A scanning probe microscope with repeatable positioning

Abstract

A scanning probe microscope with repeatable positioning includes a mirror body, a stepper, a pre-tightening component, a scanning component and a sample stage; the mirror body includes three mutually parallel linear guide rails, two of which are provided with steppers, and the stepper is pressed onto the above two linear guide rails by the third linear guide rail through the pre-tightening component; the stepper includes a supporting slider, two inner sliders and three piezoelectric bodies; the cross-sections of the two top ends of the supporting slider are inclined surfaces matching the cross-sections of the above two linear guide rails, and the supporting slider and the above two linear guide rails form a large torque stable structure with four-point rigid contact. The scanning probe microscope does not produce lateral displacement during the rough approach / retraction process, and the positioning deviation of the probe in the same area of ​​the sample is less than 30 nanometers when it reciprocates in rough approach / retraction at a millimeter-level stroke. The present invention has small size, compact structure, strong environmental compatibility and repeatable positioning function.

Description

Technical Field

[0001] The invention relates to a scanning probe microscope (SPM) capable of repeatable positioning, belonging to the technical field of scanning probe microscopes. Background Art

[0002] Since the advent of scanning probe microscopy, it has become a powerful tool for characterizing the nano-surface structure and morphology of samples. In recent years, with the diversification and deepening of scientific research, some sample materials have shown novel characteristics under different test conditions (for example, when the sample is locally subjected to stress, when the scanning probe microscope multi-probe coordinated debugging, when the sample is locally subjected to temperature change test, in a variable magnetic field environment, when the electrochemical method is regulated, etc.), which has an important role in revealing the relationship between the properties and structures of the sample materials and the basic laws of material science, and has also attracted people's continuous attention. However, since the tip of the scanning probe microscope is very close to the sample when it is working (for example, the tunnel junction of the scanning tunneling microscope is often less than 1nm), it is easy to cause a drastic change in the distance between the tip and the sample when adjusting the test conditions / environment of the sample, resulting in a collision between the sample and the tip, and the test is terminated. In order to avoid this tragedy, the tip / sample is usually retreated a certain distance before changing the test environment of the sample; after the environmental regulation is completed, the tip / sample is approached again and the SPM measurement is repeated. However, due to the limitations of the traditional scanning probe microscope structure and stepping method, reapproaching the probe after withdrawing it often results in a large positioning deviation, and it is difficult for the probe to be positioned in the same area of ​​the sample twice. In order to track and observe the changes in the properties of the same area of ​​the sample before and after environmental regulation, a large area search is required during the second needle scan. However, this method is blind and inefficient, and it is often difficult to find the area to be tested after multiple scans and searches.

[0003] In fact, the traditional SPM does not have the function of repeated positioning due to the piezoelectric stepper it uses. Specifically, the various components of the traditional piezoelectric stepper are often connected together through a piezoelectric body, and the piezoelectric body plays a supporting role in the entire stepper. When the stepper is subjected to asymmetric resistance during its movement or the piezoelectric body undergoes expansion and contraction deformation, it will cause local deflection or distortion of the stepper. Therefore, during the movement of these steppers, its two ends often swing slightly, and the amplitude and direction of the swing are random, which causes the stepper to move a certain distance along the guide rail. Its position will deviate in the direction perpendicular to the movement, that is, lateral offset. This is ultimately reflected in the fact that the tip of the SPM cannot be repeatedly positioned in the same area of ​​the sample during the reciprocating rough approximation and retreat. Summary of the invention

[0004] The present invention provides a scanning probe microscope capable of repeatable positioning, so as to solve the problem that the scanning probe microscope in the prior art may generate random lateral deviation in the rough approximation stage.

[0005] The present invention provides the following technical solution: a scanning probe microscope capable of repeatable positioning, characterized in that it comprises a mirror body, a stepper, a preload component, a scanning component and a sample stage; the mirror body comprises three mutually parallel linear guide rails, two of which are provided with steppers, and the steppers are pressed onto the above two rails by the third linear guide rail through the preload component; the stepper comprises a supporting slider, two inner sliders and three piezoelectric bodies, two of which are distributed between the supporting slider and the inner slider, and the other one is distributed between the inner slider and the inner slider, so that the supporting slider and the inner slider are The inner slider and the piezoelectric body are staggered and distributed with the piezoelectric body; the inner slider and the piezoelectric body are in a pre-tightened state under the constraint of the supporting slider, and the three constitute a dense whole; the supporting slider and the inner slider generate a suitable positive pressure between the two linear guide rails under the elastic force of the pre-tightening component, so that there is a suitable friction force between the two linear guide rails; the scanning component is fixed on the stepper, and the sample stage is fixed on the mirror body, or the scanning component is fixed on the mirror body, and the sample stage is fixed on the stepper; the scanning component includes a piezoelectric body fixing table, a scanning piezoelectric body, a probe holder, and a probe; the sample stage includes a sample base and a sample.

[0006] The characteristic is that the cross section of the linear guide rail is a cylinder or an inclined surface.

[0007] It is characterized in that the two top ends of the supporting slider have two inclined surfaces that match the cross-section of the linear guide rails. Under the action of the elastic preload component, the two top inclined surfaces are in rigid contact with the two linear guide rails, and it forms a four-point contact high-torque stable structure with the two linear guide rails.

[0008] It is characterized in that the inner slider is distributed in the supporting slider along the track direction, and the cross-section of the inner slider is an inclined surface matching the cross-section of the linear guide track. Under the action of the elastic preload component, its two inclined surfaces are in rigid contact with the two linear guide tracks, and form four-point contact / two-line contact with the two linear guide tracks.

[0009] The characteristic is that the power element of the stepper is a piezoelectric body, and each piezoelectric body is controlled by an external circuit to cause the piezoelectric body to produce corresponding expansion and contraction deformation, thereby changing the thrust output by the piezoelectric body.

[0010] The invention is characterized in that the stepper and the three linear guide rails are distributed in a planar symmetrical structure, and the direction of the thrust generated by the piezoelectric body on the slider is parallel to the three linear guide rails.

[0011] The characteristic is that the supporting slider is a rigid frame structure, and when the piezoelectric body undergoes telescopic deformation or the stepper is subjected to asymmetric resistance, the supporting slider does not produce distortion or telescopic deformation.

[0012] The scanning probe microscope is characterized in that no lateral deviation occurs during the rough approach / retraction process, and when it performs a reciprocating rough approach / retraction at a millimeter-level stroke, the positioning deviation of the probe in the same area of ​​the sample is less than 30 nanometers.

[0013] The present invention has the following advantages: the mirror body has a compact structure, which can reduce the temperature drift of the system; the stepper is in a pre-tightened state, and the rigid interference ability is strong. The stepper of the scanning probe microscope will not produce lateral deviation during the rough approximation process, and its needle tip can be positioned in the same area of ​​the sample during multiple needle insertions, and has the function of repeated positioning. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the overall structure of a scanning probe microscope capable of repeatable positioning according to the present invention;

[0015] Figure 2 is a schematic diagram of the stepper structure;

[0016] Figure 3 It is a schematic diagram of the assembly cross section of the support slider and the mirror body in the stepper;

[0017] Figure 4 It is a schematic diagram of the assembly cross section of the inner slider and the mirror body in the stepper. DETAILED DESCRIPTION

[0018] like Figure 1 As shown, a scanning probe microscope with repeatable positioning of the present invention is characterized in that it includes a mirror body 1, a stepper 2, pre-tightening components 3a, 3b, 3c, a scanning component 4 and a sample stage 5; the scanning component 4 includes a piezoelectric body fixing table 4a, a scanning piezoelectric body 4b, a probe frame 4c and a probe 4d, the scanning piezoelectric body 4b is fixed on the mirror body 1 through the piezoelectric body fixing table 4a, and the probe 4d is fixed to the lower end of the scanning piezoelectric body 4b through the probe frame 4; the sample stage 5 includes a sample base 5a, a sample substrate 5b, and the sample stage 5 is fixed on the stepper 2.

[0019] like Figure 2 As shown, the stepper 2 includes a supporting slider 7, two inner sliders 8a, 8b and three piezoelectric bodies 9a, 9b, 9c. The piezoelectric bodies 9a, 9b, 9c are respectively arranged between the supporting slider 7 and the inner slider 8a, between the inner slider 8a and the inner slider 8b, and between 8b and the supporting slider 7. The inner sliders 8a, 8b and the piezoelectric bodies 9a, 9b, 9c are in a pre-tightened state under the restraint of the supporting slider 7, and the three constitute a compact whole.

[0020] like Figure 3As shown in Figure 4, the mirror body 1 includes three mutually parallel linear guide rails 6a, 6b, and 6c. The stepper 2 is placed on two of the linear guide rails 6a and 6b, and is pressed on the above-mentioned two rails 6a and 6b by the third linear guide rail 6c through pre-tightening components 3a, 3b, and 3c. Under the action of the pre-tightening components 3a, 3b, and 3c, the supporting slider 7 and the inner slider 8a, 8b have a certain positive pressure with the above-mentioned two linear guide rails 6a and 6b, so that there is a suitable maximum static friction between the two linear guide rails 6a and 6b.

[0021] like Figure 2 , 3 As shown, the cross-sections of the linear guide rails 6a and 6b are inclined surfaces, and the cross-sections of the two top ends of the supporting slider 7 are both inclined surfaces that match the cross-sections of the linear guide rails 6a and 6b. Under the action of the elastic preload components 3a and 3c, the inclined surfaces of the two top ends of the supporting slider 7 are in rigid contact with the two linear guide rails 6a and 6b, and form a four-point contact high-torque stable structure with the two linear guide rails 6a and 6b.

[0022] like Figure 2 , 4 As shown, the two inner sliders 8a, 8b are distributed in the support slider 7 along the rails 6a, 6b, 6c, and the cross-sections of the inner sliders 8a, 8b are both inclined surfaces that match the cross-sections of the linear guide rails 6a, 6b. Under the action of the elastic preload components 3a, 3b, the two inclined surfaces of the inner slider 8a are in rigid contact with the two linear guide rails 6a, 6b, and form two-line contact with the two linear guide rails 6a, 6b; under the action of the elastic preload components 3b, 3c, the two inclined surfaces of the inner slider 8b are in rigid contact with the two linear guide rails 6a, 6b, and form two-line contact with the two linear guide rails 6a, 6b.

[0023] The support slider 7 and the inner sliders 8a and 8b of the stepper satisfy that the sum of the maximum static friction between any two sliders and the guide rail is greater than the maximum static friction between the third slider and the track. The driving mode of the stepper in the present invention is:

[0024] The three piezoelectric bodies 9a, 9b, and 9c are controlled in sequence by an external circuit to switch between the deformation states of no deformation, contraction, and extension, thereby changing the mutual thrust between the supporting slider 7 and the inner sliders 8a and 8b. At this time, the two sliders on both sides that do not produce deformation form a whole. Under the action of the thrust generated by the extended piezoelectric body, the two sliders push the third slider to slide along the straight guide track; the above process is repeated continuously and reciprocatingly, thereby realizing the linear stepping of the stepper.

[0025] The stepper is a plane-symmetrical structure, and the distribution of the three linear guide rails is also a plane-symmetrical structure. The cross-section of the linear guide rail is adaptively matched with the contact surface of the stepper. The support slider 7 and the inner sliders 8a, 8b are constrained on the linear guide rails 6a, 6b under the action of the pre-tightening components 3a, 3b, 3c, thereby ensuring that the resultant force exerted on the stepper is parallel to the linear guide rails; in addition, the support slider is a rigid frame structure. When the piezoelectric body undergoes telescopic deformation or the stepper is subjected to asymmetric resistance during its movement, the support slider does not produce distortion or telescopic deformation. These two points ensure that the scanning probe microscope does not produce lateral displacement during the rough approach / retreat process and has the function of repeated positioning.

[0026] It is actually measured that the scanning probe microscope of the present invention reciprocates roughly approaching and retreating in a stroke of 4 mm, and the positioning deviation of its probe in the same microscopic area of ​​the sample is less than 30 nm.

Claims

1. A scanning probe microscope with repeatable positioning, comprising a mirror body, a stepper, a preload component, a scanning component and a sample stage, characterized in that: The mirror body includes three mutually parallel linear guide rails, two of which are provided with steppers, and the steppers are pressed onto the above two linear guide rails by the third linear guide rail through a pre-tightening component; the stepper includes a supporting slider, two inner sliders and three piezoelectric bodies; the supporting slider is a rigid frame structure; the three piezoelectric bodies are distributed between the supporting slider and the inner sliders and between the inner sliders and the inner sliders, and form a compact whole with the supporting slider and the inner sliders; the stepper is a plane symmetrical structure, the distribution of the three linear guide rails is also a plane symmetrical structure, and the cross-section of the linear guide rails is adaptively matched with the contact surface of the stepper; the scanning component / sample stage is fixed on the mirror body / stepper; the scanning component includes a scanning piezoelectric body fixing table, a scanning piezoelectric body, a probe frame, and a probe; the sample stage includes a sample base, a sample substrate, and a sample.

2. A repositionable scanning probe microscope according to claim 1, characterized in that: The cross section of the linear guide rail is a cylinder or an inclined surface.

3. A repositionable scanning probe microscope according to claim 1, characterized in that: The two top ends of the supporting slider each have two inclined surfaces that match the cross-section of the linear guide rails, and under the action of the elastic preload component, its two top inclined surfaces are in rigid contact with the two linear guide rails, and finally it forms a four-point contact high torque stable structure with the two linear guide rails.

4. A repositionable scanning probe microscope according to claim 1, characterized in that: The inner slider has two inclined surfaces matching the cross-section of the linear guide rails. Under the action of the elastic preload component, both inclined surfaces are in rigid contact with the two linear guide rails, and finally it forms four-point contact / two-line contact with the two linear guide rails.

5. The repositionable scanning probe microscope according to claim 1, characterized in that: When the piezoelectric body generates thrust or the stepper is subjected to asymmetric resistance, the support slider does not generate stretching or twisting deformation.

6. The repositionable scanning probe microscope according to claim 1, characterized in that: The scanning probe microscope does not generate lateral deviation during the rough approach / retraction process, and during the reciprocating rough approach / retraction with a millimeter-level stroke, the positioning deviation of the probe in the same area of ​​the sample is less than 30 nanometers.

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