointed out that, for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims.

Claims

1. An ultra-vacuum and ultra-low temperature atomic force microscope device, characterized in that: include The vacuum chamber (1) is used to enclose all parts inside, and can form a vacuum inside in conjunction with a negative pressure device. An operation hole is opened on the side of the vacuum chamber (1), and a flange (2) is provided outside the operation hole to connect the end surface; A shock-absorbing suspension structure (3), wherein the bottom of the shock-absorbing suspension structure (3) is connected to the support frame (4), and the top of the shock-absorbing suspension structure (3) is connected to the top of the inner shell of the vacuum chamber (1); The support frame (4) is provided with a laser detection module, a probe frame module and a scanning module therein.

2. The ultra-vacuum ultra-low temperature atomic force microscope device according to claim 1, characterized in that: The shock-absorbing suspension structure (3) comprises a spring (31), and a damper (32) is arranged inside the spring (31).

3. The ultra-vacuum ultra-low temperature atomic force microscope device according to claim 1, characterized in that: The laser detection module comprises a two-dimensional manual displacement stage (18), wherein the two-dimensional manual displacement stage (18) is arranged on one side of the top of the support frame (4), and the two-dimensional manual displacement stage (18) is connected to a laser emitter (19), and a first reflector (5) is arranged on the opposite side of the laser emitter (19), and a semi-transparent reflector (15) is arranged at the bottom of the first reflector (5), and the scanning module is arranged at the bottom of the semi-transparent reflector (15), and the probe frame module is arranged on the top of the scanning module, and a second reflector (16) is arranged obliquely above the probe frame module, and the second reflector (16) is fixed on a flat-plate adjustment frame (17), and a four-quadrant detector (6) is arranged on the opposite side of the second reflector (16).

4. The ultra-vacuum ultra-low temperature atomic force microscope device according to claim 3, characterized in that: A CCD sensor (7) is provided on the side of the semi-transparent reflective mirror (15).

5. The ultra-vacuum ultra-low temperature atomic force microscope device according to claim 1, characterized in that: The probe rack module comprises a probe seat (8), and a detection probe (14) is connected to a side of the probe seat (8).

6. The ultra-vacuum ultra-low temperature atomic force microscope device according to claim 1, characterized in that: The scanning module comprises a sample stage (9), and an X piezoelectric displacement stage (11), a Y piezoelectric displacement stage (12), a Z piezoelectric scanner (10) and a Z-axis displacement stage (13) are respectively arranged at the bottom of the sample stage (9).

7. The ultra-vacuum and ultra-low temperature atomic force microscope device according to claim 6, characterized in that: The bottom of the sample stage (9) is connected to a low-temperature sealed chamber (21).

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