Screening method and screening system for detection marks and detection method

Abstract

The invention provides a screening method, a screening system and a detection method for detection markers. According to the screening method, feature information of a current detection mark is compared with standard information, whether the current detection mark is qualified or not is judged according to a comparison result, under the condition that the current detection mark is not qualified, a next detection mark can be continuously searched, the comparison process is executed on the searched detection mark again, and the screening accuracy is improved. Until the found detection mark meets the requirement of the standard information. By utilizing the screening method provided by the invention, the unqualified detection marks can be filtered out, the qualified detection marks can be screened out, the subsequent detection process is ensured to be carried out based on the qualified detection marks, and the accuracy of the detection result is improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a screening method and screening system for detection markers, and a detection method. Background Art

[0002] In the field of semiconductor manufacturing, it is usually necessary to perform multiple film deposition processes, photolithography processes, and etching processes on a substrate to form a semiconductor device composed of a plurality of patterned film layers on the substrate. In the manufacturing process of the device, in order to ensure process stability and form a film pattern that meets the requirements, a detection mark for detection is usually formed on the substrate. For example, in order to ensure that the alignment requirements between the various film layers are met, an overlay error is generally used to indicate the alignment status between the patterned film layers. Specifically, an overlay mark is formed on the substrate, and the overlay mark is detected to determine the alignment status between the film layers formed under different photolithography processes.

[0003] However, in the actual process of detecting the detection mark, the detection mark or the captured image containing the detection mark often appears abnormal, resulting in inaccurate detection results. Summary of the invention

[0004] The object of the present invention is to provide a method for screening detection markers, which is used to screen detection markers to ensure that subsequent detection processes are performed based on qualified detection markers, thereby improving the accuracy of detection results.

[0005] In this regard, the present invention provides a method for screening detection marks, including: step one, obtaining characteristic information of the current detection mark; step two, comparing the characteristic information with standard information to determine whether the characteristic information matches the standard information; if so, determining that the current detection mark is qualified; if not, determining that the current detection mark is unqualified, and then looking for the next detection mark, repeating steps one and two for the next detection mark until a qualified detection mark is obtained.

[0006] Optionally, the method for obtaining characteristic information of the current detection mark includes: obtaining an image of the detection mark and obtaining grayscale information of the image; intercepting a portion of the grayscale information whose grayscale value is within a preset interval; and obtaining the number of grayscale peaks and the width of each grayscale peak within the preset interval to constitute the characteristic information.

[0007] Optionally, the method for obtaining the standard information includes: providing a standard image, wherein the standard image has a qualified detection mark, and obtaining grayscale information of the standard image; selecting a grayscale interval in which the grayscale value of the detection mark is located from the grayscale information of the standard image, and setting the grayscale interval as the preset interval; and obtaining the number of grayscale peaks and the width of each grayscale peak from the grayscale interval, and using the number of grayscale peaks and the width of each grayscale peak in the grayscale interval as comparison items in the standard information.

[0008] Optionally, the method for finding the next detection mark includes: obtaining a relative position between the next detection mark and the current detection mark, and finding the next detection mark according to the relative position.

[0009] Optionally, after finding the next detection mark, the method further includes verifying the position coordinates of the next detection mark. The method for verifying the position coordinates of the detection mark includes: setting a verification standard, and the method for setting the verification standard includes: setting an auxiliary mark, defining the position of the auxiliary mark as the origin (0, 0), and obtaining the coordinates (X, Y) of the theoretical position of the detection mark to be verified from the origin, and combining the size (Dx, Dy) of the detection mark to set the verification standard (X±Dx, Y±Dy); and comparing the coordinates of the actual position of the detection mark found with the verification standard, judging whether the coordinates of the actual position of the detection mark found exceeds the verification standard, so as to confirm whether the detection mark currently found is the expected detection mark.

[0010] Optionally, the detection mark is formed in a substrate using a photolithography process. Wherein, at least two detection marks are formed in the same product unit, and when one of the detection marks is detected as unqualified, other detection marks in the same product unit are found as the next detection mark; or, only one detection mark is formed in the same product unit, and when the detection mark in the current product unit is determined to be unqualified, a detection mark in another adjacent product unit is found as the next detection mark.

[0011] Optionally, the screening method includes: step S100, obtaining an image of the current detection mark; step S200, collecting grayscale information of the image; step S300, intercepting the part of the grayscale information whose grayscale value is within a preset interval, and obtaining the number of grayscale peaks and the width of each grayscale peak within the preset interval; step S400, comparing the number of grayscale peaks and the width of each grayscale peak of the current detection mark within the preset interval with the number of grayscale peaks and the width range of grayscale peaks within the preset interval in the standard information one by one; wherein, when all comparison results match, the current detection mark is determined to be qualified; when any comparison result does not match, execute step S500; step S500, search for the next detection mark; step S600, verify the position coordinates of the found detection mark; wherein, when the verification fails, return to step S500 to find the required detection mark again and verify the position coordinates until the verification passes; if the verification passes, return to step S100.

[0012] Optionally, the detection mark includes an overlay mark.

[0013] The present invention also provides a detection method, comprising: using the above-mentioned method for screening detection markers to screen out qualified detection markers; and performing detection based on the qualified detection markers.

[0014] The present invention also provides a screening system for detection marks, comprising: an information collection unit, used to collect characteristic information of the detection mark; an information processing unit, used to compare the characteristic information with standard information to determine whether the characteristic information matches the standard information; if so, the detection mark is judged to be qualified; if not, the detection mark is judged to be unqualified; and a positioning unit, used to locate the position of the detection mark, and when receiving a signal from the information processing unit that the detection mark is unqualified, locate the position of the next detection mark to find the next detection mark.

[0015] Optionally, the screening system further includes: an image acquisition unit for acquiring an image of the detection mark. And the information acquisition unit is used to acquire grayscale information of the image, and intercept the portion of the grayscale information whose grayscale value is within a preset interval, to obtain the number of grayscale peaks within the preset interval and the width of each grayscale peak, so as to form the characteristic information.

[0016] Optionally, the information processing unit is also used to verify the position coordinates of the detection mark, including: setting a verification standard, and comparing the coordinates of the actual position of the detection mark found with the verification standard, and determining whether the coordinates of the actual position of the detection mark found exceeds the verification standard, so as to confirm whether the detection mark found is the expected detection mark.

[0017] In the screening method for detection marks provided by the present invention, the characteristic information of the current detection mark is compared with the standard information. When the characteristic information of the detection mark matches the standard information, it can be judged that the current detection mark is qualified, and the subsequent detection operation can be performed based on the current detection mark; and when the characteristic information of the detection mark does not meet the preset range of the standard information, it can be judged that the current detection mark is unqualified, and the next detection mark can be searched for, and the information collection and information comparison process as described above is performed on the detection mark until the detection mark found meets the requirements of the standard information. Using the screening method provided by the present invention, unqualified detection marks can be filtered out, qualified detection marks can be screened out, and the subsequent detection process can be ensured to be performed based on qualified detection marks, thereby improving the accuracy of the detection results. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The included drawings are used to provide a further understanding of the embodiments of the present application, which constitute a part of the specification, are used to illustrate the implementation of the present application, and together with the text description, explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application.

[0019] Figure 1 and Figure 2 Schematic diagram of two structures of overlay marking.

[0020] Figure 3 Schematic diagram of a process for screening detection markers in one embodiment of the present invention.

[0021] Figure 4 Schematic diagram of the structure of a screening system for detecting markers in one embodiment of the present invention. DETAILED DESCRIPTION

[0022] The core idea of ​​the present invention is to provide a method for screening detection markers, which is used to preferentially screen whether the detection markers are qualified before testing the detection markers, so as to avoid the problem of inaccurate detection results caused by subsequent testing based on abnormal detection markers.

[0023] The screening method provided in one embodiment of the present invention specifically includes: step one, obtaining characteristic information of the current detection mark; step two, comparing the characteristic information with the standard information to determine whether the characteristic information matches the standard information; if so, the current detection mark is determined to be qualified and can be used for subsequent detection operations; if not, the current detection mark is determined to be unqualified, then the next detection mark is found, and steps one and two are repeated until a qualified detection mark is obtained.

[0024] In the screening method provided by the present invention, unqualified detection markers are filtered out by feature judgment of the detection markers, and qualified detection markers are screened out, ensuring that the subsequent detection process is based on the qualified detection markers, thereby improving the accuracy of the detection results.

[0025] The following is a further detailed description of the screening method, screening system and detection method for detection markers proposed by the present invention in conjunction with the accompanying drawings and specific embodiments. According to the following description, the advantages and features of the present invention will be clearer, and those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. It should be noted that the drawings are all in a very simplified form and are all in non-precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. It should be recognized that relative terms such as "above", "below", "top", "bottom", "above" and "below" shown in the drawings can be used to describe the relationship between various elements. These relative terms are intended to cover different orientations of elements other than the orientations depicted in the drawings. For example, if the device is inverted relative to the view in the drawing, an element described as "above" another element will now be below the element.

[0026] In a specific example, the detection mark can be formed on a substrate, for example, it can be set in the scribe line area of ​​the substrate or can be set in the corner of each product unit (shot). The detection mark includes, for example, an overlay mark, which can reflect the offset state between different film layers formed based on different photolithography processes. For details, please refer to Figure 1 As shown, the overlay mark may include: a first film layer 110 and a second film layer 120 formed in different photolithography processes. By measuring the horizontal offset between the first film layer 110 and the second film layer 120, the overlay deviation (OVL) between the corresponding front-end photolithography process and the back-end photolithography process can be obtained. It should be recognized that the specific graphic design of the overlay mark can be set according to actual needs and is not limited here. For example, in other examples, the overlay mark can also be as follows Figure 2 As shown, it also includes a first film layer 110 and a second film layer 120 formed in different photolithography processes.

[0027] In a specific example, the screening process of the detection mark can be directly performed using a corresponding detection device, which preferentially screens the found detection marks to obtain qualified detection marks before performing a detection operation on the detection items of the detection mark. The detection items of the detection mark described here include, for example, overlay deviation detection for the overlay mark.

[0028] Furthermore, the detection device can be used to obtain the characteristic information of the current detection mark. Among them, the method for obtaining the characteristic information of the current detection mark may include: first, obtaining the image of the detection mark and obtaining the grayscale information of the image; then, intercepting the part of the grayscale information whose grayscale value is within the preset interval, wherein the part whose grayscale value is within the preset interval is the grayscale interval corresponding to the qualified detection mark; then, obtaining the number of grayscale peaks and the width of each grayscale peak within the preset interval, wherein each grayscale peak corresponds to a stripe pattern, for example, and the width of the grayscale peak can represent the width of the corresponding stripe pattern. In addition, in practical applications, after obtaining the grayscale information of the image, it also includes filtering the grayscale information to improve the signal-to-noise ratio of the information.

[0029] After obtaining the characteristic information of the detection mark, the characteristic information can be compared with the standard information to determine whether the characteristic information matches the standard information. Among them, the standard information can specifically obtain the corresponding characteristic information according to the qualified detection mark, so that the characteristic information of the qualified detection mark is set as the standard information as the comparison target for screening and judgment. That is, the method for obtaining the standard information, for example, includes: providing a standard image, in which a qualified detection mark is displayed; then, based on the standard image, the corresponding characteristic information is obtained, and it is set as the standard information. More specifically, the method for obtaining the standard information includes: obtaining the grayscale information of the standard image; then, selecting the grayscale interval corresponding to the grayscale value of the detection mark in the grayscale information, and setting the grayscale interval as a preset interval for screening and judgment; then, obtaining the number of grayscale peaks and the width of each grayscale peak from the grayscale interval, wherein each grayscale peak corresponds to a bar graph, for example, and the width of the grayscale peak can represent the width of the corresponding bar graph, and the number of grayscale peaks and the width of each grayscale peak in the grayscale interval are used as comparison items in the standard information.

[0030] That is, in the process of screening the current detection mark, the number of grayscale peaks and the width of the grayscale peaks in the preset interval of the current detection mark are compared one by one with the number of grayscale peaks and the width of the grayscale peaks in the preset interval in the standard information. When any of the comparison items does not match, the current detection mark is judged to be unqualified, and then the next detection mark is found, and the process of information collection and information comparison for the detection mark as described above is repeated until a qualified detection mark is obtained.

[0031] by Figure 1 and Figure 2 Taking the overlay mark shown as an example, the overlay mark has 8 strip patterns, and correspondingly 8 grayscale peaks can be formed, and the width of each grayscale peak corresponds to the width of each strip pattern.

[0032] In a further solution, the method for finding the next detection mark includes, for example, obtaining the relative position of the next detection mark and the current detection mark, and finding the next detection mark according to the relative position. In a specific example, an image acquisition unit of the detection device can be used to capture an image containing the detection mark and display it; and when finding the next detection mark, the image acquisition unit will move from the current position to the position where the next detection mark is set according to the relative position, and display the image of the next detection mark.

[0033] Among them, the relative position of the next detection mark and the current detection mark can be specifically expressed by coordinates. In the specific example, the relative position is (△X±Dx, △Y±Dy), where △X is the relative distance between the next detection mark and the current detection mark in the X direction, △Y is the relative distance between the next detection mark and the current detection mark in the Y direction, and Dx and Dy are the sizes of the detection mark in the X direction and the Y direction, respectively. Therefore, the relative position (△X±Dx, △Y±Dy) can be obtained based on the coordinate difference (△X, △Y) of the next detection mark relative to the current detection mark, combined with the size Dx of the detection mark in the X direction and the size Dy of the detection mark in the Y direction.

[0034] In a specific example, after the next detection mark is found, the position coordinates of the next detection mark are further verified to confirm whether the currently found detection mark is the expected detection mark.

[0035] Among them, the method for verifying the position coordinates of the detection mark includes, for example, setting a verification standard Spec, and the setting method of the verification standard Spec is, for example, defining the position of an auxiliary mark on the substrate as the origin (0, 0), and obtaining the coordinates (X, Y) of the theoretical position of the detection mark to be verified from the origin, and on this basis, combining the size Dx of the detection mark in the X direction and the size Dy of the detection mark in the Y direction, and then setting the verification standard Spec (X±Dx, Y±Dy); then, comparing the coordinates of the actual position of the detection mark found with the verification standard Spec, and judging whether the coordinates of the actual position of the detection mark found exceeds the verification standard, so as to confirm whether the detection mark currently found is the expected detection mark. When the coordinates of the actual position of the detection mark do not exceed the verification standard Spec, it means that the current detection mark is the expected detection mark; on the contrary, when the coordinates of the actual position of the detection mark exceed the verification standard Spec, it means that the current detection mark is not the expected detection mark, and displacement compensation can be performed at this time to find the real detection mark.

[0036] After the expected detection mark is determined, the process of collecting and comparing the information of the detection mark as described above can be repeated until a qualified detection mark is obtained.

[0037] In addition, as described above, the detection mark can be set in the scribe lines of the substrate, or can be set in the corners of each product unit (shot), or can be specifically set in the scribe lines of each product unit (shot).

[0038] In one example, spare marks are provided in the scribe lines of the same product unit (shot), that is, at least two detection marks are formed in the same product unit, one of which can be used as the preferred mark for detection, and the other detection marks are used as spare marks. When one of the detection marks is unqualified, other detection marks (i.e., spare marks) can be preferentially found in the same product unit as the next detection mark, and the spare marks can be screened. If the spare mark is qualified, the spare mark is used as the detection object for detection; if the spare mark in the same product unit (shot) is unqualified, it can be moved to another adjacent product unit (shot) to find the detection mark.

[0039] In another example, no spare mark is set in the scribe lines of the same product unit (shot), that is, only one detection mark is formed in the same product unit. In this case, if the current detection mark is unqualified, you can move to another adjacent product unit (shot) to find the detection mark.

[0040] In order to explain the screening method provided in this embodiment more clearly, Figure 3 The specific screening process is used as an example to illustrate.

[0041] First, step S100 is performed to obtain the current image of the detection mark. In a specific example, the image acquisition unit of the detection device can be directly used to capture the image containing the detection mark.

[0042] It should be noted that when the detection mark displayed in the image is abnormal, one possibility is that the detection mark itself is abnormal, resulting in the displayed detection mark being unqualified; or it may be that the detection mark displayed is abnormal due to interference when the device is capturing the image. For example, when capturing the image of the detection mark of metal material, the displayed mark is often abnormal due to metal discharge. Regardless of the reason for the abnormal detection mark displayed, it will affect the detection result, so it is necessary to identify and screen the detection marks that do not meet the requirements.

[0043] Then, step S200 is performed to collect grayscale information of the image, wherein the grayscale information includes information of the detection mark.

[0044] Then, step S300 is performed to intercept the part of the grayscale information whose grayscale value is within the preset interval, and obtain the number N of grayscale peaks and the width M of each grayscale peak within the preset interval as the characteristic information of the current detection mark. Among them, the method for obtaining the preset interval can refer to the above, that is, by obtaining the grayscale information of the standard image showing the qualified detection mark, and selecting the grayscale interval corresponding to the grayscale value of the detection mark in the grayscale information to be used as the preset interval. In other words, the preset interval is the interval where the grayscale value of the qualified detection mark is located, so when the current detection mark is qualified, all the corresponding grayscale information will correspond to the preset interval; on the contrary, when the current detection mark is unqualified, all the corresponding grayscale information may partially exceed the preset interval.

[0045] Then, step S400 is performed to compare the number N of grayscale peaks and the width M of each grayscale peak in the preset interval of the current detection mark with the number N' of grayscale peaks and the width range [M1, M2] of grayscale peaks in the preset interval in the standard information, where M1 is the minimum width value and M2 is the maximum width value. When any comparison result does not match, that is, any comparison result is NG, step S500 is performed.

[0046] Among them, when the current detection mark is qualified, all the corresponding grayscale information will be located in the preset interval, and the number N of grayscale peaks and the width M of each grayscale peak in the preset interval match the number of grayscale peaks N' and the width range [M1, M2] of the grayscale peaks in the preset interval in the standard information one by one (that is, N = N', and M1 ≤ M ≤ M2). Therefore, when the characteristic information of the detection mark matches the standard information, it can be determined that the current detection mark is qualified.

[0047] On the contrary, when the current detection mark is unqualified, all the corresponding grayscale information may partially exceed the preset interval and not be intercepted. At this time, the number N of grayscale peaks and the width M of each grayscale peak in the preset interval cannot match the number of grayscale peaks N' and the width range [M1, M2] of each grayscale peak in the preset interval in the standard information; or, even if all the grayscale information of the detection mark is within the preset interval, when the displayed detection mark is abnormal, it will still cause the number N of grayscale peaks and the width M of each grayscale peak in the preset interval to be unable to match the number of grayscale peaks N' and the width range [M1, M2] of each grayscale peak in the preset interval in the standard information. Therefore, when the characteristic information of the detection mark does not match the standard information, it can be determined that the current detection mark is unqualified, and step S500 is continued.

[0048] Then, step S500 is executed to find the next detection mark. As described above, the image acquisition unit of the detection device can be moved to the position of the next detection mark according to the relative position (△X±Dx, △Y±Dy) between the next detection mark and the current detection mark. When a spare mark is set in the same product unit (shot), the spare mark in the same product unit can be found as the next detection mark; or, when no spare mark is set in the same product unit (shot), the next detection mark can be moved to another adjacent product unit (shot) to find the next detection mark.

[0049] Then execute step S600 to verify the position coordinates of the detection mark found. Wherein, the method of position coordinate verification can refer to the above, that is, the coordinates of the actual position of the detection mark found are compared with the verification standard Spec (X ± Dx, Y ± Dy), and it is determined whether the coordinates of the actual position of the detection mark found exceed the verification standard Spec (X ± Dx, Y ± Dy). If the coordinates of the actual position of the detection mark exceed the verification standard Spec, then verify NG, which means that the detection mark found is not the expected detection mark required, and then return to step S500 to find the required detection mark again, and continue to execute step S600 to verify the position coordinates thereof, until the verification is OK. If the coordinates of the actual position of the detection mark do not exceed the verification standard Spec, then verify OK, which means that the detection mark found is the expected detection mark required, and then return to step S100 until the judgment result of step S400 is OK, to find a qualified detection mark.

[0050] Based on the above screening method, this embodiment also provides a screening system. For example, refer to Figure 4As shown, the screening system in one embodiment of the present invention includes: an information collection unit, an information processing unit and a positioning unit. The information collection unit is used to collect characteristic information of the detection mark; the information processing unit is used to compare the characteristic information with the standard information to determine whether the characteristic information matches the standard information, and then determine whether the detection mark is qualified; the positioning unit is used to locate the position of the detection mark, and when receiving a signal from the information processing unit that the detection mark is unqualified, locate the position of the next detection mark to find the next detection mark.

[0051] In a specific example, the screening system further includes an image acquisition unit for acquiring an image of the detection mark. In this example, the information acquisition unit can be used to acquire grayscale information of the image, and the portion of the grayscale information whose grayscale value is within a preset interval is intercepted to obtain the number of grayscale peaks within the preset interval and the width of each grayscale peak to form the characteristic information of the detection mark.

[0052] Continue to refer Figure 4 As shown, the screening system may also include a storage unit for storing standard information. The information acquisition unit receives the characteristic information of the detection mark from the information acquisition unit, and retrieves the corresponding standard information in the storage unit for comparison and judgment. In addition, the image acquisition unit may also be connected to the storage unit for storing the acquired image in the storage unit. At this time, for example, the image of the detection mark acquired by the image acquisition unit each time may be stored in the storage unit, which is conducive to the subsequent tracing of the image in the screening process of the detection mark.

[0053] In a further scheme, the information processing unit is also used to verify the position coordinates of the found detection mark, specifically including: setting a verification standard, the setting method of the verification standard Spec is, for example, defining the position of an auxiliary mark on the substrate as the origin (0, 0), and obtaining the coordinates (X, Y) of the theoretical position of the detection mark to be verified from the origin, and on this basis, combining the size Dx of the detection mark in the X direction and the size Dy of the detection mark in the Y direction, and then setting the verification standard Spec (X±Dx, Y±Dy); then, comparing the coordinates of the actual position of the detection mark found with the verification standard, and judging whether the coordinates of the actual position of the detection mark found exceeds the verification standard, so as to confirm whether the detection mark found is the expected detection mark.

[0054] In this embodiment, the working process of the screening system includes, for example: first, using the positioning unit to locate the position of the required detection mark; then, the image acquisition unit moves to the position of the detection mark according to the positioning, and captures an image containing the detection mark; then, using the information acquisition unit to collect feature information in the image and send it to the information processing unit; then, the information processing unit compares the feature information with the standard information retrieved from the storage unit to determine whether the current detection mark is qualified; if it is unqualified, the signal is fed back to the positioning unit to enable the positioning unit to locate the position of the next detection mark, and continue the process of information collection and information judgment for the next detection mark.

[0055] The positioning unit can locate the position of the next detection mark according to whether a spare mark is set in the current product unit (shot). Specifically, when a spare mark is set in the scribe lines of the same product unit (shot), the positioning unit can preferentially locate the spare mark in the same product unit as the next detection mark. When no spare mark is set in the scribe lines of the same product unit (shot), the positioning unit can locate the detection mark in another adjacent product unit (shot) as the next detection mark.

[0056] In an optional scheme, after the positioning unit locates the position of the next detection mark and before collecting information on it, the positioning unit also sends the coordinate information of the actual position of the next detection mark found to the information processing unit. The information processing unit receives the coordinates of the actual position of the next detection mark and verifies the position coordinates thereof, specifically including: setting a verification standard, and comparing the coordinates of the actual position of the detection mark to be verified with the verification standard, and determining whether the coordinates of the actual position of the next detection mark found exceed the verification standard, so as to confirm whether the detection mark found is the expected detection mark. After the position coordinates are verified, the information processing unit also sends its verification result to the positioning unit, wherein when the verification result is qualified (i.e., the detection mark found is the expected detection mark), the positioning unit may send the position coordinates of the next detection mark located to the image acquisition unit to instruct the image acquisition unit to move to the position of the detection mark according to the positioning and capture an image containing the detection mark; conversely, when the verification result is unqualified (i.e., the detection mark found is not the expected detection mark), the positioning unit may search for the required detection mark again, and continue to send the coordinate information of the actual position of the detection mark found again to the information processing unit, so that the information processing unit can verify its position coordinates until the verification result is qualified.

[0057] A detection method is also provided in this embodiment. In this detection method, before performing a detection operation on the detection item of the detection mark, the found detection marks are preferentially screened to obtain qualified detection marks. Specifically, the detection method includes: using the above-mentioned screening method for the detection mark to screen out qualified detection marks; then, performing detection based on the qualified detection marks. In this way, the accuracy of the detection result is improved. Alternatively, the detection method includes: using the above-mentioned screening system for the detection mark to screen out qualified detection marks; then, performing detection based on the qualified detection marks. In this way, the accuracy of the detection result is improved. In a specific example, the detection method may include overlay deviation detection, in which the overlay mark (for example Figure 1 and Figure 2 The overlay marks are screened (see the schematic diagram of the overlay marks shown in FIG. 1 ), and the screened qualified overlay marks are subjected to overlay deviation detection.

[0058] It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referred to each other. For the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description.

[0059] Although the present invention has been disclosed as above with preferred embodiments, the above embodiments are not intended to limit the present invention. The present invention can also be implemented or applied through other different specific implementation methods, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. For any technician familiar with the art, without departing from the scope of the technical solution of the present invention, the technical content disclosed above can be used to make many possible changes and modifications to the technical solution of the present invention, or modified into equivalent embodiments of equivalent changes. Therefore, any simple modification, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still belong to the scope of protection of the technical solution of the present invention.

[0060] It must be noted that the singular forms "a" and "an" as used herein and in the appended claims include plural references unless the context clearly indicates otherwise. For example, reference to "a step" or "a device" means reference to one or more steps or devices, and may include secondary steps as well as secondary devices. Also, the term "comprises / includes" when used herein refers to the presence of a feature, whole, step or component, but does not exclude the presence or addition of one or more other features, wholes, steps or components. In addition, all conjunctions used should also be understood in the broadest sense. Also, the word "or" should be understood to have the definition of a logical "or", rather than a logical "exclusive or", unless the context clearly indicates otherwise.

Claims

1. A method for screening a detection marker, characterized in that: include: Step 1, obtaining feature information of the current detection mark; Step 2: compare the characteristic information with the standard information to determine whether the characteristic information matches the standard information; if so, determine that the current detection mark is qualified; if not, determine that the current detection mark is unqualified, and then find the next detection mark, repeat steps 1 and 2 for the next detection mark, until a qualified detection mark is obtained.

2. The method for screening a detection marker according to claim 1, wherein: The method of obtaining the characteristic information of the current detection mark includes: Acquire the image of the detection mark and obtain grayscale information of the image; intercepting a portion of the grayscale information whose grayscale value is within a preset interval; and, The number of grayscale peaks and the width of each grayscale peak within the preset interval are obtained to form the characteristic information.

3. The method for screening a detection marker according to claim 2, wherein: The method for obtaining the standard information includes: Providing a standard image, wherein the standard image has a qualified detection mark, and obtaining grayscale information of the standard image; Selecting a grayscale interval where the grayscale value of the detection mark is located from the grayscale information of the standard image, and setting the grayscale interval as the preset interval; The number of grayscale peaks and the width of each grayscale peak are obtained from the grayscale interval, and the number of grayscale peaks and the width of each grayscale peak in the grayscale interval are used as comparison items in the standard information.

4. The method for screening a detection marker according to claim 1, wherein: The method for finding the next detection mark includes: obtaining the relative position of the next detection mark and the current detection mark, and finding the next detection mark according to the relative position.

5. The method for screening a detection marker according to claim 1, wherein: After finding the next detection mark, it also includes verifying the position coordinates of the next detection mark; The method for verifying the position coordinates of the detection mark includes: A verification standard is set, and the verification standard setting method includes: setting an auxiliary mark, and defining the position of the auxiliary mark as the origin (0, 0), and obtaining the coordinates (X, Y) of the theoretical position of the detection mark to be verified from the origin, and combining the size Dx of the detection mark in the X direction and the size Dy of the detection mark in the Y direction, setting the verification standard (X±Dx, Y±Dy); and, The coordinates of the actual position of the found detection mark are compared with the verification standard to determine whether the coordinates of the actual position of the found detection mark exceed the verification standard, so as to confirm whether the currently found detection mark is the expected detection mark.

6. The method for screening a detection marker according to claim 1, wherein: The detection mark is formed in a substrate by using a photolithography process; Wherein, at least two detection marks are formed in the same product unit, and when one of the detection marks is detected as unqualified, other detection marks in the same product unit are found as the next detection mark; or, Only one detection mark is formed in the same product unit. When the detection mark in the current product unit is determined to be unqualified, the detection mark in another adjacent product unit is found as the next detection mark.

7. The method for screening a detection marker according to claim 1, wherein: include: Step S100, obtaining the current detection mark image; Step S200, collecting grayscale information of the image; Step S300, intercepting a portion of the grayscale information whose grayscale value is within a preset interval, and obtaining the number of grayscale peaks and the width of each grayscale peak within the preset interval; Step S400, comparing the number of grayscale peaks and the width of each grayscale peak in the preset interval of the current detection mark with the number of grayscale peaks and the width range of the grayscale peaks in the preset interval in the standard information respectively; When all comparison results match, the current detection mark is determined to be qualified; when any comparison result does not match, step S500 is executed; Step S500, searching for the next detection mark; Step S600, verifying the position coordinates of the found detection mark; if the verification fails, return to step S500 to find the required detection mark again and verify the position coordinates until the verification passes; if the verification passes, return to step S100.

8. The method for screening a detection marker according to any one of claims 1 to 7, characterized in that: The detection mark includes an overlay mark.

9. A detection method, characterized in that: include: Using the method for screening detection markers as described in any one of claims 1 to 8 to screen out qualified detection markers; as well as, Detection is performed based on qualified detection markers.

10. A screening system for detecting a marker, characterized in that include: An information collection unit, used to collect characteristic information of the detection mark; An information processing unit, used to compare the characteristic information with the standard information to determine whether the characteristic information matches the standard information; if so, determine that the detection mark is qualified; if not, determine that the detection mark is unqualified; The positioning unit is used to locate the position of the detection mark, and when receiving the signal from the information processing unit that the detection mark is unqualified, locate the position of the next detection mark to find the next detection mark.

11. The screening system for detecting markers according to claim 10, wherein: Also includes: An image acquisition unit, used to acquire an image of the detection mark; Furthermore, the information acquisition unit is used to acquire grayscale information of the image, and to intercept the portion of the grayscale information whose grayscale value is within a preset interval, to obtain the number of grayscale peaks and the width of each grayscale peak within the preset interval, so as to constitute the feature information.

12. The screening system for detecting markers according to claim 10, wherein: The information processing unit is also used to verify the position coordinates of the detection mark, including: setting a verification standard, and comparing the coordinates of the actual position of the detection mark found with the verification standard, determining whether the coordinates of the actual position of the detection mark found exceeds the verification standard, so as to confirm whether the detection mark found is the expected detection mark.

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