Wafer detection method and device

Abstract

The invention provides a wafer detection method and device. The method comprises the following steps: respectively carrying out crack detection on each crystal grain of a wafer under a backlight source and an axial light source; on the crystal grain distribution diagram of the wafer, marking the detected crystal grains with cracks as unqualified crystal grains; determining a crack pattern according to the position of the grain with the crack in the grain distribution diagram; and marking the crystal grains in the first radius range of the crystal grains at the two ends of the crack pattern as unqualified crystal grains.

Description

Technical Field

[0001] This disclosure relates to the field of semiconductor technology, and in particular to a wafer inspection method and apparatus. Background Technology

[0002] In the semiconductor manufacturing process, Automatic Optical Inspection (AOI) is a technology that automatically identifies grain defects in wafers through optical imaging and algorithm analysis.

[0003] However, current AOI technology can only identify surface defects and has difficulty identifying latent defects. Summary of the Invention

[0004] This disclosure provides a wafer inspection method and apparatus to enhance the detection of latent defects. The technical solution is as follows: In a first aspect, embodiments of this disclosure provide a wafer inspection method, the method comprising: Crack detection was performed on each grain of the wafer under both backlight and axial light sources. On the grain distribution map of the wafer, grains with cracks are marked as defective grains; The crack pattern is determined based on the location of the cracked grains in the grain distribution diagram. Grains located within the first radius range of the grains at both ends of the crack pattern are marked as defective grains.

[0005] Optionally, the step of detecting cracks in each grain of the wafer under both backlight and axial light sources includes: Place the wafer on the stage; Under the illumination of the backlight, the wafer is scanned to obtain a first wafer image; Convert the first wafer image into a first binary image; The wafer is scanned under the illumination of the axial light source to obtain a second wafer image; Convert the second wafer image into a second binary image; Crack detection is performed on each grain of the wafer based on the first binary image and the second binary image.

[0006] Optionally, crack detection is performed on each grain of the wafer based on the first binary image and the second binary image, including: Crack detection of each grain is performed in the first binary image and the second binary image respectively using image recognition; When a crack is detected in the grain at the same location in the first binary image and the second binary image, it is determined whether the colors of the crack in the first binary image and the crack in the second binary image are opposite. If the cracks in the first binary image and the cracks in the second binary image have opposite colors, then the grain is determined to be the grain with cracks.

[0007] Optionally, grains found to have cracks are marked as defective grains, including: The grain located in the middle of a series of continuously arranged cracked grains is marked with a first anomalous pattern; The grains located at the ends of a series of continuously arranged cracked grains are marked with a second anomaly pattern.

[0008] Optionally, determining the crack pattern based on the location of the cracked grains in the grain distribution diagram includes: Determine whether the multiple continuously arranged cracked grains are aligned in a predetermined direction; When a plurality of the cracked grains are arranged in a predetermined direction in a continuous arrangement, the plurality of the cracked grains in a continuous arrangement constitute the crack pattern.

[0009] Optionally, the first radius range is one grain or two grains.

[0010] Secondly, embodiments of this disclosure provide a wafer inspection apparatus, the apparatus comprising: The detection module is used to detect cracks in each grain of the wafer under both backlight and axial light sources. The labeling module is used to mark grains with cracks as unqualified grains on the grain distribution map of the wafer. The determination module is used to determine the crack pattern based on the location of the cracked grains in the grain distribution diagram. The labeling module is also used to label grains within the first radius range of grains located at both ends of the crack pattern as unqualified grains.

[0011] Optionally, the detection module includes: The scanning unit is used to scan the wafer under the illumination of the backlight when the wafer is placed on the stage to obtain a first wafer image; and to scan the wafer under the illumination of the axial light source to obtain a second wafer image. An image processing unit is configured to convert the first wafer image into a first binary image and convert the second wafer image into a second binary image. The detection unit is used to perform crack detection on each grain of the wafer based on the first binary image and the second binary image.

[0012] Optionally, the detection unit is configured to perform crack detection on each grain in the first binary image and the second binary image respectively through image recognition; When a crack is detected in the grain at the same location in the first binary image and the second binary image, it is determined whether the colors of the crack in the first binary image and the crack in the second binary image are opposite. If the cracks in the first binary image and the cracks in the second binary image have opposite colors, then the grain is determined to be the grain with cracks.

[0013] Optionally, the first radius range is one grain or two grains.

[0014] Thirdly, embodiments of this disclosure provide a computer device, the computer device comprising: a processor; a memory configured to store processor-executable instructions; wherein the processor is configured to perform the wafer inspection method according to any one of the first aspects.

[0015] Fourthly, embodiments of this disclosure provide a computer-readable storage medium that, when instructions in the computer-readable storage medium are executed by a processor of a computer device, enables the computer device to perform the wafer inspection method according to any one of the first aspects.

[0016] The beneficial effects of the technical solutions provided in this disclosure are: In this embodiment, crack detection accuracy can be guaranteed by performing crack detection on each grain of the wafer under both backlight and axial light sources. After detecting grains with cracks, these grains are first marked as unqualified grains, that is, grains with visible cracks are marked. Then, the entire crack pattern is determined. After determining the crack pattern, grains near the endpoints of the crack pattern are identified and marked as unqualified grains. Since the ends of cracks are usually grains with hidden cracks (dark cracks), they cannot be detected by optical detection. The above method improves the problem of not being able to detect dark crack grains and enhances the detection of hidden defects.

[0017] Experimental verification showed that the risk of dark crack grain outflow was reduced from 50% to 5%, greatly improving the control measures for this anomaly. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a flowchart of a wafer inspection method provided in an embodiment of this disclosure; Figure 2 This is a schematic diagram of a grain crack provided in an embodiment of this disclosure; Figure 3 This is a flowchart of a wafer inspection method provided in an embodiment of this disclosure; Figure 4 This is an example of a grain distribution map provided in an embodiment of this disclosure; Figure 5 This is a schematic diagram of a wafer inspection device provided in an embodiment of the present disclosure; Figure 6 This is a structural block diagram of a computer device provided in an embodiment of this disclosure.

[0020] Explanation of reference numerals in the attached figures: 301: Detection module; 302: Labeling module; 303: Determination module; 400: Computer equipment; 401: Central processing unit; 402: Random access memory; 403: Read-only memory; 404: System memory; 405: System bus; 406: Basic input / output system; 407: Mass storage device; 408: Display; 409: Input device; 410: Input / output controller; 411: Network interface unit; 412: Network; 413: Operating system; 414: Application program; 415: Other program modules. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this disclosure clearer, the embodiments of this disclosure will be described in further detail below with reference to the accompanying drawings.

[0022] Figure 1 This is a flowchart of a wafer inspection method provided in an embodiment of this disclosure. See also... Figure 1 The method includes the following steps: 101: Crack detection was performed on each grain of the wafer under both backlight and axial light sources.

[0023] In this embodiment of the disclosure, the wafer includes a plurality of grains arranged in an array.

[0024] In this embodiment of the disclosure, the wafer can be a wafer formed during the fabrication of a light-emitting diode (LED), and the die is an LED chip. In other examples, the wafer can also be a wafer formed during the fabrication of other semiconductor devices.

[0025] In this embodiment of the disclosure, the backlight source refers to a light source located directly below the wafer, through which light penetrates from the bottom to the top of the wafer. Typically, under backlight illumination, the normal portions of the die appear dark, while the cracked portions appear bright.

[0026] An axial light source is a light source that is on the same optical axis as the inspection lens, with the light direction perpendicularly downwards, directly illuminating the wafer surface. Typically, under axial light source illumination, normal parts of the grain appear bright, while cracked parts appear dark.

[0027] During the inspection, the two light sources mentioned above are used to detect cracks, which distinguishes cracks from abnormalities such as scratches / contamination on the grain surface and eliminates the aforementioned interference items.

[0028] 102: On the grain distribution map of the wafer, grains with cracks are marked as unqualified grains.

[0029] The grain distribution map is a schematic diagram showing the distribution of grains in a wafer. The map includes an array of grids, with each grid cell corresponding to a grain in the wafer.

[0030] In this diagram, markings are made. For example, qualified grains are not marked, and the corresponding grid cell is blank; unqualified grains are marked, and the corresponding grid cell has a corresponding mark. This is usually called NG BIN, where NG means unqualified (Not Good) and BIN means classification.

[0031] 103: Determine the crack pattern based on the location of the cracked grains in the grain distribution diagram.

[0032] Typically, cracks in a wafer pass through multiple grains. By identifying the location of the grains containing the crack, the complete pattern of the crack can be determined, thus laying the foundation for subsequently determining the positions of the two ends of the crack.

[0033] 104: Grains within the first radius range of the grains located at both ends of the crack pattern are marked as unqualified grains.

[0034] Figure 2 This is a schematic diagram of a grain crack provided in an embodiment of this disclosure. For example... Figure 2 As shown, A and I are normal grains, BG are grains with visible cracks, and H is a grain with hidden cracks (dark cracks).

[0035] Observe the distribution pattern of crack patterns in the wafer. Dark cracks are often accompanied by chip breakage, edge chipping, corner chipping and other anomalies around the grains. The distribution is generally linear. Dark cracks are 1-2 grains extending from the head and tail of the strip crack pattern.

[0036] In this embodiment, crack detection accuracy can be guaranteed by performing crack detection on each grain of the wafer under both backlight and axial light sources. After detecting grains with cracks, these grains are first marked as unqualified grains, that is, grains with visible cracks are marked. Then, the entire crack pattern is determined. After determining the crack pattern, grains near the endpoints of the crack pattern are identified and marked as unqualified grains. Since the ends of cracks are usually grains with hidden cracks (dark cracks), they cannot be detected by optical detection. The above method improves the problem of not being able to detect dark crack grains and enhances the detection of hidden defects.

[0037] Experimental verification showed that the risk of dark crack grain outflow was reduced from 50% to 5%, greatly improving the control measures for this anomaly.

[0038] Figure 3 This is a flowchart of a wafer inspection method provided in an embodiment of this disclosure. See also... Figure 3 The method includes the following steps: 201: Place the wafer on the stage.

[0039] For example, the wafer is placed on the stage of the AOI device.

[0040] Optionally, prior to this step, the method may further include: performing parameter calibration under backlight illumination and axial light illumination respectively, to confirm that the normal area and cracked area of ​​the wafer exhibit obvious differences in brightness.

[0041] After parameter calibration is completed, the method may further include: determining the grayscale threshold under backlight illumination and the grayscale threshold under axial light illumination.

[0042] Among them, the grayscale threshold refers to the grayscale threshold used to distinguish between normal areas and crack areas when performing image binarization.

[0043] This method of calibrating and determining the threshold before use is called a fixed threshold scheme. Of course, in other implementations, the threshold can be determined without prior calibration, based on the local or overall grayscale distribution of the image after scanning the wafer image; this is called a dynamic threshold scheme.

[0044] 202: Under the illumination of the backlight, the wafer is scanned to obtain a first wafer image.

[0045] In this step, the calibrated backlight is turned on, and images of the wafer are acquired at a preset acquisition time to obtain the first wafer image.

[0046] 203: Convert the first wafer image into a first binary image.

[0047] In this step, the first wafer image is converted into a first binary image based on the grayscale threshold under backlight illumination.

[0048] For example, pixels in the first wafer image whose grayscale value is not greater than the grayscale threshold are set to black, and pixels in the first wafer image whose grayscale value is greater than the grayscale threshold are set to white, thus obtaining a first binary image.

[0049] A binary image is one that includes only two gray levels, such as 0 and 255, which correspond to the binary values ​​0 and 1, respectively.

[0050] 204: Under the illumination of the axial light source, the wafer is scanned to obtain a second wafer image.

[0051] In this step, the calibrated axial light source is turned on, and images of the wafer are acquired at a preset acquisition time to obtain a second wafer image.

[0052] 205: Convert the second wafer image into a second binary image.

[0053] In this step, the second wafer image is converted into a second binary image based on the grayscale threshold under axial light source illumination.

[0054] For example, pixels in the second wafer image whose grayscale value is not greater than the grayscale threshold are set to black, and pixels in the second wafer image whose grayscale value is greater than the grayscale threshold are set to white, thus obtaining a second binary image.

[0055] 206: Based on the first binary image and the second binary image, crack detection is performed on each grain of the wafer.

[0056] As shown earlier, under backlight illumination, the normal parts of the grain appear dark, while the cracked parts appear bright. Under axial light illumination, the normal parts of the grain appear bright, while the cracked parts appear dark.

[0057] Based on this characteristic, in one example, step 206 includes: Based on the first binary image and the second binary image, crack detection is performed on each grain of the wafer, including: Crack detection of each grain is performed in the first binary image and the second binary image respectively using image recognition; When a crack is detected in the grain at the same location in the first binary image and the second binary image, it is determined whether the colors of the crack in the first binary image and the crack in the second binary image are opposite. If the cracks in the first binary image and the cracks in the second binary image have opposite colors, then the grain is determined to be the grain with cracks.

[0058] In this implementation, the different colors of the cracks under backlight and axial light are used to achieve cross-verification and ensure the accuracy of the identified cracks.

[0059] If the colors of the cracks in the first binary image and the cracks in the second binary image are not opposite, then the grain is determined not to be the grain with the crack.

[0060] Determining whether the colors of the cracks in the first binary image and the cracks in the second binary image are opposite includes: A crack is confirmed to exist only if it simultaneously meets the following conditions at the same location in both binary images: it appears white in the first binary image and black in the second binary image. If either condition is not met, then a crack is considered not to exist at that location.

[0061] Here, the crack occupies multiple pixels in the image, and the crack in the first binary image and the crack in the second binary image have opposite colors, which could mean: The crack in the first binary image has all pixels with opposite colors to the crack in the second binary image, or, wherein pixels exceeding a certain number threshold have opposite colors.

[0062] The threshold for this quantity can be 60% to 90%, and can be set according to the actual situation.

[0063] For example, if more than 80% of the pixels are opposite in color, then the crack in the first binary image is considered to have all pixels with opposite colors to the crack in the second binary image. If less than 80% of the pixels are opposite in color, then the crack in the first binary image is considered to have all pixels with non-opposite colors to the crack in the second binary image.

[0064] Specifically, detecting cracks in each grain in the first binary image and the second binary image through image recognition means learning the crack pattern in advance, and then recognizing the pattern in the first binary image and the second binary image after obtaining them to determine whether it is a crack pattern.

[0065] 207: On the grain distribution map of the wafer, the grains located in the middle of the continuous arrangement of multiple grains with cracks are marked with a first abnormal pattern; the grains located at the ends of the continuous arrangement of multiple grains with cracks are marked with a second abnormal pattern.

[0066] Typically, an "×" symbol is used to represent defective grains on a grain distribution map. However, in order to distinguish cracks from other types of defective grains, a circle is used to represent grains with cracks in this embodiment of the present disclosure.

[0067] For example, the first anomaly pattern label can be a solid circle, and the second anomaly pattern label can be a hollow circle.

[0068] Figure 4 This is an example of a grain distribution map provided in an embodiment of this disclosure. For example... Figure 4 As shown, the grid cells corresponding to solid circles and hollow circles represent grains with cracks.

[0069] Hollow circles are arranged at both ends of a series of solid circles. That is, the grains located in the middle of the series of cracked grains are marked with a first anomaly pattern; and the grains located at the ends of the series of cracked grains are marked with a second anomaly pattern.

[0070] Here, a series of continuously arranged cracked grains refers to a series of consecutively adjacent cracked grains. Adjacent can be adjacent in the row direction, the column direction, or diagonally upwards.

[0071] 208: Determine whether the plurality of continuously arranged cracked grains are arranged in a predetermined direction.

[0072] In this step, arranging according to a predetermined direction may include: Arrange by row, by column, or by diagonal.

[0073] For example Figure 4 The cracks on the left side are arranged diagonally.

[0074] Arranged in a predetermined direction may also include: There is a bend in the middle from endpoint A to endpoint B, but the bend does not extend from B to A.

[0075] For example Figure 4 The crack on the right side is a crack with a bend in the middle.

[0076] 209: When a plurality of said cracked grains are arranged in a predetermined direction in a continuous arrangement, it is determined that the plurality of said cracked grains in a continuous arrangement constitute the crack pattern.

[0077] Among them, crack pattern is the pattern corresponding to the crack on the wafer. All of the above conditions satisfy the extension mode of a single crack, so if the above conditions are met, it can be determined to be a crack pattern.

[0078] If the multiple cracked grains arranged in a continuous sequence are not arranged in a predetermined direction, it is determined that the multiple cracked grains arranged in a continuous sequence do not constitute the crack pattern, or constitute multiple crack patterns.

[0079] At this point, steps 208-209, or steps 207-209, or steps 201-209 can be repeated. By repeating the above steps, the judgment result can be verified or corrected.

[0080] 210: Grains within the first radius range of the grains located at both ends of the crack pattern are marked as unqualified grains.

[0081] As previously shown, dark cracks typically appear in the first 1-2 grains extending from the beginning to the end of the crack pattern. Therefore, the first radius range is one or two grains, thus ensuring that this method can accurately mark the wafer with dark cracks.

[0082] For example, the first radius range is one grain.

[0083] like Figure 4 As shown, the grains within one grain range around the grains at both ends of the crack pattern marked as hollow circles are marked as unqualified grains (×).

[0084] Typically, there are 8 grains within a grain radius surrounding each grain. However, when the grain is located at the edge of the wafer, the number of grains within a grain radius around it decreases, for example, to 5.

[0085] In this step, the grains within the first radius range of the grains at both ends of the crack pattern that have not yet been marked with the first or second abnormal pattern are marked as unqualified grains.

[0086] In this embodiment of the disclosure, step 207 refers to grains with cracks, and step 210 refers to grains with hidden cracks.

[0087] Figure 5This is a schematic diagram of a wafer inspection apparatus provided in an embodiment of this disclosure. This wafer inspection apparatus can be implemented as all or part of a computer device (e.g., an AOI device) through software, hardware, or a combination of both. See also... Figure 5 The wafer inspection device includes: an inspection module 301, an annotation module 302, and a determination module 303.

[0088] Among them, the detection module 301 is used to detect cracks in each grain of the wafer under backlight and axial light source respectively; The labeling module 302 is used to label grains with cracks as unqualified grains on the grain distribution map of the wafer. The determining module 303 is used to determine the crack pattern based on the location of the cracked grains in the grain distribution diagram. The labeling module 302 is also used to label grains within the first radius range of grains located at both ends of the crack pattern as unqualified grains.

[0089] Optionally, the detection module 301 includes: The scanning unit is used to scan the wafer under the illumination of the backlight when the wafer is placed on the stage to obtain a first wafer image; and to scan the wafer under the illumination of the axial light source to obtain a second wafer image. An image processing unit is configured to convert the first wafer image into a first binary image and convert the second wafer image into a second binary image. The detection unit is used to perform crack detection on each grain of the wafer based on the first binary image and the second binary image.

[0090] Optionally, the detection unit is configured to perform crack detection on each grain in the first binary image and the second binary image respectively through image recognition; When a crack is detected in the grain at the same location in the first binary image and the second binary image, it is determined whether the colors of the crack in the first binary image and the crack in the second binary image are opposite. If the cracks in the first binary image and the cracks in the second binary image have opposite colors, then the grain is determined to be the grain with cracks.

[0091] Optionally, the labeling module 302 is used to label the grains located in the middle of a plurality of continuously arranged cracked grains using a first anomalous pattern; The grains located at the ends of a series of continuously arranged cracked grains are marked with a second anomaly pattern.

[0092] Optionally, the determining module 303 is used to determine whether the plurality of continuously arranged cracked grains are arranged in a predetermined direction; When a plurality of the cracked grains are arranged in a predetermined direction in a continuous arrangement, the plurality of the cracked grains in a continuous arrangement constitute the crack pattern.

[0093] Optionally, the first radius range is one grain or two grains.

[0094] It should be noted that the wafer inspection apparatus provided in the above embodiments is only illustrated by the division of the functional modules described above. In practical applications, the functions described above can be assigned to different functional modules as needed, that is, the internal structure of the equipment can be divided into different functional modules to complete all or part of the functions described above. In addition, the wafer inspection apparatus and the wafer inspection method embodiments provided in the above embodiments belong to the same concept, and their specific implementation process can be found in the method embodiments, which will not be repeated here.

[0095] Figure 6 This is a structural block diagram of a computer device provided in an embodiment of this disclosure. The computer device 400 (e.g., the aforementioned AOI device) includes a central processing unit (CPU) 401, a system memory 404 including random access memory (RAM) 402 and read-only memory (ROM) 403, and a system bus 405 connecting the system memory 404 and the central processing unit 401. The computer device 400 also includes a basic input / output system (I / O system) 406 that facilitates the transfer of information between various devices within the computer, and a mass storage device 407 for storing an operating system 413, application programs 414, and other program modules 415.

[0096] The basic input / output system 406 includes a display 408 for displaying information and an input device 409 for user input, such as a mouse or keyboard. Both the display 408 and the input device 409 are connected to the central processing unit 401 via an input / output controller 410 connected to the system bus 405. The basic input / output system 406 may also include the input / output controller 410 for receiving and processing input from multiple other devices such as a keyboard, mouse, or electronic stylus. Similarly, the input / output controller 410 also provides output to a display screen, printer, or other types of output devices.

[0097] Mass storage device 407 is connected to central processing unit 401 via a mass storage controller (not shown) connected to system bus 405. Mass storage device 407 and its associated computer-readable media provide non-volatile storage for computer device 400. That is, mass storage device 407 may include computer-readable media (not shown) such as hard disk or CD-ROM drive.

[0098] Without loss of generality, computer-readable media can include computer storage media and communication media. Computer storage media include volatile and non-volatile, removable and non-removable media implemented using any method or technology for storing information such as computer-readable instructions, data structures, program modules, or other data. Computer storage media include RAM, ROM, EPROM, EEPROM, flash memory or other solid-state storage technologies, CD-ROM, DVD or other optical storage, magnetic tape cassettes, magnetic tape, disk storage, or other magnetic storage devices. Of course, those skilled in the art will recognize that computer storage media are not limited to the above-mentioned types. The system memory 404 and mass storage device 407 described above can be collectively referred to as memory.

[0099] According to various embodiments of this disclosure, computer device 400 can also be connected to a remote computer on a network, such as the Internet. That is, computer device 400 can be connected to network 412 via network interface unit 411 connected to system bus 405, or network interface unit 411 can be used to connect to other types of networks or remote computer systems (not shown).

[0100] The memory also includes one or more programs, which are stored in the memory. The central processing unit 401 implements these programs by executing them. Figure 1 or Figure 3 The wafer inspection method shown.

[0101] In exemplary embodiments, a non-transitory computer-readable storage medium including instructions is also provided, such as a memory including instructions that can be executed by a processor of a computer device to perform the wafer inspection methods shown in various embodiments of this disclosure. For example, the non-transitory computer-readable storage medium may be a ROM, random access memory (RAM), CD-ROM, magnetic tape, floppy disk, and optical data storage device, etc.

[0102] The above description is merely an optional embodiment of this disclosure and is not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.

Claims

1. A wafer inspection method, characterized in that, The method includes: Crack detection was performed on each grain of the wafer under both backlight and axial light sources. On the grain distribution map of the wafer, grains with cracks are marked as defective grains; The crack pattern is determined based on the location of the cracked grains in the grain distribution diagram. Grains located within the first radius range of the grains at both ends of the crack pattern are marked as defective grains.

2. The method according to claim 1, characterized in that, The method of detecting cracks in each grain of the wafer under both backlight and axial light sources includes: Place the wafer on the stage; Under the illumination of the backlight, the wafer is scanned to obtain a first wafer image; Convert the first wafer image into a first binary image; The wafer is scanned under the illumination of the axial light source to obtain a second wafer image; Convert the second wafer image into a second binary image; Crack detection is performed on each grain of the wafer based on the first binary image and the second binary image.

3. The method according to claim 2, characterized in that, Based on the first binary image and the second binary image, crack detection is performed on each grain of the wafer, including: Crack detection of each grain is performed in the first binary image and the second binary image respectively using image recognition; When a crack is detected in the grain at the same location in the first binary image and the second binary image, it is determined whether the colors of the crack in the first binary image and the crack in the second binary image are opposite. If the cracks in the first binary image and the cracks in the second binary image have opposite colors, then the grain is determined to be the grain with cracks.

4. The method according to any one of claims 1 to 3, characterized in that, Grains found to have cracks are marked as defective grains, including: The grain located in the middle of a series of continuously arranged cracked grains is marked with a first anomalous pattern; The grains located at the ends of a series of continuously arranged cracked grains are marked with a second anomaly pattern.

5. The method according to any one of claims 1 to 3, characterized in that, Based on the location of the cracked grains in the grain distribution diagram, the crack pattern is determined, including: Determine whether the multiple continuously arranged cracked grains are aligned in a predetermined direction; When a plurality of the cracked grains are arranged in a predetermined direction in a continuous arrangement, the plurality of the cracked grains in a continuous arrangement constitute the crack pattern.

6. The method according to any one of claims 1 to 3, characterized in that, The first radius range is one grain or two grains.

7. A wafer inspection device, characterized in that, The device includes: The detection module is used to detect cracks in each grain of the wafer under both backlight and axial light sources. The labeling module is used to mark grains with cracks as unqualified grains on the grain distribution map of the wafer. The determination module is used to determine the crack pattern based on the location of the cracked grains in the grain distribution diagram. The labeling module is also used to label grains within the first radius range of grains located at both ends of the crack pattern as unqualified grains.

8. The apparatus according to claim 7, characterized in that, The detection module includes: The scanning unit is used to scan the wafer under the illumination of the backlight when the wafer is placed on the stage to obtain a first wafer image; and to scan the wafer under the illumination of the axial light source to obtain a second wafer image. An image processing unit is configured to convert the first wafer image into a first binary image and convert the second wafer image into a second binary image. The detection unit is used to perform crack detection on each grain of the wafer based on the first binary image and the second binary image.

9. The apparatus according to claim 8, characterized in that, The detection unit is used to detect cracks in each grain in the first binary image and the second binary image respectively through image recognition; When a crack is detected in the grain at the same location in the first binary image and the second binary image, it is determined whether the colors of the crack in the first binary image and the crack in the second binary image are opposite. If the cracks in the first binary image and the cracks in the second binary image have opposite colors, then the grain is determined to be the grain with cracks.

10. The apparatus according to any one of claims 7 to 9, characterized in that, The first radius range is one grain or two grains.

Images