An atomic force microscope probe capable of realizing beam offset compensation

Abstract

The present invention discloses an atomic force microscope probe capable of achieving beam offset compensation. The probe includes a scanning module, a light-lever detection module, an optical microscope module, and a cantilever probe. The scanning module is composed of a three-dimensional flat scanning mechanism and a Z-direction scanner. The light-lever detection module divides the laser into two polarized light beams. One beam is used to detect the displacement of the scanning mechanism, and the other beam is used to detect the deformation of the cantilever. Subtracting the spot positions of the two beams can obtain the deformation amount of the cantilever without offset error, which is beneficial to improving the measurement accuracy during large-range scanning. The optical microscope module is independent of the light-lever detection module and does not interfere with each other. Moreover, a part of the components in the light-lever detection module are arranged outside the scanning module, which can reduce the load of the scanning mechanism and improve the scanning speed.

Description

Technical Field

[0001] The present invention relates to the field of atomic force microscopy measurement, and particularly to a probe-scanning atomic force microscope probe head capable of realizing beam offset compensation. Background Art

[0002] The atomic force microscope was invented in the 1980s. Since it can observe the topography of the microstructure surface with nanoscale resolution, it is widely used in the fields of semiconductor industry, nanomaterials, life sciences, etc. As a contact measurement method, the atomic force microscope needs to use a cantilever probe with a tip to detect the sample. The tip is used to contact the surface of the sample, and the weak force generated by the contact causes the cantilever to deform. Then, the surface topography of the sample is reflected according to the deformation amount of the cantilever.

[0003] Currently, most atomic force microscopes use an optical lever optical path to detect the deformation of the cantilever. The optical lever optical path is located inside the probe head of the atomic force microscope. Its principle is that a laser beam emitted by a laser is converged and then irradiated on the cantilever. The cantilever reflects the beam to a photodetector, and the displacement of the light spot on the detector reflects the deformation amount of the cantilever. In addition, the atomic force microscope also needs to be equipped with a nano-scanning mechanism to drive the probe and the sample to move relative to each other to obtain the complete topography of the sample. According to the different objects of the scanning motion, the structure of the atomic force microscope can be divided into three types: sample scanning (such as Figure 1 (a)), combined scanning (such as Figure 1 (b)), and probe scanning (such as Figure 1 (c)). Among them, probe scanning is to set the scanning mechanism inside the probe head. During measurement, the sample is stationary and the probe moves, which can overcome the limitations of the measured sample in terms of size and weight, and is the best structural solution for building an industrial atomic force microscope. However, in the probe-scanning atomic force microscope system, both the optical lever optical path and the scanning mechanism are integrated inside the probe head. The movement of the scanning mechanism may cause the beam of the optical lever optical path to shift, thus affecting the measurement accuracy. In the probe-scanning structure represented by the Dimension Icon atomic force microscope of Bruker Corporation, the three-dimensional scanning mechanism uses a piezoelectric ceramic tube, and a tracking lens is used to ensure that the optical lever detection beam can be focused on the cantilever during the scanning process. However, when the scanning range is large, there will still be a light spot offset phenomenon, and the tubular scanner also has a bowing effect, which distorts the measurement image. If the optical lever detection module is completely placed on the scanning mechanism, the detection optical path can be linked with the probe during scanning. Although the problem of light spot offset can be solved, it will cause the load of the scanning mechanism to be too large and reduce the scanning speed. Summary of the Invention

[0004] The object of the present invention is to overcome the defects of the above-mentioned existing technologies and design a new type of probe scanning atomic force microscope probe head. The double-beam detection optical path adopted by the probe head can simultaneously detect the movement displacement of the scanning mechanism and the deformation of the cantilever beam. Since the deformation amount of the cantilever beam includes the offset caused by the movement of the scanning mechanism, the two signals are subtracted to obtain the deformation amount of the cantilever beam without offset error. In the double-beam detection optical path structure, the photoelectric conversion device is arranged outside the scanning mechanism, greatly reducing the load of the scanning mechanism and ensuring that the probe can scan at a higher speed.

[0005] The object of the present invention can be achieved by the following technical solutions:

[0006] An atomic force microscope probe head capable of realizing beam offset compensation is composed of a scanning module, a light lever detection module, an optical microscope module, and a cantilever beam probe.

[0007] Preferably, the scanning module includes a three-dimensional flat scanning mechanism and a Z-axis scanner fixedly connected to the three-dimensional flat scanning mechanism.

[0008] Preferably, the light lever detection module includes a laser, a collimating mirror, a rectangular aperture, a first reflecting mirror, a polarization beam splitter prism, a second reflecting mirror, a converging lens, a third reflecting mirror, a fourth reflecting mirror, a quarter-wave plate, a fifth reflecting mirror, a first photodetector, a second photodetector, a first small two-dimensional displacement stage, and a second small two-dimensional displacement stage arranged in sequence along the optical path of the laser; the beams incident on the first photodetector and the second photodetector are parallel to each other.

[0009] Preferably, the Z-axis scanner is fixed below the quarter-wave plate, and a cantilever beam probe is installed below the Z-axis scanner. The cantilever beam probe forms an angle of 10 degrees with the horizontal direction.

[0010] Preferably, the cantilever beam of the cantilever beam probe is located on the converging plane after the collimated beam passes through the converging lens, the third reflecting mirror, the fourth reflecting mirror, and the quarter-wave plate. The stroke of the Z-axis scanner driving the cantilever beam probe to move is less than the focal depth of the converging lens.

[0011] Preferably, the optical microscope module is located above the fourth reflecting mirror. The optical microscope module includes an objective lens, a beam splitter, a tube lens, a CCD camera, and an illumination light source, which form an infinite conjugate microscopic optical path. The entrance pupil diameter of the objective lens is larger than the size of the lower reflecting mirror.

[0012] Preferably, the laser, collimating mirror, rectangular aperture, first mirror, polarization beam splitter prism, second mirror, converging lens, and fifth mirror are labeled as sub-structure I, and the third mirror, fourth mirror, quarter-wave plate, Z-axis scanner, and cantilever probe are labeled as sub-structure II. Sub-structure I and sub-structure II are fixed on a three-dimensional flat scanning mechanism; the first photodetector, second photodetector, first small two-dimensional displacement stage, second small two-dimensional displacement stage, and signal processing circuit are labeled as sub-structure III, and the optical microscope module is labeled as sub-structure IV. The three-dimensional flat scanning mechanism, sub-structure III, and sub-structure IV are fixed on a one-dimensional or two-dimensional or three-dimensional electric displacement stage.

[0013] Preferably, the polarization beam splitter prism divides the laser beam into P-polarized light and S-polarized light with perpendicular polarization directions. Among them, the P-polarized light is directed to the second photodetector, and the S-polarized light is directed to the cantilever probe after passing through the second mirror, converging lens, third mirror, fourth mirror, and quarter-wave plate.

[0014] Preferably, the fourth mirror forms an angle of 40 degrees with the horizontal plane, and the beam reflected by the fourth mirror can irradiate the cantilever probe perpendicularly.

[0015] Preferably, the optical axis of the quarter-wave plate forms an angle of 45 degrees with the polarization direction of the S-polarized light passing through it and directed to the cantilever probe; the beam reflected back by the cantilever probe passes through the quarter-wave plate, fourth mirror, third mirror, converging lens, second mirror, polarization beam splitter prism, and fifth mirror and then is directed to the first photodetector.

[0016] An atomic force microscope probe capable of achieving beam offset compensation according to the present invention can achieve the following beneficial effects:

[0017] (1) When the probe scanning range is smaller than the spot size, the offset of the optical lever detection beam caused by the movement of the scanning mechanism can be completely eliminated.

[0018] (2) By placing the photodetectors in the optical lever detection module and the two-dimensional displacement stages fixing them outside the three-dimensional scanning mechanism, the load of the three-dimensional scanning mechanism can be reduced, ensuring that the probe scans at a higher speed.

[0019] (3) The optical lever detection module of the cantilever probe and the optical microscope module are independent of each other and do not interfere with each other, which is beneficial to improving the measurement stability and can also achieve a good optical observation effect. Description of the Drawings

[0020] Figure 1 (a), Figure 1 (b), Figure 1 (c) are three typical scanning architectures of the atomic force microscope;

[0021] Figure 2 is the front view of the overall structure of the atomic force microscope probe of the present invention;

[0022] Figure 3 (a) is the top view of sub-structure II; Figure 3 (b) is the left view of sub-structure II.

[0023] Reference numerals in the figure: 10 - laser, 11 - converging lens, 12 - photodetector, 13 - cantilever probe, 14 - sample, 15 - three-dimensional scanning mechanism, 16 - one-dimensional scanning mechanism, 17 - two-dimensional scanning mechanism, 101 - laser, 102 - collimating mirror, 103 - aperture, 104 - first mirror, 105 - polarization beam splitter prism, 106 - second mirror, 107 - converging lens, 201 - third mirror, 202 - fourth mirror, 203 - quarter-wave plate, 204 - Z-axis scanner, 205 - cantilever probe, 301 - first photodetector, 302 - second photodetector, 303 - first small two-dimensional displacement stage, 304 - second small two-dimensional displacement stage, 305 - signal processing circuit, 401 - objective lens, 402 - beam splitter, 403 - illumination light source, 404 - tube lens, 405 - CCD camera. Detailed implementation manners

[0024] The present invention will be described in detail below with reference to the embodiments shown in the drawings. It should be noted, however, that these embodiments are not intended to limit the present invention, and any equivalent transformation or substitution in terms of function, method, or structure made by those of ordinary skill in the art based on these embodiments shall fall within the protection scope of the present invention.

[0025] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention.

[0026] An atomic force microscope probe capable of realizing beam offset compensation is composed of a scanning module, a light-lever detection module, an optical microscope module, a cantilever probe, etc., as Figure 2 、 Figure 3 (a), Figure 3 (b) shown. In the figure, the modules are placed in a three-dimensional rectangular coordinate system of XYZ, where the X-axis is perpendicular to the plane, the Y-axis is in the horizontal direction, and the Z-axis is in the vertical direction.

[0027] The scanning module includes a three-dimensional flat scanning mechanism and a Z-axis scanner 204 fixedly connected to the three-dimensional flat scanning mechanism.

[0028] Specifically, the three-dimensional flat scanning mechanism can perform three-dimensional scanning motion with a motion range of more than one hundred micrometers and a slower motion speed than the Z-axis scanner 204. The Z-axis scanner 204 can perform high-speed feedback motion in the vertical direction.

[0029] It should be further noted that the three-dimensional flat scanning mechanism can select the three-dimensional nano-positioning stage P-517.3CL of PI company. This nano-positioning stage is vertically installed. Therefore, the closed-loop strokes in the X, Y, and Z directions are: 20μm, 100μm, and 100μm respectively. The Z-axis scanner 204 can select the stacked piezoelectric ceramic NAC2015 of Noliac company, and the open-loop stroke is about 3.3μm.

[0030] As a preferred embodiment, the optical lever detection module includes a laser 101, a collimating mirror 102, a rectangular aperture 103, a first reflecting mirror 104, a polarization beam splitter prism 105, a second reflecting mirror 106, a converging lens 107, a third reflecting mirror 201, a fourth reflecting mirror 202, a quarter-wave plate 203, a fifth reflecting mirror 108, a first photodetector 301, a second photodetector 302, a first small two-dimensional displacement stage 303, and a second small two-dimensional displacement stage 304, which are arranged in sequence along the optical path of the laser 101; the light beams incident on the first photodetector 301 and the second photodetector 302 are parallel to each other.

[0031] As a preferred embodiment, the Z-axis scanner 204 is fixed below the quarter-wave plate 203, and a cantilever probe 205 is installed below the Z-axis scanner 204. The cantilever probe 205 forms an angle of 10 degrees with the horizontal direction.

[0032] As a preferred embodiment, the cantilever of the cantilever probe 205 is located on the converging plane after the collimated light beam passes through the converging lens 107, the third reflecting mirror 201, the fourth reflecting mirror 202, and the quarter-wave plate 203. The stroke of the Z-axis scanner 204 driving the cantilever probe 205 to move is less than the focal depth of the converging lens 107.

[0033] As a preferred embodiment, the polarization beam splitter prism 105 divides the laser beam into P-polarized light and S-polarized light with perpendicular polarization directions. Among them, the P-polarized light is incident on the second photodetector 302, and the S-polarized light is incident on the cantilever probe 205 after passing through the second reflecting mirror 106, the converging lens 107, the third reflecting mirror 201, the fourth reflecting mirror 202, and the quarter-wave plate 203.

[0034] As a preferred embodiment, the fourth mirror 202 forms an angle of 40 degrees with the horizontal plane, and the light beam reflected by the fourth mirror 202 can irradiate perpendicularly to the cantilever probe 205.

[0035] As a preferred embodiment, the optical axis of the quarter-wave plate 203 forms an angle of 45 degrees with the polarization direction of the S-polarized light that passes through it and irradiates the cantilever probe 205; the light beam reflected back by the cantilever probe 205 passes through the quarter-wave plate 203, the fourth mirror 202, the third mirror 201, the converging lens 107, the second mirror 106, the polarization beam splitter prism 105, and the fifth mirror 108 and then irradiates the first photodetector 301.

[0036] Specifically, the laser 101 is vertically placed and emits linearly polarized light downward. After passing through the collimating mirror 102, a collimated light beam is formed. After passing through the aperture 103, a rectangular light beam is obtained. The first mirror 104 placed at 45 degrees converts the vertical light beam into a light beam propagating horizontally to the right. After passing through the polarization beam splitter prism 105, it is divided into a P-polarized light propagating horizontally to the right and an S-polarized light propagating vertically downward. By rotating the laser 101, the intensities of the P-polarized light and the S-polarized light can reach appropriate values. Among them, the P-polarized light propagating horizontally to the right irradiates the second photodetector 302, and by rotating the aperture 103, the four sides of the square light spot are respectively parallel to the cross dividing lines of the photodetector 302; the S-polarized light propagating vertically downward is converted into a light beam propagating to the left by the second mirror 106 placed at 45 degrees, and then forms a converging light beam after passing through the converging lens 107. The converging light beam is first converted into a light beam propagating along the X direction by the third mirror 201, then converted into a light beam forming an angle of -10 degrees with the Z direction by the fourth mirror 202, and then becomes circularly polarized light after passing through the quarter-wave plate 203. This circularly polarized light irradiates the cantilever probe 205 placed at an angle of -10 degrees with the X direction and converges into a point on the cantilever of the cantilever probe 205. The converging light beam is reflected by the cantilever probe 205 and returns along the original path. The reflected circularly polarized light becomes P-polarized light after passing through the quarter-wave plate 203, and then forms a light beam propagating vertically upward after passing through the fourth mirror 202, the third mirror 201, the converging lens 107, the second mirror 106, and the polarization beam splitter prism 105, and is then converted into a light beam propagating horizontally to the right by the fifth mirror 108 placed at 45 degrees and irradiates the first photodetector 301. The first photodetector 301 is fixed on the first small two-dimensional displacement stage 303, and the second photodetector 302 is fixed on the second small two-dimensional displacement stage 304. The current signals of the first photodetector 301 and the second photodetector 302 are transmitted to the signal processing circuit 305.

[0037] It should be further noted that when the cantilever probe 205 does not deform, the optical paths of the reflected light and the incident light in the second mirror 106, the converging lens 107, the third mirror 201, the fourth mirror 202, and the quarter-wave plate 203 completely coincide. Therefore, optical elements with smaller sizes can be used, thereby reducing the load of the scanning mechanism. The first small two-dimensional displacement stage 303 and the second small two-dimensional displacement stage 304 are respectively used to adjust the positions of the first photodetector 301 and the second photodetector 302, so that the projection spot on the photodetector is located at the center of the photosensitive surface when the cantilever probe 205 does not deform. The signal processing circuit 305 converts the current signals output by the first photodetector 301 and the second photodetector 302 into voltage signals, and after operations such as amplification, filtering, and demodulation, transmits them to the main control box.

[0038] It should be further noted that the laser 101 can be a CPS780S laser from Thorlabs, with a laser wavelength of 780 nm. The first photodetector 301 and the second photodetector 302 can be quadrant detectors S5980 from Hamamatsu Photonics. The first small two-dimensional displacement stage 303 and the second small two-dimensional displacement stage 304 can be ultra-thin XY-axis displacement stages TSD-252 from Sigma Koki.

[0039] As a preferred embodiment, the optical microscope module is located above the fourth mirror 202. The optical microscope module includes an objective lens 401, a beam splitter 402, a tube lens 404, a CCD camera 405, and an illumination light source 403, which form an infinite conjugate microscopic optical path. The entrance pupil diameter of the objective lens 401 is larger than the size of the lower mirror 202.

[0040] As a preferred embodiment, the laser 101, the collimating lens 102, the rectangular aperture 103, the first mirror 104, the polarization beam splitter prism 105, the second mirror 106, the converging lens 107, and the fifth mirror 108 are marked as sub-structure I, and the third mirror 201, the fourth mirror 202, the quarter-wave plate 203, the Z-axis scanner 204, and the cantilever probe 205 are marked as sub-structure II. Sub-structure I and sub-structure II are fixed on a three-dimensional flat scanning mechanism; the first photodetector 301, the second photodetector 302, the first small two-dimensional displacement stage 303, the second small two-dimensional displacement stage 304, and the signal processing circuit 305 are marked as sub-structure III, the optical microscope module is marked as sub-structure IV, and the three-dimensional flat scanning mechanism, sub-structure III, and sub-structure IV are fixed on a one-dimensional or two-dimensional or three-dimensional electric displacement stage.

[0041] Specifically, the electric displacement stage can drive the entire probe head to move, achieving rough positioning between the probe and the sample. After the rough positioning is completed, the scanning module can drive the cantilever probe 205 to measure the surface topography of the sample.

[0042] During the actual measurement process, the tip of the cantilever probe 205 contacts the sample, and the change in the contact force causes the cantilever probe 205 to deform. Assume that when the cantilever probe 205 is not deformed, the voltages corresponding to the light intensity of the light spot on the first photodetector 301, the position of the light spot in the Z direction, and the position of the light spot in the X direction are v s0 、v z0 、v x0 , and the voltages corresponding to the light intensity of the light spot on the second photodetector 302, the position of the light spot in the Z direction, and the position of the light spot in the X direction are v' s0 、v' z0 、v' x0 . Further assume that when the cantilever probe 205 is deformed, the voltages corresponding to the positions of the light spot on the first photodetector 301 in the Z direction and the X direction are v z1 、v x1 , and the voltages corresponding to the positions of the light spot on the second photodetector 302 in the Z direction and the X direction are v' z1 、v' x1 . Then the voltage change Δv d caused by the deformation of the cantilever probe 205 in the Z direction can be expressed as:

[0043]

[0044] The voltage change Δv t caused by the deformation of the cantilever probe 205 in the Y direction can be expressed as:

[0045]

[0046] Taking the atomic force microscope operating in the contact mode as an example, the main control box compares the collected change amount Δv d with the set value. If Δv d is greater than the set value, it controls the Z-axis scanner 204 to drive the cantilever probe 205 away from the sample. If Δv d is less than the set value, it controls the Z-axis scanner 204 to drive the cantilever probe 205 closer to the sample, thereby realizing the feedback control of the force between the probe and the sample. The control algorithm can adopt the PID algorithm. The movement trajectory of the Z-axis scanner 204 during the scanning process can be used for the topography imaging of the sample surface.

[0047] If the atomic force microscope operates in the tapping mode, it is not necessary to calculate the spot displacement on the second photodetector 302. Instead, the spot displacement signal on the first photodetector 301 can be directly demodulated, and the amplitude obtained by demodulation is compared with the set value. The specific control algorithm and imaging method are the same as those in the contact mode.

[0048] Since the movement range of the Z-axis scanner 204 is small, using the above control method will limit the measurement range of the probe in the vertical direction. If the Z-axis movement unit of the three-dimensional flat scanning mechanism is used to replace the Z-axis scanner 204 as the feedback actuator, the response bandwidth of the feedback loop will be reduced, and the probe is also easily damaged. Therefore, a dual-feedback control strategy can be adopted to image the sample, where the low-speed feedback loop controls the Z-axis movement unit of the three-dimensional flat scanning mechanism to track the low-frequency components of the topography change, and the high-speed feedback loop controls the Z-axis scanner 204 to track the high-frequency components of the topography change.

[0049] The above has described in detail a specific embodiment of the present invention. It should be understood that those of ordinary skill in the art can make many modifications and variations based on the concept of the present invention without creative labor. Therefore, all technical solutions that can be obtained by those skilled in the art in the technical field based on the concept of the present invention through logical analysis, reasoning, or limited experiments on the basis of the prior art should fall within the protection scope determined by the present invention.

Claims

1. An atomic force microscope probe device capable of realizing beam offset compensation, comprising a scanning module, a light lever detection module, an optical microscope module, and a cantilever probe, characterized in that, The optical lever detection module includes a first photodetector, a second photodetector, a polarization beam splitter prism, and a converging lens. The first photodetector and the second photodetector are both arranged outside the scanning module. The polarization beam splitter prism divides the laser beam into two beams of light. One beam of light is converged by the converging lens and then projected onto the cantilever beam, and after reflection, it is projected onto the first photodetector. The other beam of light is projected onto the second photodetector. The two beams of light projected onto the first photodetector and the second photodetector are parallel to each other. The electrical signals output by the two photodetectors are subtracted to obtain the deformation amount of the cantilever beam without beam offset error. The voltage change Δv caused by the deformation of the cantilever beam probe along the Z direction d can be expressed as: The voltage change Δv caused by the deformation of the cantilever beam probe along the Y direction t can be expressed as: where v s0 , v z0 , v x0 are the voltages corresponding to the light intensity of the light spot on the first photodetector, the position of the light spot in the Z direction, and the position of the light spot in the X direction when the cantilever beam probe does not deform, respectively. v' s0 , v' z0 , v' x0 are the voltages corresponding to the light intensity of the light spot on the second photodetector, the position of the light spot in the Z direction, and the position of the light spot in the X direction when the cantilever beam probe does not deform, respectively; v z1 , v x1 are the voltages corresponding to the positions of the light spot on the first photodetector in the Z direction and the X direction when the cantilever beam deforms during the scanning of the cantilever beam probe, respectively. v' z1 , v' x1 are the voltages corresponding to the positions of the light spot on the second photodetector in the Z direction and the X direction when the cantilever beam deforms during the scanning of the cantilever beam probe, respectively.

2. The atomic force microscope probe device capable of realizing beam offset compensation according to claim 1, wherein The optical lever detection module further includes a rectangular aperture for adjusting the shape of the laser beam so that the light projected onto the first photodetector and the second photodetector is a rectangular light spot.

3. The atomic force microscope probe device capable of achieving beam offset compensation according to claim 2, wherein The optical lever detection module further includes a second mirror, a third mirror, a fourth mirror, a quarter-wave plate, and a fifth mirror. The polarization beam splitter prism splits the laser beam into a P-polarized light and an S-polarized light with perpendicular polarization directions. The P-polarized light is incident on the second photodetector, and the S-polarized light passes through the second mirror, a converging lens, the third mirror, the fourth mirror, and the quarter-wave plate in sequence, then is reflected after being incident on the cantilever probe, and the reflected beam returns along the original optical path, passes through the polarization beam splitter prism again, and is reflected by the fifth mirror and then incident on the first photodetector. By adjusting the positions of the components in the optical path, it is ensured that the beams incident on the first photodetector and the second photodetector are parallel to each other; by adjusting the position of the quarter-wave plate so that its optical axis forms an angle of approximately 45 degrees with the polarization direction of the S-polarized light passing through it and incident on the cantilever probe, it is ensured that the energy of the beam incident on the first photodetector is the largest, thereby improving the signal-to-noise ratio.

4. The atomic force microscope probe device capable of realizing beam offset compensation according to claim 3, characterized in that, The scanning module includes a three-dimensional flat scanning mechanism and a Z-direction scanner fixedly connected to the three-dimensional flat scanning mechanism. The Z-direction scanner is fixed below the quarter-wave plate, and the cantilever probe is installed below the Z-direction scanner; the optical lever detection module further includes a first small two-dimensional displacement stage and a second small two-dimensional displacement stage. The first small two-dimensional displacement stage is fixed to the first photodetector, and the second small two-dimensional displacement stage is fixed to the second photodetector, respectively used to adjust the position of the beam on the photodetector; the sub-structure I including the rectangular aperture, the polarization beam splitter prism, the second mirror, the converging lens, and the fifth mirror and the sub-structure II including the third mirror, the fourth mirror, the quarter-wave plate, the Z-direction scanner, and the cantilever probe are fixed to the three-dimensional flat scanning mechanism, and the sub-structure III including the first photodetector, the second photodetector, the first small two-dimensional displacement stage, and the second small two-dimensional displacement stage and the optical microscope module are arranged outside the three-dimensional flat scanning mechanism to reduce the load of the three-dimensional flat scanning mechanism.

5. The atomic force microscope probe device capable of achieving beam offset compensation according to claim 4, wherein, The optical lever detection module further includes a laser, a collimating mirror, a first mirror, and a fourth mirror arranged along the optical path of the laser; the cantilever of the cantilever probe is located on the focal plane after the collimated beam passes through the converging lens; the fourth mirror is arranged above the cantilever probe and is used to guide the beam to the cantilever; the optical microscope module is located above the fourth mirror. The optical microscope module includes an objective lens, a beam splitter, a tube lens, a CCD camera, and an illumination light source, which form an infinite conjugate microscopic optical path. The entrance pupil diameter of the objective lens is larger than the size of the lower mirror, facilitating the observation of the state of the cantilever probe.

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