Surface monitoring device and method for polishing pad

Abstract

The embodiment of the invention discloses a polishing pad surface monitoring device and method.The polishing pad surface monitoring device can comprise an image collecting mechanism and a controller, and the image collecting mechanism is fixed to a polishing head through a supporting assembly and used for collecting surface images of a polishing pad in real time in the CMP process. The surface image is transmitted to a controller, and the controller analyzes the collected image by using an image recognition technology so as to determine the surface state of the polishing pad.

Description

Technical Field

[0001] The disclosed embodiments relate to the field of semiconductor manufacturing technology, and more particularly to a surface monitoring device and method for a polishing pad. Background Art

[0002] In the field of semiconductor manufacturing, chemical mechanical polishing (CMP) technology is a key process for achieving wafer surface flatness. CMP technology polishes the wafer surface to achieve the required flatness by combining chemical corrosion and mechanical friction. Debris detection during chemical mechanical polishing is a key link to ensure production efficiency and product quality. Silicon wafers are prone to fragmentation during the chemical mechanical polishing process due to mechanical stress or abnormalities in the previous process, which not only causes the silicon wafer itself to be scrapped, but may also damage expensive grinding equipment such as polishing pads and polishing heads. In addition, the presence of debris may also cause contamination to subsequent processing procedures and affect the yield of the entire production line. Therefore, effective debris detection is crucial to reducing production losses and improving the overall quality and economic benefits of silicon wafer processing.

[0003] Existing debris detection technology has obvious limitations. Currently, it mainly relies on optical reflective sensors. When silicon wafers are fragmented, this method is difficult to accurately detect the presence of fragments due to the diffuse reflection of light by the fragments. The lack of accuracy of this detection method makes it impossible to accurately determine whether the silicon wafer is fragmented in a timely manner, thereby failing to effectively prevent equipment damage and production interruptions. In addition, the existing technology cannot distinguish the size and location of fragments after they occur, making subsequent processing and repair work complicated and difficult. Therefore, improving the accuracy of fragment detection is of great significance to improving the overall efficiency and quality of silicon wafer processing. Summary of the invention

[0004] In view of this, the embodiments of the present disclosure are intended to provide a surface monitoring device and method for a polishing pad, which can solve the technical problem of insufficient accuracy of debris detection in the prior art.

[0005] The technical solution of the embodiment of the present disclosure is implemented as follows: In a first aspect, an embodiment of the present disclosure provides a surface monitoring device for a polishing pad, comprising: At least one image acquisition mechanism, fixed to the polishing head through the support assembly, for acquiring a surface image of the polishing pad during the chemical mechanical polishing process; A controller is connected in communication with the image acquisition mechanism and is used to determine the surface state of the polishing pad according to the surface image.

[0006] In some examples, the monitoring device includes a plurality of support assemblies; The plurality of support assemblies are evenly arranged in the circumferential direction of the polishing head, and each of the support assemblies is equipped with at least one image acquisition mechanism.

[0007] In some examples, the support assembly includes: A support plate extending in a radial direction of the polishing head; At least one mounting portion is disposed on the support plate and is used for mounting the image acquisition mechanism.

[0008] In some examples, the polishing head includes a rotating shaft and a body; The support plate is fixed to the body and extends along the radial direction of the body.

[0009] In some examples, the mounting portion includes a through hole; The support plate is provided with a plurality of through holes evenly arranged along the radial direction of the polishing head, which are used for installing a plurality of image acquisition mechanisms on the support plate.

[0010] In some examples, the polishing head includes a rotating shaft and a body; The support plate is fixed to the rotating shaft, and the orthographic projection of the mounting portion in the axial direction of the rotating shaft does not overlap with the orthographic projection of the body in the axial direction of the rotating shaft.

[0011] In some examples, the controller is used to determine the surface state of the polishing pad based on a comparison result between the standard image and the surface image; The standard image is at least one image of the polishing pad surface acquired when the polishing pad surface is adapted to the polishing head for chemical mechanical polishing.

[0012] In some examples, the surface state includes a normal state and an abnormal state, and the comparison result includes a similarity between the surface image and the standard image; When the similarity is less than a preset value, the surface state is determined to be an abnormal state.

[0013] In some examples, the surface state includes a normal state and an abnormal state; The controller is used for controlling the polishing head to stop the polishing process and control the polishing head to be away from the polishing pad when the surface state is abnormal.

[0014] In some examples, the image acquisition mechanism is used to receive an image acquisition instruction sent by a controller and acquire a surface image of the polishing pad at a preset sampling frequency.

[0015] In a second aspect, an embodiment of the present disclosure provides a surface monitoring method for a polishing pad, comprising: During chemical mechanical polishing, obtaining a surface image of a polishing pad; A surface condition of the polishing pad is determined based on the surface image.

[0016] The disclosed embodiments provide a polishing pad surface monitoring device and method; the polishing pad surface monitoring device can directly capture the surface image of the polishing pad in real time during the chemical mechanical polishing process by integrating at least one image acquisition mechanism into the polishing head. This design makes monitoring more accurate because it can instantly capture any changes on the surface of the polishing pad, including wear, damage or other abnormal conditions. Compared with the prior art, this direct monitoring method can respond to changes in the surface state of the polishing pad more quickly, thereby reducing equipment damage and production interruptions caused by monitoring delays. The communication connection between the controller and the image acquisition mechanism enables the device to automatically analyze and process the collected image data without manual intervention. This intelligent design improves the automation level of the CMP process, reduces the need for manual monitoring, reduces operating costs, and improves production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of a CMP device provided in an embodiment of the present disclosure.

[0018] Figure 2 It is a schematic diagram of a monitoring device in the related art.

[0019] Figure 3 It is a schematic diagram of another monitoring device in the related art.

[0020] Figure 4 A schematic diagram of an abnormal state of a polishing pad provided in an embodiment of the present disclosure.

[0021] Figure 5 A schematic diagram of a surface monitoring device for a polishing pad provided in an embodiment of the present disclosure.

[0022] Figure 6 A schematic diagram of another surface monitoring device for a polishing pad provided in an embodiment of the present disclosure.

[0023] Figure 7 A schematic diagram of the position setting of a support assembly provided in an embodiment of the present disclosure.

[0024] Figure 8 A schematic diagram of the position setting of another support assembly provided in an embodiment of the present disclosure.

[0025] Fig. 9 A system framework diagram of controller interaction provided in an embodiment of the present disclosure.

[0026] Fig.10 A schematic diagram of processor data interaction provided in an embodiment of the present disclosure.

[0027] Fig.11 A flow chart of a surface monitoring method for a polishing pad provided in an embodiment of the present disclosure.

[0028] The above drawings show clear embodiments of the present disclosure, which will be described in more detail below. These drawings and text descriptions are not intended to limit the scope of the present disclosure in any way, but to illustrate the concepts of the present disclosure to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0029] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that the disclosure will be more comprehensive and complete and to fully convey the concepts of the example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0030] In addition, the accompanying drawings are only schematic illustrations of the present disclosure and are not necessarily drawn to scale. The same reference numerals in the figures represent the same or similar parts, and their repeated description will be omitted. Some of the block diagrams shown in the accompanying drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software form, or implemented in one or more hardware modules or integrated circuits, or implemented in different networks and / or processor devices and / or microcontroller devices.

[0031] Chemical mechanical polishing (CMP) is a process used in semiconductor manufacturing to planarize the surface of wafers by combining chemical and mechanical action to smooth the wafer surface. Figure 1 In the CMP process, the wafer is fixed on the polishing head 1, and the polishing head 1 applies a certain pressure to make the wafer contact with the rotating polishing pad 2. The polishing pad 2 is usually made of polyurethane or other synthetic materials, and the surface has a specific roughness to promote the removal of materials. At the same time, the polishing liquid is sprayed on the polishing pad 2, which contains fine abrasive particles and chemical active agents. These components react chemically with the material on the surface of the wafer to form an easy-to-remove film. The combination of mechanical friction and chemical action enables the material on the surface of the wafer to be efficiently removed to achieve the required flatness. During the polishing process, parameters such as pressure, polishing liquid flow, polishing speed and polishing time need to be precisely controlled to ensure the consistency and accuracy of the polishing effect.

[0032] During the CMP process, if the polishing pressure is too high or the chemical activity of the polishing liquid is too strong, it may cause excessive wear on the silicon wafer surface, or even cracks and fragments. In addition, if the silicon wafer has micro defects before entering the CMP process, such as crystal defects or surface damage, these defects may expand during the polishing process due to stress concentration, eventually leading to silicon wafer fragments.

[0033] If the clamping force of the polishing head 1 is insufficient, the surface condition of the polishing pad 2 is not good, or the formula of the polishing liquid is not suitable for the current polishing conditions. If the polishing head 1 fails to clamp the silicon wafer evenly or firmly, the silicon wafer may slide or move on the polishing pad 2, causing the silicon wafer to slip out of the polishing head 1. In addition, if there is uneven wear or damage on the surface of the polishing pad 2, it may also cause the silicon wafer to slide. Uneven distribution of abrasive particles in the polishing liquid or chemical composition that is not suitable for material removal may also cause the silicon wafer to slide during the polishing process, resulting in the phenomenon of slipping.

[0034] Silicon wafer fragments can cause damage to polishing equipment, especially the polishing pad 2 and polishing head 1, because the fragments may scratch these components during the polishing process, shortening their service life. In addition, the presence of fragments may also cause contamination to subsequent processing, affecting the quality of other silicon wafers and reducing the yield rate of the entire production line. In extreme cases, the fragments may even cause equipment failure, resulting in production interruptions and affecting the efficiency of the entire manufacturing process.

[0035] The slip phenomenon also has a negative impact on the CMP process. The slip phenomenon can cause the polishing head 1 and the polishing pad 2 to wear out, resulting in equipment damage.

[0036] During the CMP process, debris or sliding pieces may contaminate the polishing pad 2 , so the surface of the polishing pad 2 is inspected to detect the sliding pieces and debris.

[0037] In the prior art, reference Figure 2 and Figure 3 , the state of the silicon wafer is detected by illuminating the optical reflection sensor on the grinding disk. When the sensor receives the reflection signal, it transmits the signal to the device, and the device stops grinding accordingly. This method relies on the reflection of light, but after the wafer is damaged, due to the diffuse reflection of light by the fragments, this method cannot effectively detect the fragments. And the disadvantage of optical detection is that it can only sense the area of ​​​​a point, and only in a specific area. When the sliding wafer does not reach the position of the optical sensor, it cannot be accurately detected. There are few detection points and the detection is inaccurate. It is greatly affected by bubbles or water stains on the disk surface. Sometimes bubbles or water stains are mistaken for silicon wafers and triggered by mistake. It is also impossible to detect problems such as degumming or damage of the grinding pad as shown in 4.

[0038] In order to solve the problems such as silicon chip fragments, silicon chip slipping, polishing pad debonding or damage, and colloidal particle contamination during the CMP process, the present invention proposes a surface monitoring device for the polishing pad. Figure 5 The device includes at least one image acquisition mechanism 3 and a controller 4. The image acquisition mechanism 3 is fixed to the polishing head 1 through a support assembly 5 and is used to acquire the surface image of the polishing pad 2 in real time during the CMP process. The surface image is transmitted to the controller 4, and the controller 4 analyzes the acquired image using image recognition technology to determine the surface state of the polishing pad 2. If the system detects any abnormality, such as an uneven surface or debris on the polishing pad 2, it will immediately send a stop command to the device to avoid further equipment damage and silicon wafer quality issues. This real-time monitoring and response mechanism significantly improves the safety and efficiency of the CMP process, reduces production interruptions caused by equipment failures, and also improves the quality of the final product.

[0039] In some example embodiments of the present disclosure, the image acquisition mechanism 3 is used to acquire the surface image of the polishing pad 2 during the CMP process. The image acquisition mechanism 3 may include at least one imaging device, such as a CCD camera or a CMOS camera.

[0040] The number of image acquisition mechanisms 3 can be one or more, and they are fixed to the polishing head 1 through a support assembly 5. Optionally, one or more image acquisition mechanisms 3 can be installed on one support assembly 5, and the number of support assemblies 5 can also be one or more.

[0041] Reference Figure 6 The support assembly 5 may extend in the radial direction of the polishing head 1. The polishing head 1 may include a shaft 11 and a body 12. The shaft 11 is used to connect the polishing head 1 and the main drive system of the CMP device. It allows the polishing head 1 to rotate during the polishing process to achieve uniform polishing of the silicon wafer surface. The body 12 is the main part of the polishing head 1 and is usually made of a strong material to ensure stability and durability under high pressure and long-term use.

[0042] In some examples, reference Figure 7 When there are multiple support assemblies 5, the multiple support assemblies 5 can be evenly arranged along the circumferential direction of the polishing head 1. The even arrangement can ensure that the entire polishing head 1 maintains dynamic balance when rotating at high speed.

[0043] Since the polishing head 1 needs to rotate at a very high speed during the CMP process to achieve uniform material removal on the surface of the silicon wafer, any uneven weight distribution may cause vibration and swing, thereby affecting the polishing quality and efficiency. By evenly arranging the support assembly 5 along the circumference, the weight can be effectively dispersed, and the imbalance caused by centrifugal force can be reduced, thereby achieving a more stable rotation of the polishing head 1.

[0044] The evenly arranged support assembly 5 also helps to reduce equipment wear caused by unbalanced polishing head 1. Unbalanced polishing head 1 may cause additional wear on other parts of the CMP equipment, such as bearings and drive systems. By reducing this unnecessary wear, we not only increase the service life of the equipment, but also reduce maintenance costs and downtime.

[0045] In some examples, reference Figure 7 , the support assembly 5 can be fixed to the body 12 of the polishing head 1 and extend in the radial direction of the polishing head. It should be noted that the radial directions of the body 12 of the polishing head 1 and the rotating shaft 11 are consistent. Setting the support assembly 5 in the body 12 area of ​​the polishing head 1 can enable the image acquisition mechanism 3 to be closer to the polishing pad 2, thereby obtaining a clearer surface image. Since the image acquisition mechanism 3 (such as a CCD or CMOS camera) needs to capture subtle features on the surface of the polishing pad 2, such as wear, scratches or foreign matter, the shorter the distance between them and the polishing pad 2, the clearer the captured image and the richer the details. This can improve the detection accuracy.

[0046] In other examples, refer to Figure 8 The support assembly 5 can be fixed to the rotating shaft 11 of the polishing head 1, and the orthographic projection of the mounting portion 51 in the axial direction of the rotating shaft 11 does not overlap with the orthographic projection of the body 12 in the axial direction of the rotating shaft 11, so that the image acquisition mechanism 3 installed on the mounting portion 51 can capture image information of the polishing pad 2 not covered by the polishing head 1.

[0047] Furthermore, setting the mounting portion 51 on the rotating shaft 11 can increase the flexibility and coverage of the image detection mechanism 3 installed on the mounting portion 51. The image acquisition mechanism 3 can capture the image of the edge of the polishing pad 2. Comprehensive image acquisition helps to detect problems such as wear, damage or foreign matter of the polishing pad 2 as early as possible, so that timely measures can be taken to avoid potential quality problems and equipment damage.

[0048] The following is an example in which the support assembly 5 is arranged on the polishing head 1 body 12 . The support assembly 5 is mainly composed of a support plate and at least one mounting portion 51 . The support plate and the mounting portion 51 together constitute a stable base for the image acquisition mechanism 3 .

[0049] The support plate is fixed to the body 12 of the polishing head 1 and extends in the radial direction of the polishing head 1. This layout helps to evenly distribute the weight of the support assembly 5 and reduce the impact on the balance of the polishing head 1. The support plate adopts a rectangular plate structure, and the material can be selected to support multiple image acquisition mechanisms 3 to provide sufficient strength and rigidity to ensure the stability of the image acquisition mechanism 3 during the polishing process. The specific material selection can be set based on the number and weight of the image acquisition mechanism 3, which will not be repeated here.

[0050] One end of the support plate is fixed to the body 12 of the polishing head 1, and can be welded, bolted or otherwise mechanically connected to ensure that the support plate does not move or vibrate when the polishing head 1 rotates. This secure connection can maintain accurate alignment of the image acquisition mechanism 3 and reduce image blur.

[0051] Continue to refer to Figure 7 The design of the mounting portion 51 can be diversified to meet different installation requirements and conditions. For example, the mounting portion 51 can be a through hole, allowing the image acquisition mechanism 3 to be directly installed in the through hole. This installation method is simple and direct, and easy to achieve quick replacement and maintenance. In addition, the mounting portion 51 can also be a blind hole. This design can provide additional stability because the blind hole can more tightly fix the image acquisition mechanism 3.

[0052] In addition to the traditional through-hole and blind-hole designs, the mounting portion 51 can also adopt more advanced mounting technologies, such as air pressure adsorption structure and magnetic attraction structure. The air pressure adsorption structure uses the adsorption force generated by compressed air to fix the image acquisition mechanism 3. This non-contact fixing method can reduce wear and provide fast and accurate positioning. The magnetic attraction structure uses magnetic force for fixing, which can achieve fast installation and disassembly, and is convenient for quick replacement when the image acquisition mechanism 3 is damaged.

[0053] The image acquisition mechanism 3 can capture the surface image of the polishing pad 2 at a preset sampling frequency according to the instruction sent by the controller 4. The preset sampling frequency can be once every 0.1 seconds or once every 0.05 seconds. It can also be customized according to user needs, which will not be described in detail in this example implementation. The surface image can include detailed information on the surface of the polishing pad 2, such as wear, scratches, debonding, etc.

[0054] After the surface image of the polishing pad 2 is acquired, the captured image data can be transmitted to the controller 4 via a data interface (such as GigE Vision, CameraLink, CoaXPress, etc. industrial image interface). Optionally, a standard communication protocol (such as TCP / IP, UDP, etc.) can be used to ensure reliable and efficient transmission of the surface image between the image acquisition mechanism 3 and the controller 4.

[0055] In some examples, the surface image may be encoded in a compressed format (eg, JPEG, PNG, H.264, etc.) to reduce the bandwidth and storage space required for transmission.

[0056] In some examples, after receiving the surface image, the controller 4 may perform operations such as image decoding, image preprocessing, feature extraction, and image comparison to determine the surface state of the polishing pad 2. Among them, after receiving the compressed surface image, the controller 4 may first decode and restore the surface image to its original format. The controller 4 may preprocess the image, including denoising, contrast enhancement, brightness adjustment and color balance, etc., to improve the image quality and facilitate subsequent analysis. Afterwards, the controller 4 analyzes the image and extracts key features, such as the texture, shape, and color changes on the surface of the polishing pad 2. The controller 4 compares the surface image captured by the image acquisition mechanism 3 with the pre-stored standard image to determine whether the surface state of the polishing pad 2 is normal.

[0057] According to the result of the image comparison, the controller 4 determines the surface state of the polishing pad 2, wherein the surface state may include a normal state and an abnormal state, and the image comparison result may include the similarity between the surface image and the standard image. Among them, the standard image is at least one image acquired by the image acquisition mechanism 3 when the surface of the polishing pad 2 can be adapted to the polishing head 1 for chemical mechanical polishing, that is, the standard image is a surface image of the polishing pad that meets the polishing conditions. The similarity calculation process can use template matching, feature matching, machine learning algorithms, etc. to compare the similarity between the surface image and the standard image. Specifically, it can be calculated based on the distance and correlation between the feature vectors obtained after feature extraction. The specific acquisition process can refer to the relevant technology and will not be repeated here.

[0058] If the similarity is lower than the preset value, the controller 4 determines the surface state as an abnormal state. When an abnormal state is detected, the controller 4 triggers a corresponding response mechanism, such as stopping the polishing process or adjusting the polishing parameters to prevent further damage or quality problems. The controller 4 records the image data and analysis results for subsequent quality control and equipment maintenance. Among them, the above preset values ​​can be 95%, 99%, 98.5%, etc., and can also be customized according to user needs, which will not be repeated here.

[0059] For example, refer to Fig. 9 Once the controller 4 determines that the surface state of the polishing pad 2 is abnormal, the controller can send an instruction to the CMP device 6 to instruct the polishing head 1 to stop rotating and polishing. This can prevent damage to the silicon wafer or equipment that may be caused by continuing polishing under abnormal conditions. After stopping the polishing process, the controller 4 will also instruct the polishing head 1 to move physically so that it is separated from the polishing pad 2 and maintain a safe distance. This can prevent the detected abnormal state (such as breakage, degumming, etc. of the polishing pad 2) from causing further damage to the polishing head 1 or other components. While executing the stop and move operations, the controller 4 can also trigger the alarm system to notify the operator that an abnormal situation has occurred during the polishing process and manual intervention is required.

[0060] The controller 4 may also record detailed information of the abnormal state, including time, abnormality type, measures taken, etc., to facilitate subsequent analysis and maintenance, and the detailed information of the abnormal state may be stored in the memory 7.

[0061] Refer to the following Fig.10 The surface monitoring device of the polishing pad 2 is explained. When the image acquisition mechanism 3 acquires the surface image, the lighting device 8 can be used to illuminate the polishing pad 2 to improve the clarity of the acquired surface image. After acquiring the surface image, the image acquisition mechanism 3 transmits the surface image to the controller 4. The controller 4 can perform preprocessing, measurement processing and judgment output processes. The preprocessing process may include lighting alignment, binary conversion, filtering, color extraction and other processes, and then image matching and similarity comparison are performed. Finally, the judgment result is output according to the similarity, that is, normal state or abnormal state.

[0062] The surface monitoring device of the polishing pad 2 in the embodiment of the present disclosure collects the surface image of the polishing pad 2 in real time by installing at least one image acquisition mechanism 3 on the polishing head 1, and the controller 4 analyzes these images using image recognition technology to determine the surface state of the polishing pad 2. This monitoring method improves the detection accuracy of abnormalities on the surface of the polishing pad 2, including problems such as wear, scratches, and debonding. When the controller 4 detects that the surface state of the polishing pad 2 is abnormal, it can immediately send a stop command to stop the rotation and polishing action of the polishing head 1 to avoid further damage to the silicon wafer or equipment. And it can significantly improve the safety of the CMP process. By timely detecting and responding to abnormalities on the surface of the polishing pad 2, production interruptions and material waste caused by equipment failure or polishing quality problems are reduced, and production costs are reduced. Furthermore, by arranging multiple mounting parts 51 on a support component 5 to install multiple image acquisition devices, the accuracy and density of surface image acquisition can be improved, the detection accuracy is increased, and the probability of damage to the polishing head 1 and the polishing pad 2 is further reduced.

[0063] Furthermore, the present disclosure also provides a surface monitoring method for a polishing pad, which is applied to a controller, referring to Fig.11 , the monitoring method may include steps S1110 to S1120.

[0064] In step S1110 , during the chemical mechanical polishing process, a surface image of the polishing pad is acquired.

[0065] The method for obtaining the surface image of the polishing pad has been described in detail when describing the surface monitoring device for the polishing pad, and therefore will not be described in detail here.

[0066] In step S1120, the surface state of the polishing pad is determined based on the surface image.

[0067] In some example embodiments of the present disclosure, the surface state may include a normal state and an abnormal state, wherein the abnormal state indicates that the polishing pad has wear, scratches, debonding, or conditions such as wafer fragments or whole wafers appear on the polishing pad.

[0068] After acquiring the surface image, the controller can determine the surface state of the polishing pad based on the comparison between the surface image and the standard image. The specific determination method can refer to the description of the surface monitoring device of the polishing pad, which will not be described in detail here.

[0069] In the above embodiments, the description of each embodiment has its own emphasis. For the part not described in detail in a certain embodiment, please refer to the relevant description of other embodiments. The technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, all possible combinations of the technical features in the above embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0070] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the inventions claimed herein. The present disclosure is intended to cover any variations, uses or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary technical means in the art that are not claimed in the present disclosure.

[0071] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A surface monitoring device for a polishing pad, characterized in that: include: At least one image acquisition mechanism, fixed to the polishing head through the support assembly, for acquiring a surface image of the polishing pad during the chemical mechanical polishing process; A controller is connected in communication with the image acquisition mechanism and is used to determine the surface state of the polishing pad according to the surface image.

2. The surface monitoring device according to claim 1, characterized in that: The monitoring device includes a plurality of support components; The plurality of support assemblies are evenly arranged in the circumferential direction of the polishing head, and each of the support assemblies is equipped with at least one image acquisition mechanism.

3. The surface monitoring device according to claim 2, characterized in that: The support assembly comprises: A support plate extending in a radial direction of the polishing head; At least one mounting portion is disposed on the support plate and is used for mounting the image acquisition mechanism.

4. The surface monitoring device according to claim 3, characterized in that: The polishing head comprises a rotating shaft and a body; The support plate is fixed to the body and extends along the radial direction of the body.

5. The surface monitoring device according to claim 3, characterized in that: The mounting portion includes a through hole; The support plate is provided with a plurality of through holes evenly arranged along the radial direction of the polishing head, which are used for installing a plurality of image acquisition mechanisms on the support plate.

6. The surface monitoring device according to claim 3, characterized in that: The polishing head comprises a rotating shaft and a body; The support plate is fixed to the rotating shaft, and the orthographic projection of the mounting portion in the axial direction of the rotating shaft does not overlap with the orthographic projection of the body in the axial direction of the rotating shaft.

7. The surface monitoring device according to claim 1, characterized in that: The controller is used to determine the surface state of the polishing pad according to the comparison result between the standard image and the surface image; The standard image is at least one image of the polishing pad surface acquired when the polishing pad surface is adapted to the polishing head for chemical mechanical polishing.

8. The surface monitoring device according to claim 7, characterized in that: The surface state includes a normal state and an abnormal state, and the comparison result includes a similarity between the surface image and the standard image; When the similarity is less than a preset value, the surface state is determined to be an abnormal state.

9. The surface monitoring device according to claim 8, characterized in that: The surface state includes a normal state and an abnormal state; The controller is used for controlling the polishing head to stop the polishing process and control the polishing head to be away from the polishing pad when the surface state is abnormal.

10. The surface monitoring device according to claim 1, characterized in that: The image acquisition mechanism is used to receive an image acquisition instruction sent by a controller and acquire a surface image of the polishing pad at a preset sampling frequency.

11. A method for monitoring the surface of a polishing pad, applied to a controller, characterized in that: include: During chemical mechanical polishing, obtaining a surface image of a polishing pad; A surface condition of the polishing pad is determined based on the surface image.

Images