Polishing pad detection apparatus, system and method

Abstract

To provide a polishing pad detection apparatus capable of maintaining consistency in inspection standards and saving time and human resources.SOLUTION: A polishing pad detection apparatus adapted to a chemical mechanical polishing system having a polishing pad includes: a calculation unit 111; a light source 121 electrically connected to the calculation unit 111, the light source emitting light onto a portion of the polishing pad; and a camera 131 electrically connected to the calculation unit 111, the camera capturing an image of a portion of the polishing pad to generate image information. The calculation unit 111 acquires a grayscale distribution on the basis of the image information and determines the condition of the polishing pad based on the grayscale distribution.SELECTED DRAWING: Figure 1A

Description

[Technical Field]

[0001] The present invention relates to a polishing pad detection device, system and method applied to detecting the condition of a polishing pad. [Background technology]

[0002] Polishing pads used in polishing wafers in chemical mechanical polishing systems undergo wear, which is typically inspected manually.

[0003] Typical manual inspections include, for example, visual inspection and dimensional measurement. Visual inspection involves checking the appearance of the polishing pad to ensure that its surface is flat and free of obvious scratches, wear, or dirt. Dimensional measurement involves using a measuring tool such as a vernier caliper to measure the pad's dimensions and thickness.

[0004] However, manual inspection has the disadvantages that the results of the inspection are influenced by human subjectivity, and the evaluation results vary depending on the inspector, resulting in inconsistent inspection results. It also requires a lot of time and human resources, especially when the inspection process requires individual inspections and evaluations. Summary of the Invention [Problem to be solved by the invention]

[0005] Therefore, how to automatically inspect polishing pads so as to maintain consistency in inspection standards and save time and manpower is a highly desirable problem. [Means for solving the problem]

[0006] The present invention provides a polishing pad detection apparatus, system and method that can maintain consistency in inspection standards and save time and manpower.

[0007] The present invention provides a polishing pad detection device suitable for a chemical mechanical polishing system having a polishing pad, the polishing pad detection device comprising: a computing unit; a first light source electrically connected to the computing unit and emitting light to be irradiated onto a portion of the polishing pad; and a first camera electrically connected to the computing unit and capturing an image of the portion of the polishing pad to generate image information. The computing unit obtains a first grayscale distribution based on the image information, and determines the state of the polishing pad based on the first grayscale distribution.

[0008] In some embodiments, the angle formed between the central axis of the first camera and the normal direction of the polishing pad 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 computing unit, and a second camera electrically connected to the computing unit and configured to capture an image of another portion of the polishing pad to generate another image information.

[0010] In some embodiments, the polishing pad detection device further includes a memory unit electrically connected to the calculation unit and containing initial setting operation instructions, and the calculation unit controls, based on the initial setting operation instructions, the execution of the steps of irradiating light onto the polishing pad, acquiring image information of the polishing pad, acquiring a first line segment of the image information, acquiring a first grayscale distribution in the first line segment, and determining the state of the polishing pad based on the first grayscale distribution.

[0011] The present invention 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] The present invention also provides a polishing pad detection method used to detect a polishing pad in a chemical mechanical polishing system, the polishing pad detection method including the steps of irradiating light onto the polishing pad, acquiring first image information of the polishing pad, acquiring a first line segment of the first image information, acquiring a first grayscale distribution in the first line segment, and determining the state of the polishing pad based on the first grayscale distribution.

[0013] In some embodiments, the polishing pad detection method further includes steps of acquiring a second line segment of the first image information, acquiring a second grayscale distribution in the second line segment, acquiring a peak value of the second grayscale distribution, defining a reference peak value, and defining a peak value equal to or greater than the reference peak value as a passing peak value.

[0014] In some embodiments, the polishing pad detection method further includes the steps of obtaining an interval between any two adjacent passing peak values ​​among the passing peak values ​​based on the second grayscale distribution and the passing peak values, defining a threshold value, and defining the second grayscale distribution as a bad grayscale distribution if any of the intervals is greater than the threshold value.

[0015] In some embodiments, the step of defining the reference peak value further includes the steps of calculating a first grayscale average value based on the first grayscale distribution, and defining the reference peak value as a value obtained by multiplying the first grayscale average value by a multiple.

[0016] In some embodiments, the polishing pad detection method further includes the steps of calculating a first grayscale average value based on the first grayscale distribution, acquiring second image information of the polishing pad, acquiring a third line segment of the second image information, acquiring a third grayscale distribution in the third line segment, acquiring a second grayscale average value based on the third grayscale distribution, and acquiring the state of the polishing pad based on the first grayscale average value and the second grayscale average value.

[0017] As described above, conventional polishing pad detection methods require manual inspection, which has drawbacks such as being subjective and time-consuming. In contrast, the polishing pad detection device, system, and method of the present invention have the following advantages: (1) Automatically inspects polishing pads, maintaining consistency in inspection standards and saving time and human resources; (2) Multiple polishing pads can be detected simultaneously, doubling efficiency; (3) Users can control multiple polishing pad detection devices from the same location, saving time; (4) Provides various methods for determining the wear state of polishing pads to suit various environments and needs; and (5) Predicts when polishing pads will become worn so that replacement can be prepared. [Brief explanation of the drawings]

[0018] The details of one or more embodiments of the subject matter described herein are set forth in the drawings and description below. Other features, aspects, and advantages of the subject matter described herein will become apparent from the description, the accompanying drawings, and the claims.

[0019] [Figure 1A] 1 is a block diagram of an embodiment of a polishing pad detection device according to the present invention; [Figure 1B] 1 is a schematic diagram of an embodiment of a polishing pad detection device according to the present invention; [Figure 2] 3 is a schematic diagram of another embodiment of a polishing pad detection device according to the present invention. [Figure 3] 1 is a schematic diagram of one embodiment of a polishing pad detection system according to the present invention; [Figure 4] 1 is a flowchart of an embodiment of a polishing pad detection method according to the present invention. [Figure 5] 3A to 3C are schematic diagrams of different aspects of gray scale distribution of the present invention; [Figure 6] 3A to 3C are schematic diagrams of different aspects of gray scale distribution of the present invention; [Figure 7] 3A to 3C are schematic diagrams of different aspects of gray scale distribution of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0020] As used herein, terms such as "first," "second," "third," "fourth," and "fifth" are used to describe various elements, components, regions, layers, and / or sections, but these elements, components, regions, layers, and / or sections are not intended to be limited by these terms. These terms are used only to distinguish one element, component, region, layer, or section from another. As used herein, terms such as "first," "second," "third," "fourth," and "fifth" do not imply any order or sequence unless clearly indicated by context.

[0021] Fig. 1A is a block diagram of one embodiment of a polishing pad detection device 1 according to the present invention. Fig. 1B is a schematic diagram of one embodiment of a polishing pad detection device 1 according to the present invention. As shown in Figs. 1A and 1B, the polishing pad detection device 1 of this embodiment is compatible with a chemical mechanical polishing system having a polishing pad 9, and includes a first light source 121, a first camera 131, and a computing unit 111.

[0022] A chemical mechanical polishing system compatible with the polishing pad detection device 1 includes a robotic arm, a wafer carrier, and a motor to suck and rotate the wafer.

[0023] The polishing pad 9 is a consumable material for chemical mechanical polishing of a wafer, and is disposed in a chemical mechanical polishing system for use. The polishing pad 9 has grooves, such as concentric grooves. During the polishing process, the polishing pad 9 is worn by polishing the wafer, and the grooves become shallower.

[0024] The first light source 121 is electrically connected to the calculation unit 111 and emits light L that is irradiated onto a portion of the polishing pad 9. The first light source 121 may be, but is not limited to, 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, or an X-ray light source. In this embodiment, the first light source 121 is a diffuse light source 1211. The first light source 121 is turned on and off by the calculation unit 111. When the first light source 121 is turned on, the light L emitted from the first light source 121 can illuminate the polishing pad 9. For example, the light L may illuminate the entire polishing pad 9 or only a portion of the polishing pad 9. The first light source 121 may be provided on one side of the polishing pad 9 so that the light L is incident on the polishing pad 9 along a substantially horizontal direction, thereby increasing the brightness difference between the polishing surface and the grooves of the polishing pad 9.

[0025] The first camera 131 is electrically connected to the computing unit 111 and captures an image of a portion of the polishing pad 9 to generate image information. The first camera 131 may be, but is not limited to, a color digital camera or a grayscale digital camera. In this embodiment, the first camera 131 is a color digital camera. The first camera 131 is controlled to be turned on and off by the computing unit 111 and is controlled to capture an image of a portion of the polishing pad 9 illuminated by the light L to generate image information. In some embodiments, the angle A formed between the central axis O of the first camera 131 and the normal direction of the polishing pad 9 is 20 degrees or more and 60 degrees or less. The central axis O is the central axis O or optical axis of the lens of the first camera 131. The angle A is set to 20 degrees or more and 60 degrees or less. This allows for a good imaging surface and brightness contrast to be obtained simultaneously.

[0026] The arithmetic unit 111 may include, but is not limited to, 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 processor (GPU), a field programmable logic array (FPGA), a system on a chip (SoC), or other suitable chips. The arithmetic unit 111 controls the first camera 131 to capture an image of the polishing pad 9 and generate image information, and can perform grayscale digital image processing on the generated image information. For example, the grayscale value of each pixel can be obtained by taking an arithmetic mean, such as (red subpixel value + green subpixel value + blue subpixel value) / 3, on the red, green, and blue subpixel values ​​of each pixel in the image information, thereby obtaining a grayscale image. Alternatively, a grayscale image can be obtained by calculating the grayscale value of each pixel by taking a weighted average of the red subpixel value, green subpixel value, and blue subpixel value of each pixel in the image information, such as red subpixel value * 0.299 + green subpixel value * 0.587 + blue subpixel value * 0.114, but this is not limitative.

[0027] In some embodiments, the first camera 131 is a grayscale digital camera, and the computing unit 111 can skip the grayscale digital image processing step. Because the polishing pad 9 has grooves, when the polishing pad 9 is not yet worn, the grooves of the polishing pad 9 are deep and only a small amount of light L can be irradiated onto the deep grooves. Therefore, the deep grooves appear as a dark gray in the grayscale image. A large grayscale value can be defined as the grayscale value calculated by subtracting the original grayscale value of the image pixel from the maximum grayscale value. On the other hand, when the polishing pad 9 is worn, the grooves of the polishing pad 9 become shallower and can irradiate a large amount of light L onto the shallow grooves. Therefore, the grayscale value can be calculated by subtracting the original grayscale value of the image pixel from the maximum grayscale value. Here, the magnitude is determined relatively and can be defined according to convenience and needs. This results in a first grayscale distribution of image information of the polishing pad 9, which can be used to determine the condition of the polishing pad 9. That is, the calculation unit 111 obtains a first grayscale distribution based on the image information, and determines the state of the polishing pad 9 based on the first grayscale.

[0028] In some embodiments, the polishing pad detection apparatus 1 further includes a memory unit 112 electrically connected to the computing unit 111 and including an initial setting operation command 1121. The memory unit 112 may be a non-transitory recording medium such as, but not limited to, a flash memory, a read only memory (ROM), a hard disk drive (HDD), a solid state drive (SSD), or an optical memory.

[0029] In some embodiments, the calculation unit 111 controls the execution of irradiating light L onto the polishing pad 9, acquiring image information of the polishing pad 9, acquiring a first line segment of the image information, acquiring a first grayscale distribution in the first line segment, and determining the state of the polishing pad 9 based on the first grayscale distribution based on an initial setting operation command 1121 (details will be described later).

[0030] In some embodiments, the polishing pad detection apparatus 1 may include a computer host 11. The computing unit 111 and the storage unit 112 are provided in the computer host 11.

[0031] In some embodiments, the polishing pad detection apparatus 1 may further include a detector 14, which may be, for example, but is not limited to, a time-of-flight ranging sensor, a structured light sensor, a stereo vision camera, a radar sensor, or an ultrasonic sensor. The detector 14 may determine the presence or absence of an obstacle 15 between the polishing pad 9 and the first camera 131 and avoid controlling the first camera 131 to image the polishing pad 9 in the presence of the obstacle 15. In a chemical mechanical polishing system, a typical obstacle 15 is the robot arm of the chemical mechanical polishing system.

[0032] FIG. 2 is a schematic diagram of another embodiment of the polishing pad detection apparatus 1A of the present invention. See FIGS. 1A and 2. In some embodiments, the polishing pad detection apparatus 1A further includes a second light source 122 and a second camera 132. The second light source 122 is electrically connected to the computing unit 111. The second camera 132 is electrically connected to the computing unit 111 and is used to capture an image of another portion of the polishing pad 9 to generate another image. 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, so their description will not be repeated here. It should be noted that the polishing pad detection apparatus 1 can simultaneously detect two polishing pads 9 by providing the second light source 122 and the second camera 132. In other embodiments, the polishing pad detection apparatus 1 can simultaneously detect three polishing pads 9 by providing a third light source and a third camera. In other words, the chemical mechanical polishing system may include multiple polishing pads 9, and the polishing pad detection device 1 may include a corresponding number of light sources and cameras for detection.

[0033] As described above, conventional methods for detecting polishing pads 9 require manual inspection, which has drawbacks such as being subjective and time-consuming. In contrast, the polishing pad detection apparatus 1 of the present invention includes a first light source 121, a first camera 131, and a computing unit 111. It automatically inspects polishing pads 9, thereby maintaining consistency in inspection standards and saving time and human resources. In some embodiments, the polishing pad detection apparatus 1 further includes a detector 14 that can automatically detect the presence of an obstacle 15 so that image information captured by the first camera 131 becomes usable image information. In some embodiments, the polishing pad detection apparatus 1 further includes a second light source 122 and a second camera 132, allowing two polishing pads 9 to be detected simultaneously. In other embodiments, the polishing pad detection apparatus 1 further includes an Nth light source and an Nth camera, allowing N polishing pads 9 to be detected simultaneously, thereby doubling efficiency.

[0034] 3 is a schematic diagram of one embodiment of the polishing pad detection system 2 of the present invention. As shown in FIG. 3, the polishing pad detection system 2 of this embodiment can be compatible with the polishing pad detection device 1 of FIG. 1A, but is not limited to this. The polishing pad detection device may be a polishing pad detection device other than the polishing pad detection device 1. The polishing pad detection system 2 of this embodiment includes the polishing pad detection device 1, a multi-computer switch 22, and an operation and monitoring interface 21.

[0035] As the polishing pad detection device 1, for example, a polishing pad detection device 1 as shown in FIGS. 1A and 1B may be used, and the description thereof will not be repeated here.

[0036] The multi-computer switch 22 is electrically connected to the polishing pad detection device 1 and includes a plurality of computer host ports, an operation and monitoring interface port, and an operation button. One computer host 11 can be connected to each computer host port, thereby allowing connection of a plurality of computer hosts 11. The operation and monitoring interface ports can be connected to the operation and monitoring interface 21. This allows the computer host 11 connected to the operation and monitoring interface 21 to be selected by the operation button.

[0037] The operation and monitoring interface 21 is electrically connected to the multi-computer switch 22 and includes an input device and an output device. The input device may be, for example, but not limited to, a mouse, a touchpad, a touchscreen, or a keyboard. The output device may be, for example, but not limited to, a screen, a touchscreen, a television, or a projector.

[0038] In some embodiments, a cabinet for housing the computer host 11 of the polishing pad detection device 1 is located outside the clean room, allowing for centralized management and saving space within the clean room.

[0039] As described above, conventional methods for detecting polishing pads 9 require manual inspection, which has drawbacks such as being subjective and time-consuming. The polishing pad detection system 2 of the present invention includes a polishing pad detection device 1, a multi-computer switch 22, and an operation and monitoring interface 21. It automatically inspects polishing pads 9, thereby maintaining consistency in inspection standards and saving time and manpower. The operation and monitoring interface 21 can operate multiple polishing pad detection devices 1, and the polishing pad detection devices 1 have multiple light sources and multiple cameras, allowing multiple polishing pads 9 to be detected simultaneously, doubling efficiency. Furthermore, the multi-computer switch 22 allows multiple polishing pad detection devices 1 to be controlled by a single operation and monitoring interface 21. This saves the cost and space required to install multiple operation and monitoring interfaces 21, and also allows users to control multiple polishing pad detection devices 1 from the same location, saving time.

[0040] FIG. 4 is a flowchart of one embodiment of the polishing pad detection method of the present invention. As shown in FIG. 4, step S01 is a step of irradiating light onto the polishing pad. Step S02 is a step of acquiring first image information of the polishing pad. Step S03 is a step of acquiring a first line segment of the first image information. Step S04 is a step of acquiring a first grayscale distribution in the first line segment. Step S05 is a step of determining the condition of the polishing pad based on the first grayscale distribution. Note that the polishing pad detection method of the present invention can be applied to the above-mentioned polishing pad detection apparatus 1, 1A and polishing pad detection system 2, but is not limited to these.

[0041] 5 and 6 are schematic diagrams of different aspects of the grayscale distribution in the present invention. As shown in FIGS. 1B, 3, 5, and 6, in step S01, light L is irradiated onto polishing pad 9. In this embodiment, by irradiating polishing pad 9 at an angle close to horizontal using diffused light source 1211, the surface of polishing pad 9 is brightly illuminated and the grooves of polishing pad 9 are shaded, improving the brightness contrast between the surface and grooves of polishing pad 9.

[0042] In step S02, first image information 311 of the polishing pad 9 is acquired. In this embodiment, the first image information 311 can be acquired by capturing an image of the polishing pad 9 with a grayscale digital camera, but is not limited to this. In some embodiments, the angle A formed between the central axis O of the grayscale digital camera and the normal direction N of the polishing pad 9 is 20 degrees or more and 60 degrees or less. The central axis O is the central axis O or optical axis of the lens of the first camera 131. The angle A is set to 20 degrees or more and 60 degrees or less so that a good imaging surface and brightness contrast can be obtained simultaneously.

[0043] In step S03, a first line segment 321 is acquired from the first image information 311. The first line segment 321 can be arbitrarily selected from the first image information 311. In some embodiments, the first line segment 321 spans all grooves in the polishing pad 9 in order to acquire a large amount of groove information.

[0044] In step S04, a first grayscale distribution 331 in the first line segment 321 is obtained. In this embodiment, the first image information 311 is captured by a grayscale digital camera, so it is possible to obtain the grayscale value of each pixel along the first line segment 321 from the first image information 311. In some embodiments, the grayscale value is, for example, 0 to 255. If the first line segment 321 spans 500 pixels, the first grayscale distribution 331 is obtained by obtaining 500 grayscale values ​​between 0 and 255. In this embodiment, the grayscale value is calculated by subtracting the original grayscale value of the image pixel from the maximum grayscale value of 255. Therefore, dark areas are defined as having large grayscale values ​​and bright areas as having small grayscale values, but this is not limiting.

[0045] In step S05, the condition of the polishing pad 9 is determined based on the first grayscale distribution 331. Once the grayscale distribution is obtained, the condition of the polishing pad 9 can be determined in different ways. In some embodiments, a second grayscale distribution 332 in the second line segment 322 can be obtained by acquiring the second line segment 322 of the first image information 311. A peak value 35 in the second grayscale distribution 332 is obtained. A reference peak value 351 is defined. A peak value 35 equal to or greater than the reference peak value 351 is defined as a pass peak value 352. This allows the condition of the polishing pad 9 to be determined.

[0046] The step of acquiring the second line segment 322 of the first image information 311 is similar to the step of acquiring the first line segment 321 of the first image information 311, and therefore the description thereof will not be repeated here. Note that the second line segment 322 may be the same as or different from the first line segment 321. In some embodiments, the second line segment 322 is a different line segment of the same polishing pad 9 in the first image information 311.

[0047] The steps for obtaining the second grayscale distribution 332 in the second line segment 322 are similar to the steps for obtaining the first grayscale distribution 331 in the first line segment 321, and therefore the description thereof will not be repeated here.

[0048] The acquisition of the peak value 35 of the second grayscale distribution 332 will now be described. There are multiple dark spots in a portion of the first image information 311 that correspond to the multiple grooves of the polishing pad 9. In this embodiment, the grayscale values ​​of the dark spots are large, resulting in the existence of multiple peak values ​​35. The peak values ​​35 can be acquired, for example, by finding the local maximum value of the first grayscale distribution 331 within each interval D of the first line segment 321, but this is not limiting.

[0049] The definition of the reference peak value 351 will now be described. Depending on the degree of wear of the polishing pad 9, some grooves in the polishing pad 9 may be deep and some may be shallow. Therefore, the portions of the first image information 311 corresponding to the grooves in the polishing pad 9 are partly dark and partly light. In the first image information 311, the darker the peak, the larger the grayscale peak value 35, and the brighter the peak, the smaller the grayscale peak value 35. Here, a peak value 35 equal to or greater than the reference peak value 351 can be defined as a pass peak value 352, and a peak value 35 less than the reference peak value 351 can be defined as a fail peak value.

[0050] Thus, in some embodiments, one way to determine the condition of the polishing pad 9 is to determine that the polishing pad 9 is worn and needs to be replaced if there is at least one non-passing peak value in the first line segment 321. Alternatively, to determine that the polishing pad 9 is worn and needs to be replaced if the number of line segments with at least one non-passing peak value is calculated to be greater than a threshold value (this threshold value being a number such as 1 or 2).

[0051] In another embodiment, the condition of the polishing pad 9 can be further determined by performing the following steps: Based on the second grayscale distribution 332 and the passing peak values ​​352, an interval D between any two adjacent passing peak values ​​352 is obtained. A threshold value (this threshold value is an interval threshold value, such as 100 pixels) is defined, and if any of the intervals D is greater than the threshold value (this threshold value is the interval threshold value), the second grayscale distribution 332 is defined as a defective grayscale distribution 36.

[0052] The following describes a step of obtaining the distance D between any two adjacent passing peak values ​​352 based on the second grayscale distribution 332 and the passing peak values ​​352. Because the distance between the grooves of the polishing pad 9 is constant, the distance D between the passing peak values ​​352 in the corresponding first line segment 321 is also constant. However, if a non-passing peak value 352 exists in the first line segment 321, the distance D between the surrounding passing peak values ​​352 will increase, for example, by more than two times. Therefore, a threshold value (this threshold value is the distance threshold) is defined, and if any of the distances D is greater than the threshold value (this threshold value is the distance threshold), the second grayscale distribution 332 can be defined as a defective grayscale distribution 36.

[0053] Thus, in some embodiments, one method for determining the condition of the polishing pad 9 is to determine that the polishing pad 9 is worn out and needs to be replaced if the second grayscale distribution 332 is the defective grayscale distribution 36. Alternatively, the third line segment, the fourth line segment, and the n-th line segment are taken, and if the proportion of the grayscale distributions corresponding to these line segments that are the defective grayscale distribution 36 is equal to or greater than a certain defined proportion, such as 10%, the polishing pad 9 is determined to be worn out and needs to be replaced. Alternatively, the second image information, the third image information, and the n-th image information are taken, and multiple line segments are taken from each of the image information. If the number of image information whose corresponding grayscale distributions are the defective grayscale distribution 36 is equal to or greater than a certain defined proportion, such as 10%, divided by the total number of image information is greater than a certain defined proportion, such as 60%, the polishing pad 9 is determined to be worn out and needs to be replaced. Alternatively, six pieces of image information are captured consecutively, and multiple line segments are taken from each piece of image information. If the grayscale distributions corresponding to the line segments obtained from the six consecutive pieces of image information all contain a defective grayscale distribution 36 with a defined ratio, such as 10%, it is determined that the polishing pad 9 is worn out and needs to be replaced.

[0054] In some embodiments, defining the reference peak value 351 further includes calculating a first grayscale average value 341 based on the first grayscale distribution 331, where the first grayscale average value 341 is an arithmetic average of all grayscale values ​​in the first grayscale distribution 331. Furthermore, the reference peak value 351 is defined as a value obtained by multiplying the first grayscale average value 341 by a multiple. This allows the reference peak value 351 to be automatically adjusted according to environmental brightness, differences in luminance of the first light source 121, differences in illumination angles of the first light source 121, differences in imaging angles of the first camera 131, and the like.

[0055] In another embodiment, the definition of the reference peak value 351 further includes calculating a grayscale peak average value 343 based on the first grayscale distribution 331, where the grayscale peak average value 343 is an arithmetic average of all peaks in the first grayscale distribution 331. Furthermore, the reference peak value 351 is defined as a value obtained by multiplying the grayscale peak average value 343 by a multiple. This allows the reference peak value 351 to be automatically adjusted according to the brightness of the environment, differences in luminance of the first light source 121, differences in the illumination angles of the first light source 121, differences in the imaging angles of the first camera 131, and the like.

[0056] FIG. 7 is a schematic diagram of a different aspect of the grayscale distribution of the present invention. As shown in FIGS. 4 and 7, in this embodiment, the condition of the polishing pad 9 can be determined by further performing the following steps: Calculate a first grayscale average value 341 based on the first grayscale distribution 331; Acquire second image information 312 of the polishing pad 9; Acquire a third line segment 323 of the second image information 312; Acquire a third grayscale distribution 333 in the third line segment 323; Calculate a second grayscale average value 342 based on the third grayscale distribution 333; Acquire the condition of the polishing pad 9 based on the first grayscale average value 341 and the second grayscale average value 342.

[0057] Calculation of a first grayscale average value 341 based on the first grayscale distribution 331 will now be described. The first grayscale average value 341 is the arithmetic average of all grayscale values ​​in the first grayscale distribution 331. In other embodiments, when the first grayscale average value 341 falls below a certain defined value, it can be determined that the polishing pad 9 is worn out and needs to be replaced. In some embodiments, the following steps may be performed subsequently.

[0058] This is a step of acquiring second image information 312 of the polishing pad 9, and since this step is similar to the step of acquiring first image information 311 of the polishing pad 9, the description thereof will not be repeated here. Note that in this embodiment, the second image information 312 of the polishing pad 9 may be image information captured after a certain time has elapsed, such as acquiring the second image information 312 of the polishing pad 9 one month after the first image information 311.

[0059] This is a step of obtaining the third line segment 323 of the second image information 312, and this step is similar to the step of obtaining the first line segment 321 of the first image information 311, so the description thereof will not be repeated here.

[0060] A step of obtaining a third grayscale distribution 333 in the third line segment 323, which is similar to the step of obtaining the first grayscale distribution 331 in the first line segment 321, and therefore the description thereof will not be repeated here.

[0061] The step of calculating the second grayscale mean value 342 based on the third grayscale distribution 333 is similar to the step of calculating the first grayscale mean value 341 based on the first grayscale distribution 331, and therefore the description thereof will not be repeated here.

[0062] and acquiring the state of the polishing pad 9 based on the first grayscale average value 341 and the second grayscale average value 342. For example, the time when the polishing pad 9 will be worn out can be predicted based on the change over time of the first grayscale average value 341 and the second grayscale average value 342, and preparation for replacement can be made. The prediction method may be, for example, linear extrapolation or linear regression, but is not limited to these.

[0063] As described above, conventional polishing pad detection methods require manual inspection, which has drawbacks such as being subjective and time-consuming. The polishing pad detection device, system, and method of the present invention have the following advantages: (1) Automatically inspects polishing pads, maintaining consistency in inspection standards and saving time and human resources; (2) Multiple polishing pads can be detected simultaneously, doubling efficiency; (3) Users can control multiple polishing pad detection devices from the same location, saving time; (4) Provides various methods for determining the wear state of polishing pads to suit various environments and needs; and (5) Predicts when polishing pads will become worn so that replacement can be prepared.

[0064] Terms such as "substantially" and "about," as used herein and not otherwise defined, are used to describe or account for small variations. When used in connection with an event or circumstance, the term may encompass not only the exact moment at which the event or circumstance occurs, but also its proximity. For example, when the term relates to a value, it may include a range of variation of ±10% or less of the value, e.g., ±5% or less, ±4% or less, ±3% or less, ±2% or less, ±1% or less, ±0.5% or less, ±0.1% or less, or ±0.05% or less.

[0065] The components of some embodiments of the present invention have been outlined above to allow those skilled in the art to better understand the concepts of the embodiments of the present invention. It should be understood by those skilled in the art that other processes and structures can be designed or modified based on the embodiments of the present invention to achieve the same purpose and / or achieve the same advantages as the embodiments disclosed herein. Those skilled in the art should understand that these equivalent structures do not depart from the spirit and scope of the present invention, and that various changes, substitutions, and other alterations can be made in the present specification without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the attached patent application. [Explanation of symbols]

[0066] 1: Polishing pad detection device 111: arithmetic unit 112: Memory unit 1121: Initial setting operation command 121: First light source 122: Second light source 1211: Diffused light source 131: First Camera 132: Second Camera 14: Detector 15: Obstacle 2: Polishing pad detection system 21: Operation and monitoring interface 22: Multi-computer switch 311: First image information 312: Second image information 321: First line segment 322: Second line segment 323: Third line segment 331: First grayscale distribution 332: Second grayscale distribution 333: Third grayscale distribution 341: First grayscale average value 342: Second grayscale average value 343: Grayscale peak average value 35: Peak value 351: Reference peak value 352: Pass peak value 36: Poor grayscale distribution 9: Polishing pad A: included angle D: Spacing L:Light N: Normal direction O: Central axis

Claims

1. 1. A polishing pad detection device compatible with a chemical mechanical polishing system having at least one polishing pad, comprising: A computing unit; a first light source electrically connected to the computing unit and configured to emit light that is irradiated onto a portion of the polishing pad; a first camera electrically connected to the computing unit, the first camera capturing an image of the portion of the polishing pad to generate image information; a second light source electrically connected to the computing unit; a second camera electrically connected to the computing unit for capturing an image of a portion of a different polishing pad to generate different image information; a detector electrically connected to the computing unit and detecting an obstacle between the polishing pad and the first camera; Equipped with The computing unit obtains a first grayscale distribution based on the image information, and determines a state of the polishing pad based on the first grayscale distribution; A polishing pad detection device, wherein an angle formed between a central axis of the first camera and a normal direction of the polishing pad is 20 degrees or more and 60 degrees or less.

2. a memory unit electrically connected to the arithmetic unit and containing an initial setting operation command; The arithmetic unit irradiating the polishing pad with the light; acquiring the image information of the polishing pad; obtaining a first line segment of the image information; obtaining the first grayscale distribution in the first line segment; 2. The polishing pad detecting device according to claim 1, wherein execution of the step of determining the state of the polishing pad based on the first grayscale distribution is controlled based on the initial setting operation command.

3. A plurality of polishing pad detection devices according to claim 1 or 2; a multicomputer switch electrically connected to the plurality of polishing pad detection devices; and an operation and monitoring interface electrically connected to the multi-computer switch.

4. 1. A polishing pad detection method for use in detecting a polishing pad in a chemical mechanical polishing system, comprising: irradiating the polishing pad with light; acquiring first image information of the polishing pad; obtaining a first line segment of the first image information; obtaining a first grayscale distribution in the first line segment; determining a condition of the polishing pad based on the first grayscale distribution; obtaining a second line segment of the first image information; obtaining a second grayscale distribution in the second line segment; obtaining a plurality of peak values ​​of the second grayscale distribution; defining a reference peak value; defining the plurality of peak values ​​equal to or greater than the reference peak value as a plurality of pass peak values; A method for detecting a polishing pad, comprising:

5. obtaining a plurality of intervals between any two adjacent passing peak values ​​among the plurality of passing peak values ​​based on the second grayscale distribution and the plurality of passing peak values; defining a threshold value; 5. The polishing pad detection method of claim 4, further comprising the step of: defining the second grayscale distribution as a bad grayscale distribution if any of the plurality of intervals is greater than the threshold value.

6. The step of defining the reference peak value comprises: calculating a first grayscale mean value based on the first grayscale distribution; 5. The polishing pad detection method of claim 4, further comprising the step of: defining the reference peak value as a value obtained by multiplying the first grayscale average value by a multiple.

7. calculating a first grayscale mean value based on the first grayscale distribution; acquiring second image information of the polishing pad; obtaining a third line segment of the second image information; obtaining a third grayscale distribution in the third line segment; calculating a second grayscale mean value based on the third grayscale distribution; 5. The polishing pad detection method of claim 4, further comprising the step of: acquiring a state of the polishing pad based on the first grayscale average value and the second grayscale average value.

Images