CD-SEM machine positioning method, computer equipment and computer readable storage medium

Abstract

A CD-SEM machine positioning method, a computer device and a computer readable storage medium wherein the CD-SEM machine positioning method comprises: providing a to-be-processed layout, the to-be-processed layout having a plurality of measurement points; in the to-be-processed layout, a detection window is established with the measuring points as the center, the detection window is annular, the inner diameter of the detection window is larger than or equal to a first preset size, and the outer diameter of the detection window is smaller than or equal to a second preset size; establishing a plurality of inspection windows in the detection window; and obtaining at least one target window corresponding to the measurement point from the plurality of inspection windows corresponding to the measurement point according to the graph density distribution in each inspection window, and taking the position coordinates of the target window as the coordinates of the positioning point corresponding to the measurement point, thereby facilitating the improvement of the success rate of CD-SEM machine positioning.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and in particular to a CD-SEM machine positioning method, computer equipment, and computer-readable storage medium. Background Technology

[0002] In the chip manufacturing process, critical dimension (CD) measurement equipment based on scanning electron microscopy (SEM), namely CD-SEM equipment, plays a crucial role. CD-SEM is typically used to measure the critical dimensions of each process step to monitor the health of the process.

[0003] CD-SEM requires address coordinates for critical dimension measurement, which are used to match and position the GDS pattern with the actual wafer pattern.

[0004] However, existing methods for obtaining positioning coordinates need further improvement. Summary of the Invention

[0005] The technical problem solved by this invention is to provide a CD-SEM machine positioning method, computer equipment, and computer-readable storage medium to optimize positioning coordinates.

[0006] To address the aforementioned technical problems, the present invention provides a CD-SEM machine positioning method, comprising: providing a layout to be processed, the layout having a plurality of measurement points; establishing a detection window centered on each measurement point in the layout, the detection window being annular, with its inner diameter greater than or equal to a first preset size and its outer diameter less than or equal to a second preset size; establishing a plurality of inspection windows within the detection windows; and, based on the graphic density distribution within each inspection window, obtaining at least one target window corresponding to the measurement point from the plurality of inspection windows corresponding to the measurement point, using the position coordinates of the target window as the positioning point coordinates corresponding to the measurement point.

[0007] Optionally, the step of obtaining at least one target window corresponding to the measurement point from a plurality of inspection windows corresponding to the measurement point based on the graphic density distribution within each inspection window, and using the position coordinates of the target window as the positioning point coordinates corresponding to the measurement point, includes: obtaining a first pattern evaluation value and / or a second pattern evaluation value for each inspection window based on the graphic density distribution within each inspection window; obtaining a target window from a plurality of inspection windows based on a plurality of first pattern evaluation values ​​corresponding to the measurement point, and using the position coordinates of the target window as the positioning point coordinates corresponding to the measurement point; or, based on... Based on the plurality of second pattern evaluation values ​​corresponding to the measurement point, a target window is obtained from the plurality of inspection windows, and the position coordinates of the target window are used as the coordinates of a positioning point corresponding to the measurement point; or, based on the plurality of first pattern evaluation values ​​corresponding to the measurement point, a target window is obtained from the plurality of inspection windows, and the position coordinates of the target window are used as the coordinates of a positioning point corresponding to the measurement point, and based on the plurality of second pattern evaluation values ​​corresponding to the measurement point, another target window is obtained from the plurality of inspection windows, and the position coordinates of the target window are used as the coordinates of another positioning point corresponding to the measurement point.

[0008] Optionally, obtaining the first pattern evaluation value and / or the second pattern evaluation value of each inspection window based on the graphic density distribution within each inspection window includes: obtaining the reference pattern area of ​​the graphic within each inspection window; obtaining the first pattern area change of each inspection window in a first direction; obtaining the second pattern area change of each inspection window in a second direction; obtaining the first pattern evaluation value of the inspection window based on the first pattern area change and the second pattern area change of each inspection window; obtaining the second pattern evaluation value of the inspection window based on the reference pattern area, the first pattern area change, and the second pattern area change of each inspection window; wherein the first direction and the second direction are perpendicular to each other.

[0009] Optionally, the first pattern evaluation value Value1 = △a1 * △a2, where △a1 is the change in area of ​​the first pattern and △a2 is the change in area of ​​the second pattern; the second pattern evaluation value Value2 = △a1 * △a2 * a0, where a0 is the area of ​​the reference pattern, △a1 is the change in area of ​​the first pattern and △a2 is the change in area of ​​the second pattern.

[0010] Optionally, the method for obtaining the change in the first pattern area of ​​each of the inspection windows in the first direction includes: establishing a first offset window and a second offset window in the layout to be processed, wherein the first offset window has a first offset size relative to the inspection window in the first direction, and the second offset window has a second offset size relative to the inspection window in the opposite direction to the first direction, the inspection window has a first window size in the first direction, and both the first offset size and the second offset size are smaller than the first window size; obtaining a first pattern area of ​​the graphic within the first offset window and a second pattern area of ​​the graphic within the second offset window; obtaining a first difference between the first pattern area and the reference pattern area; obtaining a second difference between the second pattern area and the reference pattern area; and obtaining the change in the first pattern area based on the first difference and the second difference, wherein the change in the first pattern area is the maximum value of the first difference and the second difference.

[0011] Optionally, both the first offset size and the second offset size are half the size of the first window.

[0012] Optionally, based on the Python language, the first offset window and the second offset window are established in the layout to be processed; based on the DRC language, the area of ​​the reference pattern, the area of ​​the first pattern, and the area of ​​the second pattern are obtained; based on the Python language, the change in the area of ​​the first pattern and the evaluation value of the first pattern are obtained.

[0013] Optionally, the method for obtaining the change in the second pattern area of ​​each of the inspection windows in the second direction includes: establishing a third offset window and a fourth offset window in the layout to be processed, wherein the third offset window has a third offset size relative to the inspection window in the second direction, the fourth offset window has a fourth offset size relative to the inspection window in the opposite direction to the second direction, the inspection window has a second window size in the second direction, and both the third offset size and the fourth offset size are smaller than the second window size; obtaining the third pattern area of ​​the graphic within the third offset window and the fourth pattern area of ​​the graphic within the fourth offset window; obtaining a third difference between the third pattern area and the reference pattern area; obtaining a fourth difference between the fourth pattern area and the reference pattern area; and obtaining the change in the second pattern area based on the third difference and the fourth difference, wherein the change in the second pattern area is the maximum value of the third difference and the fourth difference.

[0014] Optionally, both the third offset size and the fourth offset size are half the size of the second window.

[0015] Optionally, based on the Python language, the third offset window and the fourth offset window are established in the layout to be processed; based on the DRC language, the area of ​​the reference pattern, the area of ​​the third pattern, and the area of ​​the fourth pattern are obtained; based on the Python language, the change in the area of ​​the second pattern and the evaluation value of the second pattern are obtained.

[0016] Optionally, the method of establishing a plurality of inspection windows within the detection window includes: establishing a plurality of detection points in the detection window, wherein the plurality of detection points are located on one or more circles of different radii with the measurement point as the center; setting the inspection window with each of the detection points as the center; the inspection window is rectangular, one contour side of the inspection window is parallel to a first direction, and the other contour side is parallel to a second direction, wherein the first direction and the second direction are perpendicular to each other.

[0017] Optionally, the first preset size is 3μm; the second preset size is 8μm.

[0018] Optionally, the step of providing a layout to be processed, the layout to be processed having a plurality of measurement points, includes: providing a measurement point setting file, the measurement point setting file including at least one GDS file, the GDS file including at least one layout, the measurement point setting file also including the names of all preset measurement points corresponding to each of the layouts, and the GDS coordinates of each of the preset measurement points; according to the measurement point setting file, obtaining the layout to be processed from the plurality of layouts, and setting the plurality of measurement points in the layout to be processed according to the GDS coordinates of the plurality of preset measurement points.

[0019] Optionally, before establishing the detection window and before acquiring the plurality of measurement points, the plurality of preset measurement points are further rationalized to remove unreasonable portions of the preset measurement points in order to acquire the plurality of measurement points. The rationalization process includes: providing a measurement point distance setting value; acquiring the distance of the plurality of preset measurement points in the layout to be processed; and, based on the distance of the plurality of preset measurement points and the measurement point distance setting value, removing some of the preset measurement points, and using the remaining plurality of preset measurement points as the plurality of measurement points, such that the distance between two adjacent measurement points is greater than or equal to the measurement point distance setting value.

[0020] Optionally, the aforementioned rationalization process can be performed using the Python language.

[0021] Optionally, before establishing the detection window, the method further includes: flattening the GDS file; flattening the GDS file based on the tcl language.

[0022] Optionally, before establishing the detection window, the method further includes: trimming the GDS file; and trimming the GDS file based on the drc language.

[0023] Optionally, it also includes: obtaining a positioning pattern at the coordinates of the positioning point and a pattern to be measured at the measurement point based on the layout to be processed; acquiring a SEM image on the wafer corresponding to the coordinates of the positioning point using a CD-SEM machine based on the coordinates of the positioning point; when the positioning pattern and the SEM image are consistent, accurate positioning is achieved; after accurate positioning, acquiring the SEM image of the pattern to be measured based on the relative coordinates between the positioning pattern and the pattern to be measured.

[0024] Optionally, it also includes: creating a working menu for the CD-SEM machine, the working menu including positioning information, the positioning information including several measurement points and at least one positioning point coordinate corresponding to the measurement points; the working menu is executed when the CD-SEM machine is in operation.

[0025] Optionally, based on the Python language, the probe window and several inspection windows are established in the layout to be processed.

[0026] Accordingly, the present invention also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the CD-SEM machine positioning method described above.

[0027] Accordingly, the technical solution of the present invention also provides a computer-readable storage medium storing a computer program thereon, wherein when the computer program is executed by a processor, it implements the steps of the CD-SEM machine positioning method described above.

[0028] Compared with the prior art, the technical solution of the embodiments of the present invention has the following beneficial effects:

[0029] In the CD-SEM machine positioning method provided by the present invention, based on the graphic density distribution within each inspection window, at least one target window corresponding to the measurement point is obtained from a plurality of inspection windows corresponding to the measurement point. The position coordinates of the target window are used as the positioning point coordinates corresponding to the measurement point. The method of obtaining the positioning point coordinates does not rely on easily recognizable patterns, but on the graphic density distribution within each inspection window. Therefore, it is more universal and is more conducive to improving the success rate of CD-SEM machine positioning when there is a large number of measurement points.

[0030] Furthermore, based on the Python language, the detection window and several inspection windows are established in the layout to be processed. Based on the Python and DRC languages, the coordinates of the positioning points are obtained. By integrating multiple software and computer languages ​​and leveraging their complementary advantages, the system can achieve simple and efficient batch standard automatic acquisition of positioning point coordinates, thereby saving manpower and increasing the accuracy of measurement.

[0031] Furthermore, two positioning point coordinates are obtained, which provides double protection for aligning the layout graphic with the actual wafer graphic, thus improving accuracy. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the positioning coordinates in a method for obtaining positioning coordinates;

[0033] Figures 2 to 6 This is a flowchart illustrating a CD-SEM machine positioning method according to an embodiment of the present invention;

[0034] Figures 7 to 9 This is a schematic diagram of the CD-SEM machine positioning method according to an embodiment of the present invention. Detailed Implementation

[0035] It should be noted that the terms "surface" and "on" in this specification are used to describe the relative spatial position and are not limited to whether there is direct contact.

[0036] As described in the background section, existing methods for obtaining positioning coordinates need further improvement. A method for obtaining positioning coordinates will now be explained and analyzed.

[0037] Figure 1 This is a schematic diagram of the positioning coordinates in a method for obtaining positioning coordinates.

[0038] Please refer to Figure 1 In the measurement of critical dimensions, positioning coordinates are required for matching and aligning the GDS layout pattern and the actual wafer pattern. These positioning coordinates are usually patterns that are easy to identify, such as: (1) selection when there are characteristic graphics in the image; (2) selection when the arrangement order of similar graphics is characteristic; (3) selection when there are graphics that cross the entire screen in the image; (4) when all graphics in the image are exactly the same, select the middle position of the measurement frame, the position close to the measurement point, or the position of the measurement point.

[0039] The above-mentioned method for obtaining positioning coordinates requires human eyes to observe the distribution of patterns around the measurement point (MP) and find patterns that are relatively distinctive and easy to identify for CD-SEM machine alignment.

[0040] However, for actual chips, the patterns of typical positioning coordinates are not easily identifiable, making it difficult for CD-SEM equipment to find the actual wafer pattern that matches the positioning coordinate pattern, leading to measurement failures. As semiconductor process nodes continue to shrink, the patterns transferred to the wafer become increasingly complex and dense, and the number of measurement points increases dramatically, becoming extremely time-consuming and labor-intensive. This is especially true for advanced nodes requiring measurement analysis of large amounts of data. Existing methods for manually setting positioning coordinates become time-consuming when the number of measurement points is large, and the positioning failure rate also increases significantly. Therefore, there is an urgent need for a feasible, effective, and universally applicable method for finding these positioning coordinates.

[0041] To address the aforementioned issues, this invention provides a CD-SEM machine positioning method, computer device, and computer-readable storage medium. Based on the graphic density distribution within each inspection window, at least one target window corresponding to the measurement point is obtained from several inspection windows corresponding to the measurement point. The position coordinates of the target window are used as the positioning point coordinates corresponding to the measurement point. This method of obtaining positioning point coordinates does not rely on easily identifiable patterns but rather on the graphic density distribution within each inspection window. Therefore, it is more universally applicable and, when a large number of measurement points are required, is more conducive to improving the success rate of CD-SEM machine positioning.

[0042] To make the above-mentioned objectives, features and beneficial effects of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0043] Figures 2 to 6 This is a flowchart illustrating a CD-SEM machine positioning method according to an embodiment of the present invention.

[0044] In this embodiment, the CD-SEM machine positioning method includes the following steps:

[0045] Step S11: Provide a layout to be processed, wherein the layout to be processed has several measurement points;

[0046] Step S12: In the layout to be processed, a detection window is established with each measurement point as the center. The detection window is annular, and the inner diameter of the detection window is greater than or equal to a first preset size, while the outer diameter of the detection window is less than or equal to a second preset size.

[0047] Step S13: Establish several inspection windows within the detection window;

[0048] Step S14: Based on the graphic density distribution within each inspection window, obtain at least one target window corresponding to the measurement point from among the several inspection windows corresponding to the measurement point, and use the position coordinates of the target window as the positioning point coordinates corresponding to the measurement point.

[0049] Here, the method for obtaining the coordinates of the positioning points does not rely on easily recognizable patterns, but on the graphic density distribution within each inspection window. Therefore, it is more universal and more conducive to improving the success rate of CD-SEM machine positioning when there is a large demand for measurement points.

[0050] The following will be described in detail with reference to the accompanying drawings.

[0051] Figures 7 to 9 This is a schematic diagram of the CD-SEM machine positioning method according to an embodiment of the present invention.

[0052] Please refer to step S11 for execution. Figure 7 A layout 20 to be processed is provided, wherein the layout 20 to be processed has a number of measurement points MP.

[0053] In this embodiment, the provision of a layout to be processed 20, which has a plurality of measurement points MP, includes: providing a measurement point setting file, the measurement point setting file including at least one GDS file, the GDS file including at least one layout, and the measurement point setting file also including the names of all preset measurement points corresponding to each layout, and the GDS coordinates of each preset measurement point; according to the measurement point setting file, the layout to be processed is obtained from the plurality of layouts, and the plurality of measurement points are set in the layout to be processed according to the GDS coordinates of the plurality of preset measurement points. The measurement point setting file can provide multiple GDS information and their corresponding measurement point information.

[0054] It's important to note that GDS (Graphic Data System) files contain graphics layer information. GDS is a standard file format used in semiconductor chip design, storing chip layout information. In a GDS file, each physical layer is assigned to a graphics layer, and each graphics layer has a unique layer number, typically an integer. This graphics layer information determines the location, shape, and size of each physical layer in the chip layout, facilitating chip design and manufacturing processes.

[0055] In this embodiment, the layout to be processed can be any graphic layer in the GDS file. Subsequently, the CD-SEM machine positioning method based on Python, DRC and TCL languages ​​can automatically obtain the positioning coordinates of any graphic layer.

[0056] In this embodiment, before establishing the detection window and before acquiring the plurality of measurement points, the plurality of preset measurement points are further rationalized to remove unreasonable portions of the preset measurement points in order to acquire the plurality of measurement points. The purpose of the rationalization process is to reduce the problem of multiple measurements of measurement points affecting measurement accuracy (e.g., in the ADI developing and inspection process, multiple measurements of measurement points can affect the accuracy of critical dimension measurements).

[0057] In this embodiment, the rationalization process includes: providing a measurement point distance setting value; obtaining the distance between a plurality of preset measurement points in the layout to be processed; removing some of the preset measurement points based on the distance between the plurality of preset measurement points and the measurement point distance setting value, and using the remaining plurality of preset measurement points as the plurality of measurement points, such that the distance between two adjacent measurement points is greater than or equal to the measurement point distance setting value.

[0058] In this embodiment, the distance between the measurement points is set to 10 μm.

[0059] In this embodiment, the rationalization process is performed using the Python language.

[0060] It should be noted here that, for ease of explanation, Figure 7 Only one measurement point MP is shown in the figure. The number and location of the measurement points MP are set according to actual needs.

[0061] Please refer to step S12 for execution. Figure 8 And continue to refer to Figure 7 In the layout to be processed 20, a detection window 201 is established with each measurement point MP as the center. The detection window 201 is annular, and the inner diameter R1 of the detection window 201 is greater than or equal to a first preset size, and the outer diameter R2 of the detection window 201 is less than or equal to a second preset size.

[0062] It should be noted that, for ease of description, Figure 8 For illustration only Figure 7 The location of the probe window 201 and part of the inspection window.

[0063] In this embodiment, the detection window 201 is established in the layout 20 to be processed based on the Python language.

[0064] In this embodiment, before establishing the detection window 201, the GDS file is flattened. The purpose of the flattening process is to ensure that when extracting relevant information about the measurement points and the inspection window, the coordinate attributes obtained are the coordinates corresponding to the top-cell, rather than the coordinates corresponding to the sub-cells, which helps to improve the accuracy of the final obtained positioning coordinates.

[0065] In this embodiment, the GDS file is flattened based on the Tcl language.

[0066] In this embodiment, the GDS file is clipped before the detection window 201 is established. The purpose of the clipping is to reduce the file size and improve the speed of subsequent operations.

[0067] In this embodiment, the GDS file is trimmed based on the drc language.

[0068] The first preset size is 1.5 μm; the second preset size is 10 μm. The purpose of making the inner diameter R1 of the detection window 201 greater than or equal to the first preset size and the outer diameter R2 less than or equal to the second preset size is to: make the distance between the positioning point coordinates and the measurement point appropriate, so as to reduce the problem of multiple measurements of the measurement point, which affects the measurement accuracy (such as in the ADI development inspection process, multiple measurements of the measurement point will affect the accuracy of critical dimension measurement), and improve the positioning accuracy of the CD-SEM machine.

[0069] In this embodiment, the inner diameter of the detection window 201 is R1 = 2 μm and R2 = 7.4 μm.

[0070] Please refer to step S13 for further instructions. Figure 7 and Figure 8 Several inspection windows 202 are established within the detection window 201.

[0071] In this embodiment, based on the Python language, several inspection windows 202 are created within the detection window 201.

[0072] In this embodiment, the method of establishing a plurality of inspection windows 202 within the detection window 201 includes: establishing a plurality of detection points 203 in the detection window 201, wherein the plurality of detection points 203 are located on one or more circles of different radii with the measurement point MP as the center; and setting the inspection window 202 with each detection point 203 as the center.

[0073] In this embodiment, several detection points 203 are located on three circles with different radii centered on the measurement point MP, namely r1 = 3.35 μm, r2 = 4.7 μm, and r3 = 6.05 μm. Here, the three circles are evenly distributed within the detection window 201, and the distance between adjacent circles is 1.35 μm.

[0074] Specifically, the plurality of detection points 203 include a plurality of first detection points 203a, a plurality of second detection points 203b, and a plurality of third detection points 203c. The plurality of first detection points 203a are distributed on the circumference of r1, the plurality of second detection points 203b are distributed on the circumference of r2, and the plurality of third detection points 203c are distributed on the circumference of r3. A first inspection window 202a is established with the first detection point 203a as the center, a second inspection window 202b is established with the second detection point 203b as the center, and a third inspection window 202c is established with the third detection point 203c as the center. The plurality of inspection windows 202 include a plurality of first inspection windows 202a, a plurality of second inspection windows 202b, and a plurality of third inspection windows 203c.

[0075] It should be noted that, for ease of understanding, Figure 7 Taking 24 first detection points 203a, 24 first detection points 203b and 24 first detection points 203a as an example, to obtain 72 inspection windows 202; Figure 8 Only one first inspection window 202a, one first detection point 203a, one second inspection window 202b, one second detection point 203b, one third inspection window 202c, and one third detection point 203c are shown. In other embodiments, the number of inspection windows can be set according to actual needs.

[0076] In this embodiment, the inspection window 202 is rectangular, one outline of the inspection window 202 is parallel to the first direction X, and the other outline is parallel to the second direction Y. The first direction X and the second direction Y are perpendicular to each other.

[0077] The inspection window 202 has a first window size in the first direction X and a second window size in the second direction Y.

[0078] It should be noted that the size of the inspection window 202 can be selected according to the magnification of the CD-SEM. Here, taking a CD-SEM magnification of 50K as an example, the inspection window 202 is a square of 2.7μm × 2.7μm, and both the first window size and the second window size are 2.7μm.

[0079] Here, the purpose of having the same spacing between adjacent circumferences as the size of the inspection window 202 is to ensure that all the inspection windows 202 can cover all positions within the detection window 201. In other embodiments, the number and size of the inspection windows 202 can be set according to actual needs.

[0080] Execute step S14: Based on the graphic density distribution within each inspection window 202, obtain at least one target window corresponding to the measurement point from among the several inspection windows corresponding to the measurement point, and use the position coordinates of the target window as the positioning point coordinates corresponding to the measurement point.

[0081] In this embodiment, the coordinates of the positioning point are obtained based on the Python language.

[0082] In this embodiment, the step of obtaining at least one target window corresponding to the measurement point MP from among the plurality of inspection windows 202 corresponding to the measurement point MP based on the graphic density distribution within each inspection window 202, and using the position coordinates of the target window as the positioning point coordinates corresponding to the measurement point MP, includes the following steps:

[0083] Step S141: Based on the graphic density distribution within each inspection window 202, obtain the first pattern evaluation value and the second pattern evaluation value for each inspection window 202.

[0084] Step S142: Based on the plurality of first pattern evaluation values ​​corresponding to the measurement point MP, obtain a target window from the plurality of inspection windows 202, and use the position coordinates of the target window as the coordinates of a positioning point corresponding to the measurement point. Also, based on the plurality of second pattern evaluation values ​​corresponding to the measurement point MP, obtain another target window from the plurality of inspection windows 202, and use the position coordinates of the target window as the coordinates of another positioning point corresponding to the measurement point.

[0085] In this embodiment, two positioning point coordinates are obtained, providing double assurance for aligning the layout pattern with the actual wafer pattern, which helps improve accuracy. In another embodiment, one or more positioning point coordinates can be obtained.

[0086] In another embodiment, a first pattern evaluation value for each inspection window can be obtained based on the graphic density distribution within each inspection window; or a second pattern evaluation value for each inspection window can be obtained based on the graphic density distribution within each inspection window.

[0087] In another embodiment, specifically, a target window can be obtained from a plurality of inspection windows based on a plurality of first pattern evaluation values ​​corresponding to the measurement point, and the position coordinates of the target window can be used as the coordinates of a positioning point corresponding to the measurement point; or, a target window can be obtained from a plurality of inspection windows based on a plurality of second pattern evaluation values ​​corresponding to the measurement point, and the position coordinates of the target window can be used as the coordinates of a positioning point corresponding to the measurement point.

[0088] In this embodiment, the step of obtaining the first pattern evaluation value and / or the second pattern evaluation value of each inspection window based on the pattern density distribution within each inspection window is described in the following reference. Figure 4 This includes the following steps:

[0089] Step S1411: Obtain the reference pattern area of ​​the graphic within each inspection window 202;

[0090] Step S1412: Obtain the change in the area of ​​the first pattern of each inspection window 202 in the first direction X;

[0091] Step S1413: Obtain the change in the area of ​​the second pattern of each inspection window 202 in the second direction Y;

[0092] Step S1414: Obtain the first pattern evaluation value of the inspection window based on the first pattern area change and the second pattern area change of each inspection window 202.

[0093] Step S1415: Based on the reference pattern area, the change in the first pattern area, and the change in the second pattern area of ​​each inspection window 202, obtain the second pattern evaluation value of the inspection window.

[0094] In this embodiment, the first pattern evaluation value Value1 = △a1 * △a2, where △a1 is the change in the area of ​​the first pattern and △a2 is the change in the area of ​​the second pattern.

[0095] Specifically, among the several first pattern evaluation values ​​Value1 corresponding to the measurement point MP, the inspection window 202 with the largest first pattern evaluation value Value1 is taken as the target window.

[0096] Taking 72 inspection windows 202 as an example, among the 72 inspection windows 202, one inspection window (with the largest corresponding first pattern evaluation value Value1) is selected as the first target window, and then the position coordinates of the first target window are used as the coordinates of the first positioning point corresponding to the measurement point MP.

[0097] Here, the first pattern evaluation value Value1 is the largest, which means that the relatively isolated pattern near the measurement point is used as the positioning.

[0098] In this embodiment, the second pattern evaluation value Value2 = △a1*△a2*a0, where a0 is the area of ​​the reference pattern, △a1 is the change in the area of ​​the first pattern, and △a2 is the change in the area of ​​the second pattern.

[0099] Specifically, among the several second pattern evaluation values ​​Value2 corresponding to the measurement point MP, the inspection window 202 with the largest second pattern evaluation value Value2 is taken as the target window.

[0100] Taking the 72 inspection windows 202 as an example, among the 72 inspection windows 202, another inspection window (with the largest corresponding second pattern evaluation value Value2) is selected as the second target window, and then the position coordinates of the second target window are used as the coordinates of the second positioning point corresponding to the measurement point MP.

[0101] Here, the second pattern evaluation value Value2 is the largest, which means that the relatively dense pattern near the measurement point is used for positioning, and the pattern density near the positioning point coordinates varies greatly.

[0102] In this embodiment, the method for obtaining the change in the first pattern area Δa1 of each inspection window 202 in the first direction X is described in the following reference. Figure 5 and Figure 9 This includes the following steps:

[0103] S14121, a first offset window 301 and a second offset window 302 are established in the layout to be processed 20, the first offset window 301 being relative to the inspection window 202 (e.g., ...). Figure 9 The area shown in the red box in the middle has a first offset size in the first direction X, and the second offset window 302 has a second offset size in the opposite direction of the first direction X relative to the inspection window 202. The inspection window 202 has a first window size in the first direction X, and both the first offset size and the second offset size are smaller than the first window size.

[0104] S14122, obtain the first pattern area a1 of the graphic within the first offset window 301 and the second pattern area a2 of the graphic within the second offset window 302;

[0105] S14123, obtain the first difference between the area a1 of the first pattern and the area a0 of the reference pattern;

[0106] S14124, Obtain the second difference between the area a2 of the second pattern and the area a0 of the reference pattern;

[0107] S14125, based on the first difference and the second difference, obtain the change in the area of ​​the first pattern △a1, where the change in the area of ​​the first pattern △a1 is the maximum value between the first difference and the second difference.

[0108] That is, the change in the area of ​​the first pattern is Δa1 = max((a1-a0), (a2-a0)).

[0109] In this embodiment, both the first offset size and the second offset size are half of the first window size.

[0110] In this embodiment, the first offset window and the second offset window are established in the layout to be processed based on the Python language.

[0111] In this embodiment, the reference pattern area a0, the first pattern area a1, and the second pattern area a2 are obtained based on the DRC language; the change in the first pattern area Δa1 and the first pattern evaluation value Value1 are obtained based on the Python language.

[0112] In this embodiment, the method for obtaining the change in the area of ​​the second pattern in the second direction Y of each inspection window 202 is described in reference [reference needed]. Figure 6 And continue to refer to Figure 9 This includes the following steps:

[0113] Step S14131: In the layout to be processed 20, a third offset window 303 and a fourth offset window 304 are established. The third offset window 303 has a third offset size relative to the inspection window 202 in the second direction Y. The fourth offset window 304 has a fourth offset size relative to the inspection window 202 in the opposite direction of the second direction Y. The inspection window 202 has a second window size in the second direction Y. Both the third offset size and the fourth offset size are smaller than the second window size.

[0114] Step S14132: Obtain the third pattern area a3 of the graphic within the third offset window 303 and the fourth pattern area a4 of the graphic within the fourth offset window 304.

[0115] Step S14133: Obtain the third difference between the area a3 of the third pattern and the area a0 of the reference pattern;

[0116] Step S14134: Obtain the fourth difference between the area a4 of the fourth pattern and the area a0 of the reference pattern;

[0117] Step S14135: Based on the third difference and the fourth difference, obtain the change in the area of ​​the second pattern △a2, where the change in the area of ​​the second pattern △a2 is the maximum value among the third difference and the fourth difference.

[0118] That is, the change in area of ​​the second pattern, Δa2, is equal to max((a3-a0), (a4-a0)).

[0119] In this embodiment, both the third offset size and the fourth offset size are half the size of the second window.

[0120] In this embodiment, the third offset window and the fourth offset window are established in the layout 20 to be processed based on the Python language.

[0121] In this embodiment, the area a0 of the reference pattern, the area a3 of the third pattern, and the area a4 of the fourth pattern are obtained based on the DRC language; the change in the area of ​​the second pattern Δa2 and the evaluation value of the second pattern Value2 are obtained based on the Python language.

[0122] Thus, based on the Python language, the detection window and several inspection windows are established in the layout to be processed. Based on the Python and DRC languages, the coordinates of the positioning points are obtained. By integrating multiple software and computer languages ​​and leveraging their complementary advantages, the system achieves simple and efficient batch standard automatic acquisition of positioning point coordinates, thereby saving manpower and increasing the accuracy of measurement.

[0123] In a more specific embodiment, before obtaining the changes in the area of ​​the first pattern and the area of ​​the second pattern, important information of the entire system is output based on the DRC language: the relevant information of the measurement point (including the coordinates of the measurement point) and the relevant information of the corresponding inspection window (including the coordinates of the center point of the inspection window, the number of graphics in the inspection window, the area of ​​the reference pattern a0, the area of ​​the first pattern a1, the area of ​​the second pattern a2, the area of ​​the third pattern a3 and the area of ​​the fourth pattern a4 corresponding to the inspection window), providing a basis for obtaining the coordinates of the positioning point.

[0124] In this embodiment, after obtaining the coordinates of the positioning point, the positioning pattern at the coordinates of the positioning point and the pattern to be measured at the measurement point are obtained according to the layout to be processed 20. According to the coordinates of the positioning point, the SEM image corresponding to the coordinates of the positioning point is acquired on the wafer by a CD-SEM machine. When the positioning pattern and the SEM image are consistent, the positioning is accurate. After accurate positioning, the SEM image of the pattern to be measured is obtained according to the relative coordinates between the positioning pattern and the pattern to be measured.

[0125] In this embodiment, a working menu for the CD-SEM machine is also created. The working menu includes positioning information, which includes several measurement points and the coordinates of at least one positioning point corresponding to the measurement points. The working menu is executed when the CD-SEM machine is in operation.

[0126] Accordingly, one embodiment of the present invention also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the CD-SEM machine positioning method described above.

[0127] Accordingly, one embodiment of the present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, it implements the steps of the CD-SEM machine positioning method described above.

[0128] 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 CD-SEM machine positioning method, characterized in that, include: A layout to be processed is provided, the layout having several measurement points; In the layout to be processed, a detection window is established with each measurement point as the center. The detection window is annular, and the inner diameter of the detection window is greater than or equal to a first preset size, while the outer diameter of the detection window is less than or equal to a second preset size. Several inspection windows are established within the detection window; Based on the graphic density distribution within each of the inspection windows, at least one target window corresponding to the measurement point is obtained from the plurality of inspection windows corresponding to the measurement point, and the position coordinates of the target window are used as the positioning point coordinates corresponding to the measurement point.

2. The CD-SEM machine positioning method as described in claim 1, characterized in that, The step of obtaining at least one target window corresponding to the measurement point from a plurality of inspection windows based on the graphic density distribution within each inspection window, and using the position coordinates of the target window as the positioning point coordinates corresponding to the measurement point, includes: obtaining a first pattern evaluation value and / or a second pattern evaluation value for each inspection window based on the graphic density distribution within each inspection window; obtaining a target window from a plurality of inspection windows based on a plurality of first pattern evaluation values ​​corresponding to the measurement point, and using the position coordinates of the target window as the positioning point coordinates corresponding to the measurement point; or, obtaining a target window from a plurality of inspection windows based on a plurality of second pattern evaluation values ​​corresponding to the measurement point, and using the position coordinates of the target window as the positioning point coordinates corresponding to the measurement point; or, obtaining a target window from a plurality of inspection windows based on a plurality of first pattern evaluation values ​​corresponding to the measurement point, using the position coordinates of the target window as the positioning point coordinates corresponding to the measurement point, and obtaining another target window from a plurality of inspection windows based on a plurality of second pattern evaluation values ​​corresponding to the measurement point, and using the position coordinates of the target window as the positioning point coordinates corresponding to the measurement point.

3. The CD-SEM machine positioning method as described in claim 2, characterized in that, The step of obtaining a first pattern evaluation value and / or a second pattern evaluation value for each inspection window based on the graphic density distribution within each inspection window includes: obtaining a reference pattern area for the graphic within each inspection window; obtaining a first pattern area change in each inspection window in a first direction; obtaining a second pattern area change in each inspection window in a second direction; obtaining a first pattern evaluation value for each inspection window based on the first pattern area change and the second pattern area change; and obtaining a second pattern evaluation value for each inspection window based on the reference pattern area, the first pattern area change, and the second pattern area change; wherein the first direction and the second direction are perpendicular to each other.

4. The CD-SEM machine positioning method as described in claim 3, characterized in that, The first pattern evaluation value Value1 = △a1 * △a2, where △a1 is the change in area of ​​the first pattern and △a2 is the change in area of ​​the second pattern; the second pattern evaluation value Value2 = △a1 * △a2 * a0, where a0 is the area of ​​the reference pattern, △a1 is the change in area of ​​the first pattern and △a2 is the change in area of ​​the second pattern.

5. The CD-SEM machine positioning method as described in claim 3, characterized in that, The method for obtaining the change in the first pattern area of ​​each inspection window in a first direction includes: establishing a first offset window and a second offset window in the layout to be processed, wherein the first offset window has a first offset size relative to the inspection window in a first direction, and the second offset window has a second offset size relative to the inspection window in the opposite direction to the first direction, the inspection window has a first window size in the first direction, and both the first offset size and the second offset size are smaller than the first window size; obtaining a first pattern area of ​​the graphic within the first offset window and a second pattern area of ​​the graphic within the second offset window; obtaining a first difference between the first pattern area and the reference pattern area; obtaining a second difference between the second pattern area and the reference pattern area; and obtaining the change in the first pattern area based on the first difference and the second difference, wherein the change in the first pattern area is the maximum value of the first difference and the second difference.

6. The CD-SEM machine positioning method as described in claim 5, characterized in that, Both the first offset size and the second offset size are half the size of the first window.

7. The CD-SEM machine positioning method as described in claim 5, characterized in that, Based on the Python language, the first offset window and the second offset window are established in the layout to be processed; Based on the DRC language, the area of ​​the reference pattern, the area of ​​the first pattern, and the area of ​​the second pattern are obtained; Using Python, the change in the area of ​​the first pattern and the evaluation value of the first pattern are obtained.

8. The CD-SEM machine positioning method as described in claim 3, characterized in that, The method for obtaining the change in the area of ​​the second pattern in the second direction of each of the inspection windows includes: establishing a third offset window and a fourth offset window in the layout to be processed, wherein the third offset window has a third offset size relative to the inspection window in the second direction, and the fourth offset window has a fourth offset size relative to the inspection window in the opposite direction of the second direction, and the inspection window has a second window size in the second direction, wherein both the third offset size and the fourth offset size are smaller than the second window size; obtaining the third pattern area of ​​the graphic within the third offset window and the fourth pattern area of ​​the graphic within the fourth offset window; obtaining a third difference between the third pattern area and the reference pattern area; obtaining a fourth difference between the fourth pattern area and the reference pattern area; and obtaining the change in the area of ​​the second pattern based on the third difference and the fourth difference, wherein the change in the area of ​​the second pattern is the maximum value of the third difference and the fourth difference.

9. The CD-SEM machine positioning method as described in claim 8, characterized in that, Both the third offset size and the fourth offset size are half the size of the second window.

10. The CD-SEM machine positioning method as described in claim 8, characterized in that, Based on the Python language, the third offset window and the fourth offset window are established in the layout to be processed; Based on the DRC language, obtain the area of ​​the reference pattern, the area of ​​the third pattern, and the area of ​​the fourth pattern; Using Python, the change in the area of ​​the second pattern and the evaluation value of the second pattern are obtained.

11. The CD-SEM machine positioning method as described in claim 1, characterized in that, The method for establishing a plurality of inspection windows within the detection window includes: establishing a plurality of detection points within the detection window, wherein the plurality of detection points are located on one or more circles of different radii with the measurement point as the center; setting the inspection window with each of the detection points as the center; the inspection window is rectangular, wherein one contour side of the inspection window is parallel to a first direction, and the other contour side is parallel to a second direction, wherein the first direction and the second direction are perpendicular to each other.

12. The CD-SEM machine positioning method as described in claim 1, characterized in that, The first preset size is 3μm; the second preset size is 8μm.

13. The CD-SEM machine positioning method as described in claim 1, characterized in that, The provision of a layout to be processed, the layout having a plurality of measurement points, includes: providing a measurement point setting file, the measurement point setting file including at least one GDS file, the GDS file including at least one layout, the measurement point setting file also including the names of all preset measurement points corresponding to each layout, and the GDS coordinates of each preset measurement point; according to the measurement point setting file, obtaining the layout to be processed from the plurality of layouts, and setting the plurality of measurement points in the layout to be processed according to the GDS coordinates of the plurality of preset measurement points.

14. The CD-SEM machine positioning method as described in claim 13, characterized in that, Before establishing the detection window and before acquiring the plurality of measurement points, the plurality of preset measurement points are further rationalized by removing unreasonable portions of the preset measurement points to acquire the plurality of measurement points. The rationalization process includes: providing a measurement point distance setting value; acquiring the distance of the plurality of preset measurement points in the layout to be processed; and removing some of the preset measurement points based on the distance of the plurality of preset measurement points and the measurement point distance setting value, using the remaining plurality of preset measurement points as the plurality of measurement points, such that the distance between two adjacent measurement points is greater than or equal to the measurement point distance setting value.

15. The CD-SEM machine positioning method as described in claim 14, characterized in that, The aforementioned rationalization process was performed using the Python language.

16. The CD-SEM machine positioning method as described in claim 13, characterized in that, Before establishing the detection window, the process also includes: flattening the GDS file; flattening the GDS file based on the tcl language.

17. The CD-SEM machine positioning method as described in claim 13, characterized in that, Before establishing the detection window, the process also includes: trimming the GDS file; and trimming the GDS file based on the drc language.

18. The CD-SEM machine positioning method as described in claim 1, characterized in that, Also includes: Based on the layout to be processed, obtain the positioning graphic at the coordinates of the positioning point and the measurement graphic at the measurement point; Based on the coordinates of the positioning point, a SEM image corresponding to the coordinates of the positioning point is acquired on the wafer using a CD-SEM machine. When the positioning pattern and the SEM image are consistent, the positioning is accurate. Once accurately located, the SEM image of the image to be tested is obtained based on the relative coordinates between the located image and the image to be tested.

19. The CD-SEM machine positioning method as described in claim 1, characterized in that, Also includes: Create a working menu for the CD-SEM machine. The working menu includes positioning information, which includes several measurement points and the coordinates of at least one positioning point corresponding to each measurement point. The CD-SEM machine executes the working menu during operation.

20. The CD-SEM machine positioning method as described in claim 1, characterized in that, Using the Python language, the probe window and several inspection windows are established in the layout to be processed.

21. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the CD-SEM machine positioning method according to any one of claims 1 to 20.

22. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the CD-SEM machine positioning method according to any one of claims 1 to 20.

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