CN111649693A - A kind of sample topography measuring device and method - Google Patents

Abstract

The present disclosure provides a sample topography measurement device and method. The device comprises: a light source component (101), an illumination component (102), a projection grating component (103), a diaphragm component (104), a projection optical component (105), and a detection optical component (105) arranged in sequence. 107), a detection grating assembly (108), a data acquisition assembly (109), and a moving stage (110) disposed on the optical path between the projection optical assembly (105) and the detection optical assembly (107), and the sample to be tested (106) Placed on the exercise table (110). The aperture component is used to screen out the low diffraction order signal to measure the sample height to ensure the measurement range, and the high diffraction order signal is selected according to the measurement result to measure the sample height again to improve the measurement accuracy.

Description

A kind of sample topography measuring device and method

technical field

The present disclosure relates to a reflective sample topography measuring device and method.

Background technique

In the fields of optical processing, optical inspection, electron beam imaging, and lithography, it is often necessary to precisely control the position information of the sample in the Z direction (height direction). To ensure that the sample is always in the ideal position, it is necessary to precisely measure the surface topography of the sample. When measuring the high-precision topography of the sample surface, although the scanning electron microscope and the atomic force microscope have high measurement resolution, their measurement speed is slow, and the requirements for the measurement environment are harsh, so they are not suitable for online measurement. Optical non-contact measurement has become the main method of online measurement due to its fast measurement speed and high resolution.

In the related art, in the optical measurement method of the surface topography of the sample, the topography information of the sample is mainly obtained by imaging the projection grating and the imaging grating to form moire fringes. In this technology, the measurement accuracy is improved by using grating marks with small periods, but the measurement range is small. In order to cover the thickness tolerance range of the sample to be measured, the period of the grating marks cannot be too small. In addition, since only low diffraction orders are used, the nonlinear effect of the measurement signal is greater, especially when the projection grating error and the aberration of the imaging optical system are seriously affected. How to reduce the nonlinearity of the measurement signal and improve the measurement accuracy under the condition of ensuring the measurement range is a problem that researchers are concerned about at present.

SUMMARY OF THE INVENTION

(1) Technical problems to be solved

In view of the above problems, the present disclosure provides a sample topography measurement device and method, which utilizes a diaphragm to select and measure a signal of a required diffraction order, and improves measurement accuracy on the basis of ensuring the measurement range.

(2) Technical solutions

One aspect of the present disclosure provides a sample topography measurement device, the device includes: a light source component 101, an illumination component 102, a projection grating component 103, a diaphragm component 104, and a projection optical component 105, which are arranged in sequence. The detection optical assembly 107 , the detection grating assembly 108 , the data acquisition assembly 109 , and the moving stage 110 arranged on the optical path between the projection optical assembly 105 and the detection optical assembly 107 , and the sample to be tested 106 is placed on the moving stage 110 ; wherein, the illumination component 102 uses the measurement light generated by the light source component 101 to illuminate the projection grating component 103 to generate a multi-diffraction order signal; the diaphragm component 104 filters out the multi-diffraction order signal in the the zero-order signal, and filter out the first diffraction order signal, the first diffraction order signal includes +m diffraction order signal and -m diffraction order signal, m is an integer greater than 0; the projection optical component 105 Image the image of the projection grating assembly 103 under the first diffraction order signal onto the surface of the sample to be tested 106; the detection optical assembly 107 images the image of the projection grating assembly 103 carrying the first height information of the sample to be tested 106 to the detection On the grating assembly 108, the first height information of the sample to be tested 106 is obtained through the data acquisition assembly 109; the diaphragm assembly 104 is further used to filter out the second diffraction order signal according to the first height information, and the second The diffraction order signal includes +n diffraction order signal and -n diffraction order signal, n>m; the projection optical component 105 is also used to image the image of the projection grating component 103 under the second diffraction order signal to the to-be-measured The surface of the sample 106; the detection optical component 107 images the image of the projection grating component 103 carrying the second height information of the sample 106 to be tested onto the detection grating component 108, and obtains the second height of the sample 106 to be tested through the data acquisition component 109 information.

Optionally, the moving stage 110 is configured to move in a plane perpendicular to the height direction of the sample to be tested 106 , so that the data acquisition component 109 obtains the topographic information of the sample to be tested 106 .

Optionally, the period of the detection grating component 108 is smaller than the period of the projection grating component 103 .

Optionally, the detection grating assembly 108 separates the image of the projection grating assembly 103 carrying the first height information or the second height information of the sample 106 to be tested into a first imaging and a second imaging, the first imaging and the second imaging. The distance between the two images is 1/4 of the period of the projection grating assembly 103 .

Optionally, the center of the detection grating assembly 108 is offset from the center of the projection grating assembly 103 by 1/8 of the period of the projection grating assembly 103 .

Optionally, the projection optical component 105 and the detection optical component 107 are reflective components or transmissive components, the diaphragm component 104 is arranged on the aperture diaphragm surface of the projection optical component 105, and the sample morphology The measuring device is a double telecentric measuring device.

Optionally, the projection grating component 103 is an amplitude grating for enhancing the intensity of the first diffraction order signal or the second diffraction order signal.

Optionally, the projection grating component 103 is an array composed of a plurality of projection gratings, so as to measure the first height information or the second height information at multiple positions of the sample to be tested 106 at the same time.

Optionally, the angle θ of the measurement light irradiated on the projection grating assembly 103 satisfies:

Wherein, d is the period of the projection grating assembly 103 , and λ is the minimum wavelength of the measurement light irradiated on the projection grating assembly 103 .

Another aspect of the present disclosure provides a method for measuring the topography of a sample to be measured by using the above-mentioned sample topography measuring device, the method comprising:

The data acquisition component 109 calculates the first height information at a position of the sample to be measured 106 according to the acquired transmission intensities of the two images separated by the detection grating component 108, and the obtained first height information is:

Wherein, h ₁ is the first height information, d is the period of the projection grating assembly 103, m is the diffraction order of the first diffraction order signal screened by the diaphragm assembly 104, and α is the incident signal to the sample to be measured The angles of the light rays of 106, I ₁ and I ₂ are respectively the transmission intensities of the two images separated by the detection grating assembly 108 when the diaphragm assembly 104 filters out the first diffraction order signal;

The diaphragm assembly 104 screens the second diffraction order signal according to the first height information, and the data acquisition assembly 109 calculates the position of the sample to be measured 106 according to the acquired transmission intensities of the two images separated by the detection grating assembly 108 The second height information at , the obtained second height information is:

Wherein, h ₂ is the second height information, n is the diffraction order of the second diffraction order signal screened by the diaphragm assembly 104 , n>m, and I ₃ and I ₄ are the first diffraction orders screened out by the diaphragm assembly 104 , respectively. Detecting the transmission intensities of the two images separated by the grating assembly 108 when there are two diffraction orders;

The moving stage 110 is moved in a plane perpendicular to the height direction of the sample to be tested 106 , and the data acquisition component 109 calculates any position of the sample to be tested 106 according to the acquired transmission intensities of the two images separated by the detection grating component 108 The second height information is obtained to obtain the topography information of the sample 106 to be tested.

(3) Beneficial effects

The sample topography measurement device and method provided by the embodiments of the present disclosure have the following beneficial effects:

(1) Use the diaphragm assembly to screen out the low diffraction order signal to measure the sample height to ensure the measurement range, and select the high diffraction order signal according to the measurement result to measure the sample height again to improve the measurement accuracy;

(2) The aperture component filters out the zero-order signal, reduces the fringe interval of the projected grating image, improves the signal contrast, and further reduces the fringe interval of the projected grating image by selecting the high diffraction order signal, and improves the measurement accuracy;

(3) The period of the detection grating component is set to be smaller than the period of the projection grating component, so as to ensure the interference of high diffraction order signals.

Description of drawings

FIG. 1 schematically shows a schematic structural diagram of a sample topography measurement device provided by an embodiment of the present disclosure;

FIG. 2 schematically shows a schematic structural diagram of a sample topography measurement device provided by another embodiment of the present disclosure;

FIG. 3A and FIG. 3B respectively schematically show schematic diagrams of measurement signals corresponding to different diffraction orders.

Description of reference numbers:

101-light source assembly; 102-illumination assembly; 103-projection grating assembly; 104-diaphragm assembly; 105-projection optical assembly; 106-sample to be tested; 107-detection optical assembly; 108-detection grating assembly; 109-data acquisition Component; 110 - Motion table.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present disclosure clearer, the present disclosure will be further described in detail below with reference to the specific embodiments and the accompanying drawings.

FIG. 1 schematically shows a schematic structural diagram of a sample topography measurement device provided by an embodiment of the present disclosure. Referring to FIG. 1 , and in conjunction with FIGS. 2 to 3B , the sample topography measuring device in this embodiment will be described in detail.

Referring to FIG. 1 , the sample topography measurement device includes a light source assembly 101, an illumination assembly 102, a projection grating assembly 103, a diaphragm assembly 104, and a projection optical assembly 105, and a detection optical assembly 107 and a detection grating assembly arranged in sequence. 108 , a data acquisition assembly 109 , and a moving stage 110 disposed on the optical path between the projection optical assembly 105 and the detection optical assembly 107 , and the sample to be tested 106 is placed on the moving stage 110 .

The light source assembly 101 is used to generate measurement light to provide the device with measurement light. The spot size and numerical aperture of the measurement light generated by the light source assembly 101 should meet the illumination requirements of the lighting assembly 102, and should have high energy stability and uniformity. The light source assembly 101 is, for example, a high pressure mercury lamp, a white light emitting diode (Light Emitting Diode, LED) or the like.

The illumination component 102 is used for illuminating the projection grating component 103 with the measurement light generated by the light source component 101, so as to generate a multi-diffraction order signal. The multi-diffraction order signal includes optical signals of multiple diffraction orders, for example, including the 0th diffraction order signal, the ±1st diffraction order signal, the ±2nd diffraction order signal, ..., the ±Nth diffraction order signal Wait.

The projection grating component 103 is an amplitude grating for enhancing the intensity of the first diffraction order signal or the second diffraction order signal. The first diffraction order signal and the second diffraction order signal are the signals screened by the diaphragm assembly 104, the first diffraction order signal includes the +m diffraction order signal and the -m diffraction order signal, and m is an integer greater than 0 , the second diffraction order signal includes +n diffraction order signal and -n diffraction order signal, n>m. Amplitude grating refers to an optical element that can generate periodic spatial modulation of the amplitude of incident light, which can be used to enhance the amplitude of the first diffraction order signal or the second diffraction order signal, thereby enhancing the first diffraction order signal or the second diffraction order signal. The intensity of the diffracted order signal. For example, the projection grating component 103 is used to enhance the intensity of the ±5th diffraction order signal, and the ±5th diffraction order signal is the first diffraction order signal or the second diffraction order signal.

In this embodiment, the angle θ of the measurement light irradiated on the projection grating assembly 103 satisfies:

Wherein, d is the period of the projection grating assembly 103 , and λ is the minimum wavelength of the measurement light irradiated on the projection grating assembly 103 . Setting the angle θ of the measurement light within the above range can ensure that the diffraction light spots of each diffraction order signal at the diaphragm assembly 104 are separated from each other, so that the diaphragm assembly 104 can select the ±m diffraction orders for sample topography measurement therefrom. Secondary signal or ±n diffracted order signal.

The diaphragm assembly 104 is used to filter out the zero-order signal (ie, the 0-diffraction-order signal) in the multi-diffraction-order signals, and filter out the first diffraction-order signal or the second diffraction-order signal. In this embodiment, the aperture component 104 is used to filter out the zero-order signal, so as to reduce the fringe interval of the projection grating, and at the same time to improve the contrast of the signals of each diffraction order, and further by diffracting the second diffraction order signal of the high diffraction order The fringe interval of the projection grating is reduced, and the measurement accuracy is improved.

The projection optical component 105 images the image of the projection grating component 103 under the first diffraction order signal or the second diffraction order signal onto the surface of the sample to be tested 106 . The projection optical component 105 images the image of the projection grating component 103 under the first diffraction order signal or the second diffraction order signal onto the surface of the sample to be tested 106, and after being reflected by the sample to be tested 106, it will carry the first diffraction signal of the sample to be tested 106. The signal of the height information or the second height information is reflected to the detection optical component 107 .

In this embodiment, the projection optical component 105 is a reflective component or a transmissive component. When the projection optical component 105 is a transmissive component, the detection optical component 107 is also a transmissive component, as shown in FIG. 1; when the projection optical component 105 is a reflective component, the detection optical component 107 is also a reflective component, as shown in FIG. 2 shown. The diaphragm assembly 104 is arranged on the aperture diaphragm surface of the projection optical assembly 105, and the sample topography measurement device is a double telecentric measurement device.

The detection optical assembly 107 images the image of the projection grating assembly 103 carrying the first height information or the second height information of the sample 106 to be tested onto the detection grating assembly 108 . The detection grating assembly 108 separates the image of the projection grating assembly 103 carrying the first height information or the second height information of the sample 106 to be tested into two images, which are the first image and the second image respectively, so that the data acquisition component 109 according to the acquisition The obtained first imaging and second imaging calculate the first height information or the second height information of the sample 106 to be tested.

In this embodiment, the distance between the first imaging and the second imaging is 1/4 of the period of the projection grating assembly 103 , and the center of the detection grating assembly 108 is offset from the center of the projection grating assembly 103 by the projection grating assembly 1/8 of the period of 103, so as to reduce the influence of the stability of the light source power and the environment on the measurement result, and to make the algorithm in the data acquisition component 109 simpler. Further, the period d _det of the detection grating assembly 108 should also be smaller than the period d of the projection grating assembly 103 , that is, d _det <d, to ensure that the high diffraction order signal interferes, thereby ensuring that the first diffraction order signal and the second diffraction order signal The secondary signal exists in the interference region.

The moving stage 110 is used to move in a plane perpendicular to the height direction of the sample 106 to be tested, that is, in the XY plane shown in FIGS. 1 and 2 , and is fixed after moving to a position (x, y), waiting for The sample topography measuring device measures the second height information at the position (x, y) until the measurement of the second height information corresponding to all points in the XY plane of the sample to be tested is completed, thereby obtaining the topography of the sample to be tested 106 information, the topography information is the three-dimensional topography of the sample 106 to be tested.

According to an embodiment of the present disclosure, the projection grating component 103 may be a single projection grating, or may be an array composed of a plurality of projection gratings. When the projection grating component 103 is an array composed of a plurality of projection gratings, the projection optical component 105 can image the image of each projection grating under the first diffraction order signal or the second diffraction order signal to different parts of the surface of the sample to be tested 106 Therefore, the sample topography measuring device can measure the first height information or the second height information at multiple positions of the sample 106 to be measured at the same time, thereby improving the measurement efficiency.

In this embodiment, when the height corresponding to a certain position of the sample 106 to be tested is h, the image of the projection grating assembly 103 will be shifted by Δx at the detection grating assembly 108, and the two images collected by the data acquisition assembly 109 The transmission intensity of is:

Wherein, I ₁ and I ₂ are the transmission intensities of the two images separated by the detection grating assembly 108 when the diaphragm assembly 104 screens out the second diffraction order signal, E is the amplitude of the +m diffraction order signal, and E ₂ is The amplitude of the -m diffraction order signal, k _1x is the component of the wave vector of the +m diffraction order signal in the x direction, k _2x is the component of the -m diffraction order signal wave vector in the x direction, and T(k) is The Fourier variation of the grating assembly 108 is detected. For any sample topography measuring device, after the parameters of the projection grating assembly 103, the diaphragm assembly 104, the projection optical assembly 105, the detection optical assembly 107, and the detection grating assembly 108 are determined, E ₁ , E ₂ , k _1x , k _2x , T(k) are constants, and ideally, E ₁ =E ₂ , k _1x =k _2x , T(k _x -k _1x )=T(k _x -k _2x ), the data acquisition component 109 collects To calculate the transmission intensities of the two images, we can get:

Further, according to the basic principle of optical triangulation, the first height information and the second height information at the position of the sample to be tested 106 can be obtained as follows:

Wherein, h ₁ is the first height information, h ₂ is the second height information, d is the period of the projection grating assembly 103, α is the angle of the light entering the sample 106 to be tested, I ₃ and I ₄ are the diaphragm assemblies respectively 104 detects the transmission intensities of the two images separated by the grating assembly 108 when the second diffraction order signal is filtered out.

The transmission intensities of the two images collected by the data acquisition component 109 are sinusoidal functions. When the height of the sample to be tested 106 is relatively large, the transmission intensities I ₁ and I ₂ of the two images vary nonlinearly with the height. Factors such as optical system aberration and the environment have a great influence on the measurement accuracy. Therefore, the linear region in the middle of the sine function is usually selected as the effective signal region, as shown in FIGS. 3A and 3B . 3A and 3B, it can be seen that the higher the diffraction order of the signal, the higher the accuracy of the measured height information; the lower the diffraction order of the signal, the larger the measurement range of the measured height information, and the higher the accuracy. Low.

In the sample topography measuring device in this embodiment, first, the first diffraction order signal of the lower diffraction order is used to measure the first height information at a position of the sample 106 to be measured, so as to ensure its measurement range, the first diffraction order The diffraction order m of the secondary signal is, for example, 1; then, according to the first height information, the second diffraction order signal of the corresponding higher diffraction order is selected, and the diffraction order n of the second diffraction order signal is, for example, 5, using The second diffraction order signal measures the second height information at this position of the sample to be tested 106. Compared with the first height information, the second height information has higher accuracy, thereby improving the measurement accuracy of the device; moving the motion stage 110, The above measurement process is repeated to measure the second height information at each position of the sample to be tested 106 , so as to obtain the topographic information of the sample to be tested 106 . Another embodiment of the present disclosure provides a method for measuring the topography of a sample to be measured by the sample topography measuring device shown in FIG. 1 to FIG. 3B , the method includes:

First, the data acquisition component 109 calculates the first height information at a position of the sample to be tested 106 according to the acquired transmission intensities of the two images separated by the detection grating component 108, and the obtained first height information is:

Wherein, h is the first height information, d is the period of the projection grating assembly 103, m is the diffraction order of the first diffraction order signal screened by the diaphragm assembly 104, and α is the angle of the light entering the sample to be measured 106. , I ₁ and I ₂ are respectively the transmission intensities of the two images separated by the detection grating component 108 when the aperture component 104 filters out the first diffraction order signal.

Then, the diaphragm component 104 filters the second diffraction order signal according to the first height information, and the data acquisition component 109 calculates the transmission intensities of the two images separated by the detection grating component 108. The second height information, the obtained second height information is:

Wherein, h ₂ is the second height information, n is the diffraction order of the second diffraction order signal screened by the diaphragm assembly 104, n>m, I ₃ and I ₄ are the second diffraction orders screened by the diaphragm assembly 104, respectively The transmission intensities of the two images separated by the grating assembly 108 are detected when the order signal is used.

Finally, the moving stage 110 is moved in a plane perpendicular to the height direction of the sample to be tested 106 , and the data acquisition component 109 calculates any position of the sample to be tested 106 according to the acquired transmission intensities of the two images separated by the detection grating component 108 The second height information is obtained to obtain the topography information of the sample 106 to be tested.

In this embodiment, the operation performed by the method for measuring the topography of the sample to be measured by the sample topography measuring device is the same as the working process of the sample topography measuring device in the embodiment shown in FIG. 1 to FIG. 3B , which will not be repeated here. . For details not exhausted in this embodiment, please refer to the description of the sample topography measuring device in the embodiment shown in FIG. 1 to FIG. 3B .

The specific embodiments described above further describe the purpose, technical solutions and beneficial effects of the present invention in further detail. It should be understood that the above descriptions are only specific embodiments of the present invention, and are not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. A sample topography measuring device, wherein the device comprises: A light source assembly (101), an illumination assembly (102), a projection grating assembly (103), a diaphragm assembly (104), and a projection optical assembly (105) arranged in sequence, a detection optical assembly (107), and a detection grating arranged in sequence an assembly (108), a data acquisition assembly (109), and a moving stage (110) arranged on the optical path between the projection optical assembly (105) and the detection optical assembly (107), the sample to be tested (106) is placed on the on the sports platform (110); Wherein, the illumination component (102) uses the measurement light generated by the light source component (101) to illuminate the projection grating component (103) to generate a multi-diffraction order signal; the diaphragm component (104) filters out the The zero-order signal in the multi-diffraction order signal, and the first diffraction order signal is screened out, and the first diffraction order signal includes the +m diffraction order signal and the -m diffraction order signal, and m is greater than 0. integer; the projection optical component (105) images the image of the projection grating component (103) under the first diffraction order signal onto the surface of the sample to be tested (106); the detection optical component (107) will carry the sample to be tested (106) The image of the projection grating assembly (103) of the first height information is imaged on the detection grating assembly (108), and the first height information of the sample to be tested (106) is obtained through the data acquisition assembly (109); The diaphragm assembly (104) is further configured to filter out a second diffraction order signal according to the first height information, where the second diffraction order signal includes a +n diffraction order signal and a −n diffraction order signal, n>m; the projection optical assembly (105) is further used to image the image of the second diffraction order signal lower projection grating assembly (103) onto the surface of the sample to be tested (106); the detection optical assembly (107) will The image of the projection grating assembly (103) carrying the second height information of the sample to be tested (106) is imaged on the detection grating assembly (108), and the second height information of the sample to be tested (106) is obtained through the data acquisition assembly (109) . 2 . The sample topography measuring device according to claim 1 , wherein the moving stage ( 110 ) is used to move in a plane perpendicular to the height direction of the sample to be measured ( 106 ), so that the data The acquisition component (109) obtains the topography information of the sample to be tested (106). 3 . The sample topography measuring device according to claim 1 , wherein the period of the detection grating component ( 108 ) is smaller than the period of the projection grating component ( 103 ). 4 . 4. The sample topography measuring device according to claim 1, wherein the detection grating assembly (108) is a projection grating assembly (108) that carries the first height information or the second height information of the sample to be measured (106). The image of 103) is separated into a first imaging and a second imaging, and the distance between the first imaging and the second imaging is 1/4 of the period of the projection grating assembly (103). 5. The sample topography measuring device according to claim 1, wherein the center of the detection grating assembly (108) is offset from the projection grating assembly (103) with respect to the center of the projection grating assembly (103). 103) of 1/8 of the period. 6. The sample topography measuring device according to claim 1, wherein the projection optical component (105) and the detection optical component (107) are reflective components or transmissive components, and the diaphragm component (104) ) is arranged on the aperture stop surface of the projection optical assembly (105), and the sample topography measurement device is a double telecentric measurement device. 7 . The sample topography measuring device according to claim 1 , wherein the projection grating component ( 103 ) is an amplitude grating, which is used to enhance the signal of the first diffraction order or the signal of the second diffraction order. 8 . strength. 8. The sample topography measuring device according to claim 1, characterized in that, the projection grating component (103) is an array composed of a plurality of projection gratings, so as to measure a plurality of the sample to be tested (106) at the same time The first altitude information or the second altitude information at the location. 9. The sample topography measuring device according to claim 1, wherein the angle θ of the measuring light irradiated on the projection grating component (103) satisfies:

Wherein, d is the period of the projection grating component (103), and λ is the minimum wavelength of the measurement light irradiated on the projection grating component (103). 10. A method for measuring the topography of a sample to be measured by using the sample topography measuring device according to any one of claims 1-10, wherein the method comprises: The data acquisition component (109) calculates the first height information at a position of the sample to be tested (106) according to the acquired transmission intensities of the two images separated by the detection grating component (108), and the obtained first height information is:

Wherein, h ₁ is the first height information, d is the period of the projection grating assembly (103), m is the diffraction order of the first diffraction order signal screened by the diaphragm assembly (104), and α is the incident The angle of the light rays of the sample to be tested (106), _I1 and _I2 are respectively the transmission intensities of the two images separated by the detection grating assembly (108) when the diaphragm assembly (104) screens out the first diffraction order signal; The diaphragm assembly (104) screens the second diffraction order signal according to the first height information, and the data acquisition assembly (109) calculates the transmission intensity of the two images separated by the detection grating assembly (108) according to the collected transmission intensities. The second height information at a position of the sample to be tested (106), the obtained second height information is:

Wherein, h2 is the _second height information, n is the diffraction order of the second diffraction order signal screened by the diaphragm assembly (104), n>m, and _I3 and _I4 are the diaphragm assembly (104) respectively. ) when the second diffraction order signal is filtered out, the transmission intensities of the two images separated by the grating assembly (108) are detected; The moving stage (110) is moved in a plane perpendicular to the height direction of the sample to be tested (106), and the data acquisition component (109) calculates the transmission intensity of the two images separated by the acquired detection grating component (108) The second height information at any position of the sample to be tested (106) obtains the topographic information of the sample to be tested (106).

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