Wafer inspection method

Abstract

The wafer inspection method includes acquiring an inspection image from the edge region of the wafer, generating a color curve of the inspection image along the radial direction of the wafer, detecting the side surface of a layer formed on the wafer based on the change of the color curve along a first direction from the side surface of the wafer toward the center of the wafer, and calculating the distance between the side surface of the layer and the side surface of the wafer.

Description

Technical Field

[0001] This disclosure relates to a wafer inspection method. More specifically, this disclosure relates to a wafer inspection method for inspecting the distance between the side surfaces of a wafer and the side surfaces of layers formed on the wafer. Background Technology

[0002] Semiconductor devices can be formed on a substrate such as a silicon wafer by repeatedly performing a series of manufacturing processes. For example, a deposition process can be performed to form a layer on the wafer, a photolithography process can be performed to form a photoresist pattern on the layer, an etching process can be performed to pattern the layer formed on the wafer by using the photoresist pattern as an etching mask, and a planarization process can be performed to planarize the layer formed on the wafer.

[0003] The photolithography process can include a coating process to form a photoresist layer on a wafer, as well as an exposure and development process to pattern the photoresist layer in order to form a photoresist pattern. Simultaneously, the edge portions of the photoresist layer can be removed by an edge bead removal (EBR) process or a wafer edge exposure (EEW) process to reduce particle generation in subsequent processes.

[0004] Furthermore, an inspection process can be performed on the edge region of the wafer exposed by removing the edge portion of the photoresist layer (hereinafter referred to as the "EBR region"). Specifically, the apparatus for performing the inspection process on the EBR region can illuminate the EBR region with light, detect the light reflected from the EBR region, and calculate the width of the EBR region by analyzing the detected light. In addition, the EBR inspection apparatus can rotate the wafer and can repeatedly measure the width of the EBR region while rotating the wafer.

[0005] However, in order to perform the EBR inspection process as described above, the EBR inspection apparatus needs to be separate from the apparatus that performs the EBR process. Therefore, it may take considerable time and cost to transfer the wafer to the EBR inspection apparatus and use the EBR inspection apparatus to perform the EBR inspection process. Summary of the Invention

[0006] Embodiments of the present invention provide a wafer inspection method that can reduce the time and cost of inspecting wafers and improve the reliability of inspection results.

[0007] According to an aspect of the present invention, a wafer inspection method may include acquiring an inspection image from an edge region of the wafer, generating a color curve of the inspection image along the radial direction of the wafer, and detecting the side surface of a layer formed on the wafer based on the change of the color curve along a first direction from the side surface of the wafer toward the center of the wafer.

[0008] According to some embodiments of the present invention, obtaining an inspection image may include obtaining a color image of the wafer by imaging the wafer, extracting a first image corresponding to an edge region of the wafer from the color image, converting the first image into a strip-shaped second image, and extracting a portion of the second image to obtain an inspection image.

[0009] According to some embodiments of the present invention, the color curve may include color level values ​​and gray level values ​​that constitute the inspected image.

[0010] According to some embodiments of the present invention, the color curve may include color ratio values ​​calculated from color level values.

[0011] According to some embodiments of the present invention, generating a color curve may include detecting red, green, blue and gray level values ​​of pixels constituting an inspection image, calculating the horizontal average value of the red, green, blue and gray level values ​​along a second direction perpendicular to the first direction, and using the horizontal average value to generate a color level curve and a gray level curve of the inspection image along the first direction.

[0012] According to some embodiments of the present invention, generating a color curve may further include generating a color ratio curve of the inspection image using a color level curve of the inspection image.

[0013] According to some embodiments of the present invention, detecting the side surface of the layer may include selecting a color from red, green and blue based on the color of the layer, and searching for a color ratio curve corresponding to the selected color from a color ratio curve along a first direction to detect pixels having a predetermined color ratio of the selected color.

[0014] According to some embodiments of the present invention, the side surface of the detection layer may further include a color ratio curve searched from the detected pixel along a first direction to detect a second pixel having a predetermined color ratio of the selected color when the color level value of the selected color of the detected pixel or the gray level value of the detected pixel is lower than a predetermined value.

[0015] According to some embodiments of the present invention, for pixels whose color level value or grayscale value of the selected color is lower than a predetermined value, the search along the first direction can be skipped.

[0016] According to some embodiments of the present invention, when an inflection point exists in a portion of the color ratio curve that is above or below a predetermined color ratio, a pixel having a predetermined color ratio can be detected by searching the color ratio curve from the inflection point along a first direction.

[0017] According to some embodiments of the present invention, the wafer inspection method may further include the distance between the side surface of the computation layer and the side surface of the wafer.

[0018] According to another aspect of the present invention, a wafer inspection method may include acquiring a color image of the wafer by imaging the wafer, extracting an inspection image corresponding to a portion of the edge region of the wafer from the color image, and generating a color scale curve of the inspection image along the radial direction of the wafer. Based on a change in the color scale curve along a first direction from the side surface of the wafer toward the center of the wafer, the side surface of a layer formed on the wafer is detected, and the distance between the side surface of the layer and the side surface of the wafer is calculated.

[0019] According to some embodiments of the present invention, extracting an inspection image may include extracting a first image corresponding to an edge region of a wafer from a color image, converting the first image into a strip-shaped second image, and extracting a portion of the second image to obtain an inspection image.

[0020] According to some embodiments of the present invention, generating a color ratio curve may include detecting red, green, and blue level values ​​of pixels constituting an inspection image, and calculating a horizontal average value of the red, green, and blue level values ​​along a second direction perpendicular to the first direction. The horizontal average value is used to generate red, green, and blue level curves of the inspection image along the first direction, and the horizontal average value is also used to generate red, green, and blue ratio curves of the inspection image along the first direction.

[0021] According to some embodiments of the present invention, detecting the side surface of the layer may include selecting a color from red, green and blue based on the color of the layer, and searching for a color ratio curve corresponding to the selected color from a color ratio curve along a first direction to detect pixels having a predetermined color ratio of the selected color.

[0022] According to some embodiments of the present invention, the wafer inspection method may further include generating a grayscale level curve of an inspection image along the radial direction of the wafer.

[0023] According to some embodiments of the present invention, generating a grayscale level curve may include detecting grayscale level values ​​of pixels constituting an inspection image, calculating a horizontal average value of grayscale level values ​​along a second direction perpendicular to a first direction, and using the horizontal average value to generate a grayscale level curve of the inspection image along the first direction.

[0024] According to some embodiments of the present invention, the side surface of the detection layer may further include a color ratio curve searched from the detected pixel along a first direction to detect a second pixel having a predetermined color ratio of the selected color when the gray level value of the detected pixel is lower than a predetermined value.

[0025] According to some embodiments of the present invention, for pixels with grayscale values ​​lower than a predetermined value, the search along the first direction can be skipped.

[0026] According to another aspect of the invention, a wafer inspection method may include acquiring a color image of the wafer by imaging the wafer, extracting a first image corresponding to an edge region of the wafer from the color image, converting the first image into a strip-shaped second image, extracting a portion of the second image to obtain an inspection image, merging pixels of the inspection image along a second direction perpendicular to a first direction from the side of the wafer toward the center of the wafer to obtain a second inspection image having a line shape extending along the first direction, generating a color curve of the second inspection image along the first direction, and detecting the side surface of a layer formed on the wafer based on changes in the color curve along the first direction.

[0027] The foregoing overview of the invention is not intended to describe every illustrative embodiment or every implementation of the invention. These embodiments are illustrated in more detail in the following detailed description and claims. Attached Figure Description

[0028] Embodiments of the present invention can be understood in more detail from the following description taken in conjunction with the accompanying drawings, wherein:

[0029] Figure 1 This is a flowchart illustrating a wafer inspection method according to an embodiment of the present invention;

[0030] Figure 2 This indicates that it is suitable for implementation. Figure 1 A schematic diagram of a wafer inspection apparatus for the wafer inspection method shown;

[0031] Figure 3 This is to explain how Figure 2 A schematic diagram of the wafer shown;

[0032] Figure 4 It is by Figure 1 An example of an inspection image acquired by the image processing unit shown;

[0033] Figure 5 This explains how... Figure 4 The image shown contains graphs of the color level curves and grayscale level curves generated in the inspection image.

[0034] Figure 6 This explains how... Figure 5 The graph shows the color scale curve generated by the color level curve.

[0035] Figure 7 Through such Figure 1 Another example of an inspection image obtained through the image processing procedure shown;

[0036] Figure 8 This explains how... Figure 7The graphs shown depict the color level curves and grayscale level curves generated from the examined image; and

[0037] Figure 9 This explains how... Figure 8 The graph shows the color scale curve generated by the color level curve.

[0038] While various modifications and alternatives may be made to the various embodiments, their specific details have been shown by way of example in the accompanying drawings and will be described in detail. However, it should be understood that the invention is not intended to limit the claimed invention to the specific embodiments described. Rather, it is intended to cover all modifications, equivalents, and alternatives that fall within the spirit and scope of the subject matter defined in the claims. Detailed Implementation

[0039] Embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described below, but is practiced in various other forms. The following embodiments are provided not to fully accomplish the entire invention, but to fully convey the scope of the invention to those skilled in the art.

[0040] In the specification, when a component is referred to as being on or connected to another component or layer, it can be directly on or connected to that other component or layer, or there may be an intermediate component or layer. Conversely, when a component is referred to as being directly on or connected to another component or layer, it means that no intermediate component exists. Furthermore, although terms such as first, second, and third are used to describe various regions and layers in the embodiments of the invention, these regions and layers are not limited to these terms.

[0041] The terminology used below is for describing specific embodiments only and does not limit the invention. Furthermore, unless otherwise defined herein, all terms, including technical or scientific terms, are to have the same meaning as commonly understood by those skilled in the art.

[0042] Embodiments of the present invention are described with reference to schematic diagrams of preferred embodiments. Therefore, variations in manufacturing methods and / or permissible errors may be expected from the forms depicted in the drawings. Consequently, the description of embodiments of the invention is not limited to the specific forms or areas shown in the drawings and includes deviations in form. These areas may be entirely schematic, and their forms may not describe or depict the exact form or structure of any given area, and are not intended to limit the scope of the invention.

[0043] Figure 1 This is a flowchart illustrating a wafer inspection method according to an embodiment of the present invention. Figure 2 This indicates that it is suitable for implementation. Figure 1A schematic diagram of the wafer inspection apparatus for the wafer inspection method shown, and Figure 3 This is an explanation Figure 2 A schematic diagram of the wafer shown.

[0044] Reference Figure 1 and Figure 2 The wafer inspection method according to an embodiment of the present invention can be used to inspect wafer 10 during the manufacturing process of a semiconductor device. Specifically, the wafer inspection method can be used to inspect the width of the edge region of wafer 10 (i.e., the EBR region 12 after the edge portion of the photoresist layer 20 formed on wafer 10 has been removed).

[0045] A wafer inspection apparatus 100 for performing a wafer inspection method can be disposed between an EBR process module 220 for removing edge portions of the photoresist layer 20 and a wafer transfer module 210 for transferring the wafer 10. That is, the wafer inspection apparatus 100 can be disposed within an EBR process apparatus 200 for performing the EBR process. The wafer transfer module 210 may include a loading port 212 on which a housing 50 for accommodating the wafer 10 is placed, and a wafer transfer robot 214 for transferring the wafer 10 between the housing 50 and the EBR process module 220. The wafer inspection apparatus 100 can acquire a color image of the wafer 10 by imaging the wafer 10 transferred by the wafer transfer robot 214.

[0046] Specifically, after the EBR process is executed by the EBR process module 220, the wafer 10 can be transferred to the housing 50 by the wafer transfer robot 214, and the wafer inspection device 100 can image the wafer 10 transferred by the wafer transfer robot 214. For example, the wafer transfer robot 214 may include a robotic arm 216 for transferring the wafer 10, and the wafer inspection device 100 may include a camera unit 110 disposed above the transfer path of the wafer 10 and configured to image the wafer 10.

[0047] A line scan camera can be used as the camera unit 110, and an illumination unit 112 for providing illumination light to the wafer 10 can be provided on one side of the line scan camera 110. Furthermore, the wafer inspection apparatus 100 may include a control unit 120 for controlling the operation of the camera unit 110 and the illumination unit 112. The control unit 120 can operate the illumination unit 112 according to the operation of the wafer transfer robot 214, and can control the operation of the camera unit 110 so that the camera unit 110 captures the transfer path of the wafer 10 within a predetermined time after the illumination unit 112 is operated.

[0048] For example, the EBR process apparatus 200 can generate an event log file related to the operation of the wafer transfer robot 214, and the control unit 120 can operate the illumination unit 112 based on the event log file. Specifically, the EBR process apparatus 200 can generate an event log file recording the time when the wafer transfer robot 214 begins transferring the wafer 10, and the control unit 120 can turn on the illumination unit 112 based on the transfer start time of the wafer 10 recorded in the event log file. Furthermore, the control unit 120 can control the operation of the camera unit 110 so as to image the transfer path of the wafer 10 after the illumination unit 112 is turned on, thereby acquiring a color image of the wafer 10.

[0049] According to an embodiment of the present invention, the wafer inspection apparatus 100 may include an image processing unit 130 for processing a color image of the wafer 10 acquired by the camera unit 110. The image processing unit 130 can extract a first annular image corresponding to an edge region of the wafer 10 from the color image of the wafer 10, and can convert the first image into a strip-shaped second image. For example, the first image may have an annular shape, while the second image may have a strip-shaped shape, having a predetermined width along a first direction from the side surface of the wafer 10 toward the center of the wafer 10, and extending along a second direction perpendicular to the first direction.

[0050] Furthermore, the image processing unit 130 can extract a portion of the second image to obtain the inspection image 30 (reference). Figure 4 Specifically, the image processing unit 130 can extract multiple inspection images 30 from the second image to inspect the width of the EBR region 12. For example, the inspection image 30 may include 300 pixels along a first direction and 100 pixels along a second direction. That is, the inspection image 30 may have a size of 300×100. As another example, the inspection image 30 may have a line shape including 300 pixels along the first direction.

[0051] Figure 4 It is as follows Figure 1 The image shown is an example of an inspection image acquired by the image processing unit. Figure 5 This explains how... Figure 4 The graph shown is a diagram of the color level curve and grayscale level curve generated from the examined image, and... Figure 6 This explains how... Figure 5 The graph shows the color scale curve generated by the color level curve. Figure 7 It is by Figure 1 Another example of an inspection image acquired by the image processing unit shown. Figure 8 This is to explain from Figure 7 The graphs shown depict the color level curves and grayscale level curves generated in the examined image, and Figure 9This is to explain from Figure 8 The graph shows the color scale curve generated by the color level curve.

[0052] Reference Figures 4 to 9 The image processing unit 130 can generate a color curve for the inspection image 30 to detect the side surface of the photoresist layer 20. According to an embodiment of the present invention, the image processing unit 130 can detect the color level values ​​and grayscale level values ​​of the pixels constituting the inspection image 30, and can generate a color level curve and a grayscale level curve for the inspection image 30 from the color level values ​​and grayscale level values. Furthermore, the image processing unit 130 can calculate a color ratio value from the color level value and generate a color ratio curve from the color ratio value.

[0053] For example, the image processing unit 130 can detect the red level value, green level value, blue level value and gray level value of the pixels constituting the inspection image 30, and can calculate the horizontal average value of the red level value, green level value, blue level value and gray level value along the second direction.

[0054] The image processing unit 130 can generate red, green, blue, and grayscale curves of the inspection image 30 along the first direction using horizontal average values. Further, the image processing unit 130 can calculate red, green, and blue ratio values ​​from the color horizontal average values, i.e., the red, green, and blue horizontal average values, and can generate red, green, and blue ratio curves from these values.

[0055] As another example, the image processing unit 130 can generate a second inspection image (not shown) with a linear shape by merging pixels in a second direction constituting the inspection image 30. That is, a second inspection image with a size of 300×1 can be generated from the inspection image 30 with a size of 300×100, and a color level curve, a gray level curve, and a color ratio curve can be generated from the second inspection image.

[0056] The control unit 120 can detect the side surface of layer 20, i.e., photoresist layer 20, formed on wafer 10 based on changes in the color curve. For example, the control unit 120 can select a color from red, green, and blue based on the color of layer 20, and can search for a color ratio curve corresponding to the selected color along a first direction from the color ratio curves to detect pixels having a predetermined color ratio of the selected color. In this case, the color of layer 20 formed on wafer 10 can be determined by the material constituting layer 20.

[0057] For example, in the case of photoresist layer 20, the red level may be relatively higher than the green and blue levels, and therefore the control unit 120 can select red from red, green, and blue. In this case, the control unit 120 can detect pixels with a predetermined red ratio by searching a red ratio curve along a first direction, and the detected pixels may be the side surface of photoresist layer 20. Furthermore, the control unit 120 can calculate the distance between the side surface of photoresist layer 20 and the side surface of wafer 10, i.e., the width of EBR region 12.

[0058] Meanwhile, compared to the photoresist layer 20 on wafer 10, the color level value of the EBR region 12 of the inspected image 30 may be relatively low. Accordingly, even when the red ratio value of the detected pixel is equal to or higher than a predetermined red ratio value, if the red level value of the detected pixel is lower than the predetermined level value, the control unit 120 can determine that the detected pixel is not a side surface of the photoresist layer 20. That is, pixels with a color level value lower than the predetermined level value can be included in the EBR region 12, therefore, even if a pixel with a red ratio value equal to or higher than the predetermined ratio value is detected, it is preferable to determine that the detected pixel is not a side surface of the photoresist layer 20.

[0059] Furthermore, the EBR region 12 of the inspected image 30 may appear relatively darker compared to the photoresist layer 20 on the wafer 10. Accordingly, when the grayscale level value of the detected pixel is lower than a predetermined level value, the control unit 120 can determine that the detected pixel is not a side surface of the photoresist layer 20. For example, when the red level value and grayscale level value of the detected pixel are higher than the predetermined level value, and the red ratio value of the detected pixel is equal to or higher than the predetermined ratio value, the control unit 120 can determine that the detected pixel is a side surface of the photoresist layer 20.

[0060] Reference Figure 5 and Figure 6 Pixels with a red ratio value higher than a predetermined ratio value can be detected in the EBR region 12. However, in this case, the red level value and gray level value of the detected pixel may be lower than the predetermined level value, such as 100. Therefore, the control unit 120 can determine that the detected pixel is not a side surface of the photoresist layer 20.

[0061] Reference Figure 8 and Figure 9When a pixel with a red ratio value higher than a predetermined ratio value is detected, and then a pixel with a red ratio value lower than a predetermined ratio value is detected, the control unit 120 can determine that the detected pixels are included in the EBR region 12. According to an embodiment of the present invention, when a predetermined number of pixels with a red ratio value higher than or equal to a predetermined ratio value are continuously detected, the control unit 120 can determine that the continuously detected pixels are the photoresist layer 20. Furthermore, the control unit 120 can determine that the first pixel among the continuously detected pixels is a side surface of the photoresist layer 20.

[0062] According to embodiments of the present invention, such as Figure 9 As shown, when the red ratio curve has multiple inflection points, the control unit 120 can detect pixels with a predetermined ratio value by searching the red ratio curve along a first direction from inflection points above or below a predetermined ratio value. For example, when there are inflection points above or below a predetermined ratio value in the portion where the red level value is above a predetermined level value (e.g., 100), the control unit 120 can detect pixels with a predetermined ratio value by searching the red ratio curve along the first direction from the inflection points.

[0063] The wafer inspection method according to an embodiment of the present invention will now be described with reference to the accompanying drawings.

[0064] Reference Figure 1 In step S110, an inspection image 30 can be obtained from the edge region of wafer 10. Specifically, although not shown in the figures, step S110 may include obtaining a color image of wafer 10 by imaging wafer 10, extracting a first image (not shown) from the color image that has a ring-shaped structure corresponding to the edge region of wafer 10, converting the first image into a second image (not shown) that has a strip-like shape extending along a second direction, and obtaining an inspection image 30 extending along a first direction by extracting a portion of the second image. Although not shown in the figures, multiple inspection images 30 can be extracted from the second image to inspect the width of the EBR region 12. As an example, the inspection image 30 can be extracted from the second image to have a size of approximately 300 × 100.

[0065] Meanwhile, as wafer 10 is being transported by wafer transfer robot 214, color images can be acquired by camera unit 110, and inspection images 30 can be acquired by image processing unit 130.

[0066] In step S120, a color curve for the inspection image 30 may be generated along the radial direction of the wafer 10. For example, although not shown, step S120 may include detecting the red level value, green level value, blue level value, and gray level value of the pixels constituting the inspection image 30, calculating the horizontal average value of the red level value, green level value, blue level value, and gray level value along a second direction, generating a color level curve and a gray level curve for the inspection image 30 along a first direction using the horizontal average value, and generating a color scale curve for the inspection image 30 using the color level curve.

[0067] Step S120 can be performed by the image processing unit 130. The image processing unit 130 can generate a red horizontal curve, a green horizontal curve, a blue horizontal curve, a grayscale horizontal curve, a red scale curve, a green scale curve, and a blue scale curve for the inspection image 30.

[0068] As another example, the image processing unit 130 can generate a linear second inspection image by merging the pixels of the inspection image 30 along the second direction. That is, the image processing unit 130 can generate a second inspection image with a size of 300×1 from the inspection image 30, and can generate a color level curve, a grayscale level curve, and a color ratio curve from the second inspection image.

[0069] Refer again Figure 1 In step S130, the A-side surface of a layer (e.g., photoresist layer 20) formed on wafer 10 can be detected based on changes in the color curve along the first direction. Specifically, although not shown, step S130 may include selecting a color from red, green, and blue according to the color of layer 20, and detecting pixels with a predetermined color ratio by searching for a color ratio curve corresponding to the selected color from the color ratio curves along the first direction.

[0070] For example, the control unit 120 can select red from red, green and blue, and detect pixels with a predetermined red ratio by searching a red ratio curve along a first direction.

[0071] In particular, when the red level value or gray level value of the detected pixel is lower than a predetermined level value, the control unit 120 can determine that the detected pixel is not a side surface of the photoresist layer 20, and can detect a second pixel with a predetermined red ratio by searching the red ratio curve from the detected pixel along the first direction.

[0072] As another example, the control unit 120 can skip searching for pixels with red or gray levels below a predetermined level along a first direction. Specifically, pixels with red or gray levels below the predetermined value may belong to the EBR region 12, therefore, the control unit 120 can skip searching for portions of red or gray levels below the predetermined value. Further, when the red ratio curve has an inflection point above or below the predetermined ratio value in a portion where the red level value is above the predetermined level value (e.g., 100), the control unit 120 can detect pixels with the predetermined ratio value by searching the red ratio curve from the inflection point along the first direction. As described above, by skipping the search for portions of the selected color with a red or gray level value below the predetermined level value or starting the search after the inflection point, the time required to detect the side surface of the photoresist layer 20 can be reduced.

[0073] After detecting the side surface of the photoresist layer 20 as described above, in step S140, the control unit 120 can calculate the distance between the side surface of the photoresist layer 20 and the side surface of the wafer 10, and determine whether the EBR process should be executed normally based on the calculated distance.

[0074] In particular, the inspection steps described above can be repeatedly performed on multiple inspection images 30. In this case, the color curve of the EBR region 12 may be different in each inspection image 30, therefore, the inspection recipe for each inspection image 30 can be set differently. For example, the color selected from each inspection image 30 can be changed according to the color ratio curve of the inspection image 30, and the color ratio reference value of the selected color can be changed. Furthermore, the color level value and grayscale level value for skipping searches can be set differently for each inspection image 30. As described above, different inspection recipes can be set for each inspection image 30, and the inspection images 30 and inspection recipes can be stored in a data storage device.

[0075] The inspection image 30 can be used as a reference image in subsequent wafer inspection processes. For example, after acquiring the inspection image from the wafer in a subsequent inspection process, the control unit 120 can compare the inspection image with the reference image and select the reference image with the highest image matching rate. The control unit 120 can then perform inspection steps on the inspection image using an inspection recipe corresponding to the selected reference image.

[0076] According to the embodiments of the present invention described above, after the EBR process is performed, an inspection process can be performed using a color image of wafer 10 acquired during wafer 10 transfer. Therefore, compared to the prior art, no separate inspection equipment is required, and inspection time and cost can be significantly reduced. In particular, the color of the side surface of layer 20 formed on wafer 10 can be selected based on the color ratio of layer 20, thereby significantly improving the reliability of the inspection process.

[0077] Although exemplary embodiments of the present invention have been described with reference to specific examples, they are not limited thereto. Therefore, those skilled in the art will readily understand that various modifications and variations can be made therein without departing from the spirit and scope of the appended claims.

Claims

1. Wafer inspection methods, including: Obtain inspection images from the edge region of the wafer; Generate a color curve of the inspection image along the radial direction of the wafer; and The side surface of the layer formed on the wafer is detected based on the change of the color curve in a first direction along the side surface of the wafer toward the center of the wafer. The side surface of the layer being detected includes: Choose one color from red, green, and blue based on the color of the layer; and A color ratio curve corresponding to the selected color is searched from the color ratio curves along the first direction to detect pixels having a predetermined color ratio of the selected color; and The color ratio curve is searched along the first direction from the detected pixel to detect a second pixel having the predetermined color ratio of the selected color when the color level value of the selected color of the detected pixel or the gray level value of the detected pixel is lower than a predetermined value.

2. The wafer inspection method as described in claim 1, wherein acquiring the inspection image comprises: A color image of the wafer is obtained by imaging the wafer; Extract a first image of a ring corresponding to the edge region of the wafer from the color image; Convert the first image into a strip-shaped second image; as well as Extract a portion of the second image to obtain the inspection image.

3. The wafer inspection method of claim 1, wherein the color curve comprises color level values ​​and grayscale level values ​​constituting the inspection image.

4. The wafer inspection method of claim 3, wherein the color curve comprises a color ratio value calculated from the color level values.

5. The wafer inspection method of claim 1, wherein generating the color curve comprises: Detect the red level value, green level value, blue level value, and gray level value of the pixels that constitute the inspected image; Calculate the horizontal average of the red, green, blue, and grayscale levels along a second direction perpendicular to the first direction; and The color level curve and grayscale level curve of the inspected image along the first direction are generated using the horizontal average value.

6. The wafer inspection method of claim 5, wherein generating the color curve further comprises: The color level curve of the inspected image is used to generate the color scale curve of the inspected image.

7. The wafer inspection method of claim 1, wherein for pixels whose color level value or grayscale level value of the selected color is lower than a predetermined value, the search along the first direction is skipped.

8. The wafer inspection method of claim 1, wherein when an inflection point exists in a portion of the color ratio curve that is above or below the predetermined color ratio, the pixel having the predetermined color ratio is detected by searching the color ratio curve from the inflection point along the first direction.

9. The wafer inspection method as described in claim 1, further comprising: Calculate the distance between the side surface of the layer and the side surface of the wafer.

10. Wafer inspection methods, including: A color image of the wafer is obtained by imaging the wafer; Extract an inspection image corresponding to a portion of the edge region of the wafer from the color image; A color scaling curve for the inspection image is generated along the radial direction of the wafer; The side surface of the layer formed on the wafer is detected based on a change in one of the color ratio curves along a first direction from the side surface of the wafer toward the center of the wafer; as well as Calculate the distance between the side surface of the layer and the side surface of the wafer. The side surface of the layer being detected includes: Choose one color from red, green, and blue based on the color of the layer; and Search for a color ratio curve corresponding to the selected color from the color ratio curves along the first direction to detect pixels having a predetermined color ratio of the selected color; and The color ratio curve is searched along the first direction from the detected pixel to detect a second pixel having the predetermined color ratio of the selected color when the color level value of the selected color of the detected pixel or the gray level value of the detected pixel is lower than a predetermined value.

11. The wafer inspection method of claim 10, wherein extracting the inspection image comprises: Extract a first image of a ring corresponding to the edge region of the wafer from the color image; Convert the first image into a strip-shaped second image; and A portion of the second image is extracted to obtain the inspection image.

12. The wafer inspection method of claim 10, wherein generating the color ratio curve comprises: Detect the red, green, and blue level values ​​of the pixels that constitute the inspected image; Calculate the horizontal average of the red, green, and blue level values ​​along a second direction perpendicular to the first direction; The horizontal average value is used to generate a red horizontal curve, a green horizontal curve, and a blue horizontal curve for the inspected image along the first direction; as well as The horizontal average value is used to generate red, green, and blue scale curves of the inspected image along the first direction.

13. The wafer inspection method of claim 10, further comprising: Generate a grayscale level curve of the inspection image along the radial direction of the wafer.

14. The wafer inspection method of claim 13, wherein generating the grayscale level curve comprises: Detect the grayscale level values ​​of the pixels that constitute the inspected image; Calculate the horizontal average value of the grayscale level along a second direction perpendicular to the first direction; and The grayscale level curve of the inspected image along the first direction is generated using the horizontal average value.

15. The wafer inspection method of claim 13, wherein for pixels with grayscale values ​​lower than a predetermined value, the search along the first direction is skipped.

16. Wafer inspection methods, including: A color image of the wafer is obtained by imaging the wafer; Extract a first image of a ring corresponding to the edge region of the wafer from the color image; Convert the first image into a strip-shaped second image; Extract a portion of the second image to obtain the inspection image; The pixels of the inspection image are merged along a second direction perpendicular to a first direction from the side of the wafer toward the center of the wafer to obtain a second inspection image having a line shape extending along the first direction; Generate a color curve for the second inspection image along the first direction, and The side surface of the layer formed on the wafer is detected based on the change in the color curve along the first direction. The side surface of the layer being detected includes: Choose one color from red, green, and blue based on the color of the layer; and Search for a color ratio curve corresponding to the selected color from the color ratio curves along the first direction to detect pixels having a predetermined color ratio of the selected color; and The color ratio curve is searched along the first direction from the detected pixel to detect a second pixel having the predetermined color ratio of the selected color when the color level value of the selected color of the detected pixel or the gray level value of the detected pixel is lower than a predetermined value.

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