Device and method for in-situ temperature measurement and calibration based on atomic force microscope

Abstract

The invention discloses a device and a method for in-situ temperature measurement and calibration based on an atomic force microscope. The device comprises the atomic force microscope, a three-dimensional displacement console and a laser displacement sensor, wherein the atomic force microscope is provided with a micro-cantilever beam and a probe, and the probe is fixedly connected with the micro-cantilever beam; the atomic force microscope with the micro-cantilever is placed on the three-dimensional displacement console, and the three-dimensional displacement console is used for controlling the micro-cantilever to enable the probe to be in contact with the substrate to be measured; the laser displacement sensor is arranged above the micro-cantilever and used for measuring the deflection degree of the micro-cantilever, recording the temperature of the substrate to be measured and obtaining the corresponding relation between the deflection degree of the micro-cantilever and the temperature of the substrate to be measured. According to the invention, in-situ measurement and calibration of accurate positions of regional temperatures of different substrates are realized.

Description

Technical Field

[0001] The present invention relates to the technical field of temperature measurement, and in particular to a device and method for in-situ temperature measurement and calibration based on an atomic force microscope. Background Art

[0002] Atomic force microscopy (AFM) is a type of scanning probe microscope. AFM does not require a conductive circuit to be formed between the probe and the sample, thus breaking through the limitation of sample conductivity, making it more widely used in scientific research applications. When scanning an image, the AFM tip gently contacts the sample surface, and there is a weak interaction force between the atoms at the tip of the tip and the atoms on the sample surface, which causes a slight change in the cantilever. This slight change is detected and used as feedback to keep the force constant, so that the position change of the microcantilever corresponding to each scanning point can be obtained, thereby obtaining an image of the sample surface morphology.

[0003] Temperature measurement technology is of great significance not only in processing and production but also in equipment maintenance. However, the current contact temperature measurement technology cannot accurately measure the temperature changes of micro-nano-scale points, and it is difficult to achieve measurement without affecting the original temperature field of the object to be measured. The AFM probe is controlled to contact the substrate to be measured in contact mode. Heat transfer occurs between the substrate and the probe, causing the probe temperature to rise, thereby causing thermal expansion of the probe. At the same time, due to the contact between the probe and the substrate, the reaction force generated by the thermal expansion will cause the micro-cantilever to be slightly deflected. At the same time, a high-precision laser displacement sensor is used to measure the deflection degree of the micro-cantilever. When the heat transfer reaches a steady state, the thermal expansion stops, and the micro-cantilever no longer deflects. The relationship between the substrate temperature and the cantilever deflection degree can be obtained. The one-to-one correspondence between the deflection displacement and the measured temperature can complete the in-situ temperature measurement and calibration of the probe and any material substrate.

[0004] Patent CN109297606A discloses a temperature calibration device for an infrared thermal imaging temperature measurement component. With this invention, there is no need to move the position of the black body when calibrating the temperature. It is only necessary to rotate the adapter plate, thereby improving the efficiency of calibration. Multiple temperature measurement components can be fixed circumferentially on the adapter plate, and multiple calibration processes can be completed in one temperature rise and fall process, thereby improving the efficiency of calibration. Patent CN1451957A discloses a distributed optical fiber temperature measurement system and method based on double-end temperature calibration, including a temperature-sensitive optical fiber, a distributed optical fiber temperature measurement host, a temperature calibration system, and a temperature correction host. This invention solves the problem of poor accuracy at the end of the optical fiber by performing temperature calibration at the head and end of the optical fiber, thereby extending the coverage length of the distributed optical fiber temperature measurement. None of the above inventions can achieve in-situ precise point temperature measurement and calibration at the micro-nano scale. Summary of the invention

[0005] The purpose of the present invention is to provide a device and method for in-situ temperature measurement and calibration based on an atomic force microscope, which realizes in-situ precise point temperature measurement and calibration of substrate temperature using an atomic force microscope probe.

[0006] The above technical problems of the present invention are mainly solved by the following technical solutions:

[0007] A device for in-situ temperature measurement and calibration based on an atomic force microscope, comprising an atomic force microscope, a three-dimensional displacement console and a laser displacement sensor;

[0008] The atomic force microscope is provided with a micro cantilever and a probe, and the probe is fixedly connected to the micro cantilever; the atomic force microscope with the micro cantilever is placed on a three-dimensional displacement console, and the three-dimensional displacement console is used to control the micro cantilever so that the probe comes into contact with the substrate to be measured;

[0009] The laser displacement sensor is arranged above the micro-cantilever beam to measure the deflection degree of the micro-cantilever beam, record the temperature of the substrate to be measured, and obtain the corresponding relationship between the deflection degree of the micro-cantilever beam and the temperature of the substrate to be measured.

[0010] Furthermore, when measuring the deflection degree of the micro-cantilever beam, the atomic force microscope adopts a contact mode.

[0011] Furthermore, the control part of the three-dimensional displacement control console is controlled by piezoelectric ceramics, and the adjustment accuracy range is 0 to 50 nanometers.

[0012] Furthermore, the tip radius of the atomic force microscope is in the range of 5 to 30 nm, the probe tilt angle is in the range of 5° to 30°, and the material is semiconductor.

[0013] Furthermore, the accuracy of the laser displacement sensor is at nanometer level.

[0014] Furthermore, the size of the micro cantilever is in micrometer order.

[0015] Furthermore, the micro cantilever beam material is a semiconductor.

[0016] In another aspect, the present invention provides a method for in-situ temperature measurement and calibration based on an atomic force microscope, comprising the following steps:

[0017] Step S1. Fixing the atomic force microscope on a three-dimensional displacement console;

[0018] Step S2. heating the substrate to a set temperature;

[0019] Step S3. Turn on the laser displacement sensor to monitor the deflection displacement of a certain point of the micro-cantilever beam in real time;

[0020] Step S4. adjusting the three-dimensional displacement control console so that the atomic force microscope forms a contact mode with the substrate to be measured;

[0021] Step S5. Heat transfer occurs between the substrate to be measured and the probe, causing the probe temperature to rise, thereby causing thermal expansion of the probe. At the same time, since the probe is in contact with the substrate to be measured, the reaction force generated by the thermal expansion will cause the micro-cantilever beam to deflect;

[0022] Step S6. When the displacement monitored by the laser displacement sensor does not change, the deflection displacement of the micro-cantilever beam corresponding to the substrate temperature is recorded;

[0023] Step S7. Repeat steps S1 to S6 to obtain a plurality of sets of correspondences between micro-cantilever beam deflection displacement and substrate temperature;

[0024] Step S8. Draw a calibration curve based on the corresponding relationship between the micro-cantilever beam deflection displacement and the substrate temperature obtained in step S7, and complete the calibration of the temperature measurement of the probe and the substrate of the material;

[0025] Step S9: The calibration curve obtained in step S8 is used for temperature measurement of a substrate with unknown temperature.

[0026] Furthermore, the step S9 includes the following steps:

[0027] Step S91. Fixing the atomic force microscope on the three-dimensional displacement console;

[0028] Step S92. heating the substrate to an unknown temperature;

[0029] Step S93. Turn on the laser displacement sensor to monitor the deflection displacement of a certain point of the micro-cantilever beam in real time;

[0030] Step S94. adjusting the three-dimensional displacement control console so that the atomic force microscope forms a contact mode with the substrate to be measured;

[0031] Step S95. When the deflection displacement of the micro-cantilever beam monitored by the laser displacement sensor no longer changes, the corresponding deflection displacement magnitude at the substrate temperature is recorded;

[0032] Step S96: Compare the measured deflection displacement with the calibration curve in step S8 to obtain the temperature of a certain point on the substrate to be measured.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] 1. The present invention controls the contact mode of the AFM probe, and heat transfer occurs between the substrate and the probe, causing the probe temperature to rise, thereby causing thermal expansion of the probe. At the same time, due to the contact between the probe and the substrate, the reaction force generated by the thermal expansion will cause the micro-cantilever to be slightly deflected. At the same time, a high-precision laser displacement sensor is used to measure the degree of deflection of the micro-cantilever, and the relationship between the substrate temperature and the degree of deflection of the cantilever can be obtained. The one-to-one correspondence between the deflection displacement and the measured temperature can complete the in-situ temperature measurement and calibration of the probe and any material substrate, which is a high-precision temperature measurement and calibration technology;

[0035] 2. Since the present invention adopts an AFM probe, it can realize the temperature measurement of a certain point at the micro-nano scale, and since the tip of the probe is very small, when the contact mode is adopted, it has almost no effect on the original temperature field of the object to be measured.

[0036] 3. Thanks to the high-precision laser displacement sensor, the deflection of the micro-cantilever beam can be accurately monitored in real time, thereby obtaining accurate deflection displacement and steady-state temperature curves.

[0037] 4. The present invention is easy to operate, has simple equipment, and can be used for temperature measurement of substrates of the same material after calibration, thus greatly reducing the workload. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 Schematic diagram of the structure of an apparatus for in-situ temperature measurement and calibration based on an atomic force microscope according to an embodiment of the present invention.

[0039] Figure 2 The present invention is a flowchart of an apparatus for in-situ temperature measurement and calibration based on an atomic force microscope according to an embodiment of the present invention.

[0040] Figure 3 Schematic diagram of a cantilever beam based on an atomic force microscope according to an embodiment of the present invention.

[0041] Figure 4 Schematic diagram of temperature distribution and thermal expansion of the needle tip during the experiment of the embodiment of the present invention.

[0042] Figure 5 Schematic diagram of the change trend of the temperature of the needle tip with the displacement of the cantilever beam during the experiment of the embodiment of the present invention.

[0043] In the figure: 1- three-dimensional displacement control console; 2- high-precision laser displacement sensor; 3- micro cantilever beam; 4- probe; 5- substrate. DETAILED DESCRIPTION

[0044] In order to make the technical problems, technical solutions and beneficial effects to be solved by the embodiments of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0045] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of 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 cannot be understood as a limitation on the present invention.

[0046] In the description of the present invention, unless otherwise specified, the term "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0047] The implementation process of the present invention is further described in detail below with reference to specific drawings and examples.

[0048] Example 1

[0049] See also Figure 1 This embodiment provides an in-situ temperature measurement and calibration device based on an atomic force microscope (AFM), comprising a three-dimensional displacement control console 1, a high-precision laser displacement sensor 2, a micro cantilever beam 3, an AFM probe 4 and a substrate 5. Figure 3 As shown, the probe 4 is fixedly connected to the micro-cantilever 3, the micro-cantilever 3 and the AFM probe 4 are fixed on the three-dimensional displacement console 1, the three-dimensional displacement console 1 is adjusted to make the probe 3 contact with the substrate 5, the substrate 5 and the probe 3 transfer heat, so that the temperature of the probe increases, resulting in thermal expansion, and the reaction force generated by the thermal expansion will cause the micro-cantilever 3 to deflect, and the high-precision laser displacement sensor 2 monitors the degree of deflection of the micro-cantilever 3 in real time. When a steady state is reached, the thermal expansion of the probe 3 stops, that is, the deflection of the micro-cantilever 3 stops, and the deflection displacement at this time is recorded, which corresponds to the temperature of the substrate sample.

[0050] In the above embodiment, the atomic force microscope adopts the contact mode; the control part of the three-dimensional displacement control console is controlled by piezoelectric ceramics, and the adjustment accuracy is 10 nanometers; the tip radius of the atomic force microscope is 10nm, the probe tilt angle is 10°, and the material is silicon. The atomic force microscope will transfer heat with the substrate, and the temperature rise will cause thermal expansion, and the reaction force will cause the micro cantilever beam to deflect. Figure 4The figure shows the temperature distribution and thermal expansion diagram of the needle tip after the needle tip is heated and expanded. The temperature at the tip of the needle tip is the highest and the thermal expansion distance is the largest. The temperature decreases along the root of the needle tip, and the thermal expansion distance also decreases. The reaction force will cause the micro cantilever beam to deflect.

[0051] Example 2

[0052] like Figure 2 , this embodiment provides a method for in-situ temperature measurement and calibration based on atomic force microscopy (AFM):

[0053] Step S1. Fixing the atomic force microscope on a three-dimensional displacement console;

[0054] Step S2. heating the substrate to a specific temperature;

[0055] Step S3. Turn on the high-precision laser displacement sensor to monitor the deflection displacement of a certain point of the micro-cantilever beam in real time;

[0056] Step S4. adjusting the three-dimensional displacement control console so that the atomic force microscope forms a contact mode with the substrate to be measured;

[0057] Step S5. Heat transfer occurs between the substrate and the probe, causing the probe temperature to rise, thereby causing thermal expansion of the probe. At the same time, due to the contact between the probe and the substrate, the reaction force generated by the thermal expansion will cause the micro-cantilever beam to be slightly deflected;

[0058] Step S6. When the displacement monitored by the high-precision laser displacement sensor does not change, it indicates that the heat transfer has reached a steady state, and the corresponding deflection displacement size at the substrate temperature is recorded;

[0059] Step S7: Repeat steps S1 to S6 until enough corresponding relationships between deflection displacement and temperature are calibrated.

[0060] Step S8: Plot a curve based on the data obtained in step S7, thereby completing the calibration of the temperature measurement of the probe and the material substrate.

[0061] Step S9: The calibration curve obtained in step S8 is used for temperature measurement of a substrate with unknown temperature.

[0062] In the above embodiment, the device and method for in-situ temperature measurement and calibration based on atomic force microscopy (AFM) described in step S9 include the following steps:

[0063] Step S91. Fixing the atomic force microscope on the three-dimensional displacement console;

[0064] Step S92. heating the substrate to an unknown temperature;

[0065] Step S93. Turn on the high-precision laser displacement sensor to monitor the deflection displacement of a certain point of the micro-cantilever beam in real time;

[0066] Step S94. adjusting the three-dimensional displacement control console so that the atomic force microscope forms a contact mode with the substrate to be measured;

[0067] Step S95. Heat transfer occurs between the substrate and the probe, causing the probe temperature to rise, thereby causing thermal expansion of the probe. At the same time, due to the contact between the probe and the substrate, the reaction force generated by the thermal expansion will cause the micro-cantilever beam to be slightly deflected. When the displacement monitored by the high-precision laser displacement sensor is no longer changing, it indicates that the heat transfer has reached a steady state. The corresponding deflection displacement size at the substrate temperature is recorded; as shown in Table 1:

[0068] Table 1 Corresponding table of deflection displacement size at substrate temperature

[0069] Temperature ℃ Displacement nm 20 2.5 40 5.35 60 8.46 80 11.81 100 15.36 150 24.89 200 35.09 250 45.74 300 56.66 350 67.77 400 79.01 450 90.37 500 101.8

[0070] Step S96: Compare the measured deflection displacement with the calibration curve in step S8 to obtain the temperature of a precise point on the substrate to be measured. Figure 5 The figure shows the relationship between the deflection displacement and temperature. Figure 5 The temperature of a certain point on the substrate to be measured can be obtained by comparing with the calibration curve.

[0071] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

[0072] The above are only preferred embodiments of the present invention, and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the contents of the specification of the present invention should be included in the protection scope of the present invention.

Claims

1. A device for in-situ temperature measurement and calibration based on atomic force microscopy, characterized in that: Includes atomic force microscope, three-dimensional displacement console and laser displacement sensor; The atomic force microscope is provided with a micro cantilever and a probe, and the probe is fixedly connected to the micro cantilever; the atomic force microscope with the micro cantilever is placed on a three-dimensional displacement console, and the three-dimensional displacement console is used to control the micro cantilever so that the probe comes into contact with the substrate to be measured; The laser displacement sensor is arranged above the micro-cantilever beam to measure the deflection degree of the micro-cantilever beam, record the temperature of the substrate to be measured, and obtain the corresponding relationship between the deflection degree of the micro-cantilever beam and the temperature of the substrate to be measured.

2. The device for in-situ temperature measurement and calibration based on atomic force microscopy according to claim 1, characterized in that: When measuring the deflection degree of the micro-cantilever, the atomic force microscope adopts the contact mode.

3. The device for in-situ temperature measurement and calibration based on atomic force microscopy according to claim 1, characterized in that: The control part of the three-dimensional displacement control console is controlled by piezoelectric ceramics, and the adjustment accuracy range is 0 to 50 nanometers.

4. The device for in-situ temperature measurement and calibration based on atomic force microscopy according to claim 1, characterized in that: The probe radius of the atomic force microscope is in the range of 5 to 30 nm, the probe tilt angle is in the range of 5° to 30°, and the material is semiconductor.

5. The device for in-situ temperature measurement and calibration based on atomic force microscopy according to claim 1, characterized in that: The accuracy of the laser displacement sensor is at nanometer level.

6. The device for in-situ temperature measurement and calibration based on atomic force microscopy according to claim 1, characterized in that: The size of the micro cantilever is in micrometer order. 7 . The device for in-situ temperature measurement and calibration based on atomic force microscopy according to claim 1 , wherein the micro-cantilever beam material is a semiconductor.

8. The method for in-situ temperature measurement and calibration device based on atomic force microscopy according to any one of claims 1 to 7, characterized in that: The steps include: Step S1. Fixing the atomic force microscope on a three-dimensional displacement console; Step S2. heating the substrate to a set temperature; Step S3. Turn on the laser displacement sensor to monitor the deflection displacement of a certain point of the micro-cantilever beam in real time; Step S4. adjusting the three-dimensional displacement control console so that the atomic force microscope forms a contact mode with the substrate to be measured; Step S5. Heat transfer occurs between the substrate to be measured and the probe, causing the probe temperature to rise, thereby causing thermal expansion of the probe. At the same time, since the probe is in contact with the substrate to be measured, the reaction force generated by the thermal expansion will cause the micro-cantilever beam to deflect; Step S6. When the displacement monitored by the laser displacement sensor does not change, the deflection displacement of the micro-cantilever beam corresponding to the substrate temperature is recorded; Step S7. Repeat steps S1 to S6 to obtain a plurality of sets of correspondences between micro-cantilever beam deflection displacement and substrate temperature; Step S8. Draw a calibration curve based on the corresponding relationship between the micro-cantilever beam deflection displacement and the substrate temperature obtained in step S7, and complete the calibration of the temperature measurement of the probe and the substrate of the material; Step S9: The calibration curve obtained in step S8 is used for temperature measurement of a substrate with unknown temperature.

9. The method for in-situ temperature measurement and calibration based on atomic force microscopy according to claim 8, characterized in that: The step S9 comprises the following steps: Step S91. Fixing the atomic force microscope on the three-dimensional displacement console; Step S92. heating the substrate to an unknown temperature; Step S93. Turn on the laser displacement sensor to monitor the deflection displacement of a certain point of the micro-cantilever beam in real time; Step S94. adjusting the three-dimensional displacement control console so that the atomic force microscope forms a contact mode with the substrate to be measured; Step S95. When the deflection displacement of the micro-cantilever beam monitored by the laser displacement sensor no longer changes, the corresponding deflection displacement magnitude at the substrate temperature is recorded; Step S96: Compare the measured deflection displacement with the calibration curve in step S8 to obtain the temperature of a certain point on the substrate to be measured.

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