A scanning probe microscope

Abstract

This invention provides a scanning probe microscope, including a laser, a probe, a position-sensitive detector, a camera, and a liquid lens. The liquid lens is disposed in the optical path between the camera and the probe. When the liquid lens is in a first state, the camera images the probe arm at least through the liquid lens; when the liquid lens is in a second state, the camera images the object under test at least through the liquid lens. This invention integrates the observation optical paths of the probe and the object under test into a single optical element, greatly reducing the size of the device. It enables switching between imaging of the probe arm and the surface under test without moving the optical element, reducing interference with the imaging effect caused by the movement of the optical element. It can quickly switch the imaging object, improving efficiency. The focal length of the liquid lens can be continuously varied, facilitating matching different surfaces under test and probe arm positions, thereby increasing the applicability of the scanning probe microscope.

Description

Technical Field

[0001] This invention belongs to the field of scanning probe technology, specifically relating to a scanning probe microscope. Background Technology

[0002] Scanning probe microscopy (SPM) measures the surface shape of a sample by bringing a probe close to or into contact with the sample surface. Its applications are wide-ranging, including the surface structure, physical properties, chemical reactions, nanofabrication, and information storage of materials such as conductors, semiconductors, insulators, biological materials, organic materials, and nanomaterials. Most existing SPMs employ a method known as the optical lever method to detect the analyte. Specifically, the optical lever method involves illuminating the probe's cantilever with a laser beam and detecting changes in the position of the reflected laser light through a detector. This allows the detection of the probe's position and / or orientation, thereby obtaining the position of the probe tip and / or the interaction force between the tip and the analyte.

[0003] In some cases, it is necessary to set up observation elements such as cameras to observe the position of the probe or the object under test, in order to facilitate equipment debugging or positioning. Typically, to observe the probe, a corresponding observation optical path needs to be set up to image the probe; to observe the object under test, a corresponding observation optical path needs to be set up to image the object. However, setting up separate observation optical paths requires a large volume, which increases the size of the scanning probe microscope equipment. Furthermore, the optical paths are prone to interference during adjustments, affecting operational efficiency.

[0004] The information disclosed in the background section is only intended to enhance the understanding of the background of this utility model, and therefore may contain information that does not constitute prior art known to those skilled in the art. Utility Model Content

[0005] To address the problems of increased device size and easy interference between optical paths caused by existing technologies, this application provides a scanning probe microscope, including a laser, a probe, a position-sensitive detector, a camera, and a liquid lens. The laser emits a beam that passes through the back of the probe arm of the probe and is guided to the position-sensitive detector. The position-sensitive detector is configured to generate a corresponding signal based at least on the position of the beam incident upon it. The liquid lens is disposed in the optical path between the camera and the probe, and the liquid lens is switchable between at least a first state and a second state.

[0006] When the liquid lens is in the first state, the camera images the probe arm at least through the liquid lens;

[0007] When the liquid lens is in the second state, the camera images the object being measured at least through the liquid lens.

[0008] According to one embodiment of this application, the camera and liquid lens are arranged in a direction perpendicular to the surface of the object being measured.

[0009] According to one embodiment of this application, the scanning probe microscope further includes an objective lens, and the camera images the object under test at least through the liquid lens and the objective lens.

[0010] According to one embodiment of this application, the scanning probe microscope further includes a beam splitter, the beam emitted by the laser passes through the beam splitter and illuminates the probe arm; the camera images the object under test at least through the liquid lens and the beam splitter.

[0011] According to one embodiment of this application, when the liquid lens is in the first state, the laser beam emitted by the laser illuminates the position of the probe arm, which is within the depth of focus range that enables the camera to image.

[0012] According to one embodiment of this application, when the liquid lens is in the second state, the measured position of the object is within the depth of focus range that enables the camera to image the image.

[0013] According to one embodiment of this application, the relative positions of the liquid lens and the camera are fixed.

[0014] According to one embodiment of this application, the scanning probe microscope further includes a sample carrier device, which is provided with a carrier surface capable of supporting the object to be measured.

[0015] According to one embodiment of this application, the sample carrier is configured to move the object being tested.

[0016] According to one embodiment of this application, the scanning probe microscope further includes an analysis device, which is at least communicatively connected to the position-sensitive detector.

[0017] This invention has at least the following advantages: by using a liquid lens, the observation optical path of the probe and the object under test is integrated into a single optical element, greatly reducing the size of the device; it enables switching between imaging of the probe arm and the surface under test without moving the optical element, reducing interference with the imaging effect caused by the movement of the optical element; it allows for rapid switching of the imaging object, improving efficiency; and the focal length of the liquid lens can be continuously varied, facilitating matching different surfaces under test and the positions of the probe arm, thereby increasing the applicability of the scanning probe microscope. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of one state of an embodiment of a scanning probe microscope provided in this application.

[0019] Figure 2 This is a schematic diagram of another state of one embodiment of a scanning probe microscope provided in this application.

[0020] Figure 3 This is a schematic diagram of another embodiment of a scanning probe microscope provided in this application.

[0021] Figure 4 This is a schematic diagram of yet another embodiment of a scanning probe microscope provided in this application. Detailed Implementation

[0022] To make the objectives and features of this utility model clearer and easier to understand, the specific embodiments of this utility model will be further described below with reference to the accompanying drawings. It should be noted that the drawings are all in a very simplified form and use non-precise ratios, and are only used to facilitate and clearly assist in illustrating the embodiments of this utility model.

[0023] This application provides a scanning probe microscope, including a laser 1, a probe 2, a position-sensitive detector 3, a camera 4, and a liquid lens 5. The laser 1 emits laser light and uses the probe arm 21 of the probe 2 to reflect the light and form an optical lever, thereby amplifying changes in the position, angle, etc. of the probe arm 21 for the detection of the object 6. The probe 2 includes at least a probe arm 21 and a tip 22. The tip 22 is disposed on the probe arm 21. There is an interaction between the position, angle, and other states of the probe arm 21 and the position, angle, and other states of the tip 22. Therefore, by acquiring changes in the position and angle of the probe arm 21, changes in the position and angle of the tip 21 can be analyzed. When testing the object 6, the tip 22 is brought close to the object 6, forming an interaction force with the surface being tested. This affects the position and angle of the tip 22, which in turn affects the position and angle of the probe arm 21. Therefore, by acquiring the position and angle of the probe arm 21, the interaction force between the tip 21 and the surface being tested can be analyzed, thus enabling the testing of the surface being tested. In some cases, the tip 22 of the probe 2 can also be vibrated. By analyzing the position and angle of the tip 21, the vibration state of the tip 22 can be analyzed, thereby analyzing the interaction force between the tip 22 and the surface being tested. The position-sensitive detector 3 can output a corresponding signal based on the position of the light illuminating it. Combined with the optical lever formed by the laser 1 and the probe 2, it can output a signal that is sensitive to the position, angle, and other states of the needle tip 22, so as to detect the interaction force between the needle tip 22 and the surface of the object being measured 6. The camera 4 and the liquid lens 5 work together to image the positions of the probe arm 21 of the probe 2 and the surface of the object being measured 6, so as to at least observe the probe arm 21 and the surface being measured.

[0024] It should be noted that the interaction force between the needle tip 22 and the surface of the test object 6 includes both the interaction force when they are in contact with each other and the interaction force when they are close to each other; the interaction force can be contact force, van der Waals force, electrostatic force, magnetic force, capillary force, chemical bonding force, friction force, etc., corresponding to different types of test parameters of the test surface of the test object 6.

[0025] The laser 1 emits a beam that passes through the back of the probe arm 21 of the probe 2 and is guided to the position-sensitive detector 3, thereby forming an optical lever that can amplify the position, angle, and other states of the probe tip 22. The position-sensitive detector 3 is configured to generate a corresponding signal at least according to the position of the beam irradiated on it, thereby enabling the optical lever to detect the position, angle, and other states of the probe tip 22, so as to analyze the interaction force between the tip 22 and the measured surface of the object 6, and to analyze the properties of the measured surface of the object 6.

[0026] The liquid lens 5 is disposed in the optical path between the camera 4 and the probe 2, and the liquid lens 5 can switch between at least a first state and a second state:

[0027] When the liquid lens 5 is in the first state, the camera 4 images the probe arm 21 at least through the liquid lens 5;

[0028] When the liquid lens 5 is in the second state, the camera 4 images the object 6 at least through the liquid lens 5.

[0029] The liquid lens 5 can be at least a graded refractive index lens, a liquid-filled lens, or an electrowetting effect lens, and has the characteristic of variable focal length. In this application, by controlling the change of the focal length of the liquid lens 5, the imaging surface of the imaging system composed of the camera 4 and the liquid lens 5 can be switched between the probe arm 21 and the surface under test. Correspondingly, when the focal length of the liquid lens 5 is controlled to reach a first focal length, the liquid lens 5 is in a first state, and the imaging system composed of the camera 4 and the liquid lens 5 can image the probe arm 21. When the focal length of the liquid lens 5 is controlled to reach a second focal length, the liquid lens 5 is in a second state, and the imaging system composed of the camera 4 and the liquid lens 5 can image the surface under test of the object 6.

[0030] The scanning probe microscope provided in this application integrates the observation optical paths of the probe 2 and the object under test 6 into a single optical element, greatly reducing the size of the device. It can switch between imaging the probe arm 21 and the surface under test without moving the optical element, reducing the interference of the imaging effect caused by the movement of the optical element. The switching of the first focal length and the second focal length of the liquid lens 5 can be achieved through electrical signals or mechanical movement. During the focal length switching process, the switching speed of the liquid lens 5 is significantly faster than that achieved by moving the optical element, which can quickly complete the switching of the imaging object and improve the efficiency of use. The focal length of the liquid lens 5 can be continuously changed. In some cases, the first focal length and the second focal length can be adjusted as needed to match different surfaces under test and the position of the probe arm 21, thereby increasing the applicability of the scanning probe microscope.

[0031] Please compare and refer to the following: Figure 1 , Figure 2 The diagram illustrates a feasible implementation of the liquid lens 5 in a first state and a second state. Please refer to [link / reference needed]. Figure 1 When the focal length of the liquid lens 5 is at the first focal length, the liquid lens 5 is in the first state. Light reflected from the probe arm 21 passes through the liquid lens 5 and enters the camera 4, forming an image of the probe arm 21 in the camera 4. The light entering the camera 4 after passing through the liquid lens 5 can be at least a portion of the ambient light reflected by the probe arm 21, or at least a portion of the light beam emitted by the laser source 1 reflected by the probe arm 21. (See also...) Figure 2 When the focal length of the liquid lens 5 is at the second focal length, the liquid lens 5 is in the second state. The light reflected from the surface of the object under test 6 passes through the liquid lens 5 and enters the camera 4, forming an image of the probe arm 21 in the camera 4. The light entering the camera 4 through the liquid lens 5 can be at least a portion of the ambient light reflected from the surface of the object under test 6.

[0032] In some cases, an illumination source can be further provided in the scanning probe microscope provided in this application to illuminate the probe 2 and the object 6, so as to increase the amount of light reflected from at least part of the probe 2 and the object 6 and entering the camera 4, thereby improving the imaging effect and reducing noise.

[0033] For a more feasible implementation method, please refer to Figures 1 to 4 The camera 4 and liquid lens 5 can be set along a direction perpendicular to the surface of the object being measured 6. Specifically, the camera 4 and liquid lens 5 are set along axis A, which is perpendicular to the surface of the object being measured 6. It should be noted that in some cases, the direction of the surface of the object being measured 6 is generally parallel to the direction of the bearing surface of the sample carrier 7. Correspondingly, when the object being measured 6 is not set, the camera 4 and liquid lens 5 can be configured such that they are set along a direction perpendicular to the bearing surface of the sample carrier 7, so that after the object being measured 6 is placed on it, the camera 4 and liquid lens 5 can be set along a direction perpendicular to the surface of the object being measured 6.

[0034] The incident surface of the beam emitted by laser 1 and incident on probe arm 21 can be either parallel to probe arm 21 or at a certain angle to probe arm 21. For details, please refer to... Figure 1 , Figure 2 This illustrates a beam incident on probe arm 21 with its incident surface forming an angle with the probe arm 21, for example, a right angle. See also... Figure 3 This illustrates a form in which the incident surface of the beam of the incident probe arm 21 is parallel to the probe arm 21.

[0035] In some cases, the scanning probe microscope provided in this application may also include an objective lens 9, and the camera 4 may image the object 6 at least through the liquid lens 5 and the objective lens 9, and the optical path formed by the camera 4, the liquid lens 5 and the objective lens 5 may be adjusted through the objective lens 9 to meet the corresponding imaging requirements. For example, in some cases, the image may be formed of a tiny probe 2, or the image may be formed of a tiny measured position of the object 6.

[0036] In some cases, the optical path can be configured to meet response requirements. For example, a scanning probe microscope may also include a beam splitter 8, through which the beam emitted by the laser 1 passes and illuminates the probe arm 21; the camera 4 images the object 6 at least via the liquid lens 5 and the beam splitter 8. In this way, the optical path corresponding to the beam emitted by the laser 1 and the optical path corresponding to the imaging of the object 6 by the camera 4 and the liquid lens 5 are at least partially shared, thereby reducing the volume of the optical path. Please refer to [reference needed]. Figure 4 The beam emitted by the laser 1 passes through the beam splitter 8 to illuminate the probe arm 21. After being reflected by the probe arm 21, it can either be directly transmitted to the position-sensitive detector 3, or it can be guided to the position-sensitive detector 3 by the beam splitter 8 and other lenses.

[0037] Please see Figure 4 This illustrates an implementation that simultaneously uses objective lens 9 and beam splitter 8. The beam emitted by laser 1 is irradiated onto probe arm 21 through beam splitter 8 and objective lens 9. During this process, objective lens 9 can concentrate the beam. The beam reflected by objective lens 9 and emitted by laser 1 directly irradiates position-sensitive detector 3 for detecting the surface of the object under test 6. When liquid lens 5 is in the first state, the ambient light reflected by probe arm 21 and / or the light emitted by laser 1 is incident on camera 4 through objective lens 9, beam splitter 8, and liquid lens 5, enabling camera 4 to image probe arm 21. When liquid lens 5 is in the second state, the ambient light reflected by object under test 6 is incident on camera 4 through objective lens 9, beam splitter 8, and liquid lens 5, enabling camera 4 to image object under test 6.

[0038] In some cases, when the liquid lens 5 is in the first state, the beam emitted by the laser 1 illuminates the position of the probe arm 21, which is within the focal depth range that allows the camera 4 to image the beam. This allows the camera 4 to observe the position of the beam emitted by the laser 1 on the probe arm 21, so as to adjust the optical path of the beam emitted by the laser 1 to meet the detection requirements.

[0039] In some cases, when the liquid lens 5 is in the second state, the measured position of the object 6 is within the depth of focus range that enables the camera 4 to image it, so that the measured surface of the object 6 can be observed through the camera 4 to determine the measured position and thus meet the detection requirements.

[0040] In some cases, the relative positions of the liquid lens 5 and the camera 4 can be fixed to facilitate the installation of the optical path without affecting the adjustment of the optical path.

[0041] In some cases, the scanning probe microscope may also include a sample carrier 7, which has a carrier surface capable of supporting the test object 6. In some cases, the sample carrier 6 may also be configured to move the test object 6. As a feasible implementation, the sample carrier 6 may be a displacement stage, with the test object 6 placed on the moving end of the displacement stage, thereby moving the test object 6 using the displacement stage. In some cases, the displacement stage may be a piezoelectric displacement stage or other types of precision displacement stage to precisely adjust the position of the test object 6. In some cases, it may be used to gradually move the position on the test surface of the test object 6 that generates an interaction force with the probe tip 22, thereby detecting multiple positions on the test surface of the test object 6. In some cases, scanning detection of the test surface of the test object 6 can be achieved.

[0042] In some cases, the scanning probe microscope provided in this application may also include an analysis device. This analysis device is at least communicatively connected to the position-sensitive detector 3 to receive signals output by the position-sensitive detector 3 and to analyze the properties of the measured surface of the object 6. The communication connection can be achieved through an electrical connection to transmit signals; alternatively, the analysis device and the position-sensitive detector 3 can be installed separately on a signal transmission device, with the signal transmission device facilitating signal transmission between them. The analysis device can be either wired or wirelessly connected. Specific implementations can be adjusted based on the concept of this application, and will not be elaborated further here.

[0043] The basic principles, main features, and advantages of this utility model have been shown and described above. Therefore, the above are merely embodiments of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are only the principles of this utility model. Without departing from the spirit and scope of this utility model, this utility model also includes various equivalent changes and modifications, all of which fall within the scope of this utility model as claimed.

Claims

1. A scanning probe microscope, characterized by: The system includes a laser, a probe, a position-sensitive detector, a camera, and a liquid lens. The laser emits a beam that passes through the back of the probe arm of the probe and is guided to the position-sensitive detector, which is configured to generate a corresponding signal based at least on the position of the beam incident upon it. The liquid lens is disposed in the optical path between the camera and the probe, and is capable of switching between at least a first state and a second state. When the liquid lens is in the first state, the camera images the probe arm at least through the liquid lens; When the liquid lens is in the second state, the camera images the object being measured at least through the liquid lens.

2. A scanning probe microscope as claimed in claim 1, characterized in that: The camera and liquid lens are positioned along a direction perpendicular to the surface of the object being measured.

3. A scanning probe microscope as claimed in claim 1, characterized in that: The scanning probe microscope also includes an objective lens, and the camera images the object under test through at least the liquid lens and the objective lens.

4. A scanning probe microscope as claimed in claim 1, characterized in that: The scanning probe microscope also includes a beam splitter, through which the beam emitted by the laser passes and illuminates the probe arm; the camera images the object under test at least through the liquid lens and the beam splitter.

5. A scanning probe microscope as claimed in claim 1, characterized in that: When the liquid lens is in the first state, the beam emitted by the laser illuminates the position of the probe arm, which is within the depth of focus range that enables the camera to image.

6. A scanning probe microscope as described in claim 1, characterized in that: When the liquid lens is in the second state, the measured position of the object is within the depth of focus range that enables the camera to image it.

7. A scanning probe microscope as described in claim 1, characterized in that: The relative positions of the liquid lens and the camera are fixed.

8. A scanning probe microscope as described in claim 1, characterized in that: The scanning probe microscope also includes a sample carrier device, which has a carrier surface capable of supporting the object being tested.

9. A scanning probe microscope as described in claim 8, characterized in that: The sample carrier is configured to move the object being tested.

10. A scanning probe microscope as described in claim 1, characterized in that: The scanning probe microscope also includes an analysis device, which is at least communicatively connected to the position-sensitive detector.

Images