Model and establishment method and system thereof, compensation method, equipment and storage medium

Abstract

The invention discloses a model, an establishment method and system thereof, a compensation method, equipment and a storage medium, and the establishment method comprises the steps: providing a measurement structure which comprises a plurality of measurement patterns, and the measurement patterns are etched patterns; selecting a sampling position of the measurement structure, wherein a part of measurement patterns of the sampling position represent feature information of the measurement structure; acquiring a plurality of sampling images of the sampling position; obtaining a graph contour of a measurement graph corresponding to the sampling position according to the plurality of sampling images; acquiring a plurality of measurement positions on the graph contour; obtaining an etching deviation value of the measurement position according to the graph contour; and establishing an etching deviation compensation model according to the etching deviation value of the measurement position. The precision of the etching deviation compensation model is improved.

Description

Technical Field

[0001] Embodiments of the present invention relate to the field of semiconductor manufacturing, and in particular to a model and a method and system for establishing the model, a compensation method, a device, and a storage medium. Background Art

[0002] The accuracy and efficiency of traditional rule-based etch bias compensation methods have been challenged because the etch bias table cannot cover various complex design configurations. The variable etch bias (VEB) model is a promising automatic method that can perform etch bias compensation more accurately. However, it is no longer the first choice due to its poor accuracy, large data requirements and high measurement time cost. Summary of the invention

[0003] The problem solved by the embodiments of the present invention is to provide an etching deviation compensation model and a method and system for establishing the same, a compensation method, a device and a storage medium, so as to improve the accuracy of the etching deviation compensation model.

[0004] To solve the above problems, an embodiment of the present invention provides a method for establishing an etching deviation compensation model, including: providing a measurement structure, including multiple measurement graphics, where the measurement graphics are graphics after etching; selecting a sampling position of the measurement structure, and a part of the measurement graphics at the sampling position represents characteristic information of the measurement structure; obtaining multiple sampling images of the sampling position; obtaining a graphic contour of the measurement graphics corresponding to the sampling position according to the multiple sampling images; obtaining multiple measurement positions on the graphic contour; obtaining an etching deviation value of the measurement position according to the graphic contour; and establishing an etching deviation compensation model according to the etching deviation value of the measurement position.

[0005] Optionally, selecting sampling positions of the measurement structure includes: obtaining multiple initial sampling positions of the measurement structure, the measurement graphics of the multiple initial sampling positions are different; obtaining graphic feature information of the measurement graphics of the initial sampling positions; selecting some of the initial sampling positions as sampling positions, the sum of the graphic feature information of some of the initial sampling positions covering the feature information of the measurement structure.

[0006] Optionally, obtaining graphic feature information of the measurement figure of the initial sampling position includes: obtaining an initial sampling image of the initial sampling position; setting multiple initial measurement positions on the measurement figure of the initial sampling image; obtaining graphic feature values ​​of the multiple initial measurement positions; obtaining the distribution of graphic feature information corresponding to each initial sampling image based on the multiple graphic feature values; selecting some of the initial sampling positions as sampling positions, and selecting, based on the distribution of feature information of the initial sampling images, the initial sampling positions corresponding to multiple initial sampling images whose collection of feature information distribution covers the feature information of the measurement structure as sampling positions.

[0007] Optionally, obtaining the graphic feature value of the initial measurement position includes: setting model feature parameters according to feature information of the measured structure; obtaining a simulated exposure graphic corresponding to the measured graphic; and obtaining the value of the model feature parameter at the initial measurement position as the graphic feature value according to the simulated exposure graphic.

[0008] Optionally, in obtaining a simulated exposure pattern corresponding to the measurement pattern, a simulated exposure pattern corresponding to the measurement pattern is obtained in an initial sampling image according to an initial measurement position.

[0009] Optionally, based on multiple graphic feature values, the distribution of graphic feature information corresponding to each initial sampling image is obtained, including: establishing a corresponding coordinate system space based on the model feature parameters, the coordinate axes of the coordinate system space corresponding to the model feature parameters one-to-one; using the values ​​of the model feature parameters at the initial measurement positions as the coordinates of the corresponding coordinate axes, setting multiple initial measurement positions in the coordinate system space, and obtaining spatial points corresponding to the initial measurement positions one-to-one; dividing the coordinate system space of each initial sampling image into multiple class areas based on the distribution of spatial points of each initial sampling image, and obtaining the distribution of spatial points in the multiple class areas as the distribution of graphic feature information.

[0010] Optionally, a K-means clustering method is used to divide the coordinate system space of each initial sampling image into a plurality of class areas according to the spatial point distribution of each initial sampling image.

[0011] Optionally, based on the distribution of characteristic information of the initial sampling images, initial sampling positions corresponding to multiple initial sampling images whose collection of characteristic information distribution covers the characteristic information of the measured structure are selected as sampling positions, including: obtaining the number of class areas covered by the spatial point distribution of each initial sampling image; and based on the number of class areas corresponding to the initial sampling images, selecting initial sampling positions corresponding to multiple initial sampling images in descending order as sampling positions, wherein the collection distribution of spatial points in the multiple initial sampling images covers all class areas.

[0012] Optionally, obtaining a graphic contour of a measurement graphic corresponding to a sampling position based on multiple sampling images includes: determining the corresponding position of the measurement graphic in the sampling image; obtaining the sampling contours of the measurement graphic at the corresponding position in the multiple sampling images; and obtaining the graphic contour of the measurement graphic at the sampling position corresponding to the sampling image based on the sampling contours of the multiple sampling images.

[0013] Optionally, determining the corresponding position of the measurement figure in the sampled image includes: acquiring a target figure corresponding to the measurement figure in the sampled image; and acquiring the corresponding position of the measurement figure in the sampled image in combination with the position of the target figure.

[0014] Optionally, sampling contours of the measurement figures at corresponding positions in multiple sampling images are obtained, including: obtaining an initial sampling contour of the measurement figure in multiple sampling images; obtaining the size of the initial sampling contour; obtaining the actual size of the measurement figure; calibrating the size of the initial sampling contour based on the actual size of the measurement figure, and using the calibrated initial sampling contour as the sampling contour.

[0015] Optionally, based on the sampling contours of multiple sampling images, a graphic contour of a measurement graphic at a sampling position corresponding to the sampling image is obtained, including: obtaining an average contour of the sampling contours of multiple sampling images as an initial graphic contour; and smoothing the initial graphic contour to obtain the graphic contour.

[0016] Optionally, obtaining a plurality of measurement positions on the graphic contour includes: filtering a plurality of initial measurement positions, removing initial measurement positions with the same surrounding environment, and retaining the remaining initial measurement positions as measurement positions.

[0017] Optionally, multiple initial measurement positions are filtered, including: gathering the spatial points corresponding to the initial measurement positions in multiple sampling images in the same coordinate system space; obtaining the spacing between the spatial points in the coordinate system space; when the spacing is less than or equal to the spacing threshold, removing any one of the corresponding two spatial points and retaining the remaining spatial point; otherwise, retaining the corresponding spatial point.

[0018] Optionally, obtaining an etching deviation value at the measurement position according to the graphic contour includes: obtaining a simulated exposure graphic corresponding to the measurement graphic; and obtaining a size difference between the graphic contour and the simulated exposure graphic at the measurement position as the etching deviation value.

[0019] Optionally, an etching deviation compensation model is established according to the etching deviation value at the measurement position, including: obtaining a graphic characteristic value at the measurement position; and obtaining an etching deviation compensation model by combining the etching deviation compensation value at the measurement position and the graphic characteristic value.

[0020] Optionally, the etching deviation compensation value and the graphic characteristic value at the measurement position are combined to obtain an etching deviation compensation model, including: performing function fitting on the etching deviation compensation value and the graphic characteristic value at the measurement position to obtain coefficients corresponding to the graphic characteristic value, and the coefficients and the graphic characteristic value constitute the etching deviation compensation model.

[0021] Correspondingly, an embodiment of the present invention also provides a system for establishing an etching deviation compensation model, including: a measurement structure providing module, used to provide a measurement structure, including multiple measurement graphics, where the measurement graphics are graphics after etching; a sampling position selecting module, used to select a sampling position of the measurement structure, and a partial measurement graphic at the sampling position represents characteristic information of the measurement structure; a sampling image acquiring module, used to acquire multiple sampling images of the sampling position; a graphic contour acquiring module, used to obtain a graphic contour of the measurement graphic corresponding to the sampling position according to the multiple sampling images; a measurement position acquiring module, used to acquire multiple measurement positions on the graphic contour; an etching deviation value acquiring module, used to obtain the etching deviation value of the measurement position according to the graphic contour; and an etching deviation compensation model establishing module, used to establish an etching deviation compensation model according to the etching deviation value of the measurement position.

[0022] Correspondingly, an embodiment of the present invention further provides an etching deviation compensation model, including an etching deviation compensation model obtained by using the method for establishing an etching deviation compensation model provided by an embodiment of the present invention.

[0023] Correspondingly, an embodiment of the present invention further provides an etching deviation compensation method, including an etching deviation compensation method based on an etching deviation compensation model established by the method for establishing an etching deviation compensation model provided by the embodiment of the present invention.

[0024] Correspondingly, an embodiment of the present invention also provides a device, including at least one memory and at least one processor, the memory stores one or more computer instructions, wherein the one or more computer instructions are executed by the processor to implement the etching deviation compensation method provided by the embodiment of the present invention.

[0025] Correspondingly, an embodiment of the present invention further provides a storage medium, wherein the storage medium stores one or more computer instructions, and the one or more computer instructions are used to implement the etching deviation compensation method provided by the embodiment of the present invention.

[0026] Compared with the prior art, the technical solution of the embodiment of the present invention has the following advantages:

[0027] In the method for establishing an etching deviation compensation model provided by an embodiment of the present invention, a sampling position of a measurement structure is selected, a partial measurement graphic at the sampling position represents characteristic information of the measurement structure, a plurality of sampling images of the sampling position are obtained, a graphic contour of the measurement graphic corresponding to the sampling position is obtained according to the plurality of sampling images, a plurality of measurement positions are obtained on the graphic contour, an etching deviation value of the measurement position is obtained according to the graphic contour, and an etching deviation compensation model is established according to the etching deviation value of the measurement position; in the embodiment of the present invention, a partial measurement graphic that can represent the characteristic information of the measurement structure is selected for establishing an etching deviation compensation model, which is beneficial to reducing computing power, improving model establishment efficiency, and saving computing costs; and then obtaining the graphic contour of the corresponding measurement graphic through a plurality of sampling images is beneficial to improving computing accuracy, thereby improving the accuracy of the etching deviation compensation model. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a flow chart of an embodiment of a method for establishing an etching deviation compensation model of the present invention;

[0029] Figures 2 to 7 It is a schematic diagram corresponding to each step in an embodiment of a method for establishing an etching deviation compensation model of the present invention;

[0030] Figure 8 It is a functional block diagram of an embodiment of a system for establishing an etching deviation compensation model of the present invention;

[0031] Fig. 9 It is a hardware structure diagram of an embodiment of the device provided by the present invention. DETAILED DESCRIPTION

[0032] As can be seen from the background technology, at present, when establishing an etching deviation compensation model, wafer data is usually collected by automatic measurement using a scanning electron microscope (CD-scanning electron microscope, CD-SEM) for feature size measurement. However, CD-SEM automated measurement still has disadvantages such as low data acquisition efficiency and inaccurate pattern position capture. Moreover, CD-SEM can only perform limited measurements from one image, while two different images may have the same environmental information, which leads to high time and resource costs, and once the pattern position capture error, the situation will become more serious.

[0033] The rule-based etching deviation compensation method manually analyzes and compares the collected data, and finally compiles an etching deviation table to achieve separate compensation for different types of patterns and structures. This manual operation process has limited accuracy and complexity, so it is difficult to obtain satisfactory compensation results, especially when the design is gradually reduced in the future.

[0034] The other is a model-based etching bias compensation method. It is usually necessary to define appropriate model feature parameters to capture the load effect of etching bias, and the requirements for data coverage are stricter than those of rule-based etching bias compensation methods. Therefore, the variable etching bias (VEB) model requires a large amount of data, resulting in a lot of measurement time. However, CD-SEM measurement has limitations in efficiency and accuracy, which limits the application of VEB model in actual production.

[0035] In order to solve the technical problem, an embodiment of the present invention provides a method for establishing an etching deviation compensation model. Figure 1 , showing a flow chart of an embodiment of a method for establishing an etching deviation compensation model of the present invention.

[0036] In this embodiment, the method for establishing the etching deviation compensation model includes the following basic steps:

[0037] Step S1: providing a measurement structure, including a plurality of measurement patterns, where the measurement patterns are etched patterns;

[0038] Step S2: Selecting a sampling position of the measurement structure, wherein a partial measurement graph of the sampling position represents characteristic information of the measurement structure;

[0039] Step S3: Acquire multiple sampling images of the sampling positions;

[0040] Step S4: obtaining a graphic outline of a measurement graphic corresponding to a sampling position according to a plurality of sampling images;

[0041] Step S5: obtaining a plurality of measurement positions on the graphic contour;

[0042] Step S6: obtaining an etching deviation value at a measurement position according to the graphic profile;

[0043] Step S7: establishing an etching deviation compensation model according to the etching deviation value at the measurement position.

[0044] In the method for establishing an etching deviation compensation model provided by an embodiment of the present invention, part of the measurement graphics that can characterize the characteristic information of the measured structure is selected to establish the etching deviation compensation model, which is beneficial to reducing computing power, improving model establishment efficiency, and saving computing costs. Then, the graphic contour of the corresponding measurement graphics is obtained through multiple sampling images, which is beneficial to improving the computing accuracy, thereby improving the accuracy of the etching deviation compensation model.

[0045] In order to make the above-mentioned purposes, features and advantages of the embodiments of the present invention more obvious and understandable, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0046] Figures 2 to 7 It is a schematic diagram corresponding to each step in an embodiment of a method for establishing an etching deviation compensation model of the present invention.

[0047] refer to Figure 2 , executing step S1: providing a measurement structure 100, including a plurality of measurement patterns 110, where the measurement patterns 110 are etched patterns.

[0048] In the semiconductor manufacturing process, the pattern on the mask pattern forms a corresponding structure on the wafer after an etching process. The measurement structure 100 is a structural layer transferred from the mask pattern layer to the wafer through an etching process, wherein the measurement pattern 110 is a graphic structure transferred from the target pattern in the mask pattern layer to the wafer through an etching process.

[0049] Specifically, in this embodiment, the measurement pattern 110 is used to subsequently obtain the etching deviation value.

[0050] Execute step S2: select a sampling position of the measurement structure 100 , and a partial measurement graph 110 at the sampling position represents characteristic information of the measurement structure 100 .

[0051] The characteristic information refers to information of graphic characteristics of the measurement structure 100, such as length, width, spacing, etc.

[0052] The sampling position is the position of a partial measurement graphic 110 selected from the measurement structure 100 that can characterize the characteristic information of the measurement structure 100 as a whole. Subsequently, an etching deviation compensation model is established through the measurement graphic 110 at the selected sampling position. There is no need to perform a comprehensive calculation on the entire measurement structure 100, and the characteristic information of the entire measurement structure 100 can be represented by the selected sampling position, so that the calculation is accurate and efficient.

[0053] In this embodiment, a portion of the measurement pattern 110 that can represent the characteristic information of the measurement structure 100 is selected to establish an etching deviation compensation model, which is beneficial to reducing computing power, improving model building efficiency, and saving computing costs.

[0054] In this embodiment, selecting the sampling position of the measurement structure 100 includes: acquiring a plurality of initial sampling positions of the measurement structure 100 , wherein the measurement patterns 110 of the plurality of initial sampling positions are different.

[0055] The initial sampling positions almost completely cover the measurement structure 100 , so that an appropriate number of parts are selected from the initial sampling positions as sampling positions.

[0056] In this embodiment, the graphic feature information of the measurement graphic 110 at the initial sampling position is obtained.

[0057] The graphic feature information refers to information about the graphic features of the measurement graphic 110 , such as length, width, spacing, etc. The graphic feature information of the measurement graphic 110 in the measurement structure 100 can represent the feature information of the measurement structure 100 .

[0058] The graphic feature information of the measurement graphic 110 at the initial sampling position is obtained to find the measurement graphic 110 corresponding to the graphic feature information that can characterize the feature information of the measurement structure 100 .

[0059] In this embodiment, obtaining the graphic feature information of the measurement graphic 110 at the initial sampling position includes: obtaining an initial sampling image at the initial sampling position.

[0060] An initial sampling image of the initial sampling position is obtained, so as to obtain graphic feature information corresponding to the measurement graphic 110 of the initial sampling position according to the initial sampling image.

[0061] In this embodiment, a plurality of initial measurement positions (such as Figure 2 (indicated by the double-headed arrows in the figure).

[0062] The initial measurement position is a position where specific measurements are subsequently performed, for example, a specific position for obtaining a graphic size, obtaining a graphic characteristic value, or obtaining an etching deviation value.

[0063] Specifically, in this embodiment, the specific position of the initial measurement position is represented by coordinates (x, y).

[0064] In this embodiment, graphic characteristic values ​​at a plurality of initial measurement positions are obtained.

[0065] The graphic feature value refers to the specific numerical value of the above-mentioned graphic feature, such as the length dimension value, the width dimension value, the spacing value, etc.

[0066] The graphic feature values ​​of multiple initial measurement positions are obtained for subsequently obtaining the distribution of graphic feature information corresponding to the initial sampling image.

[0067] In this embodiment, obtaining the graphic feature value of the initial measurement position includes: setting the model feature parameters according to the feature information of the measurement structure 100 .

[0068] Among them, the model characteristic parameters are characteristic information of the measurement structure 100 that is highly correlated with the establishment of the etching deviation compensation model, such as length dimension, width dimension, spacing, etc. In practical applications, appropriate model characteristic parameters are selected according to the actual situation of the current layer, such as density parameters containing short-range environmental information, interlayer parameters containing previous layer density information, etc.

[0069] According to the characteristic information of the measurement structure 100 , the model characteristic parameters are set for subsequent construction of the coordinate system space.

[0070] In this embodiment, a simulated exposure pattern corresponding to the measurement pattern 110 is obtained.

[0071] The simulated exposure pattern refers to a pattern in which the measurement pattern 110 simulates exposure in the photoresist.

[0072] The simulated exposure pattern corresponding to the measured pattern 110 is obtained to obtain the value of the model characteristic parameter, and the etching deviation value is subsequently obtained through the difference between the measured pattern 110 and the simulated exposure pattern.

[0073] In this embodiment, according to the simulated exposure pattern, the value of the model characteristic parameter at the initial measurement position is obtained as the pattern characteristic value.

[0074] Specifically, in this embodiment, one initial measurement position corresponds to values ​​of multiple model characteristic parameters.

[0075] In this embodiment, in acquiring the simulated exposure pattern corresponding to the measurement pattern 110 , the simulated exposure pattern corresponding to the measurement pattern 110 is obtained in the initial sampling image according to the initial measurement position.

[0076] Specifically, in this embodiment, the simulated exposure pattern corresponding to the measurement pattern 110 is obtained according to the specific coordinates of the initial measurement position.

[0077] In this embodiment, the distribution of graphic feature information corresponding to each initial sampling image is obtained according to a plurality of graphic feature values.

[0078] The distribution of graphic feature information corresponding to each initial sampling image is obtained. Then, through the distribution of graphic features of each initial sampling image, it is possible to find out whether the collection of graphic feature information distributions of multiple initial sampling images covers the feature information of the measurement structure 100.

[0079] refer to Figure 3 In this embodiment, the distribution of graphic feature information corresponding to each initial sampling image is obtained based on multiple graphic feature values, including: establishing a corresponding coordinate system space based on the model feature parameters, and the coordinate axes of the coordinate system space correspond one-to-one to the model feature parameters.

[0080] A corresponding coordinate system space is established according to the model feature parameters to obtain the distribution of graphic feature information in the coordinate system space.

[0081] Specifically, as an example, Figure 3 As shown, this embodiment sets three model characteristic parameters: model characteristic parameter A, model characteristic parameter B and model characteristic parameter C, forming a three-dimensional coordinate system space.

[0082] In this embodiment, the values ​​of the model characteristic parameters at the initial measurement positions are used as the coordinates of the corresponding coordinate axes, and multiple initial measurement positions are set in the coordinate system space to obtain space points corresponding to the initial measurement positions one by one.

[0083] Specifically, as an example, Figure 3 As shown, the values ​​of the model characteristic parameters at the initial measurement positions are the coordinates of the corresponding coordinate axes, that is, the coordinates (A, B, C) corresponding to each initial measurement position, and ABC are the values ​​of the model characteristic parameter A, model characteristic parameter B and model characteristic parameter C corresponding to the initial measurement position respectively.

[0084] refer to Figure 4 In this embodiment, according to the spatial point distribution of each initial sampling image, the coordinate system space of each initial sampling image is divided into multiple class areas, and the distribution of spatial points in multiple class areas is obtained as the distribution of graphic feature information.

[0085] In this embodiment, the coordinate system space of each initial sampling image is divided into a plurality of class areas according to the spatial point distribution of each initial sampling image using the K-means clustering method.

[0086] Specifically, the steps of using K-means clustering method are as follows:

[0087] The first step is to determine a k value and divide the coordinate space of each initial sampled image into K class areas.

[0088] As an example, Figure 4 As shown in A, the k value in this embodiment is 3.

[0089] In the second step, k data points are randomly selected from the spatial points as centroids.

[0090] As an example, Figure 4 As shown in A, three data points c1, c2 and c3 are randomly selected from the space points as the centroid.

[0091] The third step is to calculate the distance (such as Euclidean distance) between each spatial point in the coordinate system space and each center of mass. The point that is closest to the center of mass is classified into the set to which the corresponding center of mass belongs.

[0092] As an example, Figure 4 As shown in B, the spatial points of the set corresponding to the centroid are connected by straight lines.

[0093] The fourth step is to group all the spatial points into sets, there are k sets in total, and then recalculate the centroid of each set.

[0094] As an example, Figure 4 As shown in C, the positions of the centroids c1, c2 and c3 are recalculated based on the spatial points of each set.

[0095] In the fifth step, if the distance between the newly calculated centroid and the original centroid is less than or equal to the set threshold (indicating that the position of the recalculated centroid has not changed much and tends to be stable, or converged), it can be considered that the clustering has achieved the desired result and the algorithm terminates.

[0096] As an example, Figure 4 As shown in D, the spatial points are distributed in the divided class areas, and the spatial division of the coordinate system of each initial sampling image is obtained.

[0097] It should be noted that if the distance between the newly calculated centroid and the original centroid changes greatly (ie, is greater than the set threshold), the steps from the third step to the fifth step need to be iterated cyclically.

[0098] In this embodiment, some initial sampling positions are selected as sampling positions, and the sum of the graphic feature information of some initial sampling positions covers the feature information of the measurement structure 100 .

[0099] If the sum of the graphic feature information of some initial sampling positions covers the feature information of the measurement structure 100 , the measurement graphic 110 of the part of initial sampling positions can represent the feature information of the measurement structure 100 , and thus the part of initial sampling positions is selected as the adopted positions.

[0100] In this embodiment, some initial sampling positions are selected as sampling positions, and according to the distribution of characteristic information of the initial sampling images, initial sampling positions corresponding to multiple initial sampling images whose collection of characteristic information distribution covers characteristic information of the measurement structure 100 are selected as sampling positions.

[0101] An initial sampling position corresponding to a plurality of initial sampling images whose collection of characteristic information distribution covers characteristic information of the measurement structure 100 is selected as the sampling position, and the measurement graph 110 of the selected sampling position can represent the characteristic information of the measurement structure 100 .

[0102] In this embodiment, according to the distribution of characteristic information of the initial sampling image, the initial sampling positions corresponding to multiple initial sampling images whose collection of characteristic information distribution covers the characteristic information of the measurement structure 100 are selected as the sampling positions, including: obtaining the number of class areas covered by the spatial point distribution of each initial sampling image.

[0103] It should be noted that the coordinate system space of each initial sampling image is divided into k class areas, but ultimately each spatial point may be distributed in all class areas or in some class areas.

[0104] By obtaining the number of class areas covered by the spatial point distribution of each initial sampling image, the characteristic information of the measurement structure 100 that can be represented by each initial sampling image can be obtained based on the coverage of multiple class areas by the spatial points of each initial sampling image. Specifically, the more class areas covered by the spatial point distribution of the initial sampling image, the more characteristic information of the measurement structure 100 that can be represented by the initial sampling image.

[0105] In this embodiment, according to the number of class areas corresponding to the initial sampling images, initial sampling positions corresponding to multiple initial sampling images are selected in order from large to small as sampling positions, wherein the collection distribution of spatial points in the multiple initial sampling images covers all class areas.

[0106] According to the number of class areas corresponding to the initial sampling image, initial sampling positions corresponding to multiple initial sampling images are selected in sequence from large to small as sampling positions. That is to say, according to the amount of characteristic information of the measured structure 100 represented, initial sampling positions corresponding to multiple initial sampling images are selected in sequence from large to small as sampling positions.

[0107] It should be noted that in practical applications, a corresponding number of initial sampling graphics are selected according to actual needs and computing power.

[0108] Execute step S3: obtain multiple sampling images of the sampling positions.

[0109] A plurality of sampling images of the sampling positions are obtained to obtain the graphic contour of the measurement graphic 110 of the sampling positions.

[0110] Specifically, a plurality of sampling images are acquired for each sampling position.

[0111] In this embodiment, CD-SEM is used to obtain multiple sampling images of the sampling positions.

[0112] refer to Figure 5 , executing step S4: obtaining the graphic contour of the measurement graphic 110 corresponding to the sampling position according to the multiple sampling images.

[0113] The graphic profile is used to obtain the etching deviation value later.

[0114] In this embodiment, the graphic contour of the corresponding measurement graphic 110 is obtained through a plurality of sampling images, which is beneficial to improving the calculation accuracy, thereby improving the accuracy of the etching deviation compensation model.

[0115] In this embodiment, obtaining the graphic outline of the measurement graphic 110 corresponding to the sampling position according to the plurality of sampling images includes: determining the corresponding position of the measurement graphic 110 in the sampling image.

[0116] Determining the corresponding position of the measurement figure 110 in the sampled image is helpful to improve the accuracy of obtaining the figure contour.

[0117] In this embodiment, determining the corresponding position of the measurement graphic 110 in the sample image includes: acquiring a target graphic corresponding to the measurement graphic 110 in the sample image.

[0118] The target pattern corresponding to the measurement pattern 110 is used to calibrate the position of the measurement pattern 110 .

[0119] Specifically, in this embodiment, the corresponding position of the measurement figure 110 in the sample image is obtained in combination with the position of the target figure.

[0120] In this embodiment, sampling contours of the measurement graphics 110 at corresponding positions in a plurality of sampling images are obtained.

[0121] The sampling contours of the measurement graphics 110 at corresponding positions in the plurality of sampling images are obtained, so as to obtain the graphic contours of the measurement graphics 110 at the sampling positions corresponding to the sampling images.

[0122] As an example, Figure 5 (a) shows a plurality of sampling profiles corresponding to the acquired measurement pattern 110 .

[0123] In this embodiment, the sampling contours of the measurement figure 110 at corresponding positions in multiple sampling images are obtained, including: obtaining an initial sampling contour of the measurement figure 110 in the multiple sampling images; obtaining the size of the initial sampling contour; obtaining the actual size of the measurement figure 110; calibrating the size of the initial sampling contour based on the actual size of the measurement figure 110, and using the calibrated initial sampling contour as the sampling contour.

[0124] Due to image deviation, the initial sampling contour obtained from the sampling image may deviate from the actual size of the measurement figure 110 . Therefore, the size of the initial sampling contour is calibrated with the actual size of the measurement figure 110 to obtain a more accurate sampling contour.

[0125] In this embodiment, the actual size of the measurement pattern 110 is used as a reference, and the size of the initial sampling outline is adjusted to be the same as the actual size, so that the calibration of the initial sampling outline is completed and the sampling outline is obtained.

[0126] In this embodiment, CD-SEM is used to obtain the initial sampling profile of the measurement pattern 110 at the corresponding position.

[0127] In this embodiment, CD-SEM is used to obtain the actual size of the measurement pattern 110.

[0128] In this embodiment, according to the sampling contours of the plurality of sampling images, the graphic contours of the measurement graphics 110 at the sampling positions corresponding to the sampling images are obtained.

[0129] For one sampling position, the graphic contour of the measurement graphic 110 of the sampling position corresponding to the sampling image is obtained according to the sampling contours of multiple sampling images, which is beneficial to improving the accuracy of obtaining the graphic contour.

[0130] In this embodiment, obtaining the graphic contour of the measurement graphic 110 at the sampling position corresponding to the sampling image according to the sampling contours of the plurality of sampling images includes: obtaining the average contour of the sampling contours of the plurality of sampling images as the initial graphic contour.

[0131] The average contour of the sampling contours of multiple sampling images is obtained as the initial graphic contour, so that the results of multiple sampling images can be taken into account and the accuracy of the initial graphic contour can be improved.

[0132] In this embodiment, the initial graphic outline is smoothed to obtain the graphic outline.

[0133] The initial graphic contour is smoothed to remove some error mutations in the initial graphic contour and further improve the accuracy of the graphic contour.

[0134] Execute step S5: obtain multiple measurement positions on the graphic contour.

[0135] The measurement position is used as the position for obtaining the etching deviation value.

[0136] In this embodiment, obtaining a plurality of measurement positions on the graphic contour includes: filtering a plurality of initial measurement positions, removing initial measurement positions with the same surrounding environment, and retaining the remaining initial measurement positions as measurement positions.

[0137] For initial measurement positions with the same surrounding environment, there is no need to perform repeated measurements. Therefore, in this embodiment, multiple initial measurement positions are filtered to remove the initial measurement positions with the same surrounding environment, and the remaining initial measurement positions are retained as measurement positions, which is beneficial to improving the computational efficiency of obtaining etching deviation values ​​at the measurement positions.

[0138] In this embodiment, multiple initial measurement positions are filtered, including: gathering the spatial points corresponding to the initial measurement positions in multiple sampling images in the same coordinate system space; obtaining the spacing between the spatial points in the coordinate system space; when the spacing is less than or equal to the spacing threshold, removing any one of the corresponding two spatial points and retaining the remaining spatial points; otherwise, retaining the corresponding spatial points.

[0139] When the spacing between the spatial points in the coordinate system space is small (i.e., less than or equal to the spacing threshold), it indicates that the environments around the initial measurement positions represented by the two spatial points are similar, and thus one of the corresponding two spatial points needs to be removed. When the spacing between the spatial points in the coordinate system space is large (i.e., greater than the spacing threshold), it indicates that the environments around the initial measurement positions represented by the two spatial points are different, and thus the corresponding spatial points need to be retained.

[0140] In this embodiment, a corresponding spacing threshold is set according to actual process requirements.

[0141] As an example, Figure 6 shows the coordinate space before filtering. Figure 7 The coordinate system space after filtering is shown.

[0142] Execute step S6: obtain the etching deviation value of the measurement position according to the graphic contour.

[0143] The etching deviation value at the measurement position is obtained, which is used as the output value for subsequently establishing an etching deviation compensation model.

[0144] In this embodiment, the etching deviation value at the measurement position is obtained according to the pattern contour, including: obtaining the size difference between the pattern contour and the simulated exposure pattern at the measurement position as the etching deviation value.

[0145] The size difference between the pattern outline and the simulated exposure pattern is the deviation of the structure obtained after the actual etching process caused by the etching process. Therefore, the size difference between the pattern outline and the simulated exposure pattern at the measurement position is obtained as the etching deviation value.

[0146] Execute step S7: establish an etching deviation compensation model according to the etching deviation value at the measurement position.

[0147] According to the etching deviation value at the measuring position, the etching deviation compensation model is obtained through continuous iteration.

[0148] In this embodiment, an etching deviation compensation model is established according to the etching deviation value at the measurement position, including: acquiring a graphic feature value at the measurement position.

[0149] The graphic characteristic value of the measurement position is the graphic characteristic value of the initial measurement position selected above. The measurement position is obtained after filtering, and the graphic characteristic value corresponding to the measurement position is obtained accordingly.

[0150] In this embodiment, the etching deviation compensation model is obtained by combining the etching deviation compensation value and the graphic characteristic value at the measurement position.

[0151] The etching deviation compensation value at the measuring position is taken as the output value, and the graphic characteristic value at the measuring position is taken as the input value to establish the etching deviation compensation model.

[0152] In this embodiment, the etching deviation compensation value and the graphic characteristic value at the measurement position are combined to obtain an etching deviation compensation model, including: performing function fitting on the etching deviation compensation value and the graphic characteristic value at the measurement position to obtain coefficients corresponding to the graphic characteristic value, and the coefficients and the graphic characteristic value constitute the etching deviation compensation model.

[0153] Different graphic characteristic values ​​are set as different polynomials, and the etching deviation compensation value and the graphic characteristic value at the measured position are fitted with a function to obtain the coefficient of the polynomial corresponding to each graphic characteristic value. The coefficient is the calculation coefficient of the etching deviation compensation model. After the etching deviation compensation model is established, the graphic characteristic value of the position to be calculated is subsequently input to obtain the corresponding etching deviation compensation value.

[0154] Correspondingly, the present invention also provides a system for establishing an etching deviation compensation model. Figure 8 It is a functional block diagram of an embodiment of a system for establishing an etching deviation compensation model of the present invention.

[0155] In this embodiment, the etching deviation compensation model establishment system 50 includes: a measurement structure providing module 501, which is used to provide a measurement structure, including multiple measurement graphics, and the measurement graphics are graphics after etching; a sampling position selection module 502, which is used to select the sampling position of the measurement structure, and the partial measurement graphics at the sampling position represent the characteristic information of the measurement structure; a sampling image acquisition module 503, which is used to obtain multiple sampling images of the sampling position; a graphic contour acquisition module 504, which is used to obtain the graphic contour of the measurement graphic corresponding to the sampling position according to the multiple sampling images; a measurement position acquisition module 505, which is used to obtain multiple measurement positions on the graphic contour; an etching deviation value acquisition module 506, which is used to obtain the etching deviation value of the measurement position according to the graphic contour; an etching deviation compensation model establishment module 507, which is used to establish the etching deviation compensation model according to the etching deviation value of the measurement position.

[0156] The measurement structure providing module 501 is used to provide a measurement structure, including a plurality of measurement patterns, where the measurement patterns are patterns after etching.

[0157] In the semiconductor manufacturing process, the pattern on the mask plate pattern forms a corresponding structure on the wafer after the etching process. The measurement structure is the structural layer transferred from the mask plate layer to the wafer through the etching process, wherein the measurement pattern is the target pattern in the mask plate layer transferred to the pattern structure on the wafer through the etching process.

[0158] Specifically, in this embodiment, the measurement pattern is used to subsequently obtain the etching deviation value.

[0159] The sampling position selection module 502 is used to select the sampling position of the measurement structure, and the partial measurement graph of the sampling position represents the characteristic information of the measurement structure.

[0160] The characteristic information refers to the information of the graphic characteristics of the measurement structure, such as length, width, spacing, etc.

[0161] The sampling position is the position of a partial measurement figure selected in the measurement structure that can characterize the characteristic information of the measurement structure as a whole. The etching deviation compensation model is subsequently established through the measurement figure of the selected sampling position. There is no need to perform a comprehensive calculation of the entire measurement structure, and the characteristic information of the entire measurement structure can be represented by the selected sampling position, making the calculation accurate and efficient.

[0162] In this embodiment, some measurement graphics that can characterize characteristic information of the measured structure are selected to establish an etching deviation compensation model, which is beneficial to reducing computing power, improving model building efficiency, and saving computing costs.

[0163] In this embodiment, selecting the sampling position of the measurement structure includes: acquiring a plurality of initial sampling positions of the measurement structure, wherein the measurement patterns of the plurality of initial sampling positions are different.

[0164] The initial sampling positions will almost entirely cover the measurement structure, so that an appropriate number of parts are selected from the initial sampling positions as sampling positions.

[0165] In this embodiment, the graphic feature information of the measurement graphic at the initial sampling position is obtained.

[0166] The graphic feature information refers to the information of the graphic features of the measurement graphic, such as length, width, spacing, etc. The graphic feature information of the measurement graphic in the measurement structure can represent the feature information of the measurement structure.

[0167] The graphic feature information of the measurement graphic at the initial sampling position is obtained to find the measurement graphic corresponding to the graphic feature information capable of representing the feature information of the measurement structure.

[0168] In this embodiment, obtaining the graphic feature information of the measurement graphic at the initial sampling position includes: obtaining an initial sampling image at the initial sampling position.

[0169] An initial sampling image of the initial sampling position is obtained, and is used to obtain graphic feature information corresponding to the measurement graphic of the initial sampling position according to the initial sampling image.

[0170] In this embodiment, a plurality of initial measurement positions are set on the measurement graph of the initial sampling image.

[0171] The initial measurement position is a position where specific measurements are subsequently performed, for example, a specific position for obtaining a graphic size, obtaining a graphic characteristic value, or obtaining an etching deviation value.

[0172] Specifically, in this embodiment, the specific position of the initial measurement position is represented by coordinates (x, y).

[0173] In this embodiment, graphic characteristic values ​​at a plurality of initial measurement positions are obtained.

[0174] The graphic feature value refers to the specific numerical value of the above-mentioned graphic feature, such as the length dimension value, the width dimension value, the spacing value, etc.

[0175] The graphic feature values ​​of multiple initial measurement positions are obtained for subsequently obtaining the distribution of graphic feature information corresponding to the initial sampling image.

[0176] In this embodiment, obtaining the graphic feature value of the initial measurement position includes: setting the model feature parameters according to the feature information of the measured structure.

[0177] Among them, the model characteristic parameters are characteristic information in the measured structure that is highly correlated with the establishment of the etching deviation compensation model, such as length dimension, width dimension, spacing, etc. In practical applications, appropriate model characteristic parameters are selected according to the actual situation of the current layer, such as density parameters containing short-range environmental information, interlayer parameters containing previous layer density information, etc.

[0178] According to the characteristic information of the measured structure, the model characteristic parameters are set for the subsequent construction of the coordinate system space.

[0179] In this embodiment, a simulated exposure pattern corresponding to the measurement pattern is obtained.

[0180] The simulated exposure pattern refers to a pattern in the photoresist that is simulated by the measured pattern.

[0181] A simulated exposure pattern corresponding to the measured pattern is obtained to obtain the value of the model characteristic parameter, and subsequently an etching deviation value is obtained by the difference between the measured pattern and the simulated exposure pattern.

[0182] In this embodiment, according to the simulated exposure pattern, the value of the model characteristic parameter at the initial measurement position is obtained as the pattern characteristic value.

[0183] Specifically, in this embodiment, one initial measurement position corresponds to values ​​of multiple model characteristic parameters.

[0184] In this embodiment, in obtaining the simulated exposure pattern corresponding to the measurement pattern, the simulated exposure pattern corresponding to the measurement pattern is obtained in the initial sampling image according to the initial measurement position.

[0185] Specifically, in this embodiment, the simulated exposure pattern corresponding to the measurement pattern is obtained according to the specific coordinates of the initial measurement position.

[0186] In this embodiment, the distribution of graphic feature information corresponding to each initial sampling image is obtained according to a plurality of graphic feature values.

[0187] The distribution of graphic feature information corresponding to each initial sampling image is obtained, and then through the distribution of graphic features of each initial sampling image, it is possible to find out whether the collection of graphic feature information distributions of multiple initial sampling images covers the feature information of the measured structure.

[0188] In this embodiment, the distribution of graphic feature information corresponding to each initial sampling image is obtained according to multiple graphic feature values, including: establishing a corresponding coordinate system space according to the model feature parameters, and the coordinate axes of the coordinate system space correspond to the model feature parameters one by one.

[0189] A corresponding coordinate system space is established according to the model feature parameters to obtain the distribution of graphic feature information in the coordinate system space.

[0190] Specifically, as an example, Figure 3 As shown, this embodiment sets three model characteristic parameters: model characteristic parameter A, model characteristic parameter B and model characteristic parameter C, forming a three-dimensional coordinate system space.

[0191] In this embodiment, the values ​​of the model characteristic parameters at the initial measurement positions are used as the coordinates of the corresponding coordinate axes, and multiple initial measurement positions are set in the coordinate system space to obtain space points corresponding to the initial measurement positions one by one.

[0192] Specifically, as an example, Figure 3 As shown, the values ​​of the model characteristic parameters at the initial measurement positions are the coordinates of the corresponding coordinate axes, that is, the coordinates (A, B, C) corresponding to each initial measurement position, and ABC are the values ​​of the model characteristic parameter A, model characteristic parameter B and model characteristic parameter C corresponding to the initial measurement position respectively.

[0193] In this embodiment, according to the spatial point distribution of each initial sampling image, the coordinate system space of each initial sampling image is divided into multiple class areas, and the distribution of the spatial points in the multiple class areas is obtained as the distribution of the graphic feature information.

[0194] In this embodiment, the coordinate system space of each initial sampling image is divided into a plurality of class areas according to the spatial point distribution of each initial sampling image using the K-means clustering method.

[0195] Specifically, the steps of using K-means clustering method are as follows:

[0196] The first step is to determine a k value and divide the coordinate space of each initial sampled image into K class areas.

[0197] As an example, Figure 4 As shown in A, the k value in this embodiment is 3.

[0198] In the second step, k data points are randomly selected from the spatial points as centroids.

[0199] As an example, Figure 4 As shown in A, three data points c1, c2 and c3 are randomly selected from the space points as the centroid.

[0200] The third step is to calculate the distance (such as Euclidean distance) between each spatial point in the coordinate system space and each center of mass. The point that is closest to the center of mass is classified into the set to which the corresponding center of mass belongs.

[0201] As an example, Figure 4 As shown in B, the spatial points of the set corresponding to the centroid are connected by straight lines.

[0202] The fourth step is to group all the spatial points into sets, there are k sets in total, and then recalculate the centroid of each set.

[0203] As an example, Figure 4 As shown in C, the positions of the centroids c1, c2 and c3 are recalculated based on the spatial points of each set.

[0204] In the fifth step, if the distance between the newly calculated centroid and the original centroid is less than or equal to the set threshold (indicating that the position of the recalculated centroid has not changed much and tends to be stable, or converged), it can be considered that the clustering has achieved the desired result and the algorithm terminates.

[0205] As an example, Figure 4 As shown in D, the spatial points are distributed in the divided class areas, and the spatial division of the coordinate system of each initial sampling image is obtained.

[0206] It should be noted that if the distance between the newly calculated centroid and the original centroid changes greatly (ie, is greater than the set threshold), the steps from the third step to the fifth step need to be iterated cyclically.

[0207] In this embodiment, some initial sampling positions are selected as sampling positions, and the sum of graphic feature information of some initial sampling positions covers the feature information of the measurement structure.

[0208] If the sum of the graphic feature information of some initial sampling positions covers the feature information of the measurement structure, then the measurement graphics of the initial sampling positions of this part can represent the feature information of the measurement structure, so that the initial sampling positions of this part are selected as the adopted positions.

[0209] In this embodiment, some initial sampling positions are selected as sampling positions, and according to the distribution of characteristic information of the initial sampling images, initial sampling positions corresponding to multiple initial sampling images whose collection of characteristic information distribution covers characteristic information of the measured structure are selected as sampling positions.

[0210] An initial sampling position corresponding to a plurality of initial sampling images whose collection of characteristic information distribution covers characteristic information of the measured structure is selected as the sampling position, and the measurement pattern of the selected sampling position can represent the characteristic information of the measured structure.

[0211] In this embodiment, according to the distribution of characteristic information of the initial sampling image, the initial sampling positions corresponding to multiple initial sampling images whose collection of characteristic information distribution covers the characteristic information of the measured structure are selected as the sampling positions, including: obtaining the number of class areas covered by the spatial point distribution of each initial sampling image.

[0212] It should be noted that the coordinate system space of each initial sampling image is divided into k class areas, but ultimately each spatial point may be distributed in all class areas or in some class areas.

[0213] By obtaining the number of class areas covered by the spatial point distribution of each initial sampling image, the characteristic information of the measurement structure that can be represented by each initial sampling image can be obtained based on the coverage of multiple class areas by the spatial points of each initial sampling image. Specifically, the more class areas covered by the spatial point distribution of the initial sampling image, the more characteristic information of the measurement structure that can be represented by the initial sampling image.

[0214] In this embodiment, according to the number of class areas corresponding to the initial sampling images, initial sampling positions corresponding to multiple initial sampling images are selected in order from large to small as sampling positions, wherein the collection distribution of spatial points in the multiple initial sampling images covers all class areas.

[0215] According to the number of class areas corresponding to the initial sampling image, the initial sampling positions corresponding to the multiple initial sampling images are selected in sequence from large to small as the sampling positions. That is to say, according to the amount of characteristic information of the measured structure represented, the initial sampling positions corresponding to the multiple initial sampling images are selected in sequence from large to small as the sampling positions.

[0216] It should be noted that in practical applications, a corresponding number of initial sampling graphics are selected according to actual needs and computing power.

[0217] The sampling image acquisition module 503 is used to acquire multiple sampling images of sampling positions.

[0218] A plurality of sampling images of the sampling positions are obtained to obtain the graphic contour of the measurement graphic of the sampling positions.

[0219] Specifically, a plurality of sampling images are acquired for each sampling position.

[0220] In this embodiment, CD-SEM is used to obtain multiple sampling images of the sampling positions.

[0221] The graphic contour acquisition module 504 is used to obtain the graphic contour of the measurement graphic corresponding to the sampling position according to the multiple sampling images.

[0222] The graphic profile is used to obtain the etching deviation value later.

[0223] In this embodiment, the graphic contour of the corresponding measurement graphic is obtained through multiple sampling images, which is beneficial to improving the calculation accuracy, thereby improving the accuracy of the etching deviation compensation model.

[0224] In this embodiment, obtaining the graphic contour of the measurement graphic corresponding to the sampling position according to the plurality of sampling images includes: determining the corresponding position of the measurement graphic in the sampling image.

[0225] Determining the corresponding position of the measurement figure in the sampled image is beneficial to improving the accuracy of obtaining the figure contour.

[0226] In this embodiment, determining the corresponding position of the measurement figure in the sampled image includes: acquiring a target figure corresponding to the measurement figure in the sampled image.

[0227] The target figure corresponding to the measurement figure is used to calibrate the position of the measurement figure.

[0228] Specifically, in this embodiment, the corresponding position of the measurement figure in the sampled image is acquired in combination with the position of the target figure.

[0229] In this embodiment, sampling contours of the measurement graphics at corresponding positions in a plurality of sampling images are obtained.

[0230] The sampling contours of the measurement graphics at corresponding positions in the multiple sampling images are obtained, so as to obtain the graphic contours of the measurement graphics at the sampling positions corresponding to the sampling images.

[0231] In this embodiment, the sampling contours of the measurement figures in the multiple sampling images at the corresponding positions are obtained, including: obtaining the initial sampling contour of the measurement figures in the multiple sampling images; obtaining the size of the initial sampling contour; obtaining the actual size of the measurement figures; calibrating the size of the initial sampling contour based on the actual size of the measurement figures, and using the calibrated initial sampling contour as the sampling contour.

[0232] Due to image deviation, the initial sampling contour obtained from the sampling image may deviate from the actual size of the measured figure. Therefore, the size of the initial sampling contour is calibrated with the actual size of the measured figure to obtain a more accurate sampling contour.

[0233] In this embodiment, the actual size of the measured figure is used as a reference, the size of the initial sampling outline is adjusted to be the same as the actual size, the calibration of the initial sampling outline is completed, and the sampling outline is obtained.

[0234] In this embodiment, CD-SEM is used to obtain the initial sampling profile of the measurement pattern at the corresponding position.

[0235] In this embodiment, CD-SEM is used to obtain the actual size of the measurement pattern.

[0236] In this embodiment, according to the sampling contours of the plurality of sampling images, the graphic contours of the measurement graphics at the sampling positions corresponding to the sampling images are obtained.

[0237] For one sampling position, according to the sampling contours of a plurality of sampling images, the graphic contour of the measurement graphic of the sampling position corresponding to the sampling image is obtained, which is beneficial to improving the accuracy of obtaining the graphic contour.

[0238] In this embodiment, obtaining the graphic contour of the measurement graphic at the sampling position corresponding to the sampling image according to the sampling contours of the plurality of sampling images includes: obtaining the average contour of the sampling contours of the plurality of sampling images as the initial graphic contour.

[0239] The average contour of the sampling contours of multiple sampling images is obtained as the initial graphic contour, so that the results of multiple sampling images can be taken into account and the accuracy of the initial graphic contour can be improved.

[0240] In this embodiment, the initial graphic outline is smoothed to obtain the graphic outline.

[0241] The initial graphic contour is smoothed to remove some error mutations in the initial graphic contour and further improve the accuracy of the graphic contour.

[0242] The measurement position acquisition module 505 is used to acquire multiple measurement positions on the graphic outline.

[0243] The measurement position is used as the position for obtaining the etching deviation value.

[0244] In this embodiment, obtaining a plurality of measurement positions on the graphic contour includes: filtering a plurality of initial measurement positions, removing initial measurement positions with the same surrounding environment, and retaining the remaining initial measurement positions as measurement positions.

[0245] For initial measurement positions with the same surrounding environment, there is no need to perform repeated measurements. Therefore, in this embodiment, multiple initial measurement positions are filtered to remove the initial measurement positions with the same surrounding environment, and the remaining initial measurement positions are retained as measurement positions, which is beneficial to improving the computational efficiency of obtaining etching deviation values ​​at the measurement positions.

[0246] In this embodiment, multiple initial measurement positions are filtered, including: gathering the spatial points corresponding to the initial measurement positions in multiple sampling images in the same coordinate system space; obtaining the spacing between the spatial points in the coordinate system space; when the spacing is less than or equal to the spacing threshold, removing any one of the corresponding two spatial points and retaining the remaining spatial points; otherwise, retaining the corresponding spatial points.

[0247] When the spacing between the spatial points in the coordinate system space is small (i.e., less than or equal to the spacing threshold), it indicates that the environments around the initial measurement positions represented by the two spatial points are similar, and thus one of the corresponding two spatial points needs to be removed. When the spacing between the spatial points in the coordinate system space is large (i.e., greater than the spacing threshold), it indicates that the environments around the initial measurement positions represented by the two spatial points are different, and thus the corresponding spatial points need to be retained.

[0248] In this embodiment, a corresponding spacing threshold is set according to actual process requirements.

[0249] As an example, Figure 6 shows the coordinate space before filtering. Figure 7 The coordinate system space after filtering is shown.

[0250] The etching deviation value acquisition module 506 is used to acquire the etching deviation value of the measurement position according to the graphic contour.

[0251] The etching deviation value at the measurement position is obtained, which is used as the output value for subsequently establishing an etching deviation compensation model.

[0252] In this embodiment, the etching deviation value at the measurement position is obtained according to the pattern contour, including: obtaining the size difference between the pattern contour and the simulated exposure pattern at the measurement position as the etching deviation value.

[0253] The size difference between the pattern outline and the simulated exposure pattern is the deviation of the structure obtained after the actual etching process caused by the etching process. Therefore, the size difference between the pattern outline and the simulated exposure pattern at the measurement position is obtained as the etching deviation value.

[0254] The etching deviation compensation model establishing module 507 is used to establish an etching deviation compensation model according to the etching deviation value at the measurement position.

[0255] According to the etching deviation value at the measuring position, the etching deviation compensation model is obtained through continuous iteration.

[0256] In this embodiment, an etching deviation compensation model is established according to the etching deviation value at the measurement position, including: acquiring a graphic feature value at the measurement position.

[0257] The graphic characteristic value of the measurement position is the graphic characteristic value of the initial measurement position selected above. The measurement position is obtained after filtering, and the graphic characteristic value corresponding to the measurement position is obtained accordingly.

[0258] In this embodiment, the etching deviation compensation model is obtained by combining the etching deviation compensation value and the graphic characteristic value at the measurement position.

[0259] The etching deviation compensation value at the measuring position is taken as the output value, and the graphic characteristic value at the measuring position is taken as the input value to establish the etching deviation compensation model.

[0260] In this embodiment, the etching deviation compensation value and the graphic characteristic value at the measurement position are combined to obtain an etching deviation compensation model, including: performing function fitting on the etching deviation compensation value and the graphic characteristic value at the measurement position to obtain coefficients corresponding to the graphic characteristic value, and the coefficients and the graphic characteristic value constitute the etching deviation compensation model.

[0261] Different graphic characteristic values ​​are set as different polynomials, and the etching deviation compensation value and the graphic characteristic value at the measured position are fitted with a function to obtain the coefficient of the polynomial corresponding to each graphic characteristic value. The coefficient is the calculation coefficient of the etching deviation compensation model. After the etching deviation compensation model is established, the graphic characteristic value of the position to be calculated is subsequently input to obtain the corresponding etching deviation compensation value.

[0262] Correspondingly, an embodiment of the present invention further provides an etching deviation compensation model, including an etching deviation compensation model obtained by using the method for establishing an etching deviation compensation model provided by an embodiment of the present invention.

[0263] It can be seen from the foregoing embodiments that in the embodiments of the present invention, partial measurement graphics that can characterize the characteristic information of the measured structure are selected to establish an etching deviation compensation model, which is beneficial to reducing computing power, improving model building efficiency, and saving computing costs. Then, the graphic contour of the corresponding measurement graphic is obtained through multiple sampling images, which is beneficial to improving the computing accuracy, thereby improving the accuracy of the etching deviation compensation model.

[0264] Correspondingly, an embodiment of the present invention further provides an etching deviation compensation method, including an etching deviation compensation method based on an etching deviation compensation model established by the method for establishing an etching deviation compensation model provided by the embodiment of the present invention.

[0265] It can be seen from the foregoing embodiments that in the embodiments of the present invention, partial measurement graphics that can characterize the characteristic information of the measured structure are selected to establish an etching deviation compensation model, which is beneficial to reducing computing power, improving model building efficiency, and saving computing costs. Then, the graphic contour of the corresponding measurement graphic is obtained through multiple sampling images, which is beneficial to improving the computing accuracy, thereby improving the accuracy of the etching deviation compensation model.

[0266] The embodiment of the present invention further provides a device, which can implement the method for establishing an etching deviation compensation model provided by the embodiment of the present invention by loading the method for establishing an etching deviation compensation model in the form of a program. An optional hardware structure of the terminal device provided by the embodiment of the present invention can be as follows: Fig. 9 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.

[0267] 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 complete mutual communication through the communication bus 04. The communication interface 02 can be an interface of a communication module for network communication, such as an interface of a GSM module. The processor 01 may be a central processing unit CPU, or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement an embodiment of the present invention. The memory 03 may include a high-speed RAM memory, and may also include a non-volatile memory (NVM), such as at least one disk storage. Among them, the memory 03 stores one or more computer instructions, and the one or more computer instructions are executed by the processor 01 to implement the method for establishing the etching deviation compensation model provided in the embodiment of the present invention.

[0268] It should be noted that the above-mentioned terminal device may also include other devices (not shown) that may not be necessary for understanding the contents disclosed in the embodiments of the present invention; given that these other devices may not be necessary for understanding the contents disclosed in the embodiments of the present invention, the embodiments of the present invention will not introduce them one by one.

[0269] An embodiment of the present invention further provides a storage medium, wherein the storage medium stores one or more computer instructions, and the one or more computer instructions are used to implement the method for establishing an etching deviation compensation model provided by the embodiment of the present invention.

[0270] In an embodiment of the present invention, part of the measurement graphics that can characterize the characteristic information of the measured structure is selected to establish an etching deviation compensation model, which is beneficial to reducing computing power, improving model building efficiency, and saving computing costs. Then, the graphic contour of the corresponding measurement graphics is obtained through multiple sampling images, which is beneficial to improving the computing accuracy, thereby improving the accuracy of the etching deviation compensation model.

[0271] The above-mentioned embodiments of the present invention are combinations of elements and features of the present invention. Unless otherwise mentioned, elements or features may be considered as optional. Each element or feature may be put into practice without being combined with other elements or features. In addition, 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 configurations of any one embodiment may be included in another embodiment, and may be replaced by the corresponding configuration of another embodiment. It is obvious to those skilled in the art that claims that do not have a clear reference relationship to each other in the attached claims may be combined into embodiments of the present invention, or may be included as new claims in the amendment after submitting this application.

[0272] Embodiments of the present invention may be implemented by various means such as hardware, firmware, software or a combination thereof. In a hardware configuration, the method according to an exemplary embodiment of the present invention may 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 may be implemented in the form of modules, processes, functions, etc. The software code may be stored in a memory unit and executed by a processor. The memory unit is located inside or outside the processor and may send data to the processor and receive data from the processor via various known means.

[0273] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be 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 present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

[0274] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A method for establishing an etching deviation compensation model, characterized in that: include: Providing a measurement structure, including a plurality of measurement patterns, wherein the measurement patterns are etched patterns; Selecting a sampling position of the measurement structure, wherein a partial measurement graph of the sampling position represents characteristic information of the measurement structure; Acquire a plurality of sampling images of the sampling positions; Obtaining a graphic outline of a measurement graphic corresponding to the sampling position according to the plurality of sampling images; Acquiring a plurality of measurement locations on the graphic profile; According to the graphic profile, obtaining an etching deviation value of the measurement position; The etching deviation compensation model is established according to the etching deviation value at the measurement position.

2. The method for establishing an etching deviation compensation model according to claim 1, characterized in that: Selecting the sampling position of the measurement structure includes: acquiring a plurality of initial sampling positions of the measurement structure, wherein the measurement patterns of the plurality of initial sampling positions are different; Acquiring graphic feature information of the measurement graphic at the initial sampling position; Some of the initial sampling positions are selected as the sampling positions, and the sum of the graphic feature information of some of the initial sampling positions covers the feature information of the measurement structure.

3. The method for establishing an etching deviation compensation model according to claim 2, characterized in that: Acquiring graphic feature information of the measurement graphic at the initial sampling position, including: acquiring an initial sampling image at the initial sampling position; Setting a plurality of initial measurement positions on the measurement graph of the initial sampling image; Acquiring a plurality of graphic characteristic values ​​of the initial measurement positions; According to the plurality of graphic feature values, obtaining the distribution of graphic feature information corresponding to each of the initial sampling images; A part of the initial sampling positions is selected as the sampling positions, and according to the characteristic information distribution of the initial sampling images, initial sampling positions corresponding to multiple initial sampling images whose collection of characteristic information distribution covers the characteristic information of the measured structure are selected as the sampling positions.

4. The method for establishing an etching deviation compensation model according to claim 3, characterized in that: Acquiring the graphic feature value of the initial measurement position includes: setting model feature parameters according to feature information of the measurement structure; Obtaining a simulated exposure pattern corresponding to the measurement pattern; According to the simulated exposure pattern, the value of the model characteristic parameter at the initial measurement position is obtained as the pattern characteristic value.

5. The method for establishing an etching deviation compensation model according to claim 4, characterized in that: In acquiring the simulated exposure pattern corresponding to the measurement pattern, according to the initial measurement position, the simulated exposure pattern corresponding to the measurement pattern is obtained in the initial sampling image.

6. The method for establishing an etching deviation compensation model according to claim 4, characterized in that: Obtaining the distribution of graphic feature information corresponding to each of the initial sampling images according to the plurality of graphic feature values, including: establishing a corresponding coordinate system space according to the model feature parameters, wherein the coordinate axes of the coordinate system space correspond one-to-one to the model feature parameters; Taking the values ​​of the model characteristic parameters at the initial measurement positions as the coordinates of the corresponding coordinate axes, a plurality of initial measurement positions are set in the coordinate system space, and spatial points corresponding to the initial measurement positions are obtained one by one; According to the spatial point distribution of each of the initial sampling images, the coordinate system space of each of the initial sampling images is divided into a plurality of class areas, and the distribution of the spatial points in the plurality of class areas is obtained as the distribution of the graphic feature information.

7. The method for establishing an etching deviation compensation model according to claim 6, characterized in that: The coordinate system space of each of the initial sampling images is divided into a plurality of class areas according to the spatial point distribution of each of the initial sampling images using a K-means clustering method.

8. The method for establishing an etching deviation compensation model according to claim 6, characterized in that: According to the distribution of the characteristic information of the initial sampling images, selecting the initial sampling positions corresponding to the multiple initial sampling images whose collection of characteristic information distribution covers the characteristic information of the measured structure as the sampling positions, including: obtaining the number of class areas covered by the spatial point distribution of each of the initial sampling images; According to the number of class areas corresponding to the initial sampling image, initial sampling positions corresponding to multiple initial sampling images are selected in order from large to small as the sampling positions, wherein the collection distribution of spatial points in the multiple initial sampling images covers all the class areas.

9. The method for establishing an etching deviation compensation model according to claim 1, characterized in that: Obtaining the graphic contour of the measurement graphic corresponding to the sampling position according to the plurality of the sampling images includes: determining the corresponding position of the measurement graphic in the sampling image; Acquire sampling contours of the measurement graphics at corresponding positions in a plurality of the sampling images; According to the sampling contours of the plurality of sampling images, the graphic contours of the measurement graphics at the sampling positions corresponding to the sampling images are obtained.

10. The method for establishing an etching deviation compensation model according to claim 9, characterized in that: Determining the corresponding position of the measurement figure in the sampled image includes: acquiring a target figure corresponding to the measurement figure in the sampled image; In combination with the position of the target figure, the corresponding position of the measurement figure in the sampled image is obtained.

11. The method for establishing an etching deviation compensation model according to claim 9, characterized in that: Acquiring sampling contours of the measurement graphics at corresponding positions in a plurality of the sampling images, comprising: obtaining an initial sampling contour of the measurement graphics in the plurality of the sampling images; Obtaining the size of the initial sampling contour; Obtaining the actual size of the measured figure; The size of the initial sampling outline is calibrated based on the actual size of the measurement figure, and the calibrated initial sampling outline is used as the sampling outline.

12. The method for establishing an etching deviation compensation model according to claim 9, characterized in that: According to the sampling contours of the plurality of sampling images, obtaining the graphic contour of the measurement graphic at the sampling position corresponding to the sampling image comprises: obtaining the average contour of the sampling contours of the plurality of sampling images as the initial graphic contour; The initial graphic outline is smoothed to obtain the graphic outline.

13. The method for establishing an etching deviation compensation model according to claim 6, characterized in that: Acquiring a plurality of measurement positions on the graphic outline includes: filtering the plurality of initial measurement positions, removing initial measurement positions with the same surrounding environment, and retaining the remaining initial measurement positions as the measurement positions.

14. The method for establishing an etching deviation compensation model according to claim 13, characterized in that: Filtering the multiple initial measurement positions includes: gathering the spatial points corresponding to the initial measurement positions in the multiple sampled images into the same coordinate system space; Obtaining the spacing between spatial points in the coordinate system space; When the distance is less than or equal to the distance threshold, remove any one of the corresponding two spatial points and retain the remaining spatial point; Otherwise, the corresponding spatial point is retained.

15. The method for establishing an etching deviation compensation model according to claim 1, characterized in that: According to the pattern profile, obtaining the etching deviation value of the measurement position includes: obtaining a simulated exposure pattern corresponding to the measurement pattern; The size difference between the pattern outline and the simulated exposure pattern at the measurement position is obtained as the etching deviation value.

16. The method for establishing an etching deviation compensation model according to claim 13, characterized in that: According to the etching deviation value of the measuring position, establishing the etching deviation compensation model includes: obtaining the graphic characteristic value of the measuring position; The etching deviation compensation model is obtained by combining the etching deviation compensation value and the graphic characteristic value at the measurement position.

17. The method for establishing an etching deviation compensation model according to claim 16, characterized in that: Combining the etching deviation compensation value and the graphic characteristic value at the measurement position, the etching deviation compensation model is obtained, including: performing function fitting on the etching deviation compensation value and the graphic characteristic value at the measurement position, obtaining coefficients corresponding to the graphic characteristic values, and the coefficients and the graphic characteristic values ​​constitute the etching deviation compensation model.

18. A system for establishing an etching deviation compensation model, characterized in that: include: A measurement structure providing module, used to provide a measurement structure, including a plurality of measurement patterns, wherein the measurement patterns are patterns after etching; A sampling position selection module, used for selecting a sampling position of the measurement structure, wherein a partial measurement graph of the sampling position represents characteristic information of the measurement structure; A sampling image acquisition module, used to acquire a plurality of sampling images of the sampling position; A graphic contour acquisition module, used for obtaining the graphic contour of the measurement graphic corresponding to the sampling position according to the plurality of sampling images; A measurement position acquisition module, used to acquire a plurality of measurement positions on the graphic outline; An etching deviation value acquisition module, used to acquire the etching deviation value of the measurement position according to the graphic contour; The etching deviation compensation model establishing module is used to establish the etching deviation compensation model according to the etching deviation value at the measuring position.

19. An etching deviation compensation model established by using the method according to any one of claims 1 to 17.

20. An etching deviation compensation method based on an etching deviation compensation model established by the method according to any one of claims 1 to 17.

21. A device, characterized in that It comprises at least one memory and at least one processor, wherein the memory stores one or more computer instructions, wherein the one or more computer instructions are executed by the processor to implement the method for establishing an etching deviation compensation model as described in any one of claims 1-17.

22. A storage medium, characterized in that: The storage medium stores one or more computer instructions, and the one or more computer instructions are used to implement the method for establishing an etching deviation compensation model as described in any one of claims 1-17.

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