Method and system for acquiring an addressing pattern, metrology method, and related apparatus

Abstract

An acquisition method and system of an addressing pattern, a measurement method, and related devices; the acquisition method of the addressing pattern includes: acquiring a positioning field of view region corresponding to a target pattern, the positioning field of view region having the target pattern; dividing the positioning field of view region into a plurality of first unit regions; acquiring a pattern density of each first unit region; and acquiring a position of an addressing pattern located around the target pattern in the positioning field of view region according to a plurality of first unit regions having the largest difference in pattern density with adjacent first unit regions. The acquisition method of the addressing pattern of the embodiment is advantageous in improving the uniqueness of the selected addressing pattern, reducing the probability of the addressing pattern being similar to the patterns of other regions, thereby being advantageous in accurately positioning the addressing pattern, and further being capable of accurately positioning the target pattern based on the addressing pattern, and accordingly being advantageous in improving the process reliability, for example, improving the accuracy of the measurement result of the target pattern in the process of measuring the target pattern.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of semiconductor manufacturing, and in particular to a method and system for acquiring addressing patterns, a measurement method, and related equipment. Background Technology

[0002] With the rapid development of the integrated circuit (IC) industry, semiconductor technology, driven by Moore's Law, continues to advance towards smaller process nodes, enabling integrated circuits to develop in the direction of smaller size, higher circuit precision, and higher circuit complexity.

[0003] In the development of integrated circuits, the functional density (i.e. the number of interconnects in each chip) usually increases gradually while the geometric size (i.e. the smallest component size that can be produced by process steps) gradually decreases, which correspondingly increases the difficulty and complexity of integrated circuit manufacturing.

[0004] In the manufacturing process of integrated circuits, it is necessary to measure the critical dimensions (CD) of the target pattern. Before measuring the target pattern, addressing patterns are usually obtained around the target, and the target pattern to be measured is located based on a preset relative positional relationship between the addressing patterns and the target pattern to be measured.

[0005] However, the methods for acquiring addressable graphics and measuring target graphics still need improvement. Summary of the Invention

[0006] The problem addressed by the embodiments of the present invention is to provide a method and system for acquiring addressable patterns, a measurement method, and related equipment, so as to improve the method for acquiring addressable patterns and the method for measuring target patterns.

[0007] To address the above problems, this invention provides a method for obtaining addressable graphics, comprising: taking a positioning field of view region corresponding to a target graphic, wherein the positioning field of view region contains the target graphic; dividing the positioning field of view region into multiple first unit regions; obtaining the graphic density of each first unit region; and obtaining the position of the addressable graphics located around the target graphic in the positioning field of view region based on a number of first unit regions that have the largest graphic density difference with adjacent first unit regions.

[0008] Accordingly, this embodiment of the invention also provides a measurement method, including: obtaining an addressable positioning field of view around a target graphic to be measured, wherein the graphic in the addressable positioning field of view is used as the addressable graphic, and the position of the addressable graphic is obtained by the addressable graphic acquisition method provided in this embodiment of the invention; after obtaining the addressable positioning field of view, locating the target graphic to be measured based on a preset relative positional relationship between the addressable graphic and the target graphic to be measured.

[0009] Accordingly, embodiments of the present invention also provide an addressable graphic acquisition system, comprising: a field-of-view acquisition module, used to acquire a positioning field-of-view area corresponding to a target graphic, wherein the positioning field-of-view area contains the target graphic; a graphic segmentation module, used to divide the positioning field-of-view area into multiple first unit areas; a graphic density acquisition module, used to acquire the graphic density of each first unit area; and a position acquisition module, used to acquire the position of the addressable graphic located around the target graphic in the positioning field-of-view area based on a plurality of first unit areas having the largest graphic density difference with adjacent first unit areas.

[0010] Accordingly, embodiments of the present invention also provide an electronic device, including at least one memory and at least one processor, wherein the memory stores one or more computer instructions, wherein the one or more computer instructions are executed by the processor to implement the addressing pattern acquisition method described in the embodiments of the present invention, or the measurement method described in the embodiments of the present invention.

[0011] Accordingly, embodiments of the present invention also provide a computer program product, including computer instructions, which, when executed by a processor, are used to implement the addressing pattern acquisition method described in the embodiments of the present invention, or the measurement method described in the embodiments of the present invention.

[0012] Accordingly, embodiments of the present invention also provide a storage medium storing one or more computer instructions, which are used to implement the addressing pattern acquisition method or the measurement method described in the embodiments of the present invention.

[0013] Compared with the prior art, the technical solution of the embodiments of the present invention has the following advantages:

[0014] The addressing pattern acquisition method provided in this embodiment of the invention includes, after acquiring the positioning field of view corresponding to the target pattern, firstly dividing the positioning field of view into multiple first unit regions and acquiring the pattern density of each first unit region, and then, based on several first unit regions with the largest pattern density difference from adjacent first unit regions, acquiring the positions of addressing patterns located around the target pattern in the positioning field of view. Compared with the scheme of randomly acquiring the position of the addressing pattern, acquiring the positions of addressing patterns located around the target pattern in the positioning field of view based on several first unit regions with the largest pattern density difference from adjacent first unit regions is beneficial to improving the uniqueness of the selected addressing pattern and reducing the probability of the addressing pattern being similar to patterns in other regions, thereby facilitating the accurate positioning of the addressing pattern. This enables accurate positioning of the target pattern based on the addressing pattern, which in turn improves process reliability. For example, during the measurement of the target pattern, it helps to improve the accuracy of the measurement results. Attached Figure Description

[0015] Figure 1 This is a flowchart of a method for obtaining an addressable graphic;

[0016] Figure 2 This is a schematic diagram illustrating the principle of a positioning error occurring during the measurement of a target graphic using a randomly acquired addressing graphic.

[0017] Figure 3 This is a flowchart of an embodiment of the addressing pattern acquisition method of the present invention;

[0018] Figures 4 to 12 This is a schematic diagram of each step in one embodiment of the addressing pattern acquisition method of the present invention;

[0019] Figure 13 This is a flowchart of an embodiment of the measurement method of the present invention;

[0020] Figure 14 This is a functional block diagram of an embodiment of the addressing pattern acquisition system of the present invention;

[0021] Figure 15 This is a hardware structure diagram of an electronic device provided according to an embodiment of the present invention. Detailed Implementation

[0022] Currently, methods for acquiring addressable patterns and measuring target patterns still need improvement. This paper analyzes the reasons why methods for acquiring addressable patterns still require improvement, using one such method as an example. Figure 1 This is a flowchart of a method for obtaining an addressable graph. Figure 2 This is a schematic diagram illustrating the principle of a positioning error occurring during the measurement of a target graphic using a randomly obtained addressing graphic.

[0023] refer to Figure 1 Step s11: Obtain the positioning field of view (not shown) corresponding to the target graphic 11, wherein the positioning field of view contains the target graphic 11.

[0024] refer to Figure 1 Step s12: Randomly obtain the position of the addressing graphic 12 located around the target graphic 11 in the positioning field of view.

[0025] refer to Figure 2 Research has revealed that randomly acquiring the position of the addressing pattern 12 located around the target pattern 11 within the positioning field of view can easily lead to a high degree of similarity between the addressing pattern 12 region and other pattern 13 regions within the positioning field of view. This can easily result in misidentifying other pattern 13 regions with high similarity as the addressing pattern 12 region, indicating poor accuracy in locating the addressing pattern 12. Consequently, when locating the target pattern 11 based on the preset relative positional relationship between the addressing pattern 12 and the target pattern 11 to be measured, positioning errors occur, meaning that the acquired positioning pattern 14 is not the target pattern 11. This leads to poor process reliability and consequently, poor accuracy in the measurement results of the target pattern 11.

[0026] To address the aforementioned technical problems, embodiments of the present invention provide a method for obtaining addressable graphics, comprising: obtaining a positioning field of view region corresponding to a target graphic, wherein the positioning field of view region contains the target graphic; dividing the positioning field of view region into a plurality of first unit regions; obtaining the graphic density of each first unit region; and obtaining the position of an addressable graphic located around the target graphic in the positioning field of view region based on a plurality of first unit regions having the largest graphic density difference with adjacent first unit regions.

[0027] The addressing pattern acquisition method provided in this embodiment of the invention includes, after acquiring the positioning field of view corresponding to the target pattern, firstly dividing the positioning field of view into multiple first unit regions and acquiring the pattern density of each first unit region, and then, based on several first unit regions with the largest pattern density difference from adjacent first unit regions, acquiring the positions of addressing patterns located around the target pattern in the positioning field of view. Compared with the scheme of randomly acquiring the position of the addressing pattern, acquiring the positions of addressing patterns located around the target pattern in the positioning field of view based on several first unit regions with the largest pattern density difference from adjacent first unit regions is beneficial to improving the uniqueness of the selected addressing pattern and reducing the probability of the addressing pattern being similar to patterns in other regions, thereby facilitating the accurate positioning of the addressing pattern. This enables accurate positioning of the target pattern based on the addressing pattern, which in turn improves process reliability. For example, during the measurement of the target pattern, it helps to improve the accuracy of the measurement results.

[0028] To make the above-mentioned objects, features and advantages of the embodiments of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0029] Figure 3 This is a flowchart of an embodiment of the addressing pattern acquisition method of the present invention. Figures 4 to 12 This is a schematic diagram of each step in one embodiment of the addressing pattern acquisition method of the present invention.

[0030] refer to Figure 3 and in conjunction with references Figure 4 Step S11: Obtain the positioning field of view 100 corresponding to the target graphic 110, wherein the positioning field of view 100 contains the target graphic 110.

[0031] The positioning field of view 100 corresponding to the target graphic 110 is obtained, which is used to provide a basis for the subsequent acquisition of multiple first unit regions.

[0032] In this embodiment, in the step of obtaining the positioning field of view 100 corresponding to the target graphic 110, the positioning field of view 100 centered on the target graphic 110 is obtained.

[0033] Obtaining a positioning field of view 100 centered on the target graphic 110 helps reduce the probability that the distance between the obtained addressing graphic and the target graphic 110 is too far, thereby improving the accuracy of measuring the target graphic 110.

[0034] It should be noted that in the step of obtaining the positioning field of view 100 corresponding to the target graphic 110, the side length b2 of the positioning field of view 100 of the target graphic 110 should not be too small or too large. If the side length b2 of the positioning field of view 100 of the target graphic 110 is too small, the range of the positioning field of view 100 is likely to be too small, thereby increasing the probability of not being able to obtain the first unit region with the maximum graphic density difference from the adjacent first unit region, and thus increasing the probability of not being able to obtain the position of the addressable graphic; if the side length b2 of the positioning field of view 100 of the target graphic 110 is too large, the range of the positioning field of view 100 is likely to be too large, thereby resulting in too many first unit regions, and thus taking too much time to obtain the position of the addressable graphic. Therefore, in this embodiment, in the step of obtaining the positioning field of view 100 corresponding to the target graphic 110, the side length b2 of the positioning field of view 100 of the target graphic 110 is 20 micrometers to 30 micrometers.

[0035] refer to Figure 3 And continue to combine with references Figure 4 Step S12: Divide the positioning field of view 100 into multiple first unit regions 101.

[0036] The positioning field of view 100 is divided into multiple first unit regions 101, which provide a basis for obtaining the graphic density of each first unit region 101 in the future.

[0037] In this embodiment, in the step of dividing the positioning field of view 100 into a plurality of first unit regions 101, the plurality of first unit regions 101 are arranged in a matrix along the first direction X and the second direction Y, and the first direction X and the second direction Y are perpendicular to each other.

[0038] Multiple first unit regions 101 are arranged in a matrix along the first direction X and the second direction Y. The first direction X and the second direction Y are perpendicular to each other, which helps to reduce the difficulty of obtaining the graphic density of each first unit region 101 in the subsequent process.

[0039] It should be noted that in the step of dividing the positioning field of view 100 into multiple first unit regions 101, the proportion of the side length b1 of the first unit region 101 to the side length b2 of the positioning field of view 100 should not be too small or too large. If the proportion of the side length b1 of the first unit region 101 to the side length b2 of the positioning field of view 100 is too small, it is easy to have too many first unit regions 101, which will make the time spent on obtaining the graphic density of each first unit region 101 and obtaining the position of the addressing graphic around the target graphic 110 in the positioning field of view 100 based on several first unit regions 101 with the largest graphic density difference from the adjacent first unit regions 101 too long. If the proportion of the side length b1 of the first unit region 101 to the side length b2 of the positioning field of view 100 is large, it is easy to have too few first unit regions 101, which will easily increase the probability of not being able to obtain the first unit region 101 with the largest graphic density difference from the adjacent first unit regions 101. Therefore, in this embodiment, in the step of dividing the positioning field of view 100 into multiple first unit regions 101, the side length b1 of the first unit region 101 is 1 / 8 to 1 / 10 of the side length b2 of the positioning field of view 100.

[0040] refer to Figure 3 and in conjunction with references Figure 5 Step S13: Obtain the graphic density of each first unit region 101.

[0041] in, Figure 5 The portion with a white background represents the graphic density of the first unit region 101 located at the boundary of the positioning field of view 100. Figure 5 The portion with a gray bottom represents the graphic density of the first unit region 101 located at a non-boundary position in the positioning field of view 100.

[0042] The graphic density of each first unit region 101 is obtained to provide a basis for obtaining the position of the addressable graphic around the target graphic 110 in the positioning field of view 100 based on a plurality of first unit regions 101 that have the largest graphic density difference with adjacent first unit regions 101.

[0043] refer to Figure 3 and in conjunction with references Figures 5 to 12 Step S14: Based on a plurality of first unit regions 101 that have the largest graphic density difference with adjacent first unit regions 101, obtain the position of the addressing graphic 120 located around the target graphic 110 in the positioning field of view (e.g., Figure 12 (As shown).

[0044] in, Figure 6 (a) represents the first density gradient of each of the first unit regions 101. Figure 6 (b) represents the second density gradient of each of the first unit regions 101. Figure 7 (a) represents the value of the first gradient in each of the first unit regions 101. Figure 7 (b) represents the value of the second gradient for each of the first unit regions 101. Figure 8 The value of the third gradient for each of the first unit regions 101. Figure 9 This is a schematic diagram after selecting candidate region 125. Figure 10 This is a schematic diagram after excluding the eight adjacent first unit regions 101 surrounding the first unit region 101 where the target graphic 110 is located, and selecting the optimal region 126. Figure 11 This is a magnified view of the optimal region 126.

[0045] It should be noted that, Figure 6 (a) omits Figure 5 The first density gradient of the first unit region at the bottom and top, Figure 6 (b) omits Figure 5 The second density gradient of the leftmost and rightmost first unit regions, Figure 7 (a) is the value of the first gradient of the first unit region 101 located at a non-boundary position in the positioning field of view region 100. Figure 7 (b) is the value of the second gradient of the first unit region 101 located at a non-boundary position in the positioning field of view region 100. Figure 8 The value of the third gradient is the first unit region 101 located at a non-boundary position within the positioning field of view. Figure 9 The gray area at the bottom is candidate region 125.

[0046] Among them, the first unit regions 101 with the largest graphic density difference refer to the first unit regions 101 that all have graphic density differences with their adjacent first unit regions 101.

[0047] Compared to a scheme that randomly obtains the location of the addressing pattern, obtaining the location of the addressing pattern 120 located around the target pattern 110 within the positioning field of view 100 based on several first unit regions 101 that have the largest pattern density difference with adjacent first unit regions 101 is beneficial to improving the uniqueness of the selected addressing pattern 120 and reducing the probability that the addressing pattern 120 is similar to the pattern in other regions. This is beneficial to accurately locating the addressing pattern 120, and thus enabling accurate location of the target pattern 110 based on the addressing pattern 120. Consequently, it is beneficial to improve process reliability. For example, during the measurement of the target pattern 110, it is beneficial to improve the accuracy of the measurement results of the target pattern 110.

[0048] In this embodiment, the first unit region 101 located at the boundary position of the positioning field of view 100 is excluded, and in the remaining first unit regions 101, the position of the addressing graphic 120 located around the target graphic 110 is obtained in the positioning field of view 100 based on a number of first unit regions 101 that have the largest graphic density difference with the adjacent first unit regions 101.

[0049] Since it is impossible to fully obtain the graphic density difference between the first unit region 101 located at the boundary position of the positioning field of view 100 and its adjacent regions, excluding the first unit region 101 located at the boundary position of the positioning field of view 100 helps ensure that several first unit regions 101 with the largest graphic density difference also have graphic density differences with their adjacent regions.

[0050] In this embodiment, in the step of obtaining the position of the addressing graphic 120 located around the target graphic 110 in the positioning field of view 100 based on a plurality of first unit regions 101 that have the largest graphic density difference with adjacent first unit regions 101, the adjacent first unit regions 101 include first unit regions 101 adjacent in the first direction X and first unit regions 101 adjacent in the second direction Y (e.g., Figure 4 and Figure 5 (As shown).

[0051] The adjacent first unit region 101 includes the first unit region 101 adjacent in the first direction X and the first unit region 101 adjacent in the second direction Y, which helps to reduce the number of adjacent first unit regions 101, thereby making it easier to select several first unit regions 101 that have the largest difference in graphic density with the adjacent first unit regions 101.

[0052] In this embodiment, the selection method for several first unit regions 101 that have the largest graphic density difference with adjacent first unit regions 101 includes: calculating the gradient values ​​of the graphic density of each first unit region 101 in the positioning field of view 100 in the first direction X and the second direction Y respectively, obtaining the value of the first gradient in the first direction X and the value of the second gradient in the second direction Y; and selecting several first unit regions 101 that have the largest graphic density difference with adjacent first unit regions 101 based on the values ​​of the first gradient and the second gradient.

[0053] It is understood that the first gradient represents the degree of difference in graphic density between the first cell region 101 and its adjacent first cell region 101 in the first direction X; the second gradient represents the degree of difference in graphic density between the first cell region 101 and its adjacent first cell region 101 in the second direction Y.

[0054] First, the gradient values ​​of the graphic density of each first unit region 101 in the positioning field of view 100 in the first direction X and the second direction Y are calculated respectively to obtain the value of the first gradient in the first direction X and the value of the second gradient in the second direction Y. Then, based on the values ​​of the first gradient and the second gradient, several first unit regions 101 with the largest graphic density difference with the adjacent first unit regions 101 are selected to facilitate a balanced consideration of the gradient changes between the first unit region 101 and the adjacent first unit regions 101 in each direction.

[0055] In this embodiment, the step of calculating the gradient values ​​of the graphic density in the first direction X and the second direction Y for each first unit region 101 in the positioning field of view 100 includes: as follows Figure 5 and Figure 6 As shown in (a), along the first direction X, the density difference between each of the first unit regions 101 and its adjacent first unit regions 101 is obtained to obtain the first density gradient; as Figure 5 and Figure 6 As shown in (b), in the second direction Y, the density difference between each of the first unit regions 101 and the adjacent first unit regions 101 is obtained to obtain the second density gradient; as Figure 7 As shown in (a), in the first direction X, the vector sum of two adjacent first density gradients is obtained to get the value of the first gradient, and when the value of either of the two adjacent first density gradients is 0, the value of the corresponding first gradient is set to 0; as shown in (a), the vector sum of two adjacent first density gradients is obtained to get the value of the first gradient. Figure 7As shown in (b), in the second direction Y, the vector sum of two adjacent second density gradients is obtained to obtain the value of the second gradient, and when the value of either of the two adjacent second density gradients is 0, the value of the corresponding second gradient is set to 0.

[0056] First, obtain the first density gradient and the second density gradient between the first unit region 101 and the adjacent first unit region 101. Then, based on the first density gradient and the second density gradient, obtain the values ​​of the first gradient and the second gradient. This helps to reduce the difficulty of obtaining the values ​​of the first gradient and the second gradient.

[0057] Since a value of 0 in either of two adjacent first density gradients indicates that the first unit region is similar to an adjacent first unit region 101 in the first direction X, and a value of 0 in either of two adjacent second density gradients indicates that the first unit region 101 is similar to an adjacent first unit region 101 in the second direction Y, setting the value of the corresponding first gradient to 0 when either of two adjacent first density gradients is 0, and setting the value of the corresponding second gradient to 0 when either of two adjacent second density gradients is 0, helps reduce the difficulty of selecting several first unit regions 101 with the greatest graphic density difference from adjacent first unit regions 101 based on the values ​​of the first and second gradients.

[0058] It should be noted that this is based on the formula: Δ X = X n-1 -X n (n is a natural number), along the first direction X, the density difference between each of the first unit regions 101 and its adjacent first unit regions 101 is obtained to obtain the first density gradient [e.g., ...]. Figure 5 and Figure 6 (a) is shown; where X n-1 For the first unit region 101, X n For the adjacent first unit region 101, Δ X represents the first density gradient.

[0059] Based on the formula: Along the first direction X, obtain the vector sum of the first density gradients of every pair of adjacent elements to obtain the value of the first gradient [e.g., ...]. Figure 7 (a) is shown; where ΔX right Let ΔX be the first density gradient on the right side of any pair of adjacent first density gradients. left Let ΔX be the first density gradient on the left among two adjacent first density gradients. final It is the first gradient, and ΔX right and ΔX leftIf the value of either of them is 0, then ΔX final The value is 0.

[0060] It should also be noted that, based on the formula Δ Y = Y n-1 -Y n (n is a natural number), in the second direction Y, the density difference between each of the first unit regions 101 and the adjacent first unit regions 101 is obtained to obtain the second density gradient [e.g., Figure 5 and Figure 6 (b) is shown; where Y n-1 For the first unit region 101, Y n For the adjacent first unit region 101, Δ Y represents the second density gradient.

[0061] Based on the formula: In the second direction Y, the vector sum of two adjacent second density gradients is obtained to get the value of the second gradient [e.g., ...]. Figure 7 (b) is shown; where ΔY top For each pair of adjacent second density gradients, the second density gradient located on the upper side is ΔY. bottom For each pair of adjacent second density gradients, the second density gradient located on the lower side is ΔY. final It is the second gradient, and ΔY top and ΔY bottom If the value of either of them is 0, then ΔY final The value is 0.

[0062] Specifically, in the step of obtaining the first density gradient, the first unit regions 101 located in the first and last rows are excluded, and for the remaining first unit regions 101, the density difference between each first unit region 101 and its adjacent first unit region 101 is obtained in the first direction X; in the step of obtaining the second density gradient, the first unit regions 101 located in the first and last columns are excluded, and for the remaining first unit regions 101, the density difference between each first unit region 101 and its adjacent first unit region 101 is obtained in the second direction Y.

[0063] Since it is impossible to fully obtain the graphic density difference between the first unit region 101 located at the boundary position of the positioning field of view 100 and its adjacent regions, the first unit regions 101 located in the first and last rows are excluded in the step of obtaining the first density gradient, and the first unit regions 101 located in the first and last columns are excluded in the step of obtaining the second density gradient. This not only helps to ensure that the first unit regions 101 with the largest graphic density difference have graphic density differences with their adjacent first unit regions 101, but also helps to reduce the amount of computation, thereby improving the calculation speed.

[0064] In this embodiment, the step of selecting several first unit regions 101 with the largest graphic density difference from adjacent first unit regions 101 based on the values ​​of the first gradient and the second gradient includes: multiplying the values ​​of the first gradient and the second gradient of the same first unit region 101, and obtaining the value of the third gradient based on the result of the multiplication; and selecting several first unit regions 101 with the largest graphic density difference from adjacent first unit regions 101 based on the values ​​of the third gradient of each first unit region 101.

[0065] First, the values ​​of the first gradient and the second gradient of the same first unit region 101 are multiplied together, and the value of the third gradient is obtained based on the result of the multiplication. Then, based on the value of the third gradient of each first unit region 101, several first unit regions 101 with the largest difference in graphic density with the adjacent first unit regions 101 are selected. This helps to reduce the difficulty of considering the gradient changes between the first unit region 101 and the adjacent first unit regions 101 in each direction.

[0066] Specifically, the steps to obtain the value of the third gradient from the result of the multiplication include: Figure 8 As shown, the result of multiplication is normalized, and the normalized result is used as the value of the third gradient; the step of selecting several first unit regions 101 with the largest graphic density difference from adjacent first unit regions 101 based on the value of the third gradient of each first unit region 101 includes: selecting several first unit regions 101 with the largest graphic density difference from adjacent first unit regions 101 based on the first unit regions 101 whose third gradient value is not zero.

[0067] Normalizing the result of multiplication and using the normalized result as the value of the third gradient facilitates the rapid evaluation of the magnitude of each third gradient value. This reduces the time required to select several first unit regions 101 with the largest difference in graphic density from adjacent first unit regions 101 based on the value of the third gradient of each first unit region 101.

[0068] Since the value of the third gradient is obtained by multiplying the value of the first gradient and the value of the second gradient of the first unit region 101, the value of the third gradient is zero when either the value of the first gradient or the value of the second gradient is zero. Selecting several first unit regions 101 with the largest graphic density difference from adjacent first unit regions 101 based on the first unit regions 101 whose third gradient value is not zero helps to further reduce the difficulty of selecting such regions.

[0069] In this embodiment, the step of obtaining the position of the addressing graphic 120 located around the target graphic 110 in the positioning field of view 100 based on a plurality of first unit regions 101 that have the largest graphic density difference with adjacent first unit regions 101 includes: as follows Figure 9 As shown, several first unit regions 101 with the largest difference in graphic density from adjacent first unit regions 101 are selected as candidate regions 125; for example... Figure 10 As shown, the first unit region 101 with the lowest graphic density is selected as the optimal region 126 from the candidate regions 125; as Figure 11 and Figure 12 As shown, the position of the addressing pattern 120 located around the target pattern 110 is obtained in the optimal region 126.

[0070] First, select several first unit regions 101 with the largest difference in graphic density with the adjacent first unit regions 101 as candidate regions 125. Then, select the first unit region 101 with the smallest graphic density from the candidate regions 125 as the optimal region 126. This is beneficial to maximize the difference in graphic density between the optimal region 126 and the adjacent first unit regions 101, thereby making the optimal region 126 more unique. Correspondingly, it is also beneficial to make the selected addressing pattern 120 more unique, thereby making the effect of reducing the graphic similarity between the addressing pattern 120 and other regions better.

[0071] Specifically, after selecting several first unit regions 101 with the largest difference in graphic density from adjacent first unit regions 101 as candidate regions 125, and before selecting the first unit region 101 with the smallest graphic density from the candidate regions 125 as the optimal region 126, the process further includes: excluding eight adjacent first unit regions 101 around the first unit region 101 where the target graphic 110 is located; and selecting the first unit region 101 with the smallest graphic density from the remaining candidate regions 125 as the optimal region 126 (e.g., ...). Figure 10 (As shown).

[0072] Before selecting the first unit region 101 with the lowest graphic density from the candidate regions 125 as the optimal region 126, excluding the eight adjacent first unit regions 101 surrounding the first unit region 101 where the target graphic 110 is located helps avoid the optimal region 126 being one of the eight adjacent first unit regions 101. This helps avoid the distance between the target graphic 110 and the addressing graphic 120 being too small, and further helps reduce the probability of the CD (Critical Dimension) value of the target graphic 110 changing during the process of obtaining the position of the addressing graphic 120. For example, during the after-developing inspection (ADI) process, and during the process of obtaining the position of the addressing graphic 120, it reduces the probability that the CD of the target graphic 110 will change due to electron bombardment.

[0073] In this embodiment, reference Figure 11 The step of obtaining the position of the addressing pattern 120 located around the target pattern 110 in the optimal region 126 includes: dividing the optimal region 126 into multiple second unit regions 127; selecting the second unit region 127 that is closest to the center of the optimal region 126 and has a non-zero pattern density; and using the coordinates of the center point of the selected second unit region 127 as the coordinates of the addressing point 121 of the addressing pattern 120.

[0074] After dividing the optimal region 126 into multiple second unit regions 127, the second unit region 127 closest to the center of the optimal region 126 and with a non-zero graphic density is selected. Then, the coordinates of the center point of the selected second unit region 127 are used as the coordinates of the addressing point 121 of the addressing graphic 120. This is beneficial to further increase the graphic density in the addressing field of view 100, that is, to further increase the graphic density of the addressing graphic 120, thereby further reducing the probability of failure to locate the addressing graphic 120 due to its low graphic density.

[0075] It should be noted that in the step of dividing the optimal region 126 into multiple second unit regions 127, the proportion of the side length b3 of the second unit region 127 to the side length b1 of the optimal region 126 should not be too small or too large. If the proportion of the side length b3 of the second unit region 127 to the side length b1 of the optimal region 126 is too small, the number of second unit regions 127 will be too large, thereby increasing the computational load for calculating the graphic density of the second unit region 127. If the proportion of the side length b3 of the second unit region 127 to the side length b1 of the optimal region 126 is too large, the effect of further increasing the graphic density of the addressing graphic 120 will be poor. Therefore, in this embodiment, in the step of dividing the optimal region 126 into multiple second unit regions 127, the side length b3 of the second unit region 127 is 1 / 8 to 1 / 10 of the side length b1 of the optimal region 126.

[0076] Specifically, the step of obtaining the position of the addressing graphic 120 located around the target graphic 110 in the optimal region 126 further includes: obtaining an addressing positioning field of view (not shown) based on the coordinates of the addressing point 121 and a preset addressing field of view size, and the graphic in the addressing positioning field of view is used as the addressing graphic 120.

[0077] Based on the coordinates of the addressing point 121 and the preset addressing field of view size, the addressing positioning field of view area is obtained, and the graphic in the addressing positioning field of view area is used as the addressing graphic 120, which helps to reduce the difficulty of obtaining the addressing graphic 120.

[0078] More specifically, in the step of obtaining the addressing and positioning field of view based on the coordinates of the addressing point 121 and the preset addressing field of view size, the addressing and positioning field of view centered on the addressing point 121 is obtained.

[0079] In the step of obtaining the addressing positioning field of view based on the coordinates of the addressing point 121 and the preset addressing field of view size, obtaining the addressing positioning field of view centered on the addressing point 121 helps to further reduce the difficulty of obtaining the addressing pattern 120.

[0080] In this embodiment, in the step of obtaining the position of the addressing pattern 120 located around the target pattern 110 in the positioning field of view 100, if the position of the addressing pattern is not obtained, the measurement of the target pattern 110 is abandoned.

[0081] In this context, abandoning the measurement of the target graphic 110 means abandoning the measurement of the target graphic 110 and selecting another target graphic 110 that can obtain the position of the corresponding addressing graphic 120 for measurement.

[0082] In the step of acquiring the position of the addressing pattern 120 surrounding the target pattern 110 within the positioning field of view 100, if the position of the addressing pattern 120 is not acquired, it indicates that the measurement of the target pattern 110 is likely to fail. That is, the CD value of the target pattern 110 acquired by measurement is not the true CD value of the target pattern 110. Therefore, the measurement of the target pattern 110 should be abandoned to avoid the impact of the inaccurate CD value of the target pattern 110 on the semiconductor manufacturing process.

[0083] Accordingly, the present invention also provides a measurement method. Figure 13 This is a flowchart of an embodiment of the measurement method of the present invention.

[0084] refer to Figure 13 and in conjunction with references Figures 4 to 12 Step S21: Obtain the addressing and positioning field of view around the target graphic 110 to be measured. The graphic in the addressing and positioning field of view is used as the addressing graphic 120, and the position of the addressing graphic 120 is obtained by the addressing graphic 120 acquisition method described in the foregoing embodiment.

[0085] An addressing and positioning field of view is obtained around the target graphic 110 to be measured. The graphic in the addressing and positioning field of view is used as the addressing graphic 120, which provides a basis for locating the target graphic 110 to be measured based on the preset relative positional relationship between the addressing graphic 120 and the target graphic 110 to be measured.

[0086] In this embodiment, the target graphic 110 to be measured has a measurement point (not shown), the addressing graphic 120 has an addressing point 121, and the addressing point 121 and the measurement point have a preset distance offset.

[0087] The target graphic 110 to be measured has measurement points, and the addressing graphic 120 has addressing points 121. The addressing points 121 and the measurement points have a preset distance offset, which helps to reduce the difficulty of locating the target graphic 110 to be measured based on the preset relative positional relationship between the addressing graphic 120 and the target graphic 110 to be measured.

[0088] In this embodiment, the method for obtaining the addressable and localized field of view area around the target graphic 110 to be measured includes image matching.

[0089] Methods for obtaining the addressable and localized field of view around the target graphic 110 to be measured include image matching, which helps to reduce the difficulty of obtaining the addressable and localized field of view.

[0090] refer to Figure 13 and in conjunction with references Figures 4 to 12 Step S22: After obtaining the addressing and positioning field of view, the target graphic 110 to be measured is located based on the preset relative positional relationship between the addressing graphic 120 and the target graphic 110 to be measured.

[0091] Compared to the scheme of randomly obtaining the location of the addressing pattern, obtaining the location of the addressing pattern 120 located around the target pattern 110 in the positioning field of view 100 based on several first unit regions 101 with the largest pattern density difference with the adjacent first unit regions 101 is beneficial to improving the uniqueness of the selected addressing pattern 120 and reducing the probability that the addressing pattern 120 is similar to the pattern in other regions. This is beneficial to accurately locating the addressing pattern 120, and thus can accurately locate the target pattern 110 based on the addressing pattern 120. Correspondingly, this is beneficial to improving the accuracy of the measurement results of the target pattern 110 during the measurement process.

[0092] In this embodiment, the target graphic 110 to be measured has measurement points, and the addressing graphic 120 has addressing points 121. There is a preset distance offset between the addressing points 121 and the measurement points. Accordingly, the step of locating the target graphic 110 to be measured based on the preset relative positional relationship between the addressing graphic 120 and the target graphic 110 includes: locating the target graphic 110 to be measured based on the position of the addressing points 121 and the preset distance offset.

[0093] In this embodiment, after locating the target graphic 110 to be measured, the measurement method further includes: measuring the target graphic 110 to be measured.

[0094] It should be noted that the position of the addressing pattern 120 is obtained by the addressing pattern 120 acquisition method described in the foregoing embodiments. For a specific description of the position of the addressing pattern 120 in this embodiment, please refer to the corresponding description in the foregoing embodiments, which will not be repeated here.

[0095] It should also be noted that the measurement method described in this embodiment of the invention can be used to detect the CD value of the target pattern 110 after development, or after etching inspection (AEI) to detect the CD value of the target pattern 110, or in other semiconductor manufacturing processes to detect the CD value of the target pattern 110.

[0096] Accordingly, the present invention also provides a system for acquiring addressable patterns. Figure 14 This is a functional block diagram of an embodiment of the addressing pattern acquisition system of the present invention.

[0097] refer to Figure 14 and in conjunction with references Figures 4 to 12 In this embodiment, the addressing pattern acquisition system 50 includes: a field of view acquisition module 500, used to acquire a positioning field of view 100 corresponding to the target pattern 110, wherein the positioning field of view 100 contains the target pattern 110; a pattern segmentation module 501, used to divide the positioning field of view 100 into a plurality of first unit regions 101; a pattern density acquisition module 502, used to acquire the pattern density of each first unit region 101; and a position acquisition module 503, used to acquire the position of the addressing pattern 120 located around the target pattern 110 in the positioning field of view 100 based on a plurality of first unit regions 101 that have the largest pattern density difference with adjacent first unit regions 101.

[0098] Compared to a scheme that randomly obtains the location of the addressing pattern, obtaining the location of the addressing pattern 120 located around the target pattern 110 within the positioning field of view 100 based on several first unit regions 101 that have the largest pattern density difference with adjacent first unit regions 101 is beneficial to improving the uniqueness of the selected addressing pattern 120 and reducing the probability that the addressing pattern 120 is similar to the pattern in other regions. This is beneficial to accurately locating the addressing pattern 120, and thus enabling accurate location of the target pattern 110 based on the addressing pattern 120. Consequently, it is beneficial to improve process reliability. For example, during the measurement of the target pattern 110, it is beneficial to improve the accuracy of the measurement results of the target pattern 110.

[0099] In this embodiment, in the step of obtaining the positioning field of view 100 corresponding to the target graphic 110, the positioning field of view 100 centered on the target graphic 110 is obtained.

[0100] Obtaining a positioning field of view 100 centered on the target graphic 110 helps reduce the probability that the distance between the obtained addressing graphic and the target graphic 110 is too far, thereby improving the accuracy of measuring the target graphic 110.

[0101] It should be noted that in the step of obtaining the positioning field of view 100 corresponding to the target graphic 110, the side length b2 of the positioning field of view 100 of the target graphic 110 should not be too small or too large. If the side length b2 of the positioning field of view 100 of the target graphic 110 is too small, the range of the positioning field of view 100 is likely to be too small, thereby increasing the probability of not being able to obtain the first unit region 101 with the maximum graphic density difference from the adjacent first unit region 101, and thus increasing the probability of not being able to obtain the position of the addressing graphic 120; if the side length b2 of the positioning field of view 100 of the target graphic 110 is too large, the range of the positioning field of view 100 is likely to be too large, thereby resulting in too many first unit regions 101, and thus taking too much time to obtain the position of the addressing graphic 120. Therefore, in this embodiment, in the step of obtaining the positioning field of view 100 corresponding to the target graphic 110, the side length b2 of the positioning field of view 100 of the target graphic 110 is 20 micrometers to 30 micrometers.

[0102] It should also be noted that in the step of dividing the positioning field of view 100 into multiple first unit regions 101, the proportion of the side length b1 of the first unit region 101 to the side length b2 of the positioning field of view 100 should not be too small or too large. If the proportion of the side length b1 of the first unit region 101 to the side length b2 of the positioning field of view 100 is too small, it is easy to have too many first unit regions 101, which will make the time spent on obtaining the graphic density of each first unit region 101 and obtaining the position of the addressing graphic 120 around the target graphic 110 in the positioning field of view 100 based on several first unit regions 101 with the largest graphic density difference with the adjacent first unit regions 101 too long. If the proportion of the side length b1 of the first unit region 101 to the side length b2 of the positioning field of view 100 is large, it is easy to have too few first unit regions 101, which will easily increase the probability of not being able to obtain the first unit region 101 with the largest graphic density difference with the adjacent first unit regions 101. Therefore, in this embodiment, in the step of dividing the positioning field of view 100 into multiple first unit regions 101, the side length b1 of the first unit region 101 is 1 / 8 to 1 / 10 of the side length b2 of the positioning field of view 100.

[0103] In this embodiment, the location acquisition module 503 is used to exclude the first unit region 101 located at the boundary position of the positioning field of view 100, and in the remaining first unit regions 101, according to a number of first unit regions 101 that have the largest graphic density difference with the adjacent first unit regions 101, to acquire the position of the addressing graphic 120 located around the target graphic 110 in the positioning field of view 100.

[0104] Since it is impossible to fully obtain the graphic density difference between the first unit region 101 located at the boundary position of the positioning field of view 100 and its adjacent regions, excluding the first unit region 101 located at the boundary position of the positioning field of view 100 helps ensure that several first unit regions 101 with the largest graphic density difference also have graphic density differences with their adjacent regions.

[0105] In this embodiment, in the step of dividing the positioning field of view 100 into a plurality of first unit regions 101, the plurality of first unit regions 101 are arranged in a matrix along the first direction X and the second direction Y, and the first direction X and the second direction Y are perpendicular to each other; in the step of obtaining the position of the addressing graphic 120 located around the target graphic 110 in the positioning field of view 100 based on a plurality of first unit regions 101 having the largest graphic density difference with adjacent first unit regions 101, adjacent first unit regions 101 include first unit regions 101 adjacent in the first direction X and first unit regions 101 adjacent in the second direction Y.

[0106] Multiple first unit regions 101 are arranged in a matrix along the first direction X and the second direction Y. The first direction X and the second direction Y are perpendicular to each other, which helps to reduce the difficulty of obtaining the graphic density of each first unit region 101 in the subsequent process.

[0107] Furthermore, the adjacent first unit regions 101 include first unit regions 101 adjacent in the first direction X and first unit regions 101 adjacent in the second direction Y, which helps to reduce the number of adjacent first unit regions 101, thereby making it easier to select several first unit regions 101 that have the largest difference in graphic density with the adjacent first unit regions 101.

[0108] In this embodiment, the location acquisition module 503 includes: a gradient value acquisition unit (not shown), used to calculate the gradient values ​​of the graphic density of each first unit region 101 in the positioning field of view 100 in the first direction X and the second direction Y, respectively, and to obtain the value of the first gradient in the first direction X and the value of the second gradient in the second direction Y; and a selection unit (not shown), used to select a number of first unit regions 101 that have the largest graphic density difference with the adjacent first unit regions 101 according to the values ​​of the first gradient and the second gradient.

[0109] First, the gradient values ​​of the graphic density of each first unit region 101 in the positioning field of view 100 in the first direction X and the second direction Y are calculated respectively to obtain the value of the first gradient in the first direction X and the value of the second gradient in the second direction Y. Then, based on the values ​​of the first gradient and the second gradient, several first unit regions 101 with the largest graphic density difference with the adjacent first unit regions 101 are selected to facilitate a balanced consideration of the gradient changes between the first unit region 101 and the adjacent first unit regions 101 in each direction.

[0110] In this embodiment, the gradient value acquisition unit includes: a first density gradient acquisition subunit (not shown), used to acquire the density difference between each first unit region 101 and an adjacent first unit region 101 in the first direction X, to obtain a first density gradient; a second density gradient acquisition subunit (not shown), used to acquire the density difference between each first unit region 101 and an adjacent first unit region 101 in the second direction Y, to obtain a second density gradient; a first gradient value acquisition subunit (not shown), used to acquire the vector sum of two adjacent first density gradients in the first direction X, to obtain the value of the first gradient, and when the value of either of the two adjacent first density gradients is 0, the value of the corresponding first gradient is set to 0; a second gradient value acquisition subunit (not shown), used to acquire the vector sum of two adjacent second density gradients in the second direction Y, to obtain the value of the second gradient, and when the value of either of the two adjacent second density gradients is 0, the value of the corresponding second gradient is set to 0.

[0111] First, obtain the first density gradient and the second density gradient between the first unit region 101 and the adjacent first unit region 101. Then, based on the first density gradient and the second density gradient, obtain the values ​​of the first gradient and the second gradient. This helps to reduce the difficulty of obtaining the values ​​of the first gradient and the second gradient.

[0112] Since a value of 0 in either of two adjacent first density gradients indicates that the first unit region 101 is similar to an adjacent first unit region 101 in the first direction X, and a value of 0 in either of two adjacent second density gradients indicates that the first unit region 101 is similar to an adjacent first unit region 101 in the second direction Y, setting the value of the corresponding first gradient to 0 when either of two adjacent first density gradients is 0, and setting the value of the corresponding second gradient to 0 when either of two adjacent second density gradients is 0, helps reduce the difficulty of selecting several first unit regions 101 with the greatest graphic density difference from adjacent first unit regions 101 based on the values ​​of the first and second gradients.

[0113] It should be noted that this is based on the formula: Δ X = X n-1 -X n (n is a natural number), along the first direction X, the density difference between each of the first unit regions 101 and its adjacent first unit regions 101 is obtained to obtain the first density gradient [e.g., ...]. Figure 5 and Figure 6 (a) is shown; where X n-1 For the first unit region 101, X n For the adjacent first unit region 101, Δ X represents the first density gradient.

[0114] Based on the formula: Along the first direction X, obtain the vector sum of the first density gradients of every pair of adjacent elements to obtain the value of the first gradient [e.g., ...]. Figure 7 [As shown in (a)]; where ΔX right Let ΔX be the first density gradient on the right side of any pair of adjacent first density gradients. left Let ΔX be the first density gradient on the left among two adjacent first density gradients. final It is the first gradient, and ΔX right and ΔX left If the value of either of them is 0, then ΔX final The value is 0.

[0115] It should also be noted that, based on the formula Δ Y = Y n-1 -Y n (n is a natural number), in the second direction Y, the density difference between each of the first unit regions 101 and the adjacent first unit regions 101 is obtained to obtain the second density gradient [e.g., Figure 5 and Figure 6 (b) is shown; where Y n-1For the first unit region 101, Y n For the adjacent first unit region 101, Δ Y represents the second density gradient.

[0116] Based on the formula: In the second direction Y, the vector sum of two adjacent second density gradients is obtained to obtain the value of the second gradient [e.g., ...]. Figure 7 (b) is shown; where ΔY top For each pair of adjacent second density gradients, the second density gradient located on the upper side is ΔY. bottom ΔY represents the lower density gradient among two adjacent second density gradients. final It is the second gradient, and ΔY top and ΔY bottom If the value of either of them is 0, then ΔY final The value is 0.

[0117] Specifically, in the step of obtaining the first density gradient, the first unit regions 101 located in the first and last rows are excluded, and for the remaining first unit regions 101, the density difference between each first unit region 101 and its adjacent first unit region 101 is obtained in the first direction X; in the step of obtaining the second density gradient, the first unit regions 101 located in the first and last columns are excluded, and for the remaining first unit regions 101, the density difference between each first unit region 101 and its adjacent first unit region 101 is obtained in the second direction Y.

[0118] Since it is impossible to fully obtain the graphic density difference between the first unit region 101 located at the boundary position of the positioning field of view 100 and its adjacent regions, the first unit regions 101 located in the first and last rows are excluded in the step of obtaining the first density gradient, and the first unit regions 101 located in the first and last columns are excluded in the step of obtaining the second density gradient. This not only helps to ensure that the first unit regions 101 with the largest graphic density difference have graphic density differences with their adjacent first unit regions 101, but also helps to reduce the amount of computation, thereby improving the calculation speed.

[0119] In this embodiment, the gradient value acquisition unit further includes: a third gradient value acquisition subunit, used to multiply the first gradient value and the second gradient value of the same first unit region 101, and obtain the third gradient value based on the result of the multiplication; the selection unit is used to select several first unit regions 101 that have the largest graphic density difference with the adjacent first unit regions 101 based on the third gradient value of each first unit region 101.

[0120] First, the values ​​of the first gradient and the second gradient of the same first unit region 101 are multiplied together, and the value of the third gradient is obtained based on the result of the multiplication. Then, based on the value of the third gradient of each first unit region 101, several first unit regions 101 with the largest difference in graphic density with the adjacent first unit regions 101 are selected. This helps to reduce the difficulty of considering the gradient changes between the first unit region 101 and the adjacent first unit regions 101 in each direction.

[0121] Specifically, the step of obtaining the third gradient value based on the result of multiplication includes: normalizing the result of multiplication and using the normalized result as the third gradient value; the step of selecting several first unit regions 101 with the largest graphic density difference from adjacent first unit regions 101 based on the third gradient values ​​of each first unit region 101 includes: selecting several first unit regions 101 with the largest graphic density difference from adjacent first unit regions 101 based on the first unit regions 101 with the third gradient value not being zero.

[0122] Normalizing the result of multiplication and using the normalized result as the value of the third gradient facilitates the rapid evaluation of the magnitude of each third gradient value. This reduces the time required to select several first unit regions 101 with the largest difference in graphic density from adjacent first unit regions 101 based on the value of the third gradient of each first unit region 101.

[0123] Since the value of the third gradient is obtained by multiplying the value of the first gradient and the value of the second gradient of the first unit region 101, the value of the third gradient is zero when either the value of the first gradient or the value of the second gradient is zero. Selecting several first unit regions 101 with the largest graphic density difference from adjacent first unit regions 101 based on the first unit regions 101 whose third gradient value is not zero helps to further reduce the difficulty of selecting such regions.

[0124] In this embodiment, the location acquisition module 503 further includes: a candidate region acquisition unit (not shown), used to select several first unit regions 101 with the largest graphic density difference from adjacent first unit regions 101 as candidate regions 125; an optimal region acquisition unit (not shown), used to select the first unit region 101 with the smallest graphic density from the candidate regions 125 as the optimal region 126; and an addressing graphic acquisition unit (not shown), used to acquire the position of the addressing graphic 120 located around the target graphic 110 in the optimal region 126.

[0125] First, select several first unit regions 101 with the largest difference in graphic density with the adjacent first unit regions 101 as candidate regions 125. Then, select the first unit region 101 with the smallest graphic density from the candidate regions 125 as the optimal region 126. This is beneficial to maximize the difference in graphic density between the optimal region 126 and the adjacent first unit regions 101, thereby making the optimal region 126 more unique. Correspondingly, it is also beneficial to make the selected addressing pattern 120 more unique, thereby making the effect of reducing the graphic similarity between the addressing pattern 120 and other regions better.

[0126] Specifically, the location acquisition module 503 further includes: an exclusion unit (not shown), used to exclude eight adjacent first unit regions 101 around the first unit region 101 where the target graphic 110 is located before selecting the first unit region 101 with the largest graphic density difference from the adjacent first unit region 101 as candidate regions 125 and selecting the first unit region 101 with the smallest graphic density from the candidate regions 125 as the optimal region 126; and the optimal region acquisition unit, used to select the first unit region 101 with the smallest graphic density from the remaining candidate regions 125 as the optimal region 126.

[0127] Before selecting the first unit region 101 with the lowest pattern density from the candidate regions 125 as the optimal region 126, excluding the eight adjacent first unit regions 101 surrounding the first unit region 101 where the target pattern 110 is located helps avoid the optimal region 126 being one of the eight adjacent first unit regions 101. This helps avoid the distance between the target pattern 110 and the addressing pattern 120 being too small, and further helps reduce the probability of the CD value of the target pattern 110 changing during the process of obtaining the position of the addressing pattern 120. For example, during the post-development detection process and during the process of obtaining the position of the addressing pattern 120, it reduces the probability that the CD value of the target pattern 110 will change due to electron bombardment.

[0128] In this embodiment, the addressing pattern acquisition unit includes: a second unit region segmentation subunit (not shown), used to divide the optimal region 126 into multiple second unit regions 127; a second unit region selection subunit (not shown), used to select the second unit region 127 closest to the center of the optimal region 126 and with a pattern density of not zero; and an addressing point acquisition subunit (not shown), used to take the coordinates of the center point of the selected second unit region 127 as the coordinates of the addressing point 121 of the addressing pattern 120.

[0129] After dividing the optimal region 126 into multiple second unit regions 127, the second unit region 127 closest to the center of the optimal region 126 and with a non-zero graphic density is selected. Then, the coordinates of the center point of the selected second unit region 127 are used as the coordinates of the addressing point 121 of the addressing graphic 120. This is beneficial to further increase the graphic density in the addressing field of view, that is, to further increase the graphic density of the addressing graphic 120, thereby further reducing the probability of failure to locate the addressing graphic 120 due to its low graphic density.

[0130] It should be noted that in the step of dividing the optimal region 126 into multiple second unit regions 127, the proportion of the side length b3 of the second unit region 127 to the side length b1 of the optimal region 126 should not be too small or too large. If the proportion of the side length b3 of the second unit region 127 to the side length b1 of the optimal region 126 is too small, the number of second unit regions 127 will be too large, thereby increasing the computational load for calculating the graphic density of the second unit region 127. If the proportion of the side length b3 of the second unit region 127 to the side length b1 of the optimal region 126 is too large, the effect of further increasing the graphic density of the addressing graphic 120 will be poor. Therefore, in this embodiment, in the step of dividing the optimal region 126 into multiple second unit regions 127, the side length b3 of the second unit region 127 is 1 / 8 to 1 / 10 of the side length b1 of the optimal region 126.

[0131] Specifically, the addressing pattern acquisition unit is further configured to acquire an addressing positioning field of view based on the coordinates of the addressing point 121 and a preset addressing field of view size, wherein the pattern in the addressing positioning field of view is used as the addressing pattern 120.

[0132] Based on the coordinates of the addressing point 121 and the preset addressing field of view size, the addressing positioning field of view area is obtained, and the graphic in the addressing positioning field of view area is used as the addressing graphic 120, which helps to reduce the difficulty of obtaining the addressing graphic 120.

[0133] More specifically, in the step of obtaining the addressing and positioning field of view based on the coordinates of the addressing point 121 and the preset addressing field of view size, the addressing and positioning field of view centered on the addressing point 121 is obtained.

[0134] In the step of obtaining the addressing positioning field of view based on the coordinates of the addressing point 121 and the preset addressing field of view size, obtaining the addressing positioning field of view centered on the addressing point 121 helps to further reduce the difficulty of obtaining the addressing pattern 120.

[0135] In this embodiment, in the step of obtaining the position of the addressing pattern 120 located around the target pattern 110 in the positioning field of view 100, if the position of the addressing pattern 120 is not obtained, the measurement of the target pattern 110 is abandoned.

[0136] In this context, abandoning the measurement of the target graphic 110 means abandoning the measurement of the target graphic 110 and selecting another target graphic 110 that can obtain the position of the corresponding addressing graphic 120 for measurement.

[0137] In the step of acquiring the position of the addressing pattern 120 surrounding the target pattern 110 within the positioning field of view 100, if the position of the addressing pattern 120 is not acquired, it indicates that the measurement of the target pattern 110 is likely to fail. That is, the CD value of the target pattern 110 obtained by measurement is not the true CD value of the target pattern 110. Therefore, the measurement of the target pattern 110 should be abandoned to avoid the impact of the inaccurate CD value of the target pattern 110 on the semiconductor manufacturing process.

[0138] Accordingly, embodiments of the present invention also provide an electronic device. Figure 15 This is a hardware structure diagram of an electronic device provided according to an embodiment of the present invention.

[0139] In this embodiment, the electronic device includes at least one memory 03 and at least one processor 01. The memory 03 stores one or more computer instructions, wherein the one or more computer instructions are executed by the processor 01 to implement the addressing pattern acquisition method or the measurement method described in this embodiment of the invention.

[0140] As an example, processor 01 may be a central processing unit (CPU), a field programmable gate array (FPGA), a programmable logic controller (PLC), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the addressing pattern acquisition method described in the embodiments of the present invention, or one or more integrated circuits of the measurement method described in the embodiments of the present invention.

[0141] Memory 03 may include high-speed RAM, and may also include non-volatile memory, such as at least one disk storage device. Memory 03 stores one or more computer instructions, which are executed by processor 01 to implement the addressing pattern acquisition method described in this embodiment of the invention, or the measurement method described in this embodiment of the invention.

[0142] In this embodiment, the electronic device may further include at least one communication interface 02 and at least one communication bus 04.

[0143] Communication interface 02 can be an interface for a communication module used for network communication, such as the interface for a GSM module.

[0144] It should be noted that the electronic device may also include other devices (not shown) that may not be essential to understanding the disclosure of the embodiments of the present invention; given that these other devices may not be essential to understanding the disclosure of the embodiments of the present invention, the embodiments of the present invention will not describe them one by one.

[0145] Accordingly, embodiments of the present invention also provide a computer program product, including computer instructions, which, when executed by a processor, are used to implement the addressing pattern acquisition method of the present invention, or the measurement method described in the embodiments of the present invention.

[0146] Accordingly, embodiments of the present invention also provide a storage medium storing one or more computer instructions, which are used to implement the addressing pattern acquisition method or the measurement method described in the embodiments of the present invention.

[0147] The embodiments of the present invention described above are combinations of elements and features of the present invention. Unless otherwise stated, the elements or features described are optional. Individual elements or features may be practiced without combination with other elements or features. Furthermore, embodiments of the present invention may be constructed by combining some elements and / or features. The order of operations described in the embodiments of the present invention may be rearranged. Some constructions of any embodiment may be included in another embodiment and may be replaced by corresponding constructions of another embodiment. It will be apparent to those skilled in the art that claims in the appended claims that are not expressly referenced to each other may be combined to form embodiments of the present invention, or may be included as new claims in amendments made after the filing of this application.

[0148] Embodiments of the present invention can be implemented by various means, such as hardware, firmware, software, or combinations thereof. In a hardware configuration, the method according to an exemplary embodiment of the present invention can be implemented by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, etc.

[0149] In firmware or software configuration, embodiments of the present invention can be implemented in the form of modules, processes, functions, etc. Software code can be stored in a memory unit and executed by a processor. The memory unit is located inside or outside the processor and can send data to and receive data from the processor via various known means.

[0150] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A method for obtaining an addressable pattern, characterized in that, include: Obtain the positioning field of view region corresponding to the target graphic, wherein the positioning field of view region contains the target graphic; The positioning field of view is divided into multiple first unit regions; Obtain the graphic density of each first unit region; Based on a number of first unit regions that have the largest difference in graphic density with their adjacent first unit regions, the positions of the addressable graphics located around the target graphic are obtained in the positioning field of view.

2. The method for obtaining the addressing pattern as described in claim 1, characterized in that, In the step of obtaining the positioning field of view area corresponding to the target graphic, the positioning field of view area centered on the target graphic is obtained.

3. The method for obtaining the addressing pattern as described in claim 1, characterized in that, Exclude the first unit region located at the boundary of the positioning field of view, and in the remaining first unit regions, obtain the position of the addressable graphics around the target graphics in the positioning field of view based on a number of first unit regions that have the largest graphic density difference with the adjacent first unit regions.

4. The method for obtaining the addressing pattern as described in claim 1, characterized in that, In the step of dividing the positioning field of view into multiple first unit regions, the multiple first unit regions are arranged in a matrix along a first direction and a second direction, and the first direction and the second direction are perpendicular to each other. In the step of obtaining the position of the addressable graphic around the target graphic in the positioning field of view based on a plurality of first unit regions having the largest graphic density difference with the adjacent first unit regions, the adjacent first unit regions include first unit regions adjacent in a first direction and first unit regions adjacent in a second direction.

5. The method for obtaining the addressing pattern as described in claim 4, characterized in that, The selection method for several first unit regions that have the largest difference in graphic density with adjacent first unit regions includes: The gradient values ​​of the graphic density of each first unit region in the positioning field of view are calculated in the first direction and the second direction, respectively, to obtain the value of the first gradient in the first direction and the value of the second gradient in the second direction; Based on the values ​​of the first gradient and the second gradient, select several first unit regions that have the largest difference in graphic density with the adjacent first unit regions.

6. The method for obtaining the addressing pattern as described in claim 5, characterized in that, The steps of calculating the gradient values ​​of the graphic density in the first and second directions for each first unit region in the positioning field of view include: In the first direction, the density difference between each first unit region and the adjacent first unit region is obtained to obtain the first density gradient; In the second direction, the density difference between each first unit region and the adjacent first unit region is obtained to obtain the second density gradient; In the first direction, the vector sum of two adjacent first density gradients is obtained to get the value of the first gradient, and when the value of either of the two adjacent first density gradients is 0, the value of the corresponding first gradient is set to 0. In the second direction, the vector sum of two adjacent second density gradients is obtained to obtain the value of the second gradient, and when the value of either of the two adjacent second density gradients is 0, the value of the corresponding second gradient is set to 0.

7. The method for obtaining addressing patterns as described in claim 6, characterized in that, In the step of obtaining the first density gradient, the first cell regions located in the first and last rows are excluded, and for the remaining first cell regions, the density difference between each first cell region and the adjacent first cell region is obtained in the first direction. In the step of obtaining the second density gradient, the first unit regions located in the first and last columns are excluded, and for the remaining first unit regions, the density difference between each first unit region and its adjacent first unit region is obtained in the second direction.

8. The method for obtaining addressing patterns as described in claim 5, characterized in that, The step of selecting several first unit regions with the largest difference in graphic density from adjacent first unit regions based on the values ​​of the first gradient and the second gradient includes: Multiply the values ​​of the first gradient and the second gradient within the same first unit region, and obtain the value of the third gradient based on the result of the multiplication; Based on the value of the third gradient of each of the first unit regions, select several first unit regions that have the largest difference in graphic density with the adjacent first unit regions.

9. The method for obtaining addressing patterns as described in claim 8, characterized in that, The steps to obtain the value of the third gradient from the result of multiplication include: normalizing the result of multiplication and using the normalized result as the value of the third gradient; The step of selecting several first unit regions with the largest graphic density difference from adjacent first unit regions based on the value of the third gradient of each first unit region includes: selecting several first unit regions with the largest graphic density difference from adjacent first unit regions based on the first unit regions whose third gradient value is not zero.

10. The method for obtaining the addressing pattern as described in any one of claims 1 to 9, characterized in that, The step of obtaining the position of the addressable graphic surrounding the target graphic in the positioning field of view region based on a plurality of first unit regions having the largest graphic density difference with adjacent first unit regions includes: Several first unit regions with the largest difference in graphic density from their adjacent first unit regions are selected as candidate regions. The first unit region with the lowest graphic density among the candidate regions is selected as the optimal region. Obtain the location of the addressable graphics surrounding the target graphic within the optimal region.

11. The method for obtaining addressing patterns as described in claim 10, characterized in that, After selecting several first unit regions with the largest difference in graphic density from adjacent first unit regions as candidate regions, and before selecting the first unit region with the smallest graphic density from the candidate regions as the best region, the process further includes: excluding eight adjacent first unit regions around the first unit region where the target graphic is located. Among the remaining candidate regions, the first unit region with the lowest graphic density is selected as the optimal region.

12. The method for obtaining addressing patterns as described in claim 10, characterized in that, The step of obtaining the location of the addressable graphics surrounding the target graphics in the optimal region includes: The optimal region is divided into multiple second unit regions; Select the second unit region that is closest to the center of the optimal region and has a non-zero graphic density; The coordinates of the center point of the selected second unit area are used as the coordinates of the addressing point of the addressing graphic.

13. The method for obtaining addressing patterns as described in claim 12, characterized in that, In the step of dividing the optimal region into multiple second unit regions, the side length of the second unit region is 1 / 8 to 1 / 10 of the side length of the optimal region.

14. The method for obtaining addressing patterns as described in claim 12, characterized in that, The step of obtaining the position of the addressing graphic located around the target graphic in the optimal area further includes: obtaining the addressing positioning field of view area based on the coordinates of the addressing point and the preset addressing field of view size, wherein the graphic in the addressing positioning field of view area is used as the addressing graphic.

15. The method for obtaining the addressing pattern as described in claim 14, characterized in that, In the step of obtaining the addressing and positioning field of view based on the coordinates of the addressing point and the preset addressing field of view size, the addressing and positioning field of view centered on the addressing point is obtained.

16. The method for obtaining the addressing pattern as described in any one of claims 1 to 9, characterized in that, In the step of obtaining the positioning field of view area corresponding to the target graphic, the side length of the positioning field of view area of ​​the target graphic is 20 micrometers to 30 micrometers.

17. The method for obtaining the addressing pattern as described in any one of claims 1 to 9, characterized in that, In the step of dividing the positioning field of view into multiple first unit regions, the side length of the first unit region is 1 / 8 to 1 / 10 of the side length of the positioning field of view.

18. The method for obtaining the addressing pattern as described in any one of claims 1 to 9, characterized in that, In the step of obtaining the position of the addressable graphic located around the target graphic in the positioning field of view, if the position of the addressable graphic is not obtained, the measurement of the target graphic is abandoned.

19. A measurement method, characterized in that, include: An addressing and positioning field of view is obtained around the target graphic to be measured, the graphic in the addressing and positioning field of view is used as the addressing graphic, and the position of the addressing graphic is obtained by the method of obtaining the addressing graphic as described in any one of claims 1 to 18. After obtaining the addressing and positioning field of view, the target graphic to be measured is located based on the preset relative positional relationship between the addressing graphic and the target graphic to be measured.

20. The measurement method as described in claim 19, characterized in that, The target graphic to be measured has measurement points, the addressing graphic has addressing points, and there is a preset distance offset between the addressing points and the measurement points; The step of locating the target graphic to be measured based on the preset relative positional relationship between the addressing graphic and the target graphic to be measured includes: locating the target graphic to be measured based on the position of the addressing point and the preset distance offset.

21. The measurement method as described in claim 19, characterized in that, Methods for obtaining the addressable and localized field of view around the target graphic to be measured include image matching.

22. A system for acquiring addressable patterns, characterized in that, include: The field of view acquisition module is used to acquire the positioning field of view corresponding to the target graphic, wherein the positioning field of view contains the target graphic; The image segmentation module is used to divide the positioning field of view into multiple first unit regions; The graphics density acquisition module is used to acquire the graphics density of each first unit region; The location acquisition module is used to acquire the location of the addressable graphic located around the target graphic in the positioning field of view area based on a number of first unit regions that have the largest graphic density difference with the adjacent first unit regions.

23. An electronic device, characterized in that, It includes at least one memory and at least one processor, the memory storing one or more computer instructions, wherein the one or more computer instructions are executed by the processor to implement the addressing pattern acquisition method as described in any one of claims 1 to 18, or the measurement method as described in any one of claims 19 to 21.

24. A computer program product, characterized in that, It includes computer instructions, which, when executed by a processor, are used to implement the addressing pattern acquisition method as described in any one of claims 1 to 18, or the measurement method as described in any one of claims 19 to 21.

25. A storage medium, characterized in that, The storage medium stores one or more computer instructions, which are used to implement the addressing pattern acquisition method as described in any one of claims 1 to 18, or the measurement method as described in any one of claims 19 to 21.

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