Graphic size measurement method and system, equipment, storage medium and computer program product

Abstract

The invention discloses a graph size measurement method and system, equipment, a storage medium and a computer program product. The method comprises the following steps: acquiring a plurality of target graph structures; obtaining a measurement image of an area where each target graph structure is located, wherein the measurement image comprises a measurement graph corresponding to the target graph structure; obtaining target sizes of the plurality of target graphic structures; selecting partial measurement patterns representing the pattern features of the plurality of target pattern structures as a plurality of anchor point patterns; obtaining the measurement size of the anchor point graph; aligning the measurement size with the target size to obtain the measurement deviation of the anchor point pattern; and performing measurement compensation on the measurement pattern in the measurement image according to the measurement deviation to obtain the pattern size of the measurement pattern. According to the invention, accurate graph dimension measurement can be realized.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor manufacturing, and in particular to a method and system for measuring graphic dimensions, an apparatus, a storage medium, and a computer program product. Background Technology

[0002] In the semiconductor manufacturing industry, critical dimension scanning electron microscopy (CD-SEM) is widely used for measuring critical feature dimensions, controlling and inspecting processes, and analyzing defects. CD-SEM is also an important and effective measurement tool for measuring and evaluating the dimensions (CD) after development inspection (ADI) and after etching inspection (AEI) in optical proximity correction (OPC) processes. The establishment of OPC models, mask verification, weakpoint analysis, and the development of etching deviation compensation schemes are all based on CD-SEM measurement data.

[0003] As technology nodes shrink, layout designs become more compact, and graphic structures become more complex, traditional CD-SEM measurements are no longer sufficient. CD-SEM typically offers high accuracy for measurements of conventional one-dimensional (1D) characteristic structures. However, for complex feature structures, complex CD-SEM measurement menus are required, and some complex structures make it difficult to define measurement locations and content to obtain the expected measurement data. Ensuring accurate CD-SEM measurements at specified locations and characterizing asymmetric phenomena becomes even more challenging. Summary of the Invention

[0004] The problem solved by the embodiments of the present invention is to provide a method, system, device, storage medium and computer program product for measuring graphic dimensions, which is beneficial to achieving more accurate graphic dimension measurement.

[0005] To address the aforementioned problems, embodiments of the present invention provide a graphic dimension measurement method, comprising: acquiring multiple target graphic structures; acquiring a measurement image of the region where each target graphic structure is located, the measurement image including a measurement graphic corresponding to the target graphic structure; acquiring target dimensions of the multiple target graphic structures; selecting partial measurement graphics characterizing graphic features of the multiple target graphic structures as multiple anchor point graphics; acquiring the measurement dimensions of the anchor point graphics; obtaining the measurement deviation of the anchor point graphics by aligning the measurement dimensions with the target dimensions; and performing measurement compensation on the measurement graphics in the measurement image based on the measurement deviation to obtain the graphic dimensions of the measurement graphics.

[0006] Optionally, scanning electron microscopy can be used to obtain the target dimensions of multiple target graphic structures.

[0007] Optionally, multiple target graphic structures can be obtained, including: providing multiple graphic structures; and obtaining a graphic structure whose measurement type is structural dimension or structural spacing as the target graphic structure.

[0008] Optionally, obtaining the measurement dimensions of the anchor point graphic includes: obtaining the grayscale distribution of the measurement image, whereby the grayscale distribution includes the grayscale levels corresponding to each point in the measurement image; and obtaining the measurement dimensions of the anchor point graphic based on the grayscale distribution.

[0009] Optionally, obtaining the grayscale distribution of the measurement image includes: setting the measurement range of the anchor point graphic perpendicular to the measurement direction; setting multiple measurement reference lines within the measurement range, the measurement reference lines extending across the anchor point graphic along the measurement direction; and obtaining the grayscale distribution of the measurement image within the measurement range based on the grayscale level measurement of the anchor point graphic using the multiple measurement reference lines.

[0010] Optionally, a scanning electron microscope is used to acquire measurement images of the region where each target graphic structure is located; in the measurement images of the region where each target graphic structure is located, the measurement graphic corresponding to the target graphic structure is located at the center of the measurement image; and the target dimensions of multiple target graphic structures are obtained based on the measurement images of the target graphic structures.

[0011] Optionally, the target dimensions of multiple target graphic structures can be obtained from the measurement image of the target graphic structure, including: setting a target range of the measurement graphic perpendicular to the measurement direction; within the target range, setting and arranging multiple reference points on each side of the measurement graphic; and obtaining the target dimensions of the target graphic structure corresponding to the measurement graphic based on the multiple reference points of the measurement graphic.

[0012] Optionally, in the measurement range where anchor point graphics are set perpendicular to the measurement direction, the measurement range is set to coincide with the target range; in the measurement range where multiple measurement baselines are set, the measurement baselines are set to correspond one-to-one with the baseline points and pass through the baseline points.

[0013] Optionally, based on the measurement of the gray level of the anchor point graphic using multiple measurement baselines, the gray level distribution of the measurement image within the measurement range is obtained, including: obtaining the gray level of each pixel on each measurement baseline; obtaining the average gray level of pixels at the same position on multiple measurement baselines as the target gray level of the pixel; and establishing a gray level curve as the gray level distribution based on the relative position coordinates of the pixel and the target gray level.

[0014] Optionally, before obtaining the average gray level of pixels at the same position on multiple measurement baselines as the target gray level of the pixel, the method further includes: filtering the gray level of each pixel on the measurement baseline.

[0015] Optionally, the gray level of each pixel on the measurement baseline is filtered, including: taking any pixel on the measurement baseline as the target point; replacing the gray level of the target point and the average gray level of multiple pixels adjacent to the target point in the direction perpendicular to the measurement with the gray level of the target point.

[0016] Optionally, obtaining the measurement dimensions of the anchor point graphic based on the grayscale distribution includes: setting the center point of the relative position of the pixels in the grayscale level curve as the origin; selecting the relative positions of pixels with grayscale levels equal to the grayscale threshold on both sides of the origin as the first side position and the second side position respectively; and obtaining the difference between the first side position and the second side position as the measurement dimensions of the anchor point graphic.

[0017] Optionally, the expression CD_contour can be used. i =(Edge_right) i –Edge_left i The measured dimensions of the anchor point graphic are obtained by multiplying the pixel size by 0.5, where CD_contour... i For measuring dimensions, Edge_left i The position of the first edge, Edge_right i The position is the second side, and pixel_size is the size of the pixel.

[0018] Optionally, the relative positions of pixels with gray levels equal to the gray threshold are selected on both sides of the origin as the first side position and the second side position, respectively, and the gray threshold is set to a preset percentage of the peak value in the gray level curve.

[0019] Optionally, the relative positions of pixels with gray levels equal to the gray threshold are selected on both sides of the origin as the first side position and the second side position, respectively. This includes: obtaining two pixels on each side of the origin as candidate points, where the candidate points are the pixels closest to the origin with gray levels equal to the gray threshold; obtaining the gray level gradient corresponding to each candidate point in the gray level curve, and setting the four candidate points in the measurement direction in the order of positive and negative gray level gradients as the first point, the second point, the third point, and the fourth point; determining whether the anchor point graphic is suitable for measuring structural dimensions or structural spacing; when the anchor point graphic is suitable for measuring structural dimensions, selecting the relative positions of the first point and the fourth point as the first side position and the second side position, respectively; when the anchor point graphic is suitable for measuring structural spacing, selecting the relative positions of the second point and the third point as the first side position and the second side position, respectively.

[0020] Optionally, the measurement deviation of the anchor point graphic is obtained by aligning the measured size with the target size, including: obtaining the relative position of the pixel corresponding to the peak on one side of the first side of the origin in the grayscale curve as the first peak position; obtaining the relative position of the pixel corresponding to the peak on one side of the second side of the origin in the grayscale curve as the second peak position; obtaining the distance between the first side position and the first peak position as the first distance; obtaining the distance between the second side position and the second peak position as the second distance; and aligning the measured size with the first distance and the second distance towards the target size to obtain the measurement deviation of the anchor point graphic.

[0021] Optionally, the first expression D_E2T_left is used. i =(Edge_left) i -T100%_left i The first spacing is obtained by multiplying pixel_size, and the second expression D_E2T_right is used. i =(T100%_right) i -Edge_right i The second spacing is obtained by multiplying D_E2T_left by pixel_size. i For the first spacing, D_E2T_right i For the second spacing, Edge_left i The position of the first edge, Edge_right i For the position of the second side, T100%_left i The first peak position, T100%_right i The second peak position is defined by pixel_size, which is the pixel size; the third expression, CD_contour, is used. i +(D_E2T_left i+D_E2T_right i )×bias_ratio-CD_CDSEM i =0 yields the measurement bias, where bias_ratio is the measurement bias and CD_contour is the measurement bias. i For dimensional measurement, CD_CDSEM i The target size.

[0022] Optionally, the measurement dimensions of multiple anchor point graphics can be used to fit a function to the third expression to obtain the measurement deviation.

[0023] Optionally, the measurement graphic in the measurement image is compensated according to the measurement deviation to obtain the graphic size of the measurement graphic, including: compensating the measurement graphic by combining the first spacing and the measurement deviation to obtain the position of the first compensation edge; compensating the measurement graphic by combining the second spacing and the measurement deviation to obtain the position of the second compensation edge; and obtaining the difference between the position of the first compensation edge and the position of the second compensation edge as the graphic size of the measurement graphic.

[0024] Optionally, use the expression Edge_left_real i =Edge_left i +(D_E2T_left i The position of the first compensated edge is obtained by multiplying the bias_ratio by the pixel_size; the expression Edge_right_real is used. i =Edge_right i +(D_E2T_right i The position of the second compensation edge is obtained by multiplying the bias_ratio by the pixel_size, where Edge_left_real i The first compensated edge position, Edge_right_real i The position of the second compensation edge is D_E2T_left. i For the first spacing, D_E2T_right i For the second spacing, Edge_left i The position of the first edge, Edge_right i The second side is the position, bias_ratio is the measurement bias, and pixel_size is the size of the pixel.

[0025] Optionally, before performing measurement compensation on the measurement graphics in the measurement image based on the measurement deviation, the method further includes: obtaining the measurement dimensions of the measurement graphics corresponding to the remaining multiple target graphic structures; during the measurement compensation on the measurement graphics in the measurement image based on the measurement deviation, the method further includes: performing measurement compensation on the remaining multiple measurement dimensions, and using the obtained graphic dimensions as correction dimensions; after performing measurement compensation on the measurement graphics in the measurement image based on the measurement deviation, the method further includes: calibrating the multiple correction dimensions with the corresponding target dimensions; if the calibration result meets the standard, the graphic dimension measurement is completed; if the calibration result does not meet the standard, the method returns to the process of selecting a portion of the measurement graphics representing the graphic features of the multiple target graphic structures as multiple anchor point graphics.

[0026] Optionally, multiple calibration dimensions are calibrated with the corresponding target dimensions, including: obtaining the difference between the corresponding calibration dimensions and the target dimensions; determining whether the difference is less than a calibration threshold; if the difference is less than the calibration threshold, the calibration result is satisfactory; if the difference is not less than the calibration threshold, the calibration result is unsatisfactory.

[0027] Optionally, after performing measurement compensation on the measurement pattern in the measurement image based on the measurement deviation to obtain the graphic size of the measurement pattern, the method further includes: obtaining the graphic contour of the measurement pattern in multiple measurement images based on the graphic size; and calibrating multiple correction dimensions with the corresponding target dimensions, obtaining the correction dimension at the same position as the target dimension on the graphic contour, and calibrating it with the target dimension.

[0028] Accordingly, embodiments of the present invention also provide a graphic size measurement system, comprising: a target graphic structure acquisition module for acquiring multiple target graphic structures; a measurement graphic acquisition module for acquiring a measurement image of the region where each target graphic structure is located, the measurement image including a measurement graphic corresponding to the target graphic structure; a target size acquisition module for acquiring the target size of the multiple target graphic structures; an anchor point graphic acquisition module for selecting a portion of the measurement graphic representing the graphic features of the multiple target graphic structures as multiple anchor point graphics; a measurement size acquisition module for acquiring the measurement size of the anchor point graphics; a measurement deviation acquisition module for obtaining the measurement deviation of the anchor point graphics by aligning the measurement size with the target size; and a graphic size acquisition module for performing measurement compensation on the measurement graphic in the measurement image according to the measurement deviation to obtain the graphic size of the measurement graphic.

[0029] Accordingly, embodiments of the present invention also provide a device including at least one memory and at least one processor, wherein the memory stores one or more computer instructions, and the one or more computer instructions are executed by the processor to implement the graphic size measurement method provided in the embodiments of the present invention.

[0030] Accordingly, embodiments of the present invention also provide a storage medium storing one or more computer instructions, which are used to implement the graphic dimension measurement method provided in the embodiments of the present invention.

[0031] Accordingly, embodiments of the present invention also provide a computer program product, including a computer program / instruction, characterized in that the computer program / instruction, when executed by a processor, implements the graphic size measurement method provided in the embodiments of the present invention.

[0032] Compared with the prior art, the technical solution of the embodiments of the present invention has the following advantages:

[0033] In the graphic size measurement method provided by this invention, partial measurement graphics representing graphic features of multiple target graphic structures are selected as multiple anchor point graphics. The measurement size of the anchor point graphics is obtained. By aligning the measurement size with the target size, the measurement deviation of the anchor point graphics is obtained. Based on the measurement deviation, the measurement graphics in the measurement image are compensated to obtain the graphic size of the measurement graphics. In this invention, by first selecting anchor point graphics and aligning the measurement size of the anchor point graphics with the target size to obtain the measurement deviation, which is used to compensate for the measurement size, it is beneficial to obtain a more accurate graphic size. Moreover, by selecting partial measurement graphics representing graphic features of multiple target graphic structures as multiple anchor point graphics, the anchor point graphics are representative of multiple target graphic structures. Using representative anchor point graphics for alignment saves computing power and improves efficiency, while also making the measurement compensation of multiple target graphic structures more accurate, thereby facilitating the realization of more accurate graphic size measurement. Attached Figure Description

[0034] Figure 1 This is a flowchart of an embodiment of the graphic dimension measurement method of the present invention;

[0035] Figures 2 to 8 This is a schematic diagram of each step in one embodiment of the graphic dimension measurement method of the present invention;

[0036] Figure 9 This is a functional block diagram of an embodiment of the graphic dimension measurement system of the present invention;

[0037] Figure 10 This is a hardware structure diagram of an embodiment of the device provided by the present invention. Detailed Implementation

[0038] As the background technology indicates, exploring high-precision measurement methods for increasingly complex and diverse semiconductor applications is one of the important research directions in the semiconductor manufacturing industry. However, when using CD-SEM to obtain the dimensions of patterned structures, it is difficult to accurately measure the dimensions of some complex patterns or complex locations.

[0039] To address the aforementioned technical problems, embodiments of the present invention provide a method for measuring graphic dimensions. (See reference...) Figure 1 The flowchart of an embodiment of the graphic dimension measurement method of the present invention is shown.

[0040] In this embodiment, the graphic size measurement method includes the following basic steps:

[0041] Step S1: Obtain multiple target graphic structures;

[0042] Step S2: Obtain the measurement image of the region where each target graphic structure is located. The measurement image includes the measurement graphic corresponding to the target graphic structure.

[0043] Step S3: Obtain the target dimensions of multiple target graphic structures;

[0044] Step S4: Select partial measurement graphics that represent the graphic features of multiple target graphic structures as multiple anchor point graphics;

[0045] Step S5: Obtain the measured dimensions of the anchor point graphic;

[0046] Step S6: By aligning the measured dimension with the target dimension, the measurement deviation of the anchor point pattern is obtained;

[0047] Step S7: Perform measurement compensation on the measurement pattern in the measurement image according to the measurement deviation to obtain the graphic size of the measurement pattern.

[0048] 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.

[0049] Figures 2 to 8 This is a schematic diagram of each step in one embodiment of the layout design method of the present invention.

[0050] Step S1: Obtain multiple target graphic structures.

[0051] The target pattern structure is the structure that needs to be used to measure the pattern size. It is a pattern structure on a wafer. Subsequently, the measurement size of the target pattern structure is aligned with the target size to achieve a more accurate measurement of the pattern structure.

[0052] In this embodiment, the target pattern structure includes a developed pattern structure or an etched pattern structure on the wafer. The pattern size measurement method of this embodiment is used to measure the developed pattern structure or the etched pattern structure.

[0053] In this embodiment, obtaining multiple target graphic structures includes: providing multiple graphic structures.

[0054] Pattern structures include post-development or post-etching patterns on wafers. Specifically, in semiconductor manufacturing processes, designs need to be transferred to a design layout on the wafer, including design patterns. After optical proximity correction is performed on the design patterns of the design layout, the resulting patterns are used to create a mask. The mask is then used for photolithography to form corresponding development and etching patterns on the wafer. Subsequently, corresponding After Development Inspection (ADI) dimensions (CD) and After Etch Inspection (AEI) dimensions (CD) are obtained, which can be used for OPC model establishment, mask verification, weakpoint analysis, and the establishment of etching deviation compensation schemes.

[0055] In this embodiment, a graphic structure whose measurement type is structural dimension or structural spacing is obtained as the target graphic structure.

[0056] The measurement type is a graphic structure of structural dimensions or structural spacing. This refers to the subsequent measurement of the structural dimensions or structural spacing of the graphic structure. Since the target dimensions or structural spacing of the selected target graphic structure are relatively accurate, using the target dimensions of the target graphic structure as the alignment reference allows for more accurate compensation of the measured dimensions. Specifically, measuring structural dimensions is called measuring critical dimensions (CD), and measuring structural spacing is called measuring spacing (space).

[0057] refer to Figure 2 Step S2: Obtain a measurement image 100 of the region where each target graphic structure is located. The measurement image 100 includes a measurement graphic 110 corresponding to the target graphic structure.

[0058] Measurement image 100 is an image obtained by image acquisition of the target graphic structure, and the target graphic structure is presented as measurement graphic 110 in measurement image 100.

[0059] In this embodiment, a scanning electron microscope is used to acquire measurement images 100 of the region where each target graphic structure is located.

[0060] Electron beam scanning can be used to perform relatively efficient and accurate scanning, thereby obtaining relatively clear measurement images 100.

[0061] Specifically, in this embodiment, the scanning electron microscope is a critical dimension scanning electron microscope (CD-SEM).

[0062] In this embodiment, in the measurement image 100 of the region where each target graphic structure is located, the measurement graphic 110 corresponding to the target graphic structure is located at the center of the measurement image 100.

[0063] In this embodiment, the measurement image 100 is acquired by scanning electron microscopy. The measurement image 110 corresponding to the target graphic structure is located at the center of the measurement image 100, which makes the target graphic structure receive light more uniformly and with sufficient intensity, which is conducive to obtaining a clearer measurement image 110 and making the subsequent measurement of the measurement image 110 more accurate.

[0064] Execute step S3: Obtain the target dimensions of multiple target graphic structures.

[0065] Obtain the target dimensions of multiple target graphic structures, which will be used as alignment dimensions in the subsequent process.

[0066] In this embodiment, a scanning electron microscope is used to obtain the target dimensions of multiple target graphic structures.

[0067] Scanning electron microscopes can directly obtain the target dimensions of target graphic structures, especially for CD and space, and can obtain relatively accurate results. Therefore, the target dimensions of multiple target graphic structures obtained by scanning electron microscopes can be used as alignment references for measuring the measurement dimensions of graphic 110.

[0068] Specifically, in this embodiment, CD-SEM is used to obtain the target dimensions of multiple target graphic structures.

[0069] In this embodiment, the target dimensions of multiple target graphic structures are obtained based on the measurement image 100 of the target graphic structure.

[0070] In this embodiment, CD-SEM is used to obtain the measurement image 100 of the target graphic structure. Then, the target size of the target graphic structure can be obtained through the measurement image 110. That is, CD-SEM is used to obtain both the measurement image 100 and the target size of the target graphic structure.

[0071] Specifically, in conjunction with reference Figure 3 and Figure 4 The steps for obtaining target dimensions are illustrated, including obtaining target dimensions of multiple target graphic structures based on a measurement image 100 of the target graphic structure, including: reference... Figure 3 In the direction perpendicular to the measurement direction (e.g.) Figure 2 The target range 200a of the measurement graphic 110 is set on the Y-direction (as shown in the figure).

[0072] The target range 200a is the range from which image information is obtained in CD-SEM.

[0073] refer to Figure 4Within the target range 200a, multiple reference points 200d are set and arranged on the side of the measurement graphic 110.

[0074] The reference point 200d is the point from which image information was obtained in CD-SEM.

[0075] Specifically, in this embodiment, the target size of the target graphic structure corresponding to the measurement graphic 110 is obtained based on multiple reference points 200d of the measurement graphic 110.

[0076] Continue to refer to Figure 2 Step S4: Select partial measurement graphics 110 that represent the graphic features of multiple target graphic structures as multiple anchor patterns 120.

[0077] Select a portion of the measurement graphic 110 as the anchor point graphic 120 for subsequent dimensional alignment.

[0078] In this embodiment, partial measurement graphics 110 representing the graphic features of multiple target graphic structures are selected as multiple anchor point graphics 120. The anchor point graphics 120 are representative of the multiple target graphic structures. Using representative anchor point graphics 120 for alignment saves computing power and improves efficiency, while also making the measurement compensation of multiple target graphic structures more accurate, thereby facilitating the realization of more accurate graphic size measurement.

[0079] Specifically, as an example, in this embodiment, the multiple target graphic structures include one-dimensional (1D) characteristic structures and two-dimensional (2D) characteristic structures. The measurement graphics 110 representing 1D and 2D are selected as anchor point graphics 120 respectively, and the measurement image 100 containing the multiple anchor point graphics 120 is subsequently measured.

[0080] Reference Figures 3 to 6 Execute step S5: Obtain the measurement dimensions of anchor point graphic 120.

[0081] Obtain the measured dimensions of anchor point graphic 120 for alignment with the target dimensions.

[0082] In this embodiment, obtaining the measurement size of the anchor point graphic 120 includes: obtaining the grayscale distribution of the measurement image 100, wherein the grayscale distribution includes the grayscale level corresponding to each point in the measurement image 100.

[0083] The grayscale distribution of the measurement image 100 is obtained so as to obtain the outline of the anchor point graphic 120 and the measurement size of the anchor point graphic 120 according to the grayscale level corresponding to each point in the measurement image 100.

[0084] Specifically, the measurement image 100 obtained by image acquisition of the target graphic structure is a grayscale image, in which the edge of the anchor point graphic 120 is highlighted. The edge is usually white, so the white edge can be extracted by judging the grayscale level of each point in the measurement image 100, that is, the outline of the anchor point graphic 120 is extracted.

[0085] refer to Figure 3 Acquiring the grayscale distribution of the measurement image 100 includes setting the measurement range 200b of the anchor point graphic 120 perpendicular to the measurement direction.

[0086] The measurement range is set at 200b, which is used to obtain the grayscale distribution within the measurement range, ensuring measurement accuracy while saving computing power and improving efficiency.

[0087] In this embodiment, in the measurement range 200b in which the anchor point pattern 120 is set perpendicular to the measurement direction, the measurement range 200b is set to coincide with the target range 200a.

[0088] Setting the measurement range 200b to coincide with the target range 200a ensures that the measurement area for obtaining the measured dimension is the same as the measurement area for obtaining the target dimension, guaranteeing the consistency of measurement conditions. This makes it easier to align the measured dimension with the target dimension more effectively, and the obtained measurement deviation is more applicable.

[0089] As an example, in this embodiment, the target range 200a is 150nm perpendicular to the measurement direction, the resolution of the measurement image 100 is 1024×1024, that is, the measurement image 100 has 1024 pixels in the measurement direction and also 1024 pixels perpendicular to the measurement direction. The field of view (FOV) of the measurement image 100 is 900nm, so the size of each pixel is 0.879nm×0.879nm (900nm / 1024=0.879nm), thereby setting the measurement range 200b to 171 pixels.

[0090] refer to Figure 4 Multiple measurement reference lines 200c are set within the measurement range 200b, and the measurement reference lines 200c are along the measurement direction (e.g., Figure 4 (As shown in the X direction) Extend across the anchor point graphic 120.

[0091] It should be noted that, for the sake of clarity of the illustration, Figure 4 Only a partial measurement image 100 including anchor point pattern 120 is shown.

[0092] The measurement baseline 200c is a tangent line across the anchor point pattern 120. The measurement baseline 200c extends along the measurement direction and passes through the two opposite sides of the anchor point pattern 120. Thus, the distance between the two sides of the anchor point pattern 120 can be obtained through the measurement baseline 200c, which is the measurement dimension.

[0093] In this embodiment, among the multiple measurement reference lines 200c set within the measurement range 200b, the measurement reference lines 200c are configured to correspond one-to-one with the reference point 200d and pass through the reference point 200d.

[0094] Setting the measurement baseline 200c to correspond one-to-one with the reference point 200d and passing through the reference point 200d ensures that the measurement point for obtaining the measured dimension is the same as the measurement point for obtaining the target dimension, guaranteeing the consistency of measurement conditions. This makes it easier to align the measured dimension with the target dimension more effectively, and the obtained measurement deviation is more applicable.

[0095] As an example, in this embodiment, there are 16 measurement points 200d, which form 16 measurement baselines 200c.

[0096] Reference Figure 5 and Figure 6 Based on the gray level measurement of anchor point graphic 120 by multiple measurement baselines 200c, the gray level distribution of measurement image 100 in measurement range 200b is obtained.

[0097] Subsequently, the measurement dimensions of the anchor point graphic 120 were obtained based on the grayscale distribution of the measurement range of 200b.

[0098] Specifically, refer to Figure 5 Based on the measurement of the gray level of the anchor point graphic 120 by multiple measurement reference lines 200c, the gray level distribution of the measurement image 100 in the measurement range 200b is obtained, including: obtaining the gray level of each pixel on each measurement reference line 200c.

[0099] Obtain the grayscale level of each pixel on each measurement baseline 200c, and use the grayscale level of each pixel to determine the position of the edge of the anchor point graphic 120.

[0100] In this embodiment, before obtaining the average gray level of pixels at the same position on multiple measurement baselines 200c as the target gray level of the pixel, the method further includes: filtering the gray level of each pixel on the measurement baseline 200c.

[0101] The grayscale level of each pixel on the measurement baseline 200c is filtered to extract the effective signal, which helps to reduce the influence of noise and improve the accuracy of subsequent measurement size acquisition based on grayscale distribution.

[0102] In this embodiment, the grayscale level of each pixel on the measurement baseline 200c is filtered, including: taking any pixel on the measurement baseline 200c as the target point.

[0103] The target point is the point where information filtering is required.

[0104] In this embodiment, the gray level of the target point and the average gray level of multiple pixels adjacent to the target point in the direction perpendicular to the measurement direction are replaced with the gray level of the target point.

[0105] Replacing the gray level of the target point with the average gray level of multiple pixels adjacent to the target point in the direction perpendicular to the measurement direction, i.e., averaging the gray level of the target point with the surrounding points, can effectively filter out invalid information and enhance valid information.

[0106] Specifically, in this embodiment, a row of pixels arranged along the measurement direction is taken as a pixel row. In the direction perpendicular to the measurement direction, multiple surrounding reference lines 200p are set through multiple pixel rows adjacent to the measurement reference line 200c. The average gray level of the corresponding pixels of the measurement reference line 200c and the surrounding reference lines 200p in the direction perpendicular to the measurement direction is obtained, which constitutes the gray level distribution of the filtered measurement reference line 200c.

[0107] It should be noted that in this embodiment, when CD-SEM obtains the target size, it also performs surrounding mean averaging on each reference point 200d. Therefore, when performing filtering, the number of multiple pixels adjacent to the target point in the direction perpendicular to the measurement direction is set to be equal to the number of reference points subjected to surrounding mean averaging (sum line). This ensures the consistency of measurement conditions and makes it easier to align the measurement size with the target size more effectively, and the obtained measurement deviation is more applicable.

[0108] As an example, in this embodiment, the number of target points and multiple pixels adjacent to the target points in the direction perpendicular to the measurement direction is set to 4.

[0109] In this embodiment, the average gray level of pixels at the same position on multiple measurement baselines 200c is obtained as the target gray level of the pixel.

[0110] In this context, "same position" refers to pixels that overlap in the measurement direction.

[0111] The average gray level of pixels at the same position on multiple measurement baselines 200c is used as the target gray level of the pixel. This takes into account the gray level information of multiple positions perpendicular to the measurement direction, which is beneficial for obtaining more accurate measurement dimensions in the future.

[0112] refer to Figure 6 A grayscale curve is established based on the relative position coordinates of pixels and the target grayscale level (e.g., Figure 6 (b) is shown as a grayscale distribution.

[0113] Establishing a grayscale level curve as a grayscale distribution makes the grayscale level curve more intuitive and simplifies the subsequent method of obtaining measurement dimensions based on the grayscale level curve.

[0114] Specifically, Figure 6 (b) shows a grayscale curve with the horizontal axis representing the relative position of the pixel and the vertical axis representing the grayscale level. In the grayscale curve, the grayscale level represents the pixel brightness, and its value range is typically from 0 (black) to 255 (white). Thus, the edge of the prominent anchor point graphic 120 can be selected as the outline by using the grayscale level.

[0115] Continue to refer to Figure 6 The measurement dimensions of anchor point graphic 120 are obtained based on the grayscale distribution.

[0116] Specifically, in this embodiment, the measurement dimensions of the anchor point graphic 120 are obtained based on the grayscale level curve.

[0117] In this embodiment, obtaining the measurement dimensions of the anchor point graphic 120 based on the grayscale distribution includes: setting the center point of the relative position of the pixel in the grayscale level curve as the origin (i.e., the origin). Figure 6 (b) The triangle marked on the horizontal axis).

[0118] In the measurement image 100, the measurement image 110 corresponding to the target graphic structure is located at the center of the measurement image 100, that is, the anchor point graphic 120 is located at the center of the measurement image 100. Then, the center point of the relative position of the pixel is set as the origin, and the origin is the center point of the anchor point graphic 120 in the measurement direction.

[0119] In this embodiment, the relative positions of pixels with gray levels equal to the gray threshold are selected on both sides of the origin as the first side position and the second side position, respectively.

[0120] The edges of the anchor point graphic 120 will be highlighted, and the edges will usually be white, meaning that the gray level of the edges of the anchor point graphic 120 is high. Therefore, points with a gray level equal to the gray threshold can be used as the two sides of the anchor point graphic 120.

[0121] As an example, in this embodiment, the following is set: Figure 6 (b) The position of the first side is located at the dashed line to the left of the origin, and the position of the second side is located at the dashed line to the right of the origin.

[0122] In this embodiment, the relative positions of pixels with gray levels equal to the gray threshold are selected on both sides of the origin as the first side position and the second side position, respectively, and the gray threshold is set as a preset percentage of the peak value in the gray level curve.

[0123] The peak value in the grayscale curve represents the maximum brightness in the measurement image 100. The brightest position in the measurement image 100 is the edge position of the anchor point graphic 120. Therefore, setting the grayscale threshold to a preset percentage of the peak value in the grayscale curve can more accurately locate the edge position of the anchor point graphic 120.

[0124] As an example, Figure 6 In (b), the red dots closest to the origin on both sides are the peak values ​​of the grayscale curve. The grayscale threshold is set to 50% of the peak value in the grayscale curve.

[0125] In this embodiment, the relative positions of pixels with gray levels equal to the gray threshold are selected on both sides of the origin as the first side position and the second side position, respectively. This includes: obtaining two pixels on each side of the origin as candidate points, where the candidate points are the pixels with gray levels equal to the gray threshold closest to the origin.

[0126] For anchor point graphic 120, its edge position is the brightest, and its interior and exterior are darker than the edge position. Therefore, on each side of the origin, there are two pixels with a gray level equal to the gray level threshold, that is, a total of four candidate points are obtained.

[0127] In this embodiment, the gray level gradient corresponding to each candidate point in the gray level curve is obtained, and the four candidate points are set as the first point, the second point, the third point, and the fourth point in the measurement direction according to the positive and negative order of the gray level gradient.

[0128] Specifically, the grayscale gradient corresponding to each candidate point is obtained based on the grayscale gradient curve corresponding to the grayscale level curve. In the grayscale level curve, the grayscale gradient is positive where the grayscale level increases and negative where it decreases. For anchor point graphic 120, its edge is the brightest, while its interior and exterior are darker than the edge. Therefore, on each side of the origin, the grayscale level exhibits both an increasing and decreasing trend, i.e., according to... Figure 6 (b) The direction of increase of the horizontal coordinate, the gray gradient of the four candidate points is positive and negative in the order of positive and negative, that is, the four candidate points are the first point, the second point, the third point and the fourth point in turn.

[0129] As an example, Figure 6(c) shows a grayscale gradient curve, with the horizontal axis representing the relative position of the pixel and the vertical axis representing the grayscale gradient.

[0130] In this embodiment, it is determined that the anchor point pattern 120 is suitable for measuring structural dimensions or for measuring structural intervals.

[0131] Determine whether anchor point pattern 120 is suitable for measuring structural dimensions or structural intervals, and then select candidate points based on the measurement target.

[0132] Specifically, in this embodiment, when the anchor point pattern 120 is suitable for measuring structural dimensions (CD), the relative positions of the first point and the fourth point are selected as the first side position and the second side position, respectively; when the anchor point pattern 120 is suitable for measuring structural space, the relative positions of the second point and the third point are selected as the first side position and the second side position, respectively.

[0133] When the anchor point pattern 120 is suitable for measuring the structural dimension (CD), that is, when the anchor point pattern 120 is a protrusion on the wafer and the gray level gradually increases from the outside to the inside on both sides of the protrusion, the relative positions of the first point and the fourth point are selected as the first side position and the second side position, respectively. When the anchor point pattern 120 is suitable for measuring the structural space, that is, when the anchor point pattern 120 is a groove on the wafer and the gray level gradually decreases from the outside to the inside on both sides of the groove, the relative positions of the second point and the third point are selected as the first side position and the second side position, respectively.

[0134] In this embodiment, the difference between the position of the first side and the position of the second side is used as the measurement dimension of the anchor point pattern 120.

[0135] The positions of the first and second sides are the positions of the two sides of the anchor point graphic 120, and the difference between the positions of the first and second sides is the measured dimension of the anchor point graphic 120.

[0136] Specifically, Figure 6 (b) The spacing CD between the dashed lines is the measurement dimension.

[0137] In this embodiment, the expression CD_contour is used. i =(Edge_right) i -Edge_left i The measured dimensions of the anchor point graphic are obtained by multiplying the pixel size by 0.5, where CD_contour i For the measured dimension, Edge_left i The position of the first edge, Edge_right iThe position is the second side, and pixel_size is the size of the pixel.

[0138] It should be noted that Edge_right i and Edge_left i These are all relative positions of pixels, therefore, they need to be multiplied by the pixel size to obtain the final measurement size.

[0139] Step S6: By aligning the measured dimension with the target dimension, the measurement deviation of the anchor point pattern 120 is obtained.

[0140] The measurement deviation of the anchor point pattern 120 is obtained and used to compensate for the size of the remaining measurement patterns 110.

[0141] In this embodiment, by first selecting the anchor point graphic 120, the measured size of the anchor point graphic 120 is aligned with the target size to obtain the measurement deviation, which is used to compensate for the measurement size, thus helping to obtain a more accurate graphic size.

[0142] It should be noted that in this embodiment, before obtaining the first peak position and the second peak position in the grayscale curve, the following steps are also included: normalizing the grayscale curve, setting the maximum value of the grayscale curve to 100%, and setting the minimum value of the grayscale curve to 0%.

[0143] Normalizing the grayscale curves simplifies subsequent calculations and improves computational efficiency.

[0144] In this embodiment, the measurement deviation of the anchor point graphic 120 is obtained by aligning the measurement size with the target size, including: obtaining the relative position of the pixel corresponding to the peak on the first side of the origin in the grayscale curve as the first peak position; and obtaining the relative position of the pixel corresponding to the peak on the second side of the origin in the grayscale curve as the second peak position.

[0145] In the measurement image 100, the location with the largest grayscale gradient is the same whether the target size is acquired or the measurement size is acquired. Therefore, acquiring the first peak position and the second peak position as the reference position can enable relatively accurate alignment.

[0146] In this embodiment, the distance between the first side position and the first peak position is obtained as the first distance; the distance between the second side position and the second peak position is obtained as the second distance.

[0147] Specifically, in this embodiment, the first expression D_E2T_left is used. i =(Edge_left) i -T100%_lefti The first spacing is obtained by multiplying pixel_size, and the second expression D_E2T_right is used. i =(T100%_right) i -Edge_right i The second spacing is obtained by multiplying D_E2T_left by pixel_size. i For the first spacing, D_E2T_right i For the second spacing, Edge_left i The position of the first edge, Edge_right i For the position of the second side, T100%_left i The first peak position, T100%_right i This is the location of the second peak, and pixel_size is the size of the pixel.

[0148] It should be noted that D_E2T_left i D_E2T_right i Edge_left i Edge_right i T100%_left i and T100%_right i These are the relative positions of pixels, therefore, they need to be multiplied by the pixel size to obtain the first and second spacings.

[0149] In this embodiment, the measured dimensions are aligned with the target dimensions by combining the first and second spacings to obtain the measurement deviation of the anchor point pattern 120.

[0150] Specifically, in this embodiment, the third expression CD_contour is used. i +(D_E2T_left i +D_E2T_right i )×bias_ratio-CD_CDSEM i =0 yields the measurement bias, where bias_ratio is the measurement bias and CD_contour is the measurement bias. i For dimensional measurement, CD_CDSEM i The target size.

[0151] It should be noted that D_E2T_left i and D_E2T_right i These are all relative positions of pixels; therefore, they need to be multiplied by the pixel size to obtain the measurement bias.

[0152] In this embodiment, the measurement dimensions of multiple anchor point graphics 120 are obtained according to the aforementioned steps. Correspondingly, the measurement dimensions of the multiple anchor point graphics 120 are used to perform function fitting on the third expression to obtain the measurement deviation.

[0153] Step S7: Perform measurement compensation on the measurement pattern 110 in the measurement image 100 according to the measurement deviation to obtain the graphic size of the measurement pattern 110.

[0154] By compensating for the measurement deviation in the measurement pattern 110 in the measurement image 100, a more accurate pattern size can be obtained.

[0155] It should be noted that, in this embodiment, before performing measurement compensation on the measurement pattern 110 in the measurement image 100 according to the measurement deviation, the method further includes: obtaining the measurement dimensions of the measurement pattern 110 corresponding to the remaining multiple target graphic structures.

[0156] The remaining multiple target graphic structures corresponding to the measurement graphics 110 refer to the other measurement graphics 110 besides those selected as anchor point graphics 120.

[0157] In this embodiment, the measurement dimensions of the measurement graphics 110 corresponding to the remaining multiple target graphic structures are obtained according to the aforementioned step S5, so as to perform measurement compensation on the remaining measurement graphics 110 according to the measurement deviation, and obtain the graphic dimensions corresponding to each measurement graphics 110.

[0158] In this embodiment, the measurement graphic 110 in the measurement image 100 is compensated according to the measurement deviation to obtain the graphic size of the measurement graphic 110, including: compensating the measurement graphic 110 by combining the first spacing and the measurement deviation to obtain the position of the first compensation edge; and compensating the measurement graphic 110 by combining the second spacing and the measurement deviation to obtain the position of the second compensation edge.

[0159] The positions of the first and second compensation edges are the actual edge positions of the measured figure 110 after compensation.

[0160] Accordingly, in this embodiment, the difference between the position of the first compensation edge and the position of the second compensation edge is used as the graphic size of the measurement graphic 110.

[0161] Specifically, in this embodiment, the expression Edge_left_real is used. i =Edge_left i +(D_E2T_left i The position of the first compensated edge is obtained by multiplying the bias_ratio by the pixel_size; the expression Edge_right_real is used. i =Edge_right i+(D_E2T_right i The position of the second compensation edge is obtained by multiplying the bias_ratio by the pixel_size, where Edge_left_real i The first compensated edge position, Edge_right_real i The position of the second compensation edge is D_E2T_left. i For the first spacing, D_E2T_right i For the second spacing, Edge_left i The position of the first edge, Edge_right i The second side is the position, bias_ratio is the measurement bias, and pixel_size is the size of the pixel.

[0162] It should be noted that D_E2T_left i D_E2T_right i Edge_left i and Edge_right i These are all relative positions of pixels, therefore, they need to be multiplied by the pixel size to obtain the final graphic size.

[0163] In this embodiment, the measurement compensation of the measurement pattern 110 in the measurement image 100 according to the measurement deviation further includes: performing measurement compensation on the remaining multiple measurement dimensions, and using the obtained pattern dimensions as correction dimensions.

[0164] Obtain the corrected dimensions, which will be used for subsequent calibration of the graphic dimensions.

[0165] refer to Figure 7 After performing measurement compensation on the measurement pattern 110 in the measurement image 100 according to the measurement deviation and obtaining the graphic size of the measurement pattern 110, the method further includes: obtaining the graphic outline 111 of the measurement pattern 110 in multiple measurement images 100 according to the graphic size.

[0166] Once the graphic contour 111 is obtained, the graphic contour of the entire measurement image 100 constitutes the contour image 101. Then, the subsequent size measurement of any position in the entire measurement image 100 can be directly performed by measuring the graphic contour 111 in the contour image 101, which simplifies the size measurement of the entire measurement image 100 and is beneficial for measuring complex positions and complex graphics.

[0167] In this embodiment, after performing measurement compensation on the measurement pattern in the measurement image 100 according to the measurement deviation, the method further includes: calibrating multiple correction dimensions with the corresponding target dimensions.

[0168] Calibrate multiple correction dimensions with their corresponding target dimensions to further ensure the accuracy of graphic dimensions and improve the reliability of graphic dimension measurement in this embodiment.

[0169] In this embodiment, during the calibration of multiple correction dimensions with the corresponding target dimensions, the correction dimension at the same position as the target dimension is obtained on the graphic contour 111 and calibrated with the target dimension.

[0170] Right now Figure 7 (b) The location of the correction dimension (dashed box) and Figure 7 The target dimensions in (a) are in the same position (parallel to the dashed line).

[0171] In this embodiment, calibrating multiple correction dimensions with corresponding target dimensions includes: obtaining the difference between the corresponding correction dimensions and the target dimensions.

[0172] The difference is used to measure the deviation between the corrected size and the target size.

[0173] In this embodiment, it is determined whether the difference is less than the calibration threshold.

[0174] The calibration threshold serves as a benchmark for measuring the accuracy of the calibration dimensions.

[0175] In this embodiment, if the difference is less than the calibration threshold, the calibration result is satisfactory.

[0176] If the difference is less than the calibration threshold, it indicates that the corrected size is close to the target size, and the calibration result meets the standard.

[0177] Accordingly, in this embodiment, if the calibration result meets the standard, the graphic size measurement is completed.

[0178] In this embodiment, if the difference is not less than the calibration threshold, the calibration result is not up to standard.

[0179] If the difference is not less than the calibration threshold, it indicates that the deviation between the corrected size and the target size is large, and the calibration result does not meet the standard.

[0180] Accordingly, in this embodiment, if the calibration result does not meet the standard, the process returns to step S5: selecting partial measurement graphics 110 that characterize the graphic features of multiple target graphic structures as multiple anchor point graphics 120.

[0181] Return to the execution and select partial measurement graphics 110 representing the graphic features of multiple target graphic structures as multiple anchor point graphics 120, reselect anchor point graphics 120, and perform a new round of size alignment until the correction result meets the standard.

[0182] It should be noted that the reference Figure 8 , Figure 8The verification of measuring 141 graphic structures using the graphic dimension measurement method of this embodiment is shown. Figure 8 In (a), CD diff range represents the range of differences between the graphic size and the target size, and Distribution represents the percentage of the corresponding difference range among the 1414 graphic structures. Figure 8 In (b), the horizontal axis CD Diff represents the range of differences between the graphic size and the target size, and the vertical axis Count represents the number of corresponding difference ranges in the 1414 graphic structures. It can be seen that the graphic size obtained by the graphic size measurement method in this embodiment has good consistency with the target size and high accuracy of the graphic size.

[0183] Accordingly, the present invention also provides a graphic dimension measurement system. Figure 9 This is a functional block diagram of an embodiment of the graphic dimension measurement system of the present invention.

[0184] In this embodiment, the graphic size measurement system 50 includes: a target graphic structure acquisition module 501, used to acquire multiple target graphic structures; a measurement graphic acquisition module 502, used to acquire a measurement image of the area where each target graphic structure is located, the measurement image including a measurement graphic corresponding to the target graphic structure; a target size acquisition module 503, used to acquire the target size of the multiple target graphic structures; an anchor point graphic acquisition module 504, used to select a portion of the measurement graphic representing the graphic features of the multiple target graphic structures as multiple anchor point graphics; a measurement size acquisition module 505, used to acquire the measurement size of the anchor point graphics; a measurement deviation acquisition module 506, used to obtain the measurement deviation of the anchor point graphics by aligning the measurement size with the target size; and a graphic size acquisition module 507, used to perform measurement compensation on the measurement graphic in the measurement image according to the measurement deviation to obtain the graphic size of the measurement graphic.

[0185] The target graphic structure acquisition module 501 is used to acquire multiple target graphic structures.

[0186] The target pattern structure is the structure that needs to be used to measure the pattern size. It is a pattern structure on a wafer. Subsequently, the measurement size of the target pattern structure is aligned with the target size to achieve a more accurate measurement of the pattern structure.

[0187] In this embodiment, the target pattern structure includes a developed pattern structure or an etched pattern structure on the wafer. The pattern size measurement method of this embodiment is used to measure the developed pattern structure or the etched pattern structure.

[0188] In this embodiment, obtaining multiple target graphic structures includes: providing multiple graphic structures.

[0189] Pattern structures include post-development or post-etching patterns on wafers. Specifically, in semiconductor manufacturing processes, designs need to be transferred to a design layout on the wafer, including design patterns. After optical proximity correction is performed on the design patterns of the design layout, the resulting patterns are used to create a mask. The mask is then used for photolithography to form corresponding development and etching patterns on the wafer. Subsequently, corresponding After Development Inspection (ADI) dimensions (CD) and After Etch Inspection (AEI) dimensions (CD) are obtained, which can be used for OPC model establishment, mask verification, weakpoint analysis, and the establishment of etching deviation compensation schemes.

[0190] In this embodiment, a graphic structure whose measurement type is structural dimension or structural spacing is obtained as the target graphic structure.

[0191] The measurement type is a graphic structure of structural dimensions or structural spacing. This refers to the subsequent measurement of the structural dimensions or structural spacing of the graphic structure. Since the target dimensions or structural spacing of the selected target graphic structure are relatively accurate, using the target dimensions of the target graphic structure as the alignment reference allows for more accurate compensation of the measured dimensions. Specifically, measuring structural dimensions is called measuring critical dimensions (CD), and measuring structural spacing is called measuring spacing (space).

[0192] The measurement image acquisition module 502 is used to acquire the measurement image of the region where each target graphic structure is located. The measurement image includes the measurement image corresponding to the target graphic structure.

[0193] The measurement image is an image obtained by acquiring the target graphic structure, and the target graphic structure is presented as a measurement graphic in the measurement image.

[0194] In this embodiment, a scanning electron microscope is used to acquire measurement images of the region where each target graphic structure is located.

[0195] Electron beam scanning can be used to perform relatively efficient and accurate scanning, thereby obtaining clearer measurement images.

[0196] Specifically, in this embodiment, the scanning electron microscope is a critical dimension scanning electron microscope (CD-SEM).

[0197] In this embodiment, in the measurement image of the region where each target graphic structure is located, the measurement graphic corresponding to the target graphic structure is located at the center of the measurement image.

[0198] In this embodiment, the measurement image is acquired by scanning electron microscopy. The measurement pattern corresponding to the target graphic structure is located at the center of the measurement image, which makes the target graphic structure receive light more uniformly and with sufficient intensity, which is conducive to obtaining a clearer measurement pattern and making the subsequent measurement of the measurement pattern more accurate.

[0199] The target size acquisition module 503 is used to acquire the target size of multiple target graphic structures.

[0200] Obtain the target dimensions of multiple target graphic structures, which will be used as alignment dimensions in the subsequent process.

[0201] In this embodiment, a scanning electron microscope is used to obtain the target dimensions of multiple target graphic structures.

[0202] Scanning electron microscopy can directly obtain the target dimensions of target graphic structures, especially for CD and space, and can obtain relatively accurate results. Therefore, the target dimensions of multiple target graphic structures obtained by scanning electron microscopy can be used as the alignment reference for measuring the dimensions of the graphic.

[0203] Specifically, in this embodiment, CD-SEM is used to obtain the target dimensions of multiple target graphic structures.

[0204] In this embodiment, the target dimensions of multiple target graphic structures are obtained based on the measurement images of the target graphic structures.

[0205] In this embodiment, CD-SEM is used to obtain the measurement image of the target graphic structure. The target size of the target graphic structure can be obtained from the measurement image. That is, CD-SEM is used to obtain both the measurement image and the target size of the target graphic structure.

[0206] Specifically, the target dimensions of multiple target graphic structures are obtained based on the measurement images of the target graphic structures, including setting the target range of the measurement graphic in a direction perpendicular to the measurement direction.

[0207] The target range is the range from which image information is obtained in CD-SEM.

[0208] In this embodiment, multiple reference points are arranged on the edge of the measurement graphic within the target area.

[0209] The reference point is the point from which image information is obtained in CD-SEM.

[0210] Specifically, in this embodiment, the target size of the target graphic structure corresponding to the measurement graphic is obtained based on multiple reference points of the measurement graphic.

[0211] The anchor point pattern acquisition module 504 is used to select partial measurement patterns that characterize the graphic features of multiple target graphic structures as multiple anchor point patterns.

[0212] Select a portion of the measurement graphics as anchor point graphics for subsequent dimensional alignment.

[0213] In this embodiment, partial measurement graphics representing the graphic features of multiple target graphic structures are selected as multiple anchor point graphics. The anchor point graphics are representative of the multiple target graphic structures. Using representative anchor point graphics for alignment saves computing power and improves efficiency, while also making the measurement compensation of multiple target graphic structures more accurate, thereby facilitating the realization of more accurate graphic size measurement.

[0214] Specifically, as an example, in this embodiment, the multiple target graphic structures include one-dimensional (1D) characteristic structures and two-dimensional (2D) characteristic structures. The measurement graphics representing 1D and 2D are selected as anchor point graphics respectively, and the measurement images containing the multiple anchor point graphics are subsequently measured.

[0215] The measurement dimension acquisition module 505 is used to acquire the measurement dimensions of the anchor point graphic.

[0216] Obtain the measured dimensions of the anchor point graphic for alignment with the target dimensions.

[0217] In this embodiment, obtaining the measurement dimensions of the anchor point graphic includes: obtaining the grayscale distribution of the measurement image, wherein the grayscale distribution includes the grayscale levels corresponding to each point in the measurement image.

[0218] The grayscale distribution of the measurement image is obtained so that the outline of the anchor point graphic and the measurement size of the anchor point graphic can be obtained based on the grayscale level corresponding to each point in the measurement image.

[0219] Specifically, the measurement image obtained by acquiring the target graphic structure is a grayscale image. The edges of the anchor point graphic are highlighted, and the edges are usually white. The white edges can be extracted by judging the grayscale level of each point in the measurement image, that is, the outline of the anchor point graphic is extracted.

[0220] In this embodiment, obtaining the grayscale distribution of the measurement image includes: setting the measurement range of the anchor point graphic perpendicular to the measurement direction.

[0221] Determine the measurement range so that grayscale distribution can be obtained within the measurement range, ensuring measurement accuracy while saving computing power and improving efficiency.

[0222] In this embodiment, within the measurement range where the anchor point pattern is set perpendicular to the measurement direction, the measurement range is set to coincide with the target range.

[0223] Setting the measurement range to coincide with the target range ensures that the measurement area for obtaining the measured dimension is the same as the measurement area for obtaining the target dimension, guaranteeing consistency of measurement conditions. This makes it easier to align the measured dimension with the target dimension more effectively, and the obtained measurement deviation is more applicable.

[0224] As an example, in this embodiment, the target range is 150nm perpendicular to the measurement direction, the resolution of the measurement image is 1024×1024, that is, the measurement image has 1024 pixels in the measurement direction and also 1024 pixels perpendicular to the measurement direction. The field of view (FOV) of the measurement image is 900nm, so the size of each pixel is 0.879nm×0.879nm (900nm / 1024=0.879nm), thus setting the measurement range to 171 pixels.

[0225] In this embodiment, multiple measurement baselines are set within the measurement range, and the measurement baselines extend across the anchor point pattern along the measurement direction.

[0226] The measurement baseline is the tangent line across the anchor point figure. The measurement baseline extends along the measurement direction and passes through the two opposite sides of the anchor point figure. Thus, the distance between the two sides of the anchor point figure can be obtained through the measurement baseline, which is the measurement dimension.

[0227] In this embodiment, among the multiple measurement baselines set within the measurement range, each measurement baseline corresponds to a reference point and passes through a reference point.

[0228] Setting a measurement baseline that corresponds one-to-one with the reference point and passes through the reference point ensures that the measurement point for obtaining the measured dimension is the same as the measurement point for obtaining the target dimension, guaranteeing the consistency of measurement conditions. This makes it easier to align the measured dimension with the target dimension more effectively, and the obtained measurement deviation is more applicable.

[0229] As an example, in this embodiment, there are 16 measurement points, which form 16 measurement baselines.

[0230] In this embodiment, the grayscale distribution of the measurement image within the measurement range is obtained based on the grayscale measurement of the anchor point graphic using multiple measurement baselines.

[0231] The measurement dimensions of the anchor point graphic are then obtained based on the grayscale distribution within the measurement range.

[0232] Specifically, in this embodiment, the grayscale distribution of the measurement image within the measurement range is obtained based on the measurement of the grayscale level of the anchor point graphic using multiple measurement baselines, including: obtaining the grayscale level of each pixel on each measurement baseline.

[0233] Obtain the grayscale level of each pixel on each measurement baseline, and use the grayscale level of each pixel to determine the position of the edge of the anchor point graphic.

[0234] In this embodiment, before obtaining the average gray level of pixels at the same position on multiple measurement baselines as the target gray level of the pixel, the method further includes: filtering the gray level of each pixel on the measurement baseline.

[0235] Filtering the grayscale level of each pixel on the measurement baseline to extract the effective signal helps reduce the impact of noise and improves the accuracy of subsequent measurement size acquisition based on grayscale distribution.

[0236] In this embodiment, the grayscale level of each pixel on the measurement baseline is filtered, including: taking any pixel on the measurement baseline as the target point.

[0237] The target point is the point where information filtering is required.

[0238] In this embodiment, the gray level of the target point and the average gray level of multiple pixels adjacent to the target point in the direction perpendicular to the measurement direction are replaced with the gray level of the target point.

[0239] Replacing the gray level of the target point with the average gray level of multiple pixels adjacent to the target point in the direction perpendicular to the measurement direction, i.e., averaging the gray level of the target point with the surrounding points, can effectively filter out invalid information and enhance valid information.

[0240] Specifically, in this embodiment, a row of pixels arranged along the measurement direction is taken as a pixel row. In the direction perpendicular to the measurement direction, multiple surrounding baselines are set that pass through multiple pixel rows adjacent to the measurement baseline. The average gray level of the corresponding pixels of the measurement baseline and the surrounding baselines in the direction perpendicular to the measurement direction is obtained to form the gray level distribution of the filtered measurement baseline.

[0241] It should be noted that in this embodiment, when CD-SEM obtains the target size, it also performs surrounding mean averaging on each reference point. Therefore, when performing filtering, the number of multiple pixels adjacent to the target point in the direction perpendicular to the measurement direction is set to be equal to the number of reference points subjected to surrounding mean averaging (sum line). This ensures the consistency of measurement conditions and makes it easier to align the measurement size with the target size more effectively, and the obtained measurement deviation is more applicable.

[0242] As an example, in this embodiment, the number of target points and multiple pixels adjacent to the target points in the direction perpendicular to the measurement direction is set to 4.

[0243] In this embodiment, the average gray level of pixels at the same position on multiple measurement baselines is obtained as the target gray level of the pixel.

[0244] In this context, "same position" refers to pixels that overlap in the measurement direction.

[0245] The average gray level of pixels at the same position on multiple measurement baselines is used as the target gray level of the pixel. This takes into account the gray level information of multiple positions perpendicular to the measurement direction, which is beneficial for obtaining more accurate measurement dimensions in the future.

[0246] In this embodiment, a gray level curve is established as the gray level distribution based on the relative position coordinates of the pixels and the target gray level.

[0247] Establishing a grayscale level curve as a grayscale distribution makes the grayscale level curve more intuitive and simplifies the subsequent method of obtaining measurement dimensions based on the grayscale level curve.

[0248] In this embodiment, the measurement dimensions of the anchor point graphic are obtained based on the grayscale distribution.

[0249] Specifically, in this embodiment, the measurement dimensions of the anchor point graphic are obtained based on the grayscale level curve.

[0250] In this embodiment, obtaining the measurement dimensions of the anchor point graphic based on the grayscale distribution includes: setting the center point of the relative position of the pixel in the grayscale level curve as the origin.

[0251] In the measurement image, the measurement graphic corresponding to the target graphic structure is located at the center of the measurement image, that is, the anchor point graphic is located at the center of the measurement graphic. Then, the center point of the relative position of the pixel is set as the origin, and the origin is the center point of the anchor point graphic in the measurement direction.

[0252] In this embodiment, the relative positions of pixels with gray levels equal to the gray threshold are selected on both sides of the origin as the first side position and the second side position, respectively.

[0253] The edges of the anchor point graphic will be highlighted, and the edges are usually white, meaning that the gray level of the anchor point graphic's edges is higher. Therefore, points with a gray level equal to the gray threshold can be used as the two sides of the anchor point graphic.

[0254] In this embodiment, the relative positions of pixels with gray levels equal to the gray threshold are selected on both sides of the origin as the first side position and the second side position, respectively, and the gray threshold is set as a preset percentage of the peak value in the gray level curve.

[0255] The peak value in the grayscale curve represents the maximum brightness in the measured image. The brightest position in the measured image is the edge position of the anchor point graphic. Therefore, setting the grayscale threshold to a preset percentage of the peak value in the grayscale curve can more accurately locate the edge position of the anchor point graphic.

[0256] As an example, in this embodiment, the grayscale threshold is set to 50% of the peak value in the grayscale level curve.

[0257] In this embodiment, the relative positions of pixels with gray levels equal to the gray threshold are selected on both sides of the origin as the first side position and the second side position, respectively. This includes: obtaining two pixels on each side of the origin as candidate points, where the candidate points are the pixels with gray levels equal to the gray threshold closest to the origin.

[0258] For an anchor point graphic, its edge position is the brightest, and its interior and exterior are darker than the edge position. Therefore, on each side of the origin, there are two pixels with a gray level equal to the gray level threshold, that is, a total of four candidate points are obtained.

[0259] In this embodiment, the gray level gradient corresponding to each candidate point in the gray level curve is obtained, and the four candidate points are set as the first point, the second point, the third point, and the fourth point in the measurement direction according to the positive and negative order of the gray level gradient.

[0260] Specifically, the gray-level gradient corresponding to each candidate point is obtained based on the gray-level gradient curve corresponding to the gray-level curve. The gray-level gradient is positive at the position where the gray-level increases and negative at the position where it decreases. For the anchor point graphic, its edge position is the brightest, and its interior and exterior are darker than the edge position. Therefore, on each side of the origin, the gray-level has an increasing trend and a decreasing trend. That is, according to the increasing direction of the horizontal axis, the gray-level gradients of the four candidate points are in the order of positive-negative-positive-negative, that is, the four candidate points are the first point, the second point, the third point, and the fourth point in turn.

[0261] In this embodiment, it is determined whether the anchor point pattern is suitable for measuring structural dimensions or structural spacing.

[0262] Determine whether the anchor point pattern is suitable for measuring structural dimensions or structural intervals, and then select candidate points based on the measurement target.

[0263] Specifically, in this embodiment, when the anchor point pattern is suitable for measuring the structural dimension (CD), the relative positions of the first point and the fourth point are selected as the first side position and the second side position, respectively; when the anchor point pattern is suitable for measuring the structural space, the relative positions of the second point and the third point are selected as the first side position and the second side position, respectively.

[0264] When the anchor point pattern is suitable for measuring the structural dimension (CD), that is, when the anchor point pattern is a convex shape on the wafer and the gray level gradually increases from the outside to the inside on both sides of the convex shape, the relative positions of the first point and the fourth point are selected as the first side position and the second side position, respectively. When the anchor point pattern is suitable for measuring the structural space, that is, when the anchor point pattern is a groove on the wafer and the gray level gradually decreases from the outside to the inside on both sides of the groove, the relative positions of the second point and the third point are selected as the first side position and the second side position, respectively.

[0265] In this embodiment, the difference between the position of the first side and the position of the second side is used as the measurement dimension of the anchor point graphic.

[0266] The positions of the first and second sides are the positions of the two sides of the anchor point graphic, and the difference between the positions of the first and second sides is the measured dimension of the anchor point graphic.

[0267] In this embodiment, the expression CD_contour is used. i =(Edge_right) i -Edge_left i The measured dimensions of the anchor point graphic are obtained by multiplying the pixel size by 0.5, where CD_contour i For the measured dimension, Edge_left i The position of the first edge, Edge_right i The position is the second side, and pixel_size is the size of the pixel.

[0268] It should be noted that Edge_right i and Edge_left i These are all relative positions of pixels, therefore, they need to be multiplied by the pixel size to obtain the final measurement size.

[0269] The measurement deviation acquisition module 506 is used to obtain the measurement deviation of the anchor point pattern by aligning the measurement dimension with the target dimension.

[0270] The measurement deviation of the anchor point pattern is obtained and used to compensate for the dimensions of the remaining measurement patterns.

[0271] In this embodiment, by first selecting the anchor point graphic and aligning the measured size of the anchor point graphic with the target size, the measurement deviation is obtained and used to compensate for the measurement size, which helps to obtain a more accurate graphic size.

[0272] It should be noted that, in this embodiment, before obtaining the first peak position and the second peak position in the grayscale curve, the following steps are also included: normalizing the grayscale curve, setting the maximum value of the grayscale curve to %, and setting the minimum value of the grayscale curve to 0%.

[0273] Normalizing the grayscale curves simplifies subsequent calculations and improves computational efficiency.

[0274] In this embodiment, the measurement deviation of the anchor point graphic is obtained by aligning the measurement size with the target size, including: obtaining the relative position of the pixel corresponding to the peak on the first side of the origin in the grayscale curve as the first peak position; and obtaining the relative position of the pixel corresponding to the peak on the second side of the origin in the grayscale curve as the second peak position.

[0275] In the measurement image, whether it is the acquisition of the target size or the acquisition of the measurement size, the position of the largest gray-level gradient is the same. Therefore, obtaining the first peak position and the second peak position as the reference position can enable relatively accurate alignment.

[0276] In this embodiment, the distance between the first side position and the first peak position is obtained as the first distance; the distance between the second side position and the second peak position is obtained as the second distance.

[0277] Specifically, in this embodiment, the first expression D_E2T_left is used. i =(Edge_left) i -T%_left i The first spacing is obtained by multiplying pixel_size, and the second expression D_E2T_right is used. i =(T%_right i -Edge_right i The second spacing is obtained by multiplying D_E2T_left by pixel_size. i For the first spacing, D_E2T_right i For the second spacing, Edge_left i The position of the first edge, Edge_right i For the position of the second side, T%_left i The first peak position, T%_righti This is the location of the second peak, and pixel_size is the size of the pixel.

[0278] It should be noted that D_E2T_left i D_E2T_right i Edge_left i Edge_right i 、T%_left i and T%_right i These are the relative positions of pixels, therefore, they need to be multiplied by the pixel size to obtain the first and second spacings.

[0279] In this embodiment, the measured dimensions are aligned with the target dimensions by combining the first and second spacings to obtain the measurement deviation of the anchor point pattern.

[0280] Specifically, in this embodiment, the third expression CD_contour is used. i +(D_E2T_left i +D_E2T_right i )×bias_ratio-CD_CDSEM i =0 yields the measurement bias, where bias_ratio is the measurement bias and CD_contour is the measurement bias. i For dimensional measurement, CD_CDSEM i The target size.

[0281] It should be noted that D_E2T_left i and D_E2T_right i These are all relative positions of pixels; therefore, they need to be multiplied by the pixel size to obtain the measurement bias.

[0282] In this embodiment, the measurement dimensions of multiple anchor point graphics are obtained according to the aforementioned steps. Correspondingly, the measurement dimensions of the multiple anchor point graphics are used to perform function fitting on the third expression to obtain the measurement deviation.

[0283] The graphic size acquisition module 507 is used to perform measurement compensation on the measurement graphic in the measurement image according to the measurement deviation, and obtain the graphic size of the measurement graphic.

[0284] By compensating for measurement deviations in the measurement images, more accurate graphic dimensions can be obtained.

[0285] It should be noted that, in this embodiment, before performing measurement compensation on the measurement pattern in the measurement image based on the measurement deviation, the method further includes: obtaining the measurement dimensions of the measurement patterns corresponding to the remaining multiple target graphic structures.

[0286] The remaining multiple target graphic structures correspond to measurement graphics, which refer to the other measurement graphics besides those selected as anchor point graphics.

[0287] In this embodiment, the measurement dimensions of the measurement graphics corresponding to the remaining multiple target graphic structures are obtained according to the aforementioned module 505, so as to perform measurement compensation on the remaining measurement graphics according to the measurement deviation and obtain the graphic dimensions corresponding to each measurement graphic.

[0288] In this embodiment, the measurement graphic in the measurement image is compensated according to the measurement deviation to obtain the graphic size of the measurement graphic, including: compensating the measurement graphic by combining the first spacing and the measurement deviation to obtain the position of the first compensation edge; and compensating the measurement graphic by combining the second spacing and the measurement deviation to obtain the position of the second compensation edge.

[0289] The positions of the first and second compensation edges are the actual edge positions of the measured figure after compensation.

[0290] Accordingly, in this embodiment, the difference between the position of the first compensation edge and the position of the second compensation edge is used as the graphic size of the measurement graphic.

[0291] Specifically, in this embodiment, the expression Edge_left_real is used. i =Edge_left i +(D_E2T_left i The position of the first compensated edge is obtained by multiplying the bias_ratio by the pixel_size; the expression Edge_right_real is used. i =Edge_right i +(D_E2T_right i The position of the second compensation edge is obtained by multiplying the bias_ratio by the pixel_size, where Edge_left_real i The first compensated edge position, Edge_right_real i The position of the second compensation edge is D_E2T_left. i For the first spacing, D_E2T_right i For the second spacing, Edge_left i The position of the first edge, Edge_right i The second side is the position, bias_ratio is the measurement bias, and pixel_size is the size of the pixel.

[0292] It should be noted that D_E2T_left i D_E2T_right i Edge_lefti and Edge_right i These are all relative positions of pixels, therefore, they need to be multiplied by the pixel size to obtain the final graphic size.

[0293] In this embodiment, the measurement compensation of the measurement pattern in the measurement image based on the measurement deviation further includes: performing measurement compensation on the remaining multiple measurement dimensions, and using the obtained graphic dimensions as correction dimensions.

[0294] Obtain the corrected dimensions, which will be used for subsequent calibration of the graphic dimensions.

[0295] In this embodiment, after performing measurement compensation on the measurement pattern in the measurement image according to the measurement deviation and obtaining the graphic size of the measurement pattern, the method further includes: obtaining the graphic outline of the measurement pattern in multiple measurement images according to the graphic size.

[0296] Once the graphic contour is obtained, the graphic contour of the entire measurement image constitutes a contour image. Then, subsequent size measurements at any position in the entire measurement image can be directly performed by measuring the graphic contour in the contour image, which simplifies the size measurement of the entire measurement image and is beneficial for measuring complex positions and complex graphics.

[0297] In this embodiment, after compensating the measurement pattern in the measurement image according to the measurement deviation, the method further includes: calibrating multiple correction dimensions with the corresponding target dimensions.

[0298] Calibrate multiple correction dimensions with their corresponding target dimensions to further ensure the accuracy of graphic dimensions and improve the reliability of graphic dimension measurement in this embodiment.

[0299] In this embodiment, during the calibration of multiple correction dimensions with the corresponding target dimensions, the correction dimension at the same position as the target dimension is obtained on the graphic contour and calibrated with the target dimension.

[0300] In this embodiment, calibrating multiple correction dimensions with corresponding target dimensions includes: obtaining the difference between the corresponding correction dimensions and the target dimensions.

[0301] The difference is used to measure the deviation between the corrected size and the target size.

[0302] In this embodiment, it is determined whether the difference is less than the calibration threshold.

[0303] The calibration threshold serves as a benchmark for measuring the accuracy of the calibration dimensions.

[0304] In this embodiment, if the difference is less than the calibration threshold, the calibration result is satisfactory.

[0305] If the difference is less than the calibration threshold, it indicates that the corrected size is close to the target size, and the calibration result meets the standard.

[0306] Accordingly, in this embodiment, if the calibration result meets the standard, the graphic size measurement is completed.

[0307] In this embodiment, if the difference is not less than the calibration threshold, the calibration result is not up to standard.

[0308] If the difference is not less than the calibration threshold, it indicates that the deviation between the corrected size and the target size is large, and the calibration result does not meet the standard.

[0309] Accordingly, in this embodiment, if the calibration result does not meet the standard, the system returns to the measurement size acquisition module 505 and selects a portion of the measurement graphics that characterize the graphic features of multiple target graphic structures as multiple anchor point graphics.

[0310] Return to the execution and select partial measurement graphics representing the graphic features of multiple target graphic structures as multiple anchor point graphics. Reselect the anchor point graphics and perform a new round of size alignment until the correction result meets the standard.

[0311] It should be noted that the reference Figure 8 , Figure 8 The verification of measuring 141 graphic structures using the graphic dimension measurement method of this embodiment is shown. Figure 8 In (a), CD diff range represents the range of differences between the graphic size and the target size, and Distribution represents the percentage of the corresponding difference range among the 1414 graphic structures. Figure 8 In (b), the horizontal axis CD Diff represents the range of differences between the graphic size and the target size, and the vertical axis Count represents the number of corresponding difference ranges in the 1414 graphic structures. It can be seen that the graphic size obtained by the graphic size measurement method in this embodiment has good consistency with the target size and high accuracy of the graphic size.

[0312] This invention also provides a device that can implement the graphic size measurement method provided in this invention by loading a program, as described above. An optional hardware structure of the terminal device provided in this invention can be as follows: Figure 10 As shown, it includes: at least one processor 01, at least one communication interface 02, at least one memory 03, and at least one communication bus 04.

[0313] In this embodiment, the number of processor 01, communication interface 02, memory 03, and communication bus 04 is at least one, and the processor 01, communication interface 02, and memory 03 communicate with each other through communication bus 04. Communication interface 02 can be an interface of a communication module for network communication, such as the interface of a GSM module. Processor 01 may be a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement embodiments of the present invention. Memory 03 may include high-speed RAM and may also include non-volatile memory (NVM), 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 graphic size measurement method provided in this embodiment of the present invention.

[0314] It should be noted that the aforementioned terminal device may also include other devices (not shown) that may not be essential to understanding the content disclosed in the embodiments of the present invention; given that these other devices may not be essential for understanding the content disclosed in the embodiments of the present invention, the embodiments of the present invention will not describe them one by one.

[0315] This invention also provides a storage medium storing one or more computer instructions for implementing the graphic dimension measurement method provided in this invention.

[0316] In this embodiment of the invention, by first selecting anchor point graphics and aligning the measured dimensions of the anchor point graphics with the target dimensions to obtain the measurement deviation, which is used to compensate for the measurement dimensions, it is beneficial to obtain more accurate graphic dimensions. Moreover, by selecting some measured graphics that represent the graphic features of multiple target graphic structures as multiple anchor point graphics, the anchor point graphics are representative of the multiple target graphic structures. Using representative anchor point graphics for alignment saves computing power and improves efficiency, while also making the measurement compensation of multiple target graphic structures more accurate, thereby facilitating the realization of more accurate graphic dimension measurement.

[0317] 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.

[0318] 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. In a 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 memory units and executed by a processor. The memory units are located inside or outside the processor and can send data to and receive data from the processor via various known means.

[0319] This invention also provides a computer program product, including a computer program / instruction, which, when executed by a processor, implements the graphic size measurement method provided in this invention.

[0320] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is accorded the widest scope consistent with the principles and novel features disclosed herein.

[0321] 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 measuring the dimensions of a graphic, characterized in that, include: Obtain multiple target graphic structures; Acquire measurement images of the region where each of the target graphic structures is located, the measurement images including measurement graphics corresponding to the target graphic structures; Obtain the target dimensions of multiple target graphic structures; Select partial measurement graphics that characterize the graphic features of multiple target graphic structures as multiple anchor point graphics; Obtain the measured dimensions of the anchor point graphic; The measurement deviation of the anchor point pattern is obtained by aligning the measured dimension with the target dimension. The measurement pattern in the measurement image is compensated according to the measurement deviation to obtain the graphic size of the measurement pattern.

2. The graphic dimension measurement method as described in claim 1, characterized in that, The target dimensions of multiple target graphic structures were obtained using a scanning electron microscope.

3. The graphic dimension measurement method as described in claim 2, characterized in that, Obtain multiple target graphic structures, including: providing multiple graphic structures; Obtain a graphic structure whose measurement type is structural dimension or structural spacing as the target graphic structure.

4. The graphic dimension measurement method as described in claim 1, characterized in that, Obtaining the measurement dimensions of the anchor point graphic includes: obtaining the grayscale distribution of the measurement image, wherein the grayscale distribution includes the grayscale levels corresponding to each point in the measurement image; The measured dimensions of the anchor point graphic are obtained based on the grayscale distribution.

5. The graphic dimension measurement method as described in claim 4, characterized in that, Obtaining the grayscale distribution of the measurement image includes: setting the measurement range of the anchor point graphic perpendicular to the measurement direction; Multiple measurement baselines are set within the measurement range, and the measurement baselines extend across the anchor point pattern along the measurement direction. Based on the measurement of the gray level of the anchor point graphic using multiple measurement baselines, the gray level distribution of the measurement image within the measurement range is obtained.

6. The graphic dimension measurement method as described in claim 5, characterized in that, A scanning electron microscope was used to acquire measurement images of the region where each of the target graphic structures was located. In the measurement image of each region where the target graphic structure is located, the measurement graphic corresponding to the target graphic structure is located at the center of the measurement image; The target dimensions of multiple target graphic structures are obtained from the measurement images of the target graphic structures.

7. The graphic dimension measurement method as described in claim 6, characterized in that, Obtaining the target dimensions of multiple target graphic structures based on the measurement image of the target graphic structure includes: setting the target range of the measurement graphic in a direction perpendicular to the measurement direction; Within the target area, multiple reference points are arranged on each side of the measurement graphic; Based on multiple reference points of the measurement pattern, the target size of the target graphic structure corresponding to the measurement pattern is obtained.

8. The graphic dimension measurement method as described in claim 6, characterized in that, Within the measurement range where the anchor point pattern is set perpendicular to the measurement direction, the measurement range is set to coincide with the target range; Among the multiple measurement reference lines set within the measurement range, each measurement reference line corresponds one-to-one with a reference point and passes through the reference point.

9. The graphic dimension measurement method as described in claim 6, characterized in that, Based on the measurement of the gray level of the anchor point graphic using multiple measurement reference lines, the gray level distribution of the measurement image within the measurement range is obtained, including: acquiring the gray level of each pixel on each measurement reference line; The average gray level of pixels at the same position on multiple measurement baselines is obtained as the target gray level of the pixel. A grayscale curve is established based on the relative position coordinates of the pixels and the target grayscale level as the grayscale distribution.

10. The graphic dimension measurement method as described in claim 9, characterized in that, Before obtaining the average gray level of pixels at the same position on multiple measurement baselines as the target gray level of the pixel, the method further includes: filtering the gray level of each pixel on the measurement baseline.

11. The graphic dimension measurement method as described in claim 10, characterized in that, The grayscale level of each pixel on the measurement reference line is filtered, including: taking any pixel on the measurement reference line as the target point; Replace the gray level of the target point and the average gray level of multiple pixels adjacent to the target point in the direction perpendicular to the measurement direction with the gray level of the target point.

12. The graphic dimension measurement method as described in claim 9, characterized in that, Obtaining the measurement dimensions of the anchor point graphic based on the grayscale distribution includes: setting the center point of the relative position of the pixel as the origin in the grayscale level curve; The relative positions of pixels with gray levels equal to the gray threshold are selected on both sides of the origin and respectively serve as the first side position and the second side position. The difference between the position of the first side and the position of the second side is obtained as the measurement dimension of the anchor point graphic.

13. The graphic dimension measurement method as described in claim 12, characterized in that, Using the expression CD_contour i =(Edge_right) i -Edge_left i The measured dimensions of the anchor point graphic are obtained by multiplying the pixel size by 0.5, where CD_contour i For the measured dimension, Edge_left i The position of the first side. Edge_right i The position is the second side, and pixel_size is the size of the pixel.

14. The graphic dimension measurement method as described in claim 12, characterized in that, In the first and second side positions, the relative positions of pixels with gray levels equal to the gray threshold are selected on both sides of the origin. The gray threshold is set to a preset percentage of the peak value in the gray level curve.

15. The graphic dimension measurement method as described in claim 12, characterized in that, Selecting the relative positions of pixels with gray levels equal to the gray threshold on both sides of the origin as the first side position and the second side position respectively includes: obtaining two pixels on each side of the origin as candidate points, wherein the candidate points are the pixels with gray levels equal to the gray threshold closest to the origin. Obtain the grayscale gradient corresponding to each candidate point in the grayscale curve, and set the four candidate points as the first point, the second point, the third point, and the fourth point in the measurement direction according to the positive and negative order of the grayscale gradient. Determine whether the anchor point pattern is suitable for measuring structural dimensions or structural spacing; When the anchor point pattern is suitable for measuring structural dimensions, the relative positions of the first point and the fourth point are selected as the first side position and the second side position, respectively. When the anchor point pattern is suitable for measuring the structural spacing, the relative positions of the second point and the third point are selected as the first side position and the second side position, respectively.

16. The graphic dimension measurement method as described in claim 12, characterized in that, The measurement deviation of the anchor point graphic is obtained by aligning the measurement size with the target size, including: obtaining the relative position of the pixel corresponding to the peak on one side of the first side position of the origin in the gray level curve as the first peak position; In the grayscale curve, the relative position of the pixel corresponding to the peak on one side of the second side of the origin is obtained as the second peak position; The distance between the first edge position and the first peak position is obtained as the first distance; The distance between the second side position and the second peak position is obtained as the second distance; By aligning the measured dimensions with the first and second spacings towards the target dimensions, the measurement deviation of the anchor point pattern is obtained.

17. The graphic dimension measurement method as described in claim 16, characterized in that, Using the first expression D_E2T_left i =(Edge_left) i -T100%_left i The first spacing is obtained by multiplying pixel_size by the second expression D_E2T_right. i =(T100%_right) i -Edge_right i The second spacing is obtained by multiplying D_E2T_left by pixel_size. i For the first spacing, D_E2T_right i The second spacing, Edge_left i The position of the first edge, Edge_right i For the position of the second side, T100%_left i For the first peak position, T100%_right i This is the location of the second peak, where pixel_size is the size of the pixel. Using the third expression CD_contour i +(D_E2T_left i +D_E2T_right i )×bias_ratio-CD_CDSEM i =0 to obtain the measurement bias, where bias_ratio is the measurement bias, and CD_contour i For the measured dimension, CD_CDSEM i The target size is [the specified value].

18. The graphic dimension measurement method as described in claim 17, characterized in that, The measurement deviation is obtained by fitting the third expression with the measured dimensions of multiple anchor point graphics.

19. The graphic dimension measurement method as described in claim 16, characterized in that, The measurement compensation is performed on the measurement graphic in the measurement image according to the measurement deviation to obtain the graphic size of the measurement graphic, including: compensating the measurement graphic by combining the first spacing and the measurement deviation to obtain the position of the first compensation edge; The measurement pattern is compensated by combining the second spacing and the measurement deviation to obtain the position of the second compensation edge; The difference between the position of the first compensation edge and the position of the second compensation edge is obtained as the graphic size of the measurement graphic.

20. The graphic dimension measurement method as described in claim 19, characterized in that, Using the expression Edge_left_real i =Edge_left i +(D_E2T_left i The position of the first compensated edge is obtained by multiplying the bias_ratio by the pixel_size; the expression Edge_right_real is used. i =Edge_right i +(D_E2T_right i The position of the second compensation edge is obtained by multiplying the bias_ratio by the pixel_size, where Edge_left_real i For the position of the first compensated edge, Edge_right_real i The position of the second compensation edge is D_E2T_left. i For the first spacing, D_E2T_right i The second spacing, Edge_left i The position of the first edge, Edge_right i Here, is the position of the second side, bias_ratio is the measurement deviation, and pixel_size is the size of the pixel.

21. The graphic dimension measurement method as described in claim 1, characterized in that, Before performing measurement compensation on the measurement pattern in the measurement image based on the measurement deviation, the method further includes: obtaining the measurement dimensions of the measurement patterns corresponding to the remaining plurality of target graphic structures; The process of compensating for the measurement pattern in the measurement image based on the measurement deviation further includes: compensating for the remaining multiple measurement dimensions, and using the obtained graphic dimensions as correction dimensions. After compensating the measurement pattern in the measurement image according to the measurement deviation, the method further includes: calibrating the plurality of correction dimensions with the corresponding target dimensions; If the calibration result meets the standard, the graphic dimension measurement is completed; If the calibration result does not meet the standard, the process returns to selecting partial measurement graphics that characterize the graphic features of multiple target graphic structures as multiple anchor point graphics.

22. The graphic dimension measurement method as described in claim 21, characterized in that, The calibration of multiple correction dimensions with corresponding target dimensions includes: obtaining the difference between the corresponding correction dimensions and target dimensions; Determine whether the difference is less than the calibration threshold; If the difference is less than the calibration threshold, the calibration result meets the standard; If the difference is not less than the calibration threshold, the calibration result is not up to standard.

23. The graphic dimension measurement method as described in claim 21, characterized in that, After performing measurement compensation on the measurement pattern in the measurement image based on the measurement deviation to obtain the graphic size of the measurement pattern, the method further includes: obtaining the graphic outline of the measurement pattern in multiple measurement images based on the graphic size. In the process of calibrating multiple correction dimensions with corresponding target dimensions, a correction dimension at the same position as the target dimension is obtained on the graphic contour and calibrated with the target dimension.

24. A graphic dimension measurement system, characterized in that, include: The target graphic structure acquisition module is used to acquire multiple target graphic structures; A measurement image acquisition module is used to acquire a measurement image of the region where each of the target graphic structures is located, wherein the measurement image includes a measurement image corresponding to the target graphic structure; The target size acquisition module is used to acquire the target size of multiple target graphic structures; An anchor point graphic acquisition module is used to select partial measurement graphics that characterize the graphic features of multiple target graphic structures as multiple anchor point graphics; The measurement dimension acquisition module is used to acquire the measurement dimensions of the anchor point graphic; The measurement deviation acquisition module is used to obtain the measurement deviation of the anchor point pattern by aligning the measurement dimension with the target dimension; The graphic size acquisition module is used to perform measurement compensation on the measurement graphic in the measurement image according to the measurement deviation, and obtain the graphic size of the measurement graphic.

25. A 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 graphic dimension measurement method as described in any one of claims 1-23.

26. A storage medium, characterized in that, The storage medium stores one or more computer instructions, which are used to implement the graphic dimension measurement method as described in any one of claims 1-23.

27. A computer program product comprising a computer program / instructions, characterized in that, When the computer program / instructions are executed by the processor, they implement the graphic dimension measurement method according to any one of claims 1-23.

Images