Automated measurement method

Abstract

An automatic measurement method comprises: acquiring a to-be-measured image, the to-be-measured image having a to-be-measured pattern; performing first contour extraction on the to-be-measured pattern to obtain a first contour pattern; providing a target layout, the target layout having a plurality of target patterns; performing first alignment between the first contour pattern and the target layout according to coordinates of the to-be-measured image, the target patterns corresponding to the first contour pattern; performing second contour extraction on the to-be-measured pattern to obtain a second contour pattern, the second contour pattern corresponding to the target patterns; acquiring first and second offset amounts between the target patterns and the second contour pattern; performing second alignment on the second contour pattern according to the first and second offset amounts; and performing measurement on the second contour pattern according to the target patterns after the second alignment. The measurement accuracy of the method is improved.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to an automatic measurement method. Background Technology

[0002] Scanning electron microscopy (SEM) measurements are an important and effective method for evaluating the performance of wafer development inspection (ADI) and etching inspection (AEI).

[0003] Optical Proximity Correction (OPC) relies heavily on scanning electron microscopy (SEM) for development and etching inspections. Using SEM measurements as the actual wafer data source, the OPC bias compensation value for each product is calculated based on the actual wafer development and etching inspection data. Furthermore, mask verification, weakness detection, and compensation are performed by analyzing the SEM measurements from development and etching inspections.

[0004] However, as feature sizes become smaller and designs become more complex, scanning electron microscopy (SEM) measurements for development and etching inspection require more advanced functionality. Traditional automated SEM methods are no longer sufficient to meet these demands.

[0005] Therefore, a new automated scanning electron microscope (SEM) measurement method is needed to meet the measurement requirements. Summary of the Invention

[0006] The technical problem solved by this invention is to provide an automatic measurement method to meet measurement needs.

[0007] To address the aforementioned technical problems, the present invention provides an automatic measurement method, comprising: acquiring an image to be measured, wherein the image to be measured contains a graphic to be measured; performing a first contour extraction on the graphic to be measured to obtain a first contour graphic; providing a target layout, wherein the target layout contains a plurality of target graphics; performing a first alignment between the first contour graphic and the target layout according to the coordinates of the image to be measured, wherein the target graphics correspond to the first contour graphic; performing a second contour extraction on the graphic to be measured to obtain a second contour graphic, wherein the second contour graphic corresponds to the target graphics; acquiring a first offset and a second offset between the target graphics and the second contour graphic; performing a second alignment on the second contour graphic according to the first offset and the second offset; and after performing the second alignment, measuring the second contour graphic according to the target graphics.

[0008] Optionally, the method for extracting the first contour of the graphic to be measured includes: obtaining the first contour based on the grayscale of the graphic edges within the graphic to be measured.

[0009] Optionally, the method for aligning the first contour graphic with the target map based on the coordinates of the image to be measured includes: obtaining the first coordinates of the image to be measured; obtaining the second coordinates within the target map corresponding to the first coordinates; obtaining a comparison region within the target map with the second coordinates as the center and according to a preset radius; obtaining a first proportion of the area occupied by the first contour graphic in the image to be measured; obtaining the size of the image to be measured; obtaining a test region within the comparison region that is the same size as the image to be measured; moving the test region within the comparison region according to a preset rule; obtaining a second proportion of the area of ​​the test region occupied by the target graphic within the test region; if the ratio of the second proportion to the first proportion is greater than a preset value, then marking the first contour graphic as aligned with the target graphic within the test region.

[0010] Optionally, if the ratio of the second ratio to the first ratio is less than a preset value, the acquisition of the image to be measured and the extraction of the first contour are checked.

[0011] Optionally, the method for extracting a second contour of the image to be measured includes: obtaining the correspondence between the image to be measured and the target image based on the correspondence between the target image and the first contour image; performing image enhancement processing on the image to be measured; and extracting a second contour of the image to be measured based on the image intensity distribution to obtain a second contour image, wherein the second contour image corresponds to the target image.

[0012] Optionally, the method for extracting the second contour of the image to be measured based on image intensity includes: obtaining the intensity distribution of the image to be measured and performing a certain smoothing process on the intensity distribution; obtaining a maximum threshold value and a minimum threshold value based on the intensity distribution of the image to be measured, wherein the maximum threshold value is the maximum intensity value and the minimum threshold value is the minimum intensity value; setting a contour extraction threshold; obtaining the blurred edges of the image to be measured based on the maximum threshold value, the minimum threshold value, and the contour extraction threshold; and simulating filling the blurred edges of the image to be measured based on the edges of the target image corresponding to the image to be measured to obtain the second contour image.

[0013] Optionally, the method for obtaining the first offset and the second offset between the target graphic and the second contour graphic includes: obtaining a first axis of symmetry of the second contour graphic parallel to a first direction, obtaining a second axis of symmetry of the second contour graphic parallel to a second direction, wherein the first direction and the second direction are perpendicular; dividing the second contour graphic into a first type of line segment and a second type of line segment, wherein the first type of line segment is parallel to the first direction, and the second type of line segment is parallel to the second direction, wherein the first type of line segment includes a plurality of first line segments and a plurality of second line segments, the first line segments and the second line segments are symmetrical about the first axis of symmetry, and the second type of line segment includes a plurality of third line segments and a plurality of fourth line segments, the third line segments and the fourth line segments being symmetrical about the second axis of symmetry. The process involves: obtaining a first average value of the edge placement error between several first line segments and corresponding target graphic line segments; obtaining a second average value of the edge placement error between several second line segments and corresponding target graphic line segments; obtaining a first offset in a second direction based on the first and second average values, wherein the first offset is the average difference between the first and second average values; obtaining a third average value of the edge placement error between several third line segments and corresponding target graphic line segments; obtaining a fourth average value of the edge placement error between several fourth line segments and corresponding target graphic line segments; and obtaining a second offset in a first direction based on the third and fourth average values, wherein the second offset is the average difference between the third and fourth average values.

[0014] Optionally, the method for second alignment of the second contour pattern according to the first offset and the second offset includes: moving the second contour pattern by a first offset distance in a second direction according to the first offset; and moving the second contour pattern by a second offset distance in a first direction according to the second offset.

[0015] Optionally, the method for measuring the second contour graphic based on the target graphic includes: taking the target graphic as a reference, measuring the edge placement error, spacing, width, and length of the second contour graphic according to a preset measurement rule, and obtaining measurement data.

[0016] Optionally, the pattern to be measured includes a photoresist pattern or an etched pattern.

[0017] Optionally, when the pattern to be measured is a photoresist pattern, the target pattern is a simulated exposure pattern; when the pattern to be measured is an etched pattern, the target pattern is a design pattern.

[0018] Optionally, the image to be measured is an image from a scanning electron microscope.

[0019] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0020] The technical solution of this invention involves first performing a first alignment to align the target graphic with a first contour graphic, then performing precise second contour extraction to obtain a precise second contour graphic, and then acquiring a first offset and a second offset between the target graphic and the second contour graphic. Based on these first and second offsets, a second alignment is performed on the second contour graphic, resulting in more precise alignment. After these two alignments, the alignment accuracy between the second contour graphic and the target graphic is improved. Therefore, when measuring the second contour graphic based on the target graphic, the target graphic can accurately serve as a reference layer, allowing for the measurement of several measurement values ​​of the second contour graphic. This measurement method makes the measurement results more accurate and can adapt to the measurement needs of complex graphics. Attached Figure Description

[0021] Figures 1 to 4 This is a flowchart illustrating the automatic measurement method in an embodiment of the present invention;

[0022] Figures 5 to 10 This is a schematic diagram of the structure of the automatic measurement method implemented in an embodiment of the present invention. Detailed Implementation

[0023] As described in the background section, there is a need for a new automated scanning electron microscope image measurement method to meet measurement requirements.

[0024] Specifically, for example, to analyze the impact of complex environments, we need to obtain more information from a single electron microscope scan image, including multiple key dimensions and spacing data. Furthermore, due to process requirements, precise measurements need to be taken at the correct positions corresponding to multiple points. Currently, the asymmetry of the design graphics is more pronounced. Since there is no reference layer in the electron microscope scan image, it is impossible to directly measure the edge position error of asymmetrical graphics. For instance, if the design image shifts in one direction due to the influence of adjacent asymmetrically distributed graphics, it is impossible to quickly and accurately obtain the offset.

[0025] To address the aforementioned problems, the present invention provides an automatic measurement method. This method involves first performing a first alignment to align the target graphic with a first contour graphic, then performing precise second contour extraction to obtain an accurate second contour graphic. Next, it acquires a first offset and a second offset between the target graphic and the second contour graphic, and performs a second alignment based on these offsets, resulting in more precise alignment. After these two alignments, the alignment accuracy between the second contour graphic and the target graphic is improved. Therefore, when measuring the second contour graphic based on the target graphic, the target graphic can accurately serve as a reference layer, allowing for the measurement of several values ​​of the second contour graphic. This measurement method makes the measurement results more accurate and can adapt to the measurement needs of complex graphics.

[0026] To make the above-mentioned objectives, features and beneficial effects of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0027] Figures 1 to 4 This is a flowchart illustrating the automatic measurement method in an embodiment of the present invention.

[0028] Please refer to Figure 1 The automatic measurement method includes:

[0029] Step S10: Obtain the image to be measured, wherein the image to be measured contains the graphic to be measured;

[0030] Step S20: Extract the first contour of the graphic to be measured to obtain the first contour graphic;

[0031] Step S30: Provide a target layout, wherein the target layout contains a plurality of target graphics;

[0032] Step S40: Based on the coordinates of the image to be measured, perform a first alignment between the first contour graphic and the target map, wherein the target graphic corresponds to the first contour graphic;

[0033] Step S50: Extract the second contour of the graphic to be measured to obtain the second contour graphic, which corresponds to the target graphic;

[0034] Step S60: Obtain the first offset and the second offset between the target graphic and the second contour graphic;

[0035] Step S70: Perform a second alignment on the second contour graphic based on the first offset and the second offset;

[0036] Step S80: After the second alignment, the second contour pattern is measured according to the target pattern.

[0037] The method first performs a first alignment to align the target graphic with a first contour graphic, then performs precise second contour extraction to obtain a precise second contour graphic. Next, it acquires a first offset and a second offset between the target graphic and the second contour graphic, and performs a second alignment based on these offsets, resulting in more precise alignment. After these two alignments, the alignment accuracy between the second contour graphic and the target graphic is improved. Therefore, when measuring the second contour graphic based on the target graphic, the target graphic can accurately serve as a reference layer, allowing for the measurement of several values ​​of the second contour graphic. This measurement method makes the measurement results more accurate and can adapt to the measurement needs of complex graphics.

[0038] Next, each step will be explained separately.

[0039] Figures 5 to 10 This is a schematic diagram of the structure of the automatic measurement method implemented in an embodiment of the present invention.

[0040] Please continue to refer to this. Figure 1 Please refer to Figure 5 Step S10: Obtain the image to be measured 100, wherein the image to be measured 100 contains the graphic to be measured 101.

[0041] The pattern to be measured 101 includes a photoresist pattern (ADI) or an etched pattern (AEI).

[0042] The photoresist pattern is formed by transferring the photoresist layer from a photomask and then exposing and developing the photoresist layer. The etching pattern is formed on the wafer after etching the wafer using the photoresist pattern as a mask.

[0043] The image to be measured 100 is a scanning electron microscope (SEM) image of the layout to be measured. The scanning electron microscope image is an image of a certain area in the layout to be measured.

[0044] Please continue to refer to this. Figure 1 Please refer to Figure 6 Step S20: Extract the first contour of the graphic to be measured 101 to obtain the first contour graphic 102.

[0045] The method for extracting the first contour of the image to be measured 101 and obtaining the first contour image 102 includes: obtaining the first contour image 102 based on the gray level of the edge of the image to be measured 101 within the image to be measured 100.

[0046] The method for obtaining the first contour graphic 102 based on the grayscale of the edge of the graphic 101 to be measured in the image to be measured 100 includes: performing grayscale processing on the graphic 101 to be measured, and then using an image algorithm to extract the first contour graphic 102.

[0047] Please continue to refer to this. Figure 1 Please refer to Figure 7 Step S30: Provide a target layout 200, wherein the target layout 200 has a plurality of target graphics 201.

[0048] When the pattern to be measured 101 is a photoresist pattern, the target pattern 201 is a simulated exposure pattern; when the pattern to be measured 101 is an etched pattern, the target pattern 201 is a design pattern.

[0049] The simulated exposure pattern is the pattern obtained by simulating the exposure of the mask pattern using an optical correction model; the design pattern is the final pattern to be formed in the product design.

[0050] Please continue to refer to this. Figure 1 Step S40: Based on the coordinates of the image 100 to be measured, the first contour graphic 102 is aligned with the target layout 200, wherein the target graphic 201 corresponds to the first contour graphic 102.

[0051] Please refer to Figure 2 and Figure 8 , Figure 7 Here is a flowchart of the method. Figure 8 The diagram illustrates the structure of the first alignment. In this embodiment, the method for performing a first alignment between the first contour graphic 102 and the target layout 200 based on the coordinates of the image 100 to be measured includes:

[0052] Step S401: Obtain the first coordinates of the image 100 to be measured;

[0053] Step S402: Obtain the second coordinate corresponding to the first coordinate within the target map 200;

[0054] Step S403: Using the second coordinate as the center, obtain the comparison area A within the target map 200 according to the preset radius;

[0055] Step S404: Obtain the first proportion of the area occupied by the first contour graphic 102 in the image 100 to be measured;

[0056] Step S405: Obtain the dimensions of the image 100 to be measured;

[0057] Step S406: Obtain a test area within the comparison region that is the same size as the image 100 to be measured;

[0058] Step S407: Move the test area within the comparison area according to preset rules;

[0059] Step S408: Obtain the second proportion of the area of ​​the test area occupied by the target graphic 201 within the test area;

[0060] Step S409: If the ratio of the second ratio to the first ratio is greater than a preset value, then mark the alignment of the first contour graphic 102 with the target graphic 201 within the test area.

[0061] In this embodiment, if the ratio of the second ratio to the first ratio is less than a preset value, the acquisition of the image to be measured 100 and the extraction of the first contour are checked.

[0062] The second ratio is the proportion of the test area occupied by the target graphic 201 within the test area, and the first ratio is the proportion of the area occupied by the first contour graphic 102 in the image to be measured 100. The area of ​​the test area is the same as the area of ​​the image to be measured 100. When the ratio of the second ratio to the first ratio is greater than a preset value, it indicates that the target graphic 201 within the test area is basically the same as the first contour graphic 102 in the image to be measured 100, and thus has a relatively close graphic area ratio. Therefore, the test area corresponds to the image to be measured 100.

[0063] Please continue to refer to this. Figure 1 Please refer to Figure 9 Step S50: Extract the second contour of the image to be measured 100 to obtain the second contour graphic 103, which corresponds to the target graphic 201.

[0064] Please refer to Figure 3 In this embodiment, the method for extracting the second contour of the graphic to be measured 101 to obtain the second contour graphic 103 includes:

[0065] Step S501: Based on the correspondence between the target graphic 201 and the first contour graphic 102, obtain the correspondence between the graphic to be measured 101 and the target graphic 201;

[0066] Step S502: Perform image enhancement processing on the image to be measured 100;

[0067] Step S503: Extract the second contour of the image to be measured 101 according to the image intensity distribution to obtain the second contour image 103, which corresponds to the target image 201.

[0068] The method for extracting the second contour of the image to be measured 101 based on the image intensity distribution includes: obtaining the intensity distribution of the image to be measured and performing a certain smoothing process on the intensity distribution of the image to be measured; obtaining a maximum threshold value and a minimum threshold value based on the intensity distribution of the image to be measured, wherein the maximum threshold value is the maximum intensity value and the minimum threshold value is the minimum intensity value; setting a preset contour extraction threshold T; obtaining the blurred edge of the image to be measured based on the maximum threshold value, the minimum threshold value and the contour extraction threshold T; and simulating filling the blurred edge of the image to be measured based on the edge of the target image corresponding to the image to be measured to obtain the second contour image 103.

[0069] The image intensity is the pixel intensity of the image formed by scanning electron microscopy of the secondary electron signal intensity of the photoresist pattern or etched pattern on the wafer. The image intensity of each pattern position in the image to be measured 100 is obtained through an image processing algorithm. The pattern contour extraction threshold T is determined after debugging, calibration, and verification of selected sample points, and can accurately characterize the image intensity value corresponding to the photoresist pattern or etched pattern. When it is necessary to extract the pattern of the pattern to be measured 101, the pattern contour extraction threshold T at the edge position of the pattern to be measured 101 is set. The position corresponding to the pattern contour extraction threshold T is the position of the edge of the pattern to be measured, and the second contour pattern 103 is obtained.

[0070] Image enhancement processing is performed on the image to be measured 100 to reduce noise in the image to be measured 100, so that the extracted second contour graphic 103 is smoother and clearer.

[0071] Please continue to refer to this. Figure 1 Step S60: Obtain the first offset Y between the target graphic 201 and the second contour graphic 103. shift Second offset X shift .

[0072] Please refer to Figure 4 and Figure 7 , Figure 4 Here is a flowchart of the method. Figure 7 This is a schematic diagram of the structure for implementing the method. In this embodiment, the first offset Y between the target graphic 201 and the second contour graphic 103 is obtained. shift Second offset X shift The methods include:

[0073] Step S601: Obtain the first axis of symmetry of the second contour pattern 103 parallel to the first direction X, and obtain the second axis of symmetry of the second contour pattern 103 parallel to the second direction, wherein the first direction X and the second direction Y are perpendicular.

[0074] Step S602: Divide the second contour graphic 103 into a first type of line segment and a second type of line segment. The first type of line segment is parallel to the first direction X, and the second type of line segment is parallel to the second direction Y. The first type of line segment includes a plurality of first line segments 104 and a plurality of second line segments 105. The first line segments 104 and the second line segments 105 are symmetrical about a first axis of symmetry. The second type of line segment includes a plurality of third line segments 106 and a plurality of fourth line segments 107. The third line segments 106 and the fourth line segments 107 are symmetrical about a second axis of symmetry.

[0075] Step S603: Obtain the first average value of the edge placement error between a number of first line segments 104 and the corresponding target graphic 201 line segments, and obtain the second average value of the edge placement error between a number of second line segments 105 and the corresponding target graphic 201 line segments;

[0076] Step S604: Obtain the first offset Y in the second direction Y based on the first average value and the second average value. shift The first offset Y shift It is the average of the differences between the first average and the second average;

[0077] Step S605: Obtain the third average value of the edge placement error between several third line segments 106 and the corresponding target graphic 201 line segments, and obtain the fourth average value of the edge placement error between several fourth line segments 107 and the corresponding target graphic 201 line segments;

[0078] Step S606: Obtain the second offset in the first direction X based on the third average value and the fourth average value. shift The second offset X shift It is the average of the differences between the third and fourth averages.

[0079] In this embodiment, the absolute value of the coordinate of the first line segment 104 in the second direction Y is greater than the absolute value of the coordinate of the second line segment 105 in the second direction Y; the absolute value of the coordinate of the third line segment 106 in the first direction X is greater than the absolute value of the coordinate of the fourth line segment 107 in the first direction X.

[0080] First offset Wherein, EPEtop is the edge placement error between the first line segment 104 and the corresponding target graphic 201 line segment, and EPEbottom is the edge placement error between the second line segment 105 and the corresponding target graphic 201 line segment.

[0081] Second offset Wherein, EPEright is the edge placement error between the third line segment 106 and the corresponding target graphic 201 line segment, and EPEleft is the edge placement error between the fourth line segment 107 and the corresponding target graphic 201 line segment.

[0082] Please continue to refer to this. Figure 1 Execute step S70: Based on the first offset Y shift Second offset X shift Perform a second alignment on the second contour pattern 103.

[0083] According to the first offset Y shift Second offset X shiftThe method for performing a second alignment of the second contour pattern 103 includes: based on the first offset Y shift The second contour pattern 103 is moved by a first offset amount Y in the second direction Y. shift The distance; based on the second offset X shift The second contour pattern 103 is moved by a second offset X in the first direction X. shift The distance.

[0084] At this point, the second contour pattern 103 and the target pattern 201 are precisely aligned.

[0085] Please continue to refer to this. Figure 1 Step S80: After the second alignment is performed, the second contour pattern 103 is measured according to the target pattern 201.

[0086] The method for measuring the second contour graphic 103 based on the target graphic 201 includes: using the target graphic 201 as a reference, measuring the edge placement error (EPE), spacing (space), critical dimension (CD), width, length, and surrounding environmental information of the second contour graphic 103 according to preset measurement rules, and acquiring measurement data. This method can simultaneously meet multiple measurement requirements.

[0087] When measuring the edge placement error (EPE) of the second contour graphic 103, the target graphic 201 is used as a reference. Since the contour of the second contour graphic 103 is clearly extracted and the second contour graphic 103 is precisely aligned with the target graphic 201, the result of the reference is more accurate, and the measured edge placement error (EPE) is more precise, thus meeting the testing requirements.

[0088] 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. An automatic measurement method, characterized in that, include: Acquire an image to be measured, wherein the image to be measured contains a graphic to be measured; The first contour is extracted from the graphic to be measured to obtain the first contour graphic; A target map is provided, wherein the target map contains several target graphics; Based on the coordinates of the image to be measured, the first contour graphic is aligned with the target map, and the target graphic corresponds to the first contour graphic; The second contour extraction of the image to be measured to obtain the second contour image includes: obtaining the correspondence between the image to be measured and the target image based on the correspondence between the target image and the first contour image; performing image enhancement processing on the image to be measured; and performing the second contour extraction of the image to be measured based on the image intensity distribution to obtain the second contour image, wherein the second contour image corresponds to the target image. Obtain the first offset and the second offset between the target graphic and the second contour graphic; The second contour graphic is aligned a second time based on the first offset and the second offset. After the second alignment is performed, the second contour pattern is measured according to the target pattern.

2. The automatic measurement method as described in claim 1, characterized in that, The method for extracting the first contour of the graphic to be measured and obtaining the first contour graphic includes: obtaining the first contour graphic based on the grayscale of the graphic edge within the graphic to be measured.

3. The automatic measurement method as described in claim 1, characterized in that, The method for aligning the first contour graphic with the target map based on the coordinates of the image to be measured includes: obtaining the first coordinates of the image to be measured; obtaining the second coordinates within the target map corresponding to the first coordinates; obtaining a comparison region within the target map with the second coordinates as the center and according to a preset radius; obtaining a first proportion of the area occupied by the first contour graphic in the image to be measured; obtaining the size of the image to be measured; obtaining a test region within the comparison region that is the same size as the image to be measured; moving the test region within the comparison region according to a preset rule; obtaining a second proportion of the area of ​​the test region occupied by the target graphic within the test region; if the ratio of the second proportion to the first proportion is greater than a preset value, then marking the first contour graphic as aligned with the target graphic within the test region.

4. The automatic measurement method as described in claim 3, characterized in that, If the ratio of the second ratio to the first ratio is less than a preset value, then the acquisition of the image to be measured and the extraction of the first contour are checked.

5. The automatic measurement method as described in claim 1, characterized in that, The method for extracting a second contour of the image to be measured based on the image intensity distribution includes: acquiring the intensity distribution of the image to be measured and performing a certain smoothing process on the intensity distribution of the image to be measured; acquiring a maximum threshold value and a minimum threshold value based on the intensity distribution of the image to be measured, wherein the maximum threshold value is the maximum intensity value and the minimum threshold value is the minimum intensity value; setting a contour extraction threshold; acquiring the blurred edge of the image to be measured based on the maximum threshold value, the minimum threshold value and the contour extraction threshold; and simulating filling the blurred edge of the image to be measured based on the edge of the target image corresponding to the image to be measured to obtain a second contour image.

6. The automatic measurement method as described in claim 1, characterized in that, The method for obtaining the first offset and the second offset between the target graphic and the second contour graphic includes: obtaining a first axis of symmetry of the second contour graphic parallel to a first direction, obtaining a second axis of symmetry of the second contour graphic parallel to a second direction, wherein the first direction and the second direction are perpendicular; dividing the second contour graphic into first type line segments and second type line segments, wherein the first type line segments are parallel to the first direction, and the second type line segments are parallel to the second direction, the first type line segments include a plurality of first line segments and a plurality of second line segments, the first line segments and the second line segments are symmetrical about the first axis of symmetry, and the second type line segments include a plurality of third line segments and a plurality of fourth line segments, the third line segments and the fourth line segments are symmetrical about the second axis of symmetry; obtaining... A first average value of the edge placement error between several first line segments and corresponding target graphic line segments is obtained; a second average value of the edge placement error between several second line segments and corresponding target graphic line segments is obtained; a first offset in a second direction is obtained based on the first and second average values, wherein the first offset is the average difference between the first and second average values; a third average value of the edge placement error between several third line segments and corresponding target graphic line segments is obtained; a fourth average value of the edge placement error between several fourth line segments and corresponding target graphic line segments is obtained; a second offset in a first direction is obtained based on the third and fourth average values, wherein the second offset is the average difference between the third and fourth average values.

7. The automatic measurement method as described in claim 6, characterized in that, The method for second alignment of the second contour pattern according to the first offset and the second offset includes: moving the second contour pattern by a first offset distance in a second direction according to the first offset; and moving the second contour pattern by a second offset distance in a first direction according to the second offset.

8. The automatic measurement method as described in claim 1, characterized in that, The method for measuring the second contour graphic based on the target graphic includes: taking the target graphic as a reference, measuring the edge placement error, spacing, width, and length of the second contour graphic according to preset measurement rules, and obtaining measurement data.

9. The automatic measurement method as described in claim 1, characterized in that, The pattern to be measured includes a photoresist pattern or an etched pattern.

10. The automatic measurement method as described in claim 9, characterized in that, When the pattern to be measured is a photoresist pattern, the target pattern is a simulated exposure pattern; when the pattern to be measured is an etched pattern, the target pattern is a design pattern.

11. The automatic measurement method as described in claim 1, characterized in that, The image to be measured is an image obtained from a scanning electron microscope.

Images