Photomask inspection method and apparatus, method and apparatus for determining photomask mark

Abstract

The present disclosure provides a photomask detection method and device, a photomask mark determination method and device, which can determine at least one target pattern on a target layer on a wafer surface from a preset library, and take the at least one target pattern as a mark of a photomask corresponding to the target layer. The mark determined by the method provided in the present embodiment can improve the detection accuracy when quality detection or alignment detection is performed.

Description

Technical Field

[0001] This disclosure relates to the field of semiconductor technology, and in particular to a photomask detection method and apparatus, and a method and apparatus for determining photomask markings. Background Technology

[0002] In semiconductor manufacturing, a lithography machine places a photomask on one layer of a wafer, which has a pre-designed lithographic pattern. Then, taking advantage of the photoresist's photoresist's resistance to etching due to a chemical reaction after exposure to light, the lithography machine exposes the wafer through the photomask, thus transferring the lithographic pattern from the photomask onto the wafer's layers.

[0003] In the prior art, at least one special pattern mark is provided on the photomask, which can be used to perform quality inspection on whether the photomask is qualified after the photomask production is completed.

[0004] However, with existing technology, the positions and shapes of the marks on the photomask are relatively uniform, and they are mostly placed on the boundaries of the photomask, resulting in low accuracy in detecting the photomask using these marks. Summary of the Invention

[0005] This disclosure provides a photomask inspection method and apparatus, and a method and apparatus for determining photomask markings, to solve the technical problem of low accuracy caused by the markings used when inspecting photomasks.

[0006] The first aspect of this disclosure provides a method for determining photomask markings, comprising: determining at least one target pattern on a target layer of a wafer from a preset library; using the at least one target pattern as a marking on a photomask corresponding to the target layer of the wafer; wherein the marking is used to detect the relationship between the offset of the marking on the photomask and a preset threshold after the photomask is manufactured; or, the marking is used to detect whether the photomask is aligned with the target layer of the wafer.

[0007] In one embodiment of the first aspect of this disclosure, determining at least one target pattern on a target layer of a wafer from a preset library includes: determining at least one pattern corresponding to the type of the photomask as the target pattern from all patterns on the target layer of the wafer in the preset library.

[0008] In one embodiment of the first aspect of this disclosure, determining at least one target pattern on a target layer of a wafer from a preset library includes: determining, from the preset library, all or part of the first pattern, which has the largest number of patterns on the target layer of the wafer, as the target pattern.

[0009] In one embodiment of the first aspect of this disclosure, determining at least one target pattern on a target layer of a wafer from a preset library includes: determining, from the preset library, all or part of the second pattern with the smallest area among all patterns on the target layer of the wafer as the target pattern.

[0010] In one embodiment of the first aspect of this disclosure, determining at least one target pattern on a target layer of a wafer from a preset library includes: determining, from the preset library, all or part of a third pattern that has the smallest distance from an adjacent pattern among all patterns on the target layer of the wafer as the target pattern.

[0011] In one embodiment of the first aspect of this disclosure, determining at least one target pattern on a target layer of a wafer from a preset library includes: determining, from the preset library, at least one defect point pattern among all patterns on the target layer of the wafer as the target pattern.

[0012] In one embodiment of the first aspect of this disclosure, after using the at least one target pattern as a mark on the photomask corresponding to the target layer of the wafer, the method further includes: adjusting the number of patterns in the mark by simulating the relationship between the offset of the mark on the photomask and a preset threshold or simulating whether the photomask is aligned with the target layer of the wafer.

[0013] In one embodiment of the first aspect of this disclosure, after using the at least one target pattern as a mark on the photomask corresponding to the target layer of the wafer, the method further includes: simulating detection to determine whether the photomask is aligned with the target layer of the wafer, and scanning the location of a portion of the marks on the photomask during detection, so as to minimize the number of scans and meet the preset detection result when simulating detection of whether the photomask is aligned with the target layer of the wafer.

[0014] A second aspect of this disclosure provides a photomask inspection method, comprising: placing a photomask on the surface of a target layer of a wafer; the photomask being marked; the mark including at least one target pattern among all patterns on the target layer of the wafer; and detecting whether the photomask is aligned with the target layer of the wafer based on the mark and the at least one target pattern.

[0015] In one embodiment of the second aspect of this disclosure, the mark is determined according to the method for determining photomask marks according to any one of the first aspects of this disclosure.

[0016] In one embodiment of the second aspect of this disclosure, detecting whether the photomask is aligned with the target layer of the wafer includes: scanning the position of a portion of the markings on the photomask, and determining whether the photomask is aligned with the target layer of the wafer based on the positional relationship between the portion of the markings and the corresponding target pattern.

[0017] A third aspect of this disclosure provides a photomask inspection method, comprising: determining the offset of a mark on the photomask; the mark comprising at least one target pattern among all patterns on a target layer of a wafer corresponding to the photomask; and inspecting the photomask according to the relationship between the offset and a preset threshold.

[0018] In one embodiment of the third aspect of this disclosure, the mark is determined by the method for determining photomask marks as described in any of the first aspects of this disclosure.

[0019] The fourth aspect of this disclosure provides an apparatus for determining photomask markings for performing the method described in any of the first aspects of this application.

[0020] The fifth aspect of this disclosure provides a photomask detection apparatus for performing the method described in any one of the second or third aspects of this application.

[0021] The photomask inspection method and apparatus, and the method and apparatus for determining photomask marks provided in this disclosure, can determine at least one target pattern on a target layer on the surface of a wafer from a preset library, and use the at least one target pattern as a mark for the photomask corresponding to the target layer. Since the determined mark is based on an existing pattern on the target layer of the wafer, the determined mark can more accurately reflect the position of the photomask, thereby improving the accuracy of subsequent quality inspection or alignment inspection using the mark. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the 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.

[0023] Figure 1 This is a schematic diagram showing the position of markings set on a photomask in a certain technology;

[0024] Figure 2 A schematic diagram illustrating one application scenario provided in this disclosure;

[0025] Figure 3 This is a schematic flowchart of an embodiment of a method for determining photomask markings provided in this disclosure;

[0026] Figure 4 The first pattern determined from all patterns of the target layer provided in this disclosure is used as an example diagram of at least one target pattern;

[0027] Figure 5An example diagram for determining a second pattern as at least one target pattern from all patterns in the target layer, as provided in this disclosure;

[0028] Figure 6 An example diagram for determining a third pattern as at least one target pattern from all patterns in the target layer, as provided in this disclosure;

[0029] Figure 7 An example diagram for determining the defect point pattern from all patterns in the target layer as at least one target pattern, as provided in this disclosure;

[0030] Figure 8 This is an example diagram of an embodiment of the method for determining photomask markings provided in this disclosure;

[0031] Figure 9 This is a schematic flowchart of an embodiment of the photomask detection method provided in this disclosure;

[0032] Figure 10 A schematic diagram illustrating another application scenario provided in this disclosure;

[0033] Figure 11 A schematic flowchart of another embodiment of the photomask detection method provided in this disclosure;

[0034] Figure 12 This is a scanning diagram illustrating the process of detecting whether a photomask is aligned with a target layer of a wafer in one embodiment of the present disclosure.

[0035] Figure 13 This is a scanning diagram illustrating the detection of whether the photomask is aligned with the target layer of the wafer in another embodiment provided in this disclosure. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure. Furthermore, although the disclosure in this disclosure is based on one or several exemplary examples, it should be understood that each aspect of these disclosures can also constitute a complete implementation method on its own.

[0037] It should be noted that the brief descriptions of terms in this disclosure are only for the convenience of understanding the embodiments described below, and are not intended to limit the embodiments of this disclosure. Unless otherwise stated, these terms should be understood in their ordinary and common meaning.

[0038] The terms "first," "second," etc., used in this disclosure, the specification, claims, and the accompanying drawings are used to distinguish similar or related objects or entities and do not necessarily imply a specific order or sequence, unless otherwise specified. It should be understood that such terms can be used interchangeably where appropriate, for example, in situations where implementation can proceed in an order other than those given in the illustrations or description of embodiments of this disclosure.

[0039] Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover but not exclusively include, for example, a product or device that includes a series of components is not necessarily limited to those that are explicitly listed, but may include other components that are not explicitly listed or that are inherent to such product or device.

[0040] Figure 1 This is a schematic diagram illustrating the location of markings on a photomask in one technique. Since the photomask 20 typically has patterns corresponding to the wafer surface in its center, the markings 201 can be located on the outer boundary of the photomask 20 and along some center lines. In one technique, the markings 201 can be in the shape of the letter "L," a cross, a straight line, a circle, or a square, etc. The photomask corresponds to a target layer on the wafer.

[0041] Figure 2 This is a schematic diagram illustrating an application scenario provided by this disclosure. Figure 1 This illustrates one application scenario of the mark 201 on the photomask 20. After the photomask 20 is manufactured, the inspection device 301 can be used to check whether the photomask 20 is qualified. In one embodiment, the inspection device 301 can determine whether the photomask 20 is qualified based on the relationship between the offset of the mark 201 on the photomask 20 and a preset threshold. For example, if the offset is less than the preset threshold, the photomask 20 is determined to be qualified and can proceed with subsequent processing; if the offset is greater than the preset threshold, the photomask 20 is determined to be unqualified and needs to be remade or adjusted.

[0042] However, in such Figure 2 In the application scenarios shown, if using, for example Figure 1 The mark 201 shown is used to check whether the photomask 20 is qualified. However, since the position and shape of the mark 201 on the photomask 20 are relatively uniform and are mostly set on the boundary of the photomask 20, the accuracy of the quality inspection of the photomask based on these marks 201 is low.

[0043] Therefore, this disclosure addresses the aforementioned technical problems by providing a method for determining marks on a photomask and a method for detecting the photomask based on the marks. This method uses the pattern on the target layer of the wafer 10 corresponding to the photomask as the mark 201, enabling the mark 201 to more accurately reflect the actual positions of the printed circuit patterns on the target layer of the wafer 10, thereby improving the accuracy of quality inspection of the photomask 20. The technical solution of this disclosure will be described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0044] Figure 3 This is a flowchart illustrating an embodiment of a method for determining photomask markings provided in this disclosure, as shown below. Figure 3 The method illustrated can be executed by any electronic device with relevant data processing capabilities, such as a computer, server, workstation, etc., or it can also be executed by a lithography machine. This disclosure uses an electronic device as an example of the execution subject, and not as a limitation thereof. Figure 3 As shown, the method for determining photomask markings provided in this embodiment includes:

[0045] S101: The electronic device determines at least one target pattern on the target layer surface of the wafer from a preset library.

[0046] In one embodiment, the preset library includes a design layout library. After the designer completes the wafer setup, the electronic device can determine the wafer's design parameters from the preset library by running electronic design automation (EDA) software, thereby determining at least one target pattern on the wafer surface based on the design parameters.

[0047] In one embodiment, the wafer includes multiple layers, and the pattern obtained in S101 can be at least one target pattern on each of the multiple target layers of the wafer, or at least one target pattern on one target layer of the wafer.

[0048] In one embodiment, the design parameters include: all patterns included in the target layer of the wafer, and positional parameters for each pattern, etc.

[0049] In one embodiment, the position parameters include, for example, the length, width, area, relative position of each pattern on the target layer, and the distance between the pattern and adjacent patterns on the target layer.

[0050] In one embodiment, the target pattern is the pattern that appears most frequently, has the smallest area, or has the smallest distance from adjacent patterns among all patterns on the wafer surface; or, the target pattern may also be a weakpoint pattern on the wafer surface.

[0051] In one embodiment, when determining the markings on a photomask, the electronic device can determine at least one different pattern on the target layer corresponding to the photomask as the target pattern based on the type of the photomask. For example, photomasks can be classified into different types based on factors such as process stability. For photomasks with relatively stable processes, in S101, all or part of the pattern that appears most frequently in the target layer of the wafer can be determined as the target pattern of the target layer on the wafer; for photomasks with unstable processes, in S101, the pattern with the smallest area or the pattern with the smallest distance from adjacent patterns can be determined as the target pattern of the target layer on the wafer. The area can be measured by parameters such as the pattern's length multiplied by its width, and the distance can be measured by parameters such as the length of the space between the pattern and adjacent patterns. For photomasks where the process focuses more on defects, the pattern of the defect points in the target layer of the wafer can be used as the target pattern of that layer on the wafer.

[0052] The above classification of photomasks into different types is merely an example. In actual engineering applications, photomasks can be classified into different types according to different methods. This disclosure does not limit the specific classification and naming of the types.

[0053] S102: The electronic device uses at least one target pattern determined in S101 as a mark on the photomask corresponding to the target layer of the wafer. The mark can be used as follows: Figure 2 In the application scenario shown, after the photomask is produced, the relationship between the offset of the mark on the photomask and the preset threshold is detected, thereby detecting whether the photomask is qualified.

[0054] Understandably, when at least one target pattern is determined for each of the multiple target layers on the wafer surface via S101-S102, in S102, the electronic device can determine at least one target pattern for each of the multiple target layers on the wafer as a marker.

[0055] In summary, the method for determining photomask markings provided in this embodiment can determine at least one target pattern on the target layer of a wafer surface from a preset library, and use at least one target pattern as a marker for the photomask corresponding to the target layer. The markers determined by the method provided in this embodiment are based on existing patterns on the target layer of the wafer; therefore, the determined markers can more accurately reflect the position of the photomask, improving the accuracy of subsequent quality inspections using the markers. Furthermore, the method for determining photomask markings provided in this embodiment has strong scalability and can be applied to the processing of photomasks in different manufacturing processes and for different target layers on different wafers.

[0056] This disclosure addresses different types of photomasks, allowing for the determination of at least one different target pattern on the target layer of the wafer based on the type of photomask, and using at least one target pattern as a marker for the photomask. The following is a reference to the appendix. Figures 4-7 The present disclosure describes different methods for determining at least one target pattern from all patterns within a target layer of a wafer based on different types of photomasks.

[0057] Figure 4 The first pattern determined from all patterns in the target layer, as provided in this disclosure, serves as an example diagram of at least one target pattern. For example... Figure 4 As shown, when the photomask type is type one, after determining all patterns on the target layer of the wafer corresponding to the photomask, the electronic device selects all or part of the most frequently occurring first pattern 201A from all patterns based on the frequency of occurrence of different patterns, and uses this first pattern 201A as at least one target pattern on the target layer of the wafer. By using all or part of the most frequently occurring first pattern 201A as a marker, the accuracy of subsequent quality inspection of the photomask can be improved more accurately and effectively.

[0058] In one embodiment, the first type is a layer with relatively stable fabrication process during the photomask manufacturing process. For example, a contact layer. The first type can be preset, predetermined, or specified by the user of the electronic device through interactive devices such as a mouse or keyboard. When the electronic device determines that the target layer of the current photomask is of the first type, it can use the first pattern 201A corresponding to the type of the photomask as at least one target pattern.

[0059] In embodiments of this disclosure, the shape, size, and number of the first pattern 201A are not limited. For example, in Figure 4 In the example shown, the first pattern 201A can be a square and arranged in rows and columns. Alternatively, the first pattern 201A can also be a straight line and arranged sequentially, etc.

[0060] Figure 5This is an example diagram illustrating the determination of a second pattern as at least one target pattern from all patterns in the target layer, as provided in this disclosure. For example... Figure 5 As shown, when the photomask type is the second type, after the electronic device determines all patterns on the target layer of the wafer corresponding to the photomask, it selects all or part of the second pattern 201B with the smallest area from among all the different patterns as at least one target pattern of the wafer on the target layer. Thus, by using the second pattern 201B with the smallest area as a marker, the accuracy of subsequent quality inspection of the photomask can be improved more accurately and effectively.

[0061] In one embodiment, the second type is a layer whose fabrication process is relatively unstable during the photomask fabrication process. For example, a line layer. The second type can be preset, predetermined, or specified by the user of the electronic device through interactive devices such as a mouse and keyboard. When the electronic device determines that the target layer of the current wafer is of the second type, it can use the second pattern 201B corresponding to the photomask type as at least one target pattern.

[0062] In embodiments of this disclosure, the shape, size, and quantity of the second pattern 201B are not limited. For example, in Figure 5 In the example shown, the second pattern 201B can be a square, arranged in rows and columns. The area of ​​the second pattern 201B can then be represented by the length of each pattern multiplied by its width. Alternatively, the second pattern 201B can also be a straight line, arranged sequentially, etc. The area of ​​the second pattern 201B can then be represented by the width of each line, etc.

[0063] Figure 6 An example diagram illustrating the determination of a third pattern as at least one target pattern from all patterns in the target layer, as provided in this disclosure. For example... Figure 6 As shown, when the photomask type is the third type, after determining all patterns on the target layer of the wafer corresponding to the photomask, the electronic device, based on the distance between different patterns and adjacent patterns, selects all or part of the third pattern 201C with the smallest distance from adjacent patterns as at least one target pattern of the wafer 10 on the target layer. Thus, by using the third pattern 201C with the smallest spatial distance as a marker, the accuracy of subsequent quality inspection of the photomask can be improved more accurately and effectively.

[0064] In one embodiment, the third type is a layer whose fabrication process is relatively unstable during the photomask manufacturing process. For example, a line layer. The third type can be preset, predetermined, or specified by the user of the electronic device through interactive devices such as a mouse or keyboard. When the electronic device determines that the current photomask type is the third type, it can use the third pattern 201C corresponding to that photomask type as at least one target pattern.

[0065] In embodiments of this disclosure, the shape, size, and quantity of the third pattern 201C are not limited. For example, in Figure 6 In the example shown, the third pattern 201C can be a square, arranged in rows and columns. The area of ​​the third pattern 201C can then be represented by the distance (space) between each pattern and its adjacent patterns. Alternatively, the third pattern 201C can also be a straight line, arranged sequentially, etc. The area of ​​the second pattern 201B can then be represented by the distance (width) perpendicular to the extension direction of each line, etc. When determining the distance between a pattern and its adjacent patterns, the adjacent patterns can be the same as the current pattern, or they can be different from the current pattern.

[0066] Figure 7 An example diagram illustrating the determination of defect point patterns from all patterns in the target layer, as provided in this disclosure, is provided as at least one target pattern. For example... Figure 7 As shown, when the photomask type is type four, after determining all patterns on the target layer of the wafer corresponding to the photomask, the electronic device uses all or part of the defect point patterns 201D among all the patterns as at least one target pattern of the wafer on the target layer. Thus, by using the defect point patterns 201D on the target layer of the wafer as markers, the accuracy of subsequent quality inspection of the photomask can be improved more accurately and effectively.

[0067] In one embodiment, the fourth type is a layer used to detect the quality of the photomask during its fabrication process by identifying defect points. It can also be interpreted as a pattern of greater interest during photomask quality inspection. The fourth type can be preset, predetermined, or specified by the user of the electronic device via an interactive device such as a mouse or keyboard. Once the electronic device determines that the current photomask type is the fourth type, it can use the defect point pattern 201D corresponding to that target layer type as at least one target pattern.

[0068] In embodiments of this disclosure, the shape, size, and number of defect point patterns 201D are not limited. For example, in Figure 7In the example shown, the defect pattern 201D can be in the shape of the English letter "S", and the defect point is specifically located in the middle of the defect pattern 201D. In one embodiment, the electronic device can capture the defect pattern of the target layer on the wafer using a hotspot model.

[0069] In one embodiment, the electronic device uses, for example... Figure 3 The method shown involves determining the markings on the photomask based on the pattern on the wafer. Therefore, the markings on the photomask correspond one-to-one with the target pattern on the target layer of the wafer. Specifically, the markings on the photomask have the same shape as the target pattern on the target layer of the wafer, the same size as the target pattern on the target layer of the wafer, and the same relative position as the target pattern on the target layer of the wafer.

[0070] In one embodiment, when the electronic device passes the above... Figures 6-9 After the target pattern is determined in the manner shown, if there are multiple target patterns, the number of target patterns can be reduced by simulating quality inspection or alignment, thereby minimizing the number of marks set on the photomask.

[0071] For example, Figure 8 An example diagram is shown for one embodiment of the method for determining photomask markings provided in this disclosure. Figure 8 As shown, taking the most numerous first pattern 101A as an example, when the electronic device determines that the target layer surface of wafer 10 includes 16 first patterns 101A distributed in 4 rows and 4 columns, which are the most frequently occurring patterns, the electronic device can then perform alignment detection by simulating whether the photomask is aligned with the target layer of the wafer, and adjust the number of first patterns 101A included in the markings in real time. This ensures that the number of first patterns 101A included in the markings is minimized, while still meeting the preset detection results when simulating whether the photomask is aligned with the wafer.

[0072] For example, electronic devices can first execute software, scripts, etc., to... Figure 8In step S1, all 16 first patterns 101A are used as markers to verify whether the photomask and the target layer of the wafer are aligned. Since this is a simulated detection, the alignment result is predetermined. Therefore, based on whether the current 16 markers match the predetermined detection result, it is determined whether to adjust the number of markers. If the current 16 markers match the predetermined detection result, the number of markers can be reduced. For example, 12 of the 16 first patterns 101A shown in S2 can be used as markers, and the alignment of the photomask and the target layer of the wafer can be verified using these 12 markers. If the current 12 markers match the predetermined detection result, the number of markers can be further reduced. For example, 9 of the 16 first patterns 101A shown in S3 can be used as markers. The number of adjustments each time is not limited; for example, adjustments can be made by adding or removing one pattern each time. Ultimately, the number of first patterns 101A included in the markers is minimized so that the detection result meets the preset result. Therefore, in this embodiment, the number of markers that can be determined when identifying markers on the photomask can be reduced. Therefore, the number of markers determined in this embodiment is relatively small, which can improve the speed and efficiency of photomask quality inspection, alignment inspection and other inspections.

[0073] Figure 9 This is a schematic flowchart of an embodiment of the photomask detection method provided in this disclosure, as shown below. Figure 9 The method shown can be applied to, for example Figure 2 In the scenario shown. For example... Figure 9 The method shown can be performed by a lithography machine, or by electronic devices with relevant data processing capabilities, such as computers, servers, and workstations. Figure 9 As shown, the photomask detection method provided in this embodiment includes:

[0074] S201: Determine the offset of the markings on the photomask. The markings include at least one target pattern from all patterns on the target layer of the wafer corresponding to the photomask.

[0075] In some embodiments, the markings on the photomask provided in this disclosure can be achieved through methods such as... Figure 3 The method shown is determined. Specifically, the execution is as follows: Figure 3 The method for determining the photomask markings shown and Figure 9 The photomask inspection method shown can be performed by different devices, or it can be performed by the same device.

[0076] S202: Based on the relationship between the offset of the marker determined in S101 and the preset threshold, perform quality inspection on the photomask. For example, if the offset is less than the preset threshold, the photomask is deemed qualified and can proceed with subsequent processing; if the offset is greater than the preset threshold, the photomask is deemed unqualified and needs to be redone or adjusted.

[0077] In summary, the photomask inspection method provided in this embodiment can detect whether the photomask is qualified based on the markings on the photomask determined according to the pattern on the wafer. Since the markings are existing patterns on the wafer, they can better reflect the actual position of the markings and their positional relationship with the wafer, thus improving the accuracy of photomask quality inspection.

[0078] Figure 10 This diagram illustrates another application scenario of the mark 201 on the photomask 20 provided in this application. In this scenario, the lithography machine 302 can determine whether the wafer 10 is aligned with the photomask 20 by checking whether the mark 201 on the photomask 20 is aligned with the mark 101 on the wafer 10. Figure 10 As shown, this disclosure applies to the semiconductor manufacturing process. Specifically, the semiconductor can be Dynamic Random Access Memory (DRAM), etc. A photolithography machine can be used to process specific photolithographic patterns on a wafer (chip) 10 through photolithography; these photolithographic patterns can be specific circuits, etc. Figure 10 As shown, the lithography machine first places a photomask 20 on the wafer 10, with a pre-designed photolithographic pattern 202 on the photomask 20. Then, the lithography machine 302 exposes the wafer 10 through the photomask 20, processing the photolithographic pattern 202 on the photomask 20 to a specific location on the wafer 10, forming a photolithographic pattern 102 identical to the photolithographic pattern 202 on the wafer 10. With the shrinking of semiconductor process technology nodes, increasingly higher requirements are placed on the precision of the photomask 20's placement. To ensure that the lithography machine can accurately process the photolithographic pattern 202 on the photomask 20 to a specific location on the wafer 10, after placing the photomask 20 on the wafer 10, the lithography machine also performs alignment checks between the photomask 20 and the wafer 10. Finally, after confirming the alignment between the photomask 20 and the wafer 10, the lithography machine 302 performs the exposure process.

[0079] In some embodiments, the lithography machine 302 can detect whether the photomask 20 is aligned with the wafer 10 by the positional relationship between the mark 201 on the photomask 20 and the mark 101 on the wafer 10. If the detection result indicates that there is a bias between the photomask 20 and the wafer 10, relative adjustments need to be made in the process, such as adjusting the placement position of the photomask 20 in real time. After ensuring that the photomask 20 and the wafer 10 are aligned, exposure processing is performed by the lithography equipment 30.

[0080] Figure 11 This is a schematic flowchart of another embodiment of the photomask detection method provided in this disclosure, as shown below. Figure 11 The method shown can be applied to, for example Figure 10 In the scenario shown. For example... Figure 11 The method illustrated can be executed by a lithography machine, or by an electronic device with relevant data processing capabilities, such as a computer, server, or workstation. This disclosure uses a lithography machine as an example of the execution subject, not as a limitation thereof. Figure 11 As shown, the photomask detection method provided in this embodiment includes:

[0081] S201: The lithography machine places a photomask on the surface of the target layer of the wafer. The photomask is marked, and the mark includes at least one target pattern from all patterns on the target layer of the wafer corresponding to the photomask.

[0082] In some embodiments, the markings on the photomask provided in this disclosure can be achieved through methods such as... Figure 3 The method shown is determined. Specifically, the execution is as follows: Figure 3 The method for determining the photomask markings shown and Figure 11 The photomask inspection method shown can be performed by different devices, or it can be performed by the same device.

[0083] S202: The lithography machine detects whether the photomask is aligned with the target layer of the wafer based on the marking and at least one target pattern corresponding to the marking.

[0084] Subsequently, the lithography machine scans the photomask placed on the target layer of the wafer, and determines whether the photomask is aligned with the target layer of the wafer based on the marks on the photomask and the corresponding target patterns. This disclosure does not limit the specific method for detecting the alignment between the photomask and the wafer. For example, the alignment can be determined by comparing the offset between each mark and its corresponding target pattern with a preset threshold.

[0085] In summary, the photomask inspection method provided in this embodiment can perform alignment detection to determine whether the photomask is aligned with the target layer of the wafer based on the markings on the photomask determined according to the wafer pattern. The markings on the photomask provided in this embodiment can be used for both photomask quality inspection and photomask-wafer alignment detection, thereby enriching the functions that the markings can perform.

[0086] Meanwhile, since the mark includes at least one target pattern on the target layer of the wafer, the mark used in the photomask inspection method provided in this embodiment is an existing pattern on the wafer. Since the mark is an existing pattern on the wafer, it can better reflect the actual position of the mark and its positional relationship with the wafer. The mark can more accurately reflect whether the positions of the actual circuit patterns to be printed on the wafer are aligned, thus improving the accuracy of alignment detection.

[0087] In one embodiment, when the electronic device performs S302, it can scan only the locations of a portion of the markings on the photomask, thereby determining whether the photomask is aligned with the target layer of the wafer based on the scanning results of these markings. For example, Figure 12 This is a schematic diagram illustrating the scanning process for detecting whether a photomask is aligned with a target layer on a wafer, according to one embodiment of this disclosure. It is assumed that the photomask includes nine first patterns 101A arranged in three rows and three columns as markers. The electronic device only scans the markers in the second row (S10) and the third row (S20) of the photomask. Finally, the alignment of the photomask with the target layer on the wafer is determined by the scanning results of the six markers in the second row (S10) and the third row (S20). Therefore, the photomask detection method provided in this embodiment scans only the locations of some markers, reducing the number of markers that need to be scanned and further improving the speed and efficiency of photomask detection.

[0088] In one embodiment, the partially scanned markings during the detection of the photomask can be determined by an electronic device based on... Figure 3 The method shown is used to determine the photomask markings afterward. The electronic device can simulate whether the photomask is aligned with the target layer of the wafer and adjust the number of markings scanned during the scanning process in real time. Ultimately, it can minimize the number of markings scanned while still achieving a preset detection result based on the simulated alignment of the photomask and the wafer.

[0089] In one embodiment, the electronic device can adjust the number of scans when simulating whether the photomask is aligned with the target layer of the wafer, ultimately achieving a preset detection result while minimizing the number of scans. For example, Figure 13This is a scanning diagram of detecting whether the photomask is aligned with the target layer of the wafer in another embodiment provided by this disclosure. Assuming that the photomask includes a second pattern 101B of multiple rows of lines as a marker, the electronic device can adjust the number of scans when scanning perpendicular to the extension direction of the marker, and finally determine whether the photomask is aligned with the target layer of the wafer by scanning the marker twice in S21 and S22.

[0090] In the foregoing embodiments, the methods provided by the present disclosure have been described. To implement the functions of the methods provided by the present disclosure, the device or apparatus serving as the main body for executing the methods may include hardware structures and / or software modules, implementing the functions in the form of hardware structures, software modules, or a combination of hardware structures and software modules. Whether a particular function is executed in the form of hardware structures, software modules, or a combination of hardware structures and software modules depends on the specific application and design constraints of the technical solution.

[0091] For example, this disclosure also provides an apparatus for determining photomask markings, used to perform actions such as Figure 4 The method shown includes an acquisition module and a determination module, wherein the acquisition module is used to determine at least one target pattern on a target layer of a wafer from a preset library. The determination module is used to use the at least one target pattern as a mark on a photomask corresponding to the target layer of the wafer.

[0092] In one embodiment, the means for determining the alignment mark further includes: a first adjustment module for adjusting the number of patterns in the mark.

[0093] In one embodiment, the means for determining the alignment mark further includes a second adjustment module for adjusting the number of scans.

[0094] This disclosure also provides a photomask inspection device, which can be used to perform functions such as... Figure 10 The method includes: a determining module and a detecting module, wherein the determining module is used to determine the offset of a mark on a photomask; and the detecting module is used to detect the photomask based on the relationship between the offset and a preset threshold.

[0095] This disclosure also provides a photomask inspection device, which can be used to perform functions such as... Figure 11 The method includes a placement module and a detection module. The placement module is used to place a photomask on the surface of a target layer of a wafer. The detection module is used to detect whether the photomask is aligned with the target layer of the wafer based on the markings and the at least one target pattern.

[0096] The implementation method and principle of the device provided in this embodiment can be referred to the method provided in the foregoing embodiments of this disclosure, and will not be repeated here.

[0097] It should be noted that the division of the various modules in the above device is merely a logical functional division. In actual implementation, they can be fully or partially integrated into a single physical entity, or they can be physically separated. Furthermore, these modules can be implemented entirely in software via processing element calls; they can be fully implemented in hardware; or some modules can be implemented by processing element calls to software, while others are implemented in hardware. For example, a processing module can be a separate processing element, or it can be integrated into a chip within the above device. Alternatively, it can be stored as program code in the device's memory, and called and executed by a processing element of the device. The implementation of other modules is similar. Moreover, these modules can be fully or partially integrated together, or they can be implemented independently. The processing element mentioned here can be an integrated circuit with signal processing capabilities. In the implementation process, each step of the above method or each of the above modules can be completed through integrated logic circuits in the hardware of the processor element or through software instructions.

[0098] For example, these modules can be one or more integrated circuits configured to implement the above methods, such as one or more application-specific integrated circuits (ASICs), one or more digital signal processors (DSPs), or one or more field-programmable gate arrays (FPGAs). As another example, when a module is implemented by a processing element calling program code, that processing element can be a general-purpose processor, such as a central processing unit (CPU) or other processor capable of calling program code. Furthermore, these modules can be integrated together to implement a system-on-a-chip (SOC).

[0099] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this disclosure are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible to a computer or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid-state disk (SSD)).

[0100] For example, this application also provides an electronic device, including a processor and a memory; wherein the memory stores a computer program, and the processor can execute the computer program. When the processor executes the computer program, the processor can be used to perform steps in any of the methods in the foregoing embodiments of this disclosure.

[0101] This disclosure also provides a computer-readable storage medium storing a computer program that, when executed, can be used to perform steps in any of the methods described in the foregoing embodiments of this disclosure.

[0102] This disclosure also provides a chip for executing instructions, the chip being used to perform steps in any of the methods described above.

[0103] Those skilled in the art will understand that all or part of the steps of the above-described method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments; and the aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0104] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this disclosure, and are not intended to limit them. Although this disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this disclosure.

Claims

1. A method for determining photomask markings, characterized in that, include: Determine at least one target pattern on a target layer of a wafer from a preset library, the preset library including a design layout library; The at least one target pattern is used as a mark on the photomask corresponding to the target layer of the wafer; wherein, the mark is used to detect the relationship between the offset of the mark on the photomask and a preset threshold after the photomask is produced; Alternatively, the mark may be used to detect whether the photomask is aligned with the target layer of the wafer.

2. The method according to claim 1, characterized in that, Determining at least one target pattern on a target layer of a wafer from a preset library includes: From all patterns on the target layer of the wafer in the preset library, determine at least one pattern corresponding to the type of the photomask as the target pattern.

3. The method according to claim 1 or 2, characterized in that, Determining at least one target pattern on the target layer of a wafer from a preset library includes: From the preset library, determine all or part of the first pattern, which has the largest number of patterns on the target layer of the wafer, as the target pattern.

4. The method according to claim 1 or 2, characterized in that, Determining at least one target pattern on a target layer of a wafer from a preset library includes: From the preset library, determine all or part of the second pattern with the smallest area among all patterns on the target layer of the wafer as the target pattern.

5. The method according to claim 1 or 2, characterized in that, Determining at least one target pattern on a target layer of a wafer from a preset library includes: From the preset library, determine all or part of the third pattern that has the smallest distance from its adjacent patterns among all patterns on the target layer of the wafer as the target pattern.

6. The method according to claim 1 or 2, characterized in that, Determining at least one target pattern on a target layer of a wafer from a preset library includes: From the preset library, at least one defect point pattern is identified as the target pattern among all patterns on the target layer of the wafer.

7. The method according to claim 1, characterized in that, After using the at least one target pattern as a mark on the photomask corresponding to the target layer of the wafer, the method further includes: The number of patterns in the markings is adjusted by simulating the relationship between the offset of the markings on the photomask and a preset threshold, or by simulating whether the photomask is aligned with the target layer of the wafer.

8. The method according to claim 7, characterized in that, After using the at least one target pattern as a mark on the photomask corresponding to the target layer of the wafer, the method further includes: By simulating the detection of whether the photomask is aligned with the target layer of the wafer, and scanning the positions of some marks on the photomask during the detection, the number of scans is minimized and the preset detection result is met when simulating the detection of whether the photomask is aligned with the target layer of the wafer.

9. A method for detecting photomasks, characterized in that, include: A photomask is placed on the surface of the target layer of the wafer; The photomask is marked; the mark includes at least one target pattern from all patterns on the target layer of the wafer, the target pattern being determined from a preset library, the preset library including a design layout library; Based on the markings and the at least one target pattern, it is determined whether the photomask is aligned with the target layer of the wafer.

10. The method according to claim 9, characterized in that, The marking is determined by the method for determining photomask markings according to any one of claims 1-8.

11. The method according to claim 10, characterized in that, The step of detecting whether the photomask is aligned with the target layer of the wafer includes: The positions of some markings on the photomask are scanned, and the positional relationship between the markings and the corresponding target pattern is used to determine whether the photomask is aligned with the target layer of the wafer.

12. A method for detecting a photomask, characterized in that, include: Determine the offset of the mark on the photomask; the mark includes at least one target pattern from all patterns on the target layer of the wafer corresponding to the photomask, the target pattern being determined from a preset library, the preset library including a design layout library; The photomask is detected based on the relationship between the offset and a preset threshold.

13. The method according to claim 12, characterized in that, The mark is determined by the method for determining a mark according to any one of claims 1-8.

14. An apparatus for determining photomask markings, characterized in that, Used to perform the method as described in any one of claims 1-8.

15. A photomask detection device, characterized in that, Used to perform the method as described in any one of claims 9-13.

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