Grinding pad detection device, system and method

Abstract

The invention relates to a grinding pad detection device, system and method. The polishing pad detection device is matched with a chemical mechanical polishing system, and the chemical mechanical polishing system is provided with a polishing pad. The polishing pad detection apparatus includes an arithmetic unit; the light source is electrically connected with the arithmetic unit and emits light rays which irradiate the part of the polishing pad; and the camera is electrically connected with the arithmetic unit, shoots the part of the polishing pad and generates image information. The arithmetic unit obtains gray scale distribution according to the image information and judges the state of the polishing pad according to the gray scale distribution.

Description

Technical Field

[0001] This application relates to a polishing pad detection device, system and method for detecting the state of a polishing pad. Background Art

[0002] After the polishing pad is used on the wafer in the chemical mechanical polishing system, wear will occur, and usually, manual inspection is required to check the wear state.

[0003] General manual inspection steps, for example: Appearance inspection, check the appearance of the polishing pad to ensure that its surface is flat, without obvious damage, wear or dirt. Dimension measurement, use measuring tools such as calipers to measure the size and thickness of the pad.

[0004] However, there are also some disadvantages in manual inspection. For example: Subjectivity, the inspection results may be affected by personal subjective factors, and different inspectors may have different evaluation results, which may lead to inconsistencies in the inspection results. Time-consuming and laborious, manual inspection usually requires a lot of time and human resources, especially when the inspection process needs to be inspected and evaluated one by one.

[0005] In view of this, how to perform the inspection of the polishing pad in an automated manner to maintain the consistency of the inspection standards and save time and human resources is one of the problems that need to be solved urgently at present. Summary of the Invention

[0006] This application provides a polishing pad detection device, system and method, which can maintain the consistency of the inspection standards and save time and human resources.

[0007] This application provides a polishing pad detection device, which cooperates with a chemical mechanical polishing system. The chemical mechanical polishing system has a polishing pad. The polishing pad detection device includes an arithmetic unit; a first light source, electrically connected to the arithmetic unit, the first light source emits light, and the light irradiates a part of the polishing pad; and a first camera, electrically connected to the arithmetic unit, the first camera photographs a part of the polishing pad and generates image information. The arithmetic unit obtains a first grayscale distribution based on the image information and judges the state of the polishing pad based on the first grayscale distribution.

[0008] In some embodiments, there is an included angle between the central axis of the first camera and the normal direction of the polishing pad, and the included angle is greater than or equal to 20 degrees and less than or equal to 60 degrees.

[0009] In some embodiments, the polishing pad detection device further includes a second light source, electrically connected to the arithmetic unit; and a second camera, electrically connected to the arithmetic unit, the second camera photographs a part of another polishing pad and generates another image information.

[0010] In some embodiments, the polishing pad detection device further includes a storage unit electrically connected to the arithmetic unit. The storage unit includes default operation instructions, and the arithmetic unit controls according to the default operation instructions: irradiating the polishing pad with light; obtaining image information of the polishing pad; obtaining a first line segment in the image information; obtaining a first gray-scale distribution in the first line segment; and judging the state of the polishing pad according to the first gray-scale distribution.

[0011] This application also provides a polishing pad detection system including a polishing pad detection device; a multi-computer switch electrically connected to the polishing pad detection device; and an operation and monitoring interface electrically connected to the multi-computer switch.

[0012] This application also provides a polishing pad detection method for detecting a polishing pad of a chemical mechanical polishing system. The detection method includes irradiating the polishing pad with light; obtaining first image information of the polishing pad; obtaining a first line segment in the first image information; obtaining a first gray-scale distribution in the first line segment; and judging the state of the polishing pad according to the first gray-scale distribution.

[0013] In some embodiments, the polishing pad detection method further includes obtaining a second line segment in the first image information; obtaining a second gray-scale distribution in the second line segment; obtaining a peak value in the second gray-scale distribution; defining a peak reference value; and defining a peak value greater than or equal to the peak reference value as a qualified peak value.

[0014] In some embodiments, the polishing pad detection method further includes obtaining the distance between any two adjacent ones of the qualified peak values according to the second gray-scale distribution and the qualified peak value; defining a threshold; and when one of the distances is greater than the threshold, defining the second gray-scale distribution as an unqualified gray-scale distribution.

[0015] In some embodiments, defining the peak reference value further includes: calculating a first gray-scale average value according to the first gray-scale distribution; and defining the peak reference value as the first gray-scale average value multiplied by a multiple.

[0016] In some embodiments, the polishing pad detection method further includes calculating a first gray-scale average value according to the first gray-scale distribution; obtaining second image information of the polishing pad; obtaining a third line segment in the second image information; obtaining a third gray-scale distribution in the third line segment; calculating a second gray-scale average value according to the third gray-scale distribution; and obtaining the state of the polishing pad according to the first gray-scale average value and the second gray-scale average value.

[0017] As described above, the conventional method for detecting a polishing pad requires manual inspection, which has some drawbacks, such as subjectivity, time-consuming, and laborious. The polishing pad detection device, system, and method of the present application have the following effects: First, the inspection of the polishing pad is carried out in an automated manner, maintaining the consistency of the inspection standards and saving time and human resources. Second, multiple polishing pads can be detected simultaneously, with a multiple-fold increase in efficiency. Third, the user can control multiple polishing pad detection devices at the same location, saving time. Fourth, a variety of methods for judging the wear state of the polishing pad are provided to adapt to various environments and requirements. Fifth, the time when the polishing pad becomes a worn state can be estimated to prepare for replacement. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Details of one or more embodiments of the subject matter described in this specification are set forth in the following drawings and description. Other features, embodiments, and advantages of the subject matter of this specification will become apparent from the description, drawings, and claims, in which:

[0019] Figure 1A It is a block diagram of an embodiment of the polishing pad detection device of the present application.

[0020] Figure 1B It is a schematic diagram of an embodiment of the polishing pad detection device of the present application.

[0021] Figure 2 It is a schematic diagram of another embodiment of the polishing pad detection device of the present application.

[0022] Figure 3 It is a schematic diagram of an embodiment of the polishing pad detection system of the present application.

[0023] Figure 4 It is a flowchart of an embodiment of the polishing pad detection method of the present application.

[0024] Figures 5 to 7 It is a schematic diagram of different embodiments of the grayscale distribution of the present application.

[0025] DESCRIPTION OF THE REFERENCE NUMERALS:

[0026] 1: Polishing pad detection device;

[0027] 111: Operation unit;

[0028] 112: Storage unit;

[0029] 1121: Default operation instruction;

[0030] 121: First light source;

[0031] 122: Second light source;

[0032] 1211: Diffused light source;

[0033] 131: First camera;

[0034] 132: Second camera;

[0035] 14: Detector;

[0036] 15: Shield;

[0037] 2: Grinding pad detection system;

[0038] 21: Operation and monitoring interface;

[0039] 22: Multi-computer switcher;

[0040] 311: First image information;

[0041] 312: Second image information;

[0042] 321: First line segment;

[0043] 322: Second line segment;

[0044] 323: Third line segment;

[0045] 331: First grayscale distribution;

[0046] 332: Second grayscale distribution;

[0047] 333: Third grayscale distribution;

[0048] 341: First grayscale average value;

[0049] 342: Second grayscale average value;

[0050] 343: Grayscale peak average value;

[0051] 35: Peak value;

[0052] 351: Peak reference value;

[0053] 352: Qualified peak value;

[0054] 36: Unqualified grayscale distribution;

[0055] 9: Grinding pad;

[0056] A: Included angle;

[0057] D: Spacing;

[0058] L: Light;

[0059] N: Normal direction;

[0060] O: Central axis. Detailed implementation mode

[0061] As used herein, terms such as "first," "second," "third," "fourth," and "fifth" describe various components, elements, regions, layers, and / or sections, which should not be limited by these terms. These terms are used only to distinguish one element, element, element, region, layer, or section from another. Unless the context clearly indicates otherwise, terms such as "first," "second," "third," "fourth," and "fifth" as used herein do not imply a sequence or order.

[0062] Figure 1A This is a block diagram of an embodiment of the polishing pad detection device 1 of the present application. Figure 1B This is a schematic diagram of an embodiment of the polishing pad detection device 1 of the present application. Figure 1A and Figure 1B As shown, the polishing pad detection device 1 of this embodiment cooperates with a chemical mechanical polishing system having a polishing pad 9 . The polishing pad detection device 1 includes a first light source 121 , a first camera 131 and a computing unit 111 .

[0063] The chemical mechanical polishing system used in conjunction with the polishing pad detection device 1 includes a robotic arm, a wafer carrier, and a motor, which can pick up and rotate the wafer.

[0064] The grinding pad 9 is a consumable material for chemical mechanical polishing (CMP) wafers and is placed in a CMP system for use. The grinding pad 9 has grooves, such as concentric grooves. During the grinding process, the grinding pad 9 wears away due to the grinding of the wafer, causing the grooves to become increasingly shallow.

[0065] The first light source 121 is electrically connected to the operation unit 111, and the first light source 121 emits light L, which illuminates a portion of the polishing pad 9. The first light source 121 can be, for example, a diffuse light source 1211, a focused light source, a point light source, a line light source, a surface light source, a visible light source, an infrared light source, an ultraviolet light source, and an X-ray light source, but this is non-restrictive. In the present embodiment, the first light source 121 is a diffuse light source 1211. The first light source 121 is controlled to be turned on and off by the operation unit 111. When the first light source 121 is turned on, the light L it emits can illuminate the polishing pad 9, and can illuminate the entire polishing pad 9, or only illuminate a portion of the polishing pad 9. The first light source 121 can be arranged on one side of the polishing pad 9, and the light L is incident on the polishing pad 9 in a direction close to horizontal, thereby increasing the brightness difference between the polishing surface and the groove of the polishing pad 9.

[0066] The first camera 131 is electrically connected to the arithmetic unit 111. The first camera 131 captures a part of the polishing pad 9 and generates image information. The first camera 131 can be, for example, a color digital camera or a grayscale digital camera, but it is not limited thereto. In this embodiment, the first camera 131 is a color digital camera. The first camera 131 is controlled by the arithmetic unit 111 to be turned on and off, and is controlled to capture the part of the polishing pad 9 irradiated by the light L, generating image information. In some embodiments, there is an angle A between the central axis O of the first camera 131 and the normal direction N of the polishing pad 9, and the angle A is greater than or equal to 20 degrees and less than or equal to 60 degrees. The central axis O is the central axis O or the optical axis of the lens of the first camera 131. The angle A is set to be greater than or equal to 20 degrees and less than or equal to 60 degrees to simultaneously obtain a better shooting surface and brightness contrast.

[0067] The arithmetic unit 111 can include, for example, a sensor integrated circuit, a microcontroller (MCU), a microprocessor (MPU), a central processing unit (CPU), an application-specific integrated circuit (ASIC), a digital signal processor (DSP), a graphics processing unit (GPU), a field-programmable logic array (FPGA), or a system-on-chip (SoC), or other applicable chips, but it is not limited thereto. The arithmetic unit 111 can control the first camera 131 to capture the polishing pad 9, generate image information, and then perform grayscale digital image processing on it. For example, the arithmetic mean operation can be performed on the red sub-pixel value, green sub-pixel value, and blue sub-pixel value of each pixel in the image information, for example: (red sub-pixel value + green sub-pixel value + blue sub-pixel value) / 3, to obtain the grayscale value of each pixel and obtain a grayscale image. Or the weighted mean operation can be performed on the red sub-pixel value, green sub-pixel value, and blue sub-pixel value of each pixel in the image information, for example: red sub-pixel value * 0.299 + green sub-pixel value * 0.587 + blue sub-pixel value * 0.114, to obtain the grayscale value of each pixel and obtain a grayscale image, but it is not limited thereto.

[0068] In some embodiments, the first camera 131 is a grayscale digital camera, and the operation unit 111 can skip the steps of grayscale digital image processing. Since the polishing pad 9 has grooves, when the polishing pad 9 has not been worn, the groove depth of the polishing pad 9 is relatively deep, and only a small amount of light L can reach the grooves with a relatively deep depth, so it corresponds to a relatively deep and darker gray in the grayscale image. The grayscale value will be calculated as the maximum grayscale value minus the original grayscale value of the image pixel, so a relatively large grayscale value can be defined; when the polishing pad 9 is worn, the groove depth of the polishing pad 9 is relatively shallow, and more light L can reach the grooves with a relatively shallow depth, so it corresponds to a relatively shallow and brighter gray in the grayscale image. The grayscale value will be calculated as the maximum grayscale value minus the original grayscale value of the image pixel, so a relatively small grayscale value can be defined. The large and small here are relative and can be defined according to convenience or requirements. Thus, the first grayscale distribution of the image information of the polishing pad 9 can be obtained and used to judge the state of the polishing pad 9. That is to say, the operation unit 111 obtains the first grayscale distribution based on the image information and judges the state of the polishing pad 9 based on the first grayscale distribution.

[0069] In some embodiments, the polishing pad detection device 1 further includes a storage unit 112 electrically connected to the operation unit 111, and the storage unit 112 includes a default operation instruction 1121. The storage unit 112 can be, for example, a non-transitory storage medium such as a flash memory, a read-only memory (ROM), a hard disk drive (HDD), a solid state drive (SSD), or an optical storage device, but it is not limited thereto.

[0070] In some embodiments, the operation unit 111 controls according to the default operation instruction 1121: irradiating the polishing pad 9 with the light L; obtaining the image information of the polishing pad 9; obtaining the first line segment in the image information; obtaining the first grayscale distribution in the first line segment; and judging the state of the polishing pad 9 based on the first grayscale distribution (to be described in detail later).

[0071] In some embodiments, the polishing pad detection device 1 may include a computer host 11. The operation unit 111 and the storage unit 112 are arranged in the computer host 11.

[0072] In some embodiments, the polishing pad detection device 1 further includes a detector 14. The detector 14 can be, for example, a time-of-flight distance measurement sensor, a structured light sensor, a stereo vision camera, a radar sensor, or an ultrasonic sensor, but is not limited thereto. The detector 14 can determine whether there is an obstacle 15 between the polishing pad 9 and the first camera 131, and can avoid controlling the first camera 131 to capture the polishing pad 9 when the obstacle 15 exists. In a chemical mechanical polishing system, a common obstacle 15 is a robotic arm of the chemical mechanical polishing system.

[0073] Figure 2 Schematic diagram of another embodiment of the polishing pad detection device 1A of the present application. Please refer to Figure 1A and Figure 2 as shown. In some embodiments, the polishing pad detection device 1A further includes a second light source 122 and a second camera 132. The second light source 122 is electrically connected to the arithmetic unit 111; the second camera 132 is electrically connected to the arithmetic unit 111. The second camera 132 is used to capture a part of another polishing pad 9 and generate another image information. The structure of the second light source 122 is similar to that of the first light source 121, and the structure of the second camera 132 is similar to that of the first camera 131, which will not be described in detail here. It should be noted that by providing the second light source 122 and the second camera 132, the polishing pad detection device 1 can detect two polishing pads 9 simultaneously. In other embodiments, the polishing pad detection device 1 can also detect three polishing pads 9 simultaneously by providing a third light source and a third camera. In other words, the chemical mechanical polishing system can have multiple polishing pads 9, and the polishing pad detection device 1 can have corresponding numbers of light sources and cameras for detection.

[0074] As described above, the conventional method for detecting the polishing pad 9 requires manual inspection, and manual inspection has some disadvantages, such as subjectivity, time-consuming, and laborious. The polishing pad detection device 1 of the present application has a first light source 121, a first camera 131, and an arithmetic unit 111 to perform the inspection of the polishing pad 9 in an automated manner, maintaining the consistency of the inspection standards and saving time and human resources. In some embodiments, the polishing pad detection device 1 further has a detector 14, which can automatically detect the presence of the obstacle 15, so that the image information captured by the first camera 131 is available image information. In some embodiments, the polishing pad detection device 1 further has a second light source 122 and a second camera 132, which can detect two polishing pads 9 simultaneously. In other embodiments, the polishing pad detection device 1 further has an Nth light source and an Nth camera, which can detect N polishing pads 9 simultaneously, and the efficiency is increased by several times.

[0075] Figure 3 Schematic diagram of an embodiment of the polishing pad detection system 2 of the present application. Please refer to Figure 3 as shown. The polishing pad detection system 2 of this embodiment can be used with Figure 1AIt is coordinated with the polishing pad detection device 1, but it is not restrictive. The polishing pad detection device can also use other polishing pad detection devices different from the polishing pad detection device 1. The polishing pad detection system 2 of this embodiment includes a polishing pad detection device 1, a multi-computer switch 22, and an operation and monitoring interface 21.

[0076] The polishing pad detection device 1 can, for example, utilize a polishing pad detection device 1 such as Figure 1A , Figure 1B The polishing pad detection device 1 will not be elaborated here.

[0077] The multi-computer switch 22 is electrically connected to the polishing pad detection device 1. The multi-computer switch 22 includes a plurality of computer host ports, an operation and monitoring interface port, and control buttons. Each computer host port can be connected to a computer host 11, whereby multiple computer hosts 11 can be connected. The operation and monitoring interface port can be connected to the operation and monitoring interface 21. Thereby, the computer host 11 connected to the operation and monitoring interface 21 can be selected through the control button.

[0078] The operation and monitoring interface 21 is electrically connected to the multi-computer switch 22. The operation and monitoring interface 21 includes an input device and an output device. The input device can, for example, be a mouse, a touchpad, a touch screen, or a keyboard, but it is not restrictive. The output device can, for example, be a screen, a touch screen, a TV, or a projector, but it is not restrictive.

[0079] In some embodiments, a cabinet can be set up outside the clean room. The cabinet is used to house the computer host 11 of the polishing pad detection device 1, so that centralized management can be carried out and the space of the clean room can be saved.

[0080] As mentioned above, the conventional method for detecting the polishing pad 9 requires manual inspection, and manual inspection has some disadvantages, such as subjectivity, time-consuming, and laborious. The polishing pad detection system 2 of this application has a polishing pad detection device 1, a multi-computer switch 22, and an operation and monitoring interface 21, and inspects the polishing pad 9 in an automated manner, maintaining the consistency of the inspection standards and saving time and human resources. Since the operation and monitoring interface 21 can operate multiple polishing pad detection devices 1, and the polishing pad detection device 1 has multiple light sources and multiple cameras, multiple polishing pads 9 can be detected simultaneously, and the efficiency is increased by several times. In addition, since the multi-computer switch 22 enables a group of operation and monitoring interfaces 21 to control multiple polishing pad detection devices 1, the cost of setting up multiple groups of operation and monitoring interfaces 21 and the installation space are saved. The user can control multiple polishing pad detection devices 1 at the same location, which also saves time.

[0081] Figure 4 For a flowchart of an embodiment of the polishing pad detection method of this application, please refer to Figure 4As shown, step S01 is to irradiate the polishing pad with light. Step S02 is to obtain the first image information of the polishing pad. Step S03 is to obtain the first line segment in the first image information. Step S04 is to obtain the first gray-scale distribution in the first line segment. Step S05 is to determine the state of the polishing pad according to the first gray-scale distribution. It is worth mentioning that the polishing pad detection method of the present application can cooperate with the above-mentioned polishing pad detection devices 1, 1A and polishing pad detection system 2, but it is not restrictive.

[0082] Figure 5 and Figure 6 are schematic diagrams of different embodiments of the gray-scale distribution of the present application. Please refer to Figure 1B , Figure 3 , Figure 5 and Figure 6 As shown, in step S01, the polishing pad 9 is irradiated with light L. In this embodiment, the polishing pad 9 can be irradiated through the diffused light source 1211. The diffused light source 1211 irradiates the polishing pad 9 at an angle close to the horizontal, so that the surface of the polishing pad 9 is illuminated, and the grooves of the polishing pad 9 become shaded areas, increasing the brightness contrast between the surface and the grooves of the polishing pad 9.

[0083] In step S02, the first image information 311 of the polishing pad 9 is obtained. In this embodiment, the polishing pad 9 can be photographed through a gray-scale digital camera to obtain the first image information 311, but it is not restrictive. In some embodiments, there is an angle A between the central axis O of the gray-scale digital camera and the normal direction N of the polishing pad 9, and the angle A is greater than or equal to 20 degrees and less than or equal to 60 degrees. The central axis O is the central axis O or the optical axis of the lens of the first camera 131. The angle A is set to be greater than or equal to 20 degrees and less than or equal to 60 degrees to simultaneously obtain a better shooting surface and brightness contrast.

[0084] In step S03, the first line segment 321 in the first image information 311 is obtained. The first line segment 321 can be arbitrarily selected in the first image information 311. In some embodiments, the first line segment 321 spans all the grooves of the polishing pad 9 to obtain more groove information.

[0085] In step S04, the first gray-scale distribution 331 in the first line segment 321 is obtained. In this embodiment, the first image information 311 is photographed through a gray-scale digital camera, so the gray-scale value of each pixel can be obtained along the first line segment 321 from the first image information 311. In some embodiments, the gray-scale value is, for example, 0 to 255. If the first line segment 321 spans 500 pixels, 500 gray-scale values between 0 and 255 are obtained, thereby obtaining the first gray-scale distribution 331. In this embodiment, the gray-scale value is regarded as the maximum gray-scale value 255 minus the original gray-scale value of the image pixel, so it is defined that the dark area has a large gray-scale value and the bright area has a small gray-scale value, but it is not restrictive.

[0086] In step S05, the state of the polishing pad 9 is determined according to the first gray-scale distribution 331. After obtaining the gray-scale distribution, the state of the polishing pad 9 can be determined in different ways. In some embodiments, the second line segment 322 in the first image information 311 can be obtained. The second gray-scale distribution 332 in the second line segment 322 is obtained. The peak value 35 in the second gray-scale distribution 332 is obtained. A peak reference value 351 is defined. The peak value 35 greater than or equal to the peak reference value 351 is defined as the qualified peak value 352. To determine the state of the polishing pad 9.

[0087] Obtaining the second line segment 322 in the first image information 311 has steps similar to obtaining the first line segment 321 in the first image information 311, which will not be elaborated here. It is worth noting that the second line segment 322 can be the same as or different from the first line segment 321. In some embodiments, the second line segment 322 is different line segments of the same polishing pad 9 in the first image information 311.

[0088] Obtaining the second gray-scale distribution 332 in the second line segment 322 has steps similar to obtaining the first gray-scale distribution 331 in the first line segment 321, which will not be elaborated here.

[0089] Obtaining the peak value 35 in the second gray-scale distribution 332, there will be multiple dark areas in the part of the first image information 311 corresponding to the multiple grooves of the polishing pad 9. In this embodiment, the gray-scale value of the dark areas is larger, so there will be multiple peak values 35. The method of obtaining the peak value 35 can be, for example, to find the local maximum value of the first gray-scale distribution 331 within each interval D of the first line segment 321, but it is not restrictive.

[0090] Defining the peak reference value 351, according to the wear degree of the polishing pad 9, some of the multiple grooves of the polishing pad 9 may be deeper and some may be shallower, so some of the multiple grooves corresponding to the polishing pad 9 in the first image information 311 will be darker and some will be brighter. The darker peaks in the first image information 311 will have larger gray-scale peak values 35, and the brighter peaks will have smaller gray-scale peak values 35. Here, the peak value 35 greater than or equal to the peak reference value 351 can be defined as the qualified peak value 352, and the peak value 35 less than the peak reference value 351 is the unqualified peak value.

[0091] Thus, in some embodiments, one of the methods for determining the state of the polishing pad 9 is that when there is at least one unqualified peak value in the first line segment 321, it is determined that the polishing pad 9 is in a worn state and needs to be replaced. Or calculate that the number of line segments with at least one unqualified peak value is greater than a threshold (this threshold is a quantity threshold, for example: 1 or 2), then it is determined that the polishing pad 9 is in a worn state and needs to be replaced.

[0092] In other embodiments, the following steps can be further performed to determine the state of the polishing pad 9. Obtain the distance D between any two adjacent ones of the qualified peak values 352 based on the second gray-scale distribution 332 and the qualified peak values 352. Define a threshold value (this threshold value is a distance threshold value, for example, 100 pixels). When one of the distances D is greater than the threshold value (this threshold value is a distance threshold value), define the second gray-scale distribution 332 as a defective gray-scale distribution 36.

[0093] Obtain the distance D between any two adjacent ones of the qualified peak values 352 based on the second gray-scale distribution 332 and the qualified peak values 352. Since the distance between the grooves of the polishing pad 9 is fixed, the distance D between the qualified peak values 352 in the corresponding first line segment 321 is also fixed. However, if there are unqualified peak values 352 in the first line segment 321, it will increase the distance D between the surrounding qualified peak values 352, for example, by more than 2 times. Therefore, by defining a threshold value (this threshold value is a distance threshold value), when one of the distances D is greater than the threshold value (this threshold value is a distance threshold value), define the second gray-scale distribution 332 as a defective gray-scale distribution 36.

[0094] Thereby, in some embodiments, one of the methods for determining the state of the polishing pad 9 is that when the second gray-scale distribution 332 is a defective gray-scale distribution 36, it is determined that the polishing pad 9 is in a worn state and needs to be replaced. Or the third line segment, the fourth line segment to the nth line segment can be taken. When the proportion of the corresponding gray-scale distributions in these line segments that are defective gray-scale distributions 36 is greater than or equal to a defined proportion, for example, 10%, it is determined that the polishing pad 9 is in a worn state and needs to be replaced. Or the second image information, the third image information to the nth image information can be captured. For each image information, multiple line segments are taken. When the proportion of the number of image information in which the proportion of the corresponding gray-scale distributions that are defective gray-scale distributions 36 is greater than or equal to a defined proportion, for example, 10%, divided by the total number of image information is greater than a defined proportion, for example, 60%, it is determined that the polishing pad 9 is in a worn state and needs to be replaced. Or six image informations are continuously captured. For each, multiple line segments are taken. When the gray-scale distributions corresponding to the line segments obtained from the six continuously captured image informations all contain a defined proportion, for example, 10%, of defective gray-scale distributions 36, it is determined that the polishing pad 9 is in a worn state and needs to be replaced.

[0095] In some embodiments, defining the peak reference value 351 further includes calculating the first gray-scale average value 341 based on the first gray-scale distribution 331. The first gray-scale average value 341 is the arithmetic average of all the gray-scale values in the first gray-scale distribution 331. Then define the peak reference value 351 as the first gray-scale average value 341 multiplied by a multiple. Thereby, the peak reference value 351 can be automatically adjusted according to the environmental brightness, the brightness difference of the first light source 121, the irradiation angle difference of the first light source 121, and the shooting angle difference of the first camera 131, etc.

[0096] In other embodiments, defining the peak reference value 351 further includes calculating the average peak gray level 343 based on the first gray level distribution 331, where the average peak gray level 343 is the arithmetic mean of all the peaks in the first gray level distribution 331. Then, define the peak reference value 351 as the average peak gray level 343 multiplied by a multiple. In this way, the peak reference value 351 can be automatically adjusted according to the ambient brightness, the brightness difference of the first light source 121, the irradiation angle difference of the first light source 121, and the shooting angle difference of the first camera 131, etc.

[0097] Figure 7 For the schematic diagrams of different embodiments of the gray level distribution of the present application, please refer to Figure 4 and Figure 7 As shown, in this embodiment, the following steps can be further performed to determine the state of the polishing pad 9. Calculate the first average gray level 341 based on the first gray level distribution 331. Obtain the second image information 312 of the polishing pad 9. Obtain the third line segment 323 in the second image information 312. Obtain the third gray level distribution 333 in the third line segment 323. Calculate the second average gray level 342 based on the third gray level distribution 333. Determine the state of the polishing pad 9 based on the first average gray level 341 and the second average gray level 342.

[0098] Calculating the first average gray level 341 based on the first gray level distribution 331. The first average gray level 341 is the arithmetic mean of all the gray level values in the first gray level distribution 331. In other embodiments, it can be determined that the polishing pad 9 is in a worn state and needs to be replaced by the first average gray level 341 being lower than a certain defined value. In some embodiments, the following steps can be continued.

[0099] Obtain the second image information 312 of the polishing pad 9. This step is similar to obtaining the first image information 311 of the polishing pad 9 and will not be elaborated here. It should be noted that in this embodiment, the second image information 312 of the polishing pad 9 can be the image information taken after a period of time. For example, after an interval of 1 month from the first image information 311, the second image information 312 of the polishing pad 9 is obtained.

[0100] Obtain the third line segment 323 in the second image information 312. The steps are similar to obtaining the first line segment 321 in the first image information 311 and will not be elaborated here.

[0101] Obtain the third gray level distribution 333 in the third line segment 323. The steps are similar to obtaining the first gray level distribution 331 in the first line segment 321 and will not be elaborated here.

[0102] Calculate the second average gray level 342 based on the third gray level distribution 333. The steps are similar to calculating the first average gray level 341 based on the first gray level distribution 331 and will not be elaborated here.

[0103] The state of the polishing pad 9 is obtained based on the first grayscale average value 341 and the second grayscale average value 342. For example, the time when the polishing pad 9 reaches the worn state can be inferred from the changes in the first grayscale average value 341 and the second grayscale average value 342 over time, and replacement preparation can be carried out. The inference methods include, for example, linear extrapolation or linear regression, etc., but are not limited thereto.

[0104] In summary, the conventional polishing pad detection method requires manual inspection, which has some disadvantages, such as subjectivity, time-consuming, and laborious. The polishing pad detection device, system, and method of the present application have the following effects: First, the inspection of the polishing pad is carried out in an automated manner, maintaining the consistency of the inspection standards and saving time and human resources. Second, multiple polishing pads can be detected simultaneously, and the efficiency is increased by several times. Third, the user can control multiple polishing pad detection devices at the same location, saving time. Fourth, a variety of methods for judging the wear state of the polishing pad are provided to adapt to various environments and requirements. Fifth, the time when the polishing pad reaches the worn state can be inferred, and replacement preparation can be carried out.

[0105] As used herein and not otherwise defined, terms such as "substantially" and "about" are used to describe and account for minor variations. When associated with an event or circumstance, such terms can include the exact instance when the event or circumstance occurs, as well as the approximate point proximate to when the event or circumstance occurs. For example, when associated with a numerical value, such terms can include a variation range less than or equal to ±10% of the numerical value, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%.

[0106] The components of several embodiments are outlined above, so that those with ordinary knowledge in the technical field to which the present application pertains can better understand the concepts of the embodiments of the present application. Those with ordinary knowledge in the technical field to which the present application pertains should understand that the embodiments of the present application can be used as a basis to design or modify other processes and structures to achieve the same purpose and / or obtain the same benefits as those introduced herein. Those with ordinary knowledge in the technical field to which the present application pertains should also understand that these equivalent structures do not depart from the spirit and scope of the present application, and various changes, substitutions, and other options can be made without departing from the spirit and scope of the present application. Therefore, the protection scope of the present application shall be defined by the appended patent application scope.

Claims

1. A grinding pad detection device, characterized in that, Cooperating with at least one chemical mechanical polishing system having a polishing pad, the polishing pad detecting device includes: An arithmetic unit; A first light source electrically connected to the arithmetic unit, the first light source emitting light rays, the light rays irradiating a part of the polishing pad; and A first camera electrically connected to the arithmetic unit, the first camera photographing the part of the polishing pad and generating image information; Wherein, the arithmetic unit obtains a first gray scale distribution according to the image information and judges the state of the polishing pad according to the first gray scale distribution.

2. The grinding pad detection device according to claim 1, wherein, There is an included angle between the central axis of the first camera and the normal direction of the polishing pad, and the included angle is greater than or equal to 20 degrees and less than or equal to 60 degrees.

3. The lapping pad detection device according to claim 1, wherein It further includes: A second light source electrically connected to the arithmetic unit; And A second camera electrically connected to the arithmetic unit, the second camera photographing a part of another polishing pad and generating another image information.

4. The lapping pad detection device according to claim 1, wherein, It further includes: A storage unit electrically connected to the arithmetic unit, the storage unit includes default operation instructions, and the arithmetic unit controls according to the default operation instructions: Irradiating the polishing pad with the light rays; Obtaining the image information of the polishing pad; Obtaining a first line segment in the image information; Obtaining the first gray scale distribution in the first line segment; and Judging the state of the polishing pad according to the first gray scale distribution.

5. A lapping pad detection system, characterized in that, It includes: Multiple polishing pad detecting devices according to any one of claims 1 to 4; A multi-computer switcher electrically connected to the polishing pad detecting devices; And An operation and monitoring interface electrically connected to the multi-computer switcher.

6. A method for detecting a polishing pad, characterized in that, For detecting the polishing pad of the chemical mechanical polishing system, the detecting method includes: Irradiating the polishing pad with light rays; Obtaining first image information of the polishing pad; Obtaining a first line segment in the first image information; Obtaining a first gray scale distribution in the first line segment; and Judging the state of the polishing pad according to the first gray scale distribution.

7. The lapping pad detection method according to claim 6, wherein It further includes: Obtaining a second line segment in the first image information; Obtaining a second gray scale distribution in the second line segment; Obtaining multiple peak values in the second gray scale distribution; Defining a peak reference value; And Defining those peak values greater than or equal to the peak reference value as multiple qualified peak values.

8. The grinding pad detection method according to claim 7, wherein, It further includes: Obtaining multiple spacings between any two adjacent ones of the qualified peak values according to the second gray scale distribution and the qualified peak values; Defining a threshold value; And When one of the spacings is greater than the threshold value, defining the second gray scale distribution as a bad gray scale distribution.

9. The grinding pad detection method according to claim 7, wherein Defining the peak reference value further includes: Calculating a first gray scale average value according to the first gray scale distribution; and Defining the peak reference value as the first gray scale average value multiplied by a multiple.

10. The lapping pad detection method according to claim 6, wherein It further includes: Calculating a first gray scale average value according to the first gray scale distribution; Obtaining second image information of the polishing pad; Obtaining a third line segment in the second image information; Obtaining a third gray scale distribution in the third line segment; Calculating a second gray scale average value according to the third gray scale distribution; and Obtaining the state of the polishing pad according to the first gray scale average value and the second gray scale average value.

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