In-situ measurement device for real contact state of polishing pad and use method thereof

Abstract

This invention discloses an in-situ measurement device for the true contact state of a polishing pad and its method of use. The device includes a base, a loading mechanism, a Z-axis feeding mechanism, and an observation mechanism. The base is a hollow circular tube structure. The loading mechanism is installed in the lower part of the base, the Z-axis feeding mechanism is installed in the upper middle part of the base, and the observation mechanism is installed in the base via the Z-axis feeding mechanism. This invention utilizes an optical microscope to directly obtain images of the true contact state of the polishing pad, resulting in more accurate and reliable measurement results. During measurement, the assembled device is simply placed on the surface of the polishing pad, and removed after measurement. The entire measurement process does not damage the polishing pad and does not affect subsequent polishing processes. The invention uses nested weight blocks and support sleeves to ensure uniform loading. By batch processing images of the true contact state to extract contact feature information, this invention can analyze the chemical mechanical polishing state in real time and guide material removal stability control.

Description

Technical Field

[0001] This invention relates to the field of chemical mechanical polishing technology, specifically to an in-situ measuring device for the actual contact state of a polishing pad and its method of use. Technical Background

[0002] Chemical mechanical polishing (CMP) technology can achieve atomically smooth surfaces and possesses both local and global planarization capabilities, making it widely used in semiconductor manufacturing and optical device processing. In a typical polishing process, the polishing head rotates the workpiece and presses it against a rotating polishing pad. The surface of the polishing pad is softer and rougher than the workpiece; only some of the higher roughness peaks of the polishing pad reach the workpiece surface and form microscopic contact points. Simultaneously, the polishing slurry flows into the contact interface, and nano-abrasive particles embed themselves within these contact points and move relative to the workpiece surface along with the polishing pad. Under mechanical load and the chemical action of the polishing slurry, material removal is achieved from the workpiece surface. Therefore, the actual contact state of the polishing pad determines the actual contact stress and chemical reaction environment of CMP, significantly affecting process performance.

[0003] In actual chemical mechanical polishing (CMP) processes, the rough peaks of the polishing pad gradually wear down, and workpiece debris and polishing fluid abrasive particles continuously accumulate in the pores of the polishing pad, leading to glazing of the pad surface. In industry, dressing discs embedded with diamond particles are typically used to remove the glazed surface of the polishing pad in real time and generate new rough peaks. Therefore, the polishing pad surface is in a constantly changing state, affecting the stability of material removal by influencing the actual contact state of the polishing pad. With the increasing precision and demand for semiconductor and optical components, the stability of material removal has become a key factor limiting the improvement of CMP processing quality and efficiency. Therefore, an in-situ measurement method is needed to quickly obtain the actual contact state of the polishing pad, analyze the state of CMP in real time, and guide the control of material removal stability.

[0004] In the article titled "Computational Solid Mechanics Modeling of Asperity Deformation and Pad-Wafer Contact in CMP" (Bo, J., Mater. Res. Soc. Symp. Proc. 2007, 991.), the authors obtained the three-dimensional morphology of the polishing pad surface using confocal microscopy and imported the 3D data into Abaqus software for contact analysis to obtain the deformation and contact state of the polishing pad's roughness peaks. However, the polishing pad matrix contains a large number of porous structures, making its contact process more complex and difficult to accurately calculate using a finite element model. Furthermore, this method requires a significant amount of computation time and is inefficient.

[0005] In the article titled "Characterization of Pad–Wafer Contact and Surface Topography in Chemical Mechanical Planarization Using Laser Confocal Microscopy" (Ting, S., Jpn. J. Appl. Phys. 2010, 49: 066501.), the authors obtained true contact images of the polishing pad using optical measurement methods. However, this method requires cutting the measurement sample from the polishing pad surface, making in-situ measurement impossible, and the damaged polishing pad cannot be further polished. Therefore, this method cannot be used for real-time analysis and guidance of chemical mechanical polishing processes.

[0006] Chinese patent CN202010291072.1 discloses "An online testing device for detecting the contact characteristics of polishing pads and its usage method." The inventor places an assembled observation window on the surface of the polishing pad and uses optical measurement methods to obtain the actual contact characteristics of the polishing pad, avoiding the need for pad cutting. However, this method achieves loading by directly placing a counterweight on the observation window, which cannot guarantee the uniformity of loading, and the obtained contact state may differ from the actual situation. Furthermore, this method requires a horizontal displacement stage and support to control the microscope's observation position, resulting in large dimensions and inconvenient operation, making it difficult to apply to large-scale polishing equipment in actual industry; it also lacks a Z-axis feed mechanism, making it unable to measure polishing equipment at different heights.

[0007] In summary, existing devices and methods for measuring the contact state of polishing pads cannot accurately obtain the true contact state through morphological measurement combined with finite element deformation calculation. Optical measurement methods are mostly offline sampling measurements, which require damaging the polishing pad and cannot be used for real-time analysis and guidance of chemical mechanical polishing processes. In-situ measurement cannot guarantee the uniformity of loading and requires a displacement stage and support, which are large in size and inconvenient to operate, making them difficult to apply to large-scale polishing equipment in actual industry.

[0008] Therefore, proposing an efficient in-situ measurement device for the true contact state of polishing pads and its application method is a problem that researchers and technicians in this field need to solve. Summary of the Invention

[0009] To address the aforementioned problems in the existing technology, this invention aims to design an in-situ measurement device and its method for measuring the true contact state of a polishing pad that can be obtained in real time, efficiently, and accurately, so as to analyze the chemical mechanical polishing state in real time and guide the control of material removal stability.

[0010] To achieve the above objectives, the technical solution of the present invention is as follows: an in-situ measuring device for the actual contact state of a polishing pad, comprising a base, a loading mechanism, a Z-axis feeding mechanism, and an observation mechanism, wherein the base is a hollow circular tube structure, the loading mechanism is installed in the lower part of the base, the Z-axis feeding mechanism is installed in the upper middle part of the base, and the observation mechanism is installed in the base via the Z-axis feeding mechanism;

[0011] The loading mechanism includes a weight sleeve, a weight block, and a sapphire observation window. The weight sleeve is movably connected to the base via limiting bolts A and B. The sapphire observation window is embedded in the bottom of the weight sleeve. The lower surface of the sapphire observation window protrudes from the lower end face of the weight sleeve by a distance h, where h > 20R. a The R a The surface roughness of the polishing pad; the sapphire observation window is a double-sided polished sheet with a surface roughness R. a Better than 5nm; the weight block is embedded in the horizontal groove of the weight sleeve and is magnetically attached to the side wall of the horizontal groove of the weight sleeve for positioning;

[0012] The Z-axis feed mechanism includes an internal threaded sleeve, an external threaded knob, and a limiting support block. The internal threaded sleeve and the external threaded knob are connected by a threaded rotation. The outer wall of the internal threaded sleeve has three threaded holes of the same height, which are fixed to the base by a threaded rod to form a three-point positioning horizontal plane. The limiting support block is embedded in the top of the external threaded knob. The limiting support block is movably connected to the base by limiting connecting bolts C and D.

[0013] The observation mechanism includes a monocular microscope and a CCD camera. The monocular microscope is mounted on a recessed step in the center of a limiting support block and is fixed to the limiting support block by limiting connecting bolts C and D. The monocular microscope uses a coaxial light source. The CCD camera is mounted above the monocular microscope, connected to the monocular microscope, and wirelessly connected to a computer. The computer is equipped with image processing software to batch process the data captured by the CCD camera, obtain images of the actual contact state, and statistically analyze contact feature information.

[0014] Furthermore, the axes of the limiting connecting bolt C and the limiting connecting bolt D are on the same diameter line of the base; the axes of the limiting connecting bolt A and the limiting connecting bolt B are on the same diameter line of the base; and the three threaded holes on the outer wall of the internal threaded sleeve are evenly distributed circumferentially.

[0015] Furthermore, the diameter of the central through hole of the support sleeve is larger than the lens diameter of the monocular microscope; the bottom of the support sleeve has a circular groove, and the sapphire observation window is embedded in the bottom circular groove of the support sleeve; the horizontal grooves on both sides of the support sleeve are symmetrical.

[0016] Furthermore, the weight block is a cut-ring block, and the size and shape of the cut-ring block match the size and shape of the horizontal groove on the weight sleeve.

[0017] Furthermore, the external threaded knob has a circular groove at its top; the limiting support block is embedded in the circular groove at the top of the external threaded knob; the center of the limiting support block is connected to the barrel flange of the monocular microscope through the groove step.

[0018] Furthermore, the internal threaded sleeve and the external threaded knob are made of fine thread; the diameter of the through hole at the center of the external threaded knob is larger than the diameter of the monocular microscope tube.

[0019] Furthermore, the monocular microscope has a magnification of no less than 600x; the CCD camera has an image resolution better than 1μm / pixel.

[0020] Furthermore, there are M sets of horizontal grooves on both sides of the weight sleeve, with two horizontal grooves in each set and symmetrically positioned; the weight blocks are in groups of two, with a total of N sets, and two weight blocks in each set are symmetrically placed in the horizontal grooves on both sides of the weight sleeve. By adjusting the number of sets of weight blocks or by placing weight blocks of different masses, different pressures on the polishing pad can be obtained, where N <= M.

[0021] A method for using a device for in-situ measurement of the actual contact state of a polishing pad includes the following steps:

[0022] Step 1: Cleaning and Drying

[0023] Before measurement, the sapphire observation window and the area to be measured on the polishing pad are cleaned and dried;

[0024] Step 2: Focusing the microscope

[0025] During measurement, place the assembled device above the area to be measured on the polishing pad; control the monocular microscope to approach the sapphire observation window by rotating the external thread knob of the Z-axis feed mechanism; after approaching the sapphire observation window, adjust the focal length of the monocular microscope so that the focal plane is the contact interface between the polishing pad and the sapphire observation window; adjust the coaxial light source until a clear contact image is displayed in the field of view of the monocular microscope.

[0026] Step 3: Capture images of the actual contact state of the area to be tested.

[0027] Adjust the CCD camera parameters to capture images of the actual contact state of the polishing pad, and wirelessly transmit the captured results to the computer for storage in real time.

[0028] Step 4: Batch Measurement

[0029] The device was placed at different locations on the polishing pad to measure the actual contact state of each area of ​​the polishing pad; the brightness of the coaxial light source and the parameters of the CCD camera were kept consistent during the same batch of shooting to facilitate the batch processing of subsequent actual contact state images.

[0030] Step 5: Batch processing of real contact state images

[0031] The computer uses the image processing toolbox of Matlab 2020b commercial software to call built-in functions to process real contact state images; it uses the image user interface of Matlab 2020b commercial software to establish a human-computer operation interface; and it uses Matlab 2020b commercial software to batch process real contact state images and extract contact feature information at the same time.

[0032] Furthermore, the batch processing of contact images in step five includes the following steps: inputting a reference image, preprocessing the reference image, adjusting the binarization threshold parameter, batch reading of real contact state images, batch preprocessing of real contact state images, batch binarization processing of real contact state images, batch output of real contact state images, and output of contact feature information.

[0033] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0034] 1. This invention utilizes an optical microscope to directly obtain images of the actual contact state of the polishing pad, resulting in more accurate and reliable measurement results.

[0035] 2. During measurement, the assembled device only needs to be placed on the surface of the polishing pad. After the measurement is completed, it can be removed. The entire measurement process does not damage the polishing pad and does not affect the subsequent polishing process.

[0036] 3. The present invention can ensure uniform loading by nesting weight blocks and weight sleeves.

[0037] 4. This invention integrates the loading mechanism, Z-axis feeding mechanism and observation mechanism into one unit, with a simple and compact structure that can be directly used with various polishing equipment.

[0038] 5. This invention can obtain the actual contact state of the polishing pad in real time, efficiently and accurately. By batch processing the actual contact state images to extract contact feature information, the chemical mechanical polishing state can be analyzed in real time and the material removal stability control can be guided. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the device structure of the present invention.

[0040] Figure 2 yes Figure 1 Front view sectional view.

[0041] Figure 3 yes Figure 1 Right view sectional view.

[0042] Figure 4 This is a schematic diagram of a cut circular block.

[0043] In the diagram: 1. Sapphire observation window; 2. Weight sleeve; 3. Weight block; 4. Base; 5. Internal threaded sleeve; 6. External threaded knob; 7. Limiting bolt C; 8. Limiting bolt D; 9. Limiting support block; 10. Monocular microscope; 11. CCD camera; 12. Limiting bolt A; 13. Limiting bolt B; 14. Threaded rod. Detailed Implementation

[0044] The present invention will now be further described with reference to the accompanying drawings.

[0045] like Figure 1-4 As shown, an in-situ measurement device for the actual contact state of a polishing pad includes a base 4, a loading mechanism, a Z-axis feeding mechanism, and an observation mechanism. The base 4 is a hollow circular tube structure. The loading mechanism is installed in the lower part of the base 4, the Z-axis feeding mechanism is installed in the upper middle part of the base 4, and the observation mechanism is installed in the base 4 through the Z-axis feeding mechanism.

[0046] The loading mechanism includes a weight sleeve 2, a weight block 3, and a sapphire observation window 1. The weight sleeve 2 is movably connected to the base 4 via limiting connecting bolts A12 and B13. The sapphire observation window 1 is embedded in the bottom of the weight sleeve 2. The lower surface of the sapphire observation window 1 protrudes from the lower end face of the weight sleeve 2 by a distance h, where h > 20R. a The R a The surface roughness of the polishing pad; the sapphire observation window 1 is a double-sided polished sheet with a surface roughness R. a Better than 5nm; the weight block 3 is embedded in the horizontal groove of the weight sleeve 2, and is magnetically attached to the side wall of the horizontal groove of the weight sleeve 2 and positioned thereby.

[0047] The Z-axis feed mechanism includes an internal threaded sleeve 5, an external threaded knob 6, and a limiting support block 9. The internal threaded sleeve 5 and the external threaded knob 6 are connected by a threaded rotation. The outer wall of the internal threaded sleeve 5 has three threaded holes of the same height, which are fixed to the base 4 by a threaded rod 14 to form a three-point positioning horizontal plane. The limiting support block 9 is embedded in the top of the external threaded knob 6. The limiting support block 9 is movably connected to the base 4 by limiting connecting bolts C7 and D8.

[0048] The observation mechanism includes a monocular microscope 10 and a CCD camera 11. The monocular microscope 10 is mounted on the grooved step in the center of the limiting support block 9 and is fixed to the limiting support block 9 by limiting connecting bolts C7 and D8. The monocular microscope 10 uses a coaxial light source. The CCD camera 11 is mounted above the monocular microscope 10 and is connected to the monocular microscope 10 in conjunction with it, and is wirelessly connected to a computer. The computer is equipped with image processing software to batch process the data captured by the CCD camera 11, obtain images of the actual contact state, and statistically analyze contact feature information.

[0049] Furthermore, the axes of the limiting connecting bolts C7 and D8 are on the same diameter line of the base 4; the axes of the limiting connecting bolts A12 and B13 are on the same diameter line of the base 4; and the three threaded holes on the outer wall of the internal threaded sleeve 5 are evenly distributed circumferentially.

[0050] Furthermore, the diameter of the central through hole of the support sleeve 2 is larger than the lens diameter of the monocular microscope 10; the bottom of the support sleeve 2 has a circular groove, and the sapphire observation window 1 is embedded in the circular groove at the bottom of the support sleeve 2; the horizontal grooves on both sides of the support sleeve 2 are symmetrical.

[0051] Furthermore, the weight block 3 is a cut-ring block, and the size and shape of the cut-ring block match the size and shape of the horizontal groove on the weight sleeve 2.

[0052] Furthermore, the external threaded knob 6 has a circular groove at its top; the limiting support block 9 is embedded in the circular groove at the top of the external threaded knob 6; the center of the limiting support block 9 is connected to the barrel flange of the monocular microscope 10 through the groove step.

[0053] Furthermore, the internal threaded sleeve 5 and the external threaded knob 6 are made of fine thread; the diameter of the through hole at the center of the external threaded knob 6 is larger than the diameter of the tube of the monocular microscope 10.

[0054] Furthermore, the monocular microscope 10 has a magnification of not less than 600 times; the CCD camera 11 has an image resolution better than 1 μm / pixel.

[0055] Furthermore, there are M sets of horizontal grooves on both sides of the weight sleeve 2, with two horizontal grooves in each set and symmetrically positioned; the weight blocks 3 are in groups of two, with a total of N sets, and two weight blocks 3 in each set are symmetrically placed in the horizontal grooves on both sides of the weight sleeve 2. By adjusting the number of sets of weight blocks 3 or by placing weight blocks 3 of different masses, different pressures on the polishing pad can be obtained, where N <= M.

[0056] A method for using a device for in-situ measurement of the actual contact state of a polishing pad includes the following steps:

[0057] Step 1: Cleaning and Drying

[0058] Before measurement, the sapphire observation window 1 and the area to be measured on the polishing pad were cleaned and dried;

[0059] Step 2: Focusing the microscope

[0060] During measurement, the assembled device is placed above the area to be measured on the polishing pad; the monocular microscope 10 is controlled to approach the sapphire observation window 1 by rotating the external thread knob 6 of the Z-axis feed mechanism. After approaching the sapphire observation window 1, the focal length of the monocular microscope 10 is adjusted so that the focal plane is the contact interface between the polishing pad and the sapphire observation window 1; the coaxial light source is adjusted until a clear contact image is displayed in the field of view of the monocular microscope 10.

[0061] Step 3: Capture images of the actual contact state of the area to be tested.

[0062] Adjust the parameters of CCD camera 11 to capture images of the actual contact state of the polishing pad, and transmit the captured results to the computer for storage in real time via wireless connection;

[0063] Step 4: Batch Measurement

[0064] The device was placed at different locations on the polishing pad to measure the actual contact state of each area of ​​the polishing pad; the brightness of the coaxial light source and the parameters of the CCD camera 11 were kept consistent during the same batch of shooting to facilitate the batch processing of subsequent actual contact state images.

[0065] Step 5: Batch processing of real contact state images

[0066] The computer uses the image processing toolbox of Matlab 2020b commercial software to call built-in functions to process real contact state images; it uses the image user interface of Matlab 2020b commercial software to establish a human-computer operation interface; and it uses Matlab 2020b commercial software to batch process real contact state images and extract contact feature information at the same time.

[0067] Furthermore, the batch processing of contact images in step five includes the following steps: inputting a reference image, preprocessing the reference image, adjusting the binarization threshold parameter, batch reading of real contact state images, batch preprocessing of real contact state images, batch binarization processing of real contact state images, batch output of real contact state images, and output of contact feature information.

[0068] In an embodiment of the present invention, the obtained contact image has a pixel size of 2048×1536 and a resolution of 0.33μm / pixel.

[0069] This invention is not limited to this embodiment. Any equivalent concept or modification within the technical scope disclosed in this invention shall be included within the protection scope of this invention.

Claims

1. An in-situ measuring device for the actual contact state of a polishing pad, characterized in that: It includes a base (4), a loading mechanism, a Z-axis feeding mechanism and an observation mechanism. The base (4) is a hollow circular tube structure. The loading mechanism is installed in the lower part of the base (4). The Z-axis feeding mechanism is installed in the upper middle part of the base (4). The observation mechanism is installed in the base (4) through the Z-axis feeding mechanism. The loading mechanism includes a weight sleeve (2), a weight block (3), and a sapphire observation window (1). The weight sleeve (2) is movably connected to the base (4) via limiting connecting bolts A (12) and B (13). The sapphire observation window (1) is embedded in the bottom of the weight sleeve (2). The lower surface of the sapphire observation window (1) protrudes from the lower end face of the weight sleeve (2) by a distance h, where h > 20R. a The R a The surface roughness of the polishing pad; the sapphire observation window (1) is a double-sided polished sheet with a surface roughness R. a Better than 5nm; the weight block (3) is embedded in the horizontal groove of the weight sleeve (2) and is magnetically attached to the side wall of the horizontal groove of the weight sleeve (2) and positioned. The Z-axis feed mechanism includes an internal threaded sleeve (5), an external threaded knob (6), and a limiting support block (9). The internal threaded sleeve (5) and the external threaded knob (6) are connected by a threaded rotation. The outer wall of the internal threaded sleeve (5) has three threaded holes of the same height, which are fixed to the base (4) by a threaded rod (14) to form a three-point positioning horizontal plane. The limiting support block (9) is embedded in the top of the external threaded knob (6). The limiting support block (9) is movably connected to the base (4) by limiting connecting bolts C (7) and D (8). The observation mechanism includes a monocular microscope (10) and a CCD camera (11). The monocular microscope (10) is installed on the grooved step in the center of the limiting support block (9) and is fixed to the limiting support block (9) by limiting connecting bolts C (7) and D (8). The monocular microscope (10) uses a coaxial light source. The CCD camera (11) is installed above the monocular microscope (10), is connected to the monocular microscope (10), and is wirelessly connected to a computer. The computer is equipped with image processing software to batch process the shooting data of the CCD camera (11), obtain real contact state images, and statistically analyze contact feature information.

2. The in-situ measuring device for the actual contact state of a polishing pad according to claim 1, characterized in that: The axes of the limiting connecting bolts C (7) and D (8) are on the same diameter line of the base (4); the axes of the limiting connecting bolts A (12) and B (13) are on the same diameter line of the base (4); the three threaded holes on the outer wall of the internal threaded sleeve (5) are evenly distributed circumferentially.

3. The in-situ measuring device for the actual contact state of a polishing pad according to claim 1, characterized in that: The diameter of the central through hole of the support sleeve (2) is larger than the diameter of the lens of the monocular microscope (10); the bottom of the support sleeve (2) has a circular groove, and the sapphire observation window (1) is embedded in the circular groove at the bottom of the support sleeve (2); the horizontal grooves on both sides of the support sleeve (2) are symmetrical.

4. The in-situ measuring device for the actual contact state of a polishing pad according to claim 1, characterized in that: The weight block (3) is a cut-ring block, and the size and shape of the cut-ring block match the size and shape of the horizontal groove on the weight sleeve (2).

5. The in-situ measuring device for the actual contact state of a polishing pad according to claim 1, characterized in that: The external threaded knob (6) has a circular groove at the top; the limiting support block (9) is embedded in the circular groove at the top of the external threaded knob (6); the center of the limiting support block (9) is connected to the flange of the monocular microscope (10) through the groove step.

6. The in-situ measuring device for the actual contact state of a polishing pad according to claim 1, characterized in that: The internal threaded sleeve (5) and the external threaded knob (6) are made of fine thread; the diameter of the through hole at the center of the external threaded knob (6) is larger than the diameter of the tube of the monocular microscope (10).

7. The in-situ measuring device for the actual contact state of a polishing pad according to claim 1, characterized in that: The monocular microscope (10) has a magnification of not less than 600 times; the CCD camera (11) has an image resolution better than 1 μm / pixel.

8. The in-situ measuring device for the actual contact state of a polishing pad according to claim 1, characterized in that: The horizontal grooves on both sides of the weight sleeve (2) are in M ​​groups, with two horizontal grooves in each group and symmetrically positioned; the weight blocks (3) are in groups of two, with a total of N groups. The two weight blocks (3) in each group are symmetrically placed in the horizontal grooves on both sides of the weight sleeve (2). By adjusting the number of groups of weight blocks (3) or by placing weight blocks (3) of different masses, different pressures on the polishing pad can be obtained, where N <= M.

9. A method of using the in-situ measuring device for the actual contact state of a polishing pad as described in any one of claims 1-8, characterized in that: Includes the following steps: Step 1: Cleaning and Drying Before measurement, the sapphire observation window (1) and the area to be measured on the polishing pad were cleaned and dried; Step 2: Focusing the microscope During measurement, the assembled device is placed above the area to be measured on the polishing pad; the monocular microscope (10) is controlled to approach the sapphire observation window (1) by rotating the external thread knob (6) of the Z-axis feed mechanism. After approaching the sapphire observation window (1), the focal length of the monocular microscope (10) is adjusted so that the focal plane is the contact interface between the polishing pad and the sapphire observation window (1); the coaxial light source is adjusted until a clear contact image is displayed in the field of view of the monocular microscope (10). Step 3: Capture images of the actual contact state of the area to be tested. Adjust the parameters of the CCD camera (11), capture images of the actual contact state of the polishing pad, and transmit the captured results to the computer for storage in real time via wireless connection; Step 4: Batch Measurement The device was placed at different positions on the polishing pad, and the actual contact state of each area of ​​the polishing pad was measured. During the same batch of shooting, the brightness of the coaxial light source and the parameters of the CCD camera (11) were kept consistent, which facilitated the batch processing of the actual contact state images. Step 5: Batch processing of real contact state images The computer uses the image processing toolbox of Matlab 2020b commercial software to call built-in functions to process real contact state images; it uses the image user interface of Matlab 2020b commercial software to establish a human-computer operation interface; and it uses Matlab 2020b commercial software to batch process real contact state images and extract contact feature information at the same time.

10. The method of using the in-situ measuring device for the actual contact state of a polishing pad according to claim 9, characterized in that: Step 5 describes the batch processing of real contact state images, which includes the following steps: inputting a reference image, preprocessing the reference image, adjusting the binarization threshold parameter, batch reading of real contact state images, batch preprocessing of real contact state images, batch binarization of real contact state images, batch output of real contact state images, and output of contact feature information.

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