Method and device for parameter correction and storage medium

Abstract

The embodiment of the invention provides a parameter correction method and device and a storage medium. The method includes generating a first set of processing parameter sets based on respective initial values of one or more image processing parameters of a captured image, the processing parameter sets in the first set of processing parameter sets including respective parameter values of the one or more image processing parameters, the one or more image processing parameters are used to determine a first measurement about a target size of the wafer pattern. And generating a second group of processing parameter sets at least through a combination operation of parameter values in the first group of processing parameter sets, the processing parameter set in the second group of processing parameter sets comprising corresponding parameter values of one or more image processing parameters. One or more image processing parameters are updated based on a respective parameter value in each of the second set of processing parameters. In this way, the accuracy of image processing parameters is improved, so that a user can further obtain more accurate size information of a wafer pattern.

Description

Technical Field

[0001] Example embodiments of the present disclosure relate generally to the field of integrated circuits, and more particularly to methods, devices, and computer-readable storage media for parameter correction. Background Art

[0002] In integrated circuit (IC) manufacturing, it is usually necessary to quantitatively measure the wafers that go through each process to ensure that the key physical parameters of the process (such as film thickness, line width, doping concentration, etc.) meet the process specifications. For line width, the existing photolithography process measurement equipment obtains the line width by measuring the signal within a certain range when scanning the wafer.

[0003] A scanning electron microscope (SEM) is a microscopic analysis instrument that uses an electron beam to scan the surface of a sample to obtain high-resolution images and analyze the surface morphology and composition of the sample. Specifically, a scanning electron microscope is different from other electron microscopes. When scanning a wafer, a scanning electron microscope can generate measurement signals at specific locations in the scanned image (such as the boundary of the object to be measured), and then calculate the line width based on these measurement signals using methods such as threshold method and linear approximation. Summary of the invention

[0004] In a first aspect of the present disclosure, a method for parameter correction is provided. The method includes: generating a first set of processing parameter sets based on corresponding initial values ​​of one or more image processing parameters of a captured image, wherein the processing parameter sets in the first set of processing parameter sets include corresponding parameter values ​​of one or more image processing parameters, and the one or more image processing parameters are used to determine a first measurement result of a target size of a wafer pattern; generating a second set of processing parameter sets by at least a combination operation of the parameter values ​​in the first set of processing parameter sets, wherein the processing parameter sets in the second set of processing parameters include corresponding parameter values ​​of one or more image processing parameters; and updating one or more image processing parameters based on corresponding parameter values ​​in each processing parameter set in the second set of processing parameter sets.

[0005] In some embodiments, generating the second set of processing parameter sets includes: determining multiple processing parameter sets from the first set of processing parameter sets; and generating at least one processing parameter set as at least a part of the second set of processing parameter sets by combining parameter values ​​in the multiple processing parameter sets.

[0006] In some embodiments, a second set of processing parameters is generated: a first set of processing parameters in the second set of processing parameter sets is generated by a combination operation of parameter values ​​in the first set of processing parameter sets; and a second set of processing parameters is generated as a part of the second set of processing parameter sets by changing at least a portion of the parameter values ​​in the first set of processing parameter sets.

[0007] In some embodiments, determining multiple processing parameter sets from a first group of processing parameter sets includes: determining, for each processing parameter set in the first group of processing parameter sets, a fitness of the processing parameter set, the fitness indicating a measurement error corresponding to the processing parameter set; and selecting multiple processing parameter sets from the first group of processing parameter sets based on the corresponding fitness of the first group of processing parameter sets, wherein the fitness of the selected multiple processing parameter sets is higher than the fitness of the processing parameter sets not selected in the first group of processing parameter sets.

[0008] In some embodiments, determining the fitness of the processing parameter set includes: for each processing parameter set in a first group of processing parameter sets, determining a first measurement result corresponding to the processing parameter set based on a corresponding parameter value of the processing parameter set; determining a measurement difference corresponding to the processing parameter set based on the first measurement result and a second measurement result about a target size, the second measurement result being determined using a lithography machine that forms a wafer pattern; and determining the fitness corresponding to the processing parameter set based on the measurement difference.

[0009] In some embodiments, it also includes: updating the first measurement result according to the updated one or more image processing parameters; and in response to the updated first measurement result satisfying a predetermined condition, determining the target parameter value of the one or more image processing parameters based on the parameter value of the updated one or more image processing parameters.

[0010] In some embodiments, the predetermined condition includes at least one of the following: the number of updates of the first measurement result is greater than a threshold number, or the measurement difference corresponding to the first measurement result is less than a difference threshold, the measurement difference is determined based on the updated first measurement result and a second measurement result about the target size, and the second measurement result is determined using a lithography machine that forms a wafer pattern.

[0011] In some embodiments, the first measurement result is determined by: determining a target contour of a wafer pattern based on a captured image and one or more image processing parameters; determining one or more measurement positions on the target contour according to the one or more image processing parameters; and determining the first measurement result based on measurement values ​​of target sizes respectively determined for the one or more measurement positions.

[0012] In some embodiments, the one or more image processing parameters include at least one of: a measurement position parameter, an object contour determination parameter, or an image pre-processing parameter.

[0013] In a second aspect of the present disclosure, an image processing method is provided, which includes: processing a captured image of a target pattern on a wafer based on one or more image processing parameters to determine a target contour of the wafer pattern; and determining a measurement result of a target size of the target pattern based on the target contour.

[0014] In some embodiments, it also includes determining a first measurement result about a target size of a wafer pattern based on a captured image of a target pattern on a wafer according to one or more image processing parameters, wherein the wafer pattern is formed on the wafer using a mask pattern; determining a second measurement result about the target size, wherein the second measurement result is determined using a lithography machine that forms the wafer pattern on the wafer; and updating one or more image processing parameters based on a measurement difference between the first measurement result and the second measurement result.

[0015] In some embodiments, the wafer pattern includes multiple graphics, the first measurement result includes multiple measurement values ​​for the target size corresponding to the multiple graphics respectively, the second measurement result includes multiple reference values ​​for the target size corresponding to the multiple graphics respectively, and the measurement difference is determined as follows: for each graphic in the multiple graphics, determine the difference between the measurement value corresponding to the graphic and the reference value corresponding to the graphic; determine the measurement difference based on the differences determined respectively for the multiple graphics.

[0016] In some embodiments, updating one or more image processing parameters includes: generating a first group of processing parameter sets based on corresponding initial values ​​of the one or more image processing parameters, the corresponding initial values ​​of the one or more image processing parameters are used to generate a first measurement result, the processing parameter sets in the first group of processing parameter sets including corresponding parameter values ​​of the one or more image processing parameters; generating a second group of processing parameter sets by at least combining the parameter values ​​in the first group of processing parameter sets, the processing parameter sets in the second group of processing parameter sets including corresponding parameter values ​​of the one or more image processing parameters; and updating one or more image processing parameters based on the corresponding parameter values ​​in each processing parameter set in the second group of processing parameter sets.

[0017] In some embodiments, generating the second set of processing parameter sets includes: determining multiple processing parameter sets from the first set of processing parameter sets; and generating at least one processing parameter set as at least a part of the second set of processing parameter sets by combining parameter values ​​in the multiple processing parameter sets.

[0018] In some embodiments, determining multiple processing parameter sets from a first set of processing parameter sets includes: determining, for each processing parameter set in the first set of processing parameter sets, a fitness of the processing parameter set, the fitness indicating a measurement difference obtained using the processing parameter set; and selecting multiple processing parameter sets from the first set of processing parameter sets based on the corresponding fitness of the first set of processing parameter sets, wherein the fitness of the selected multiple processing parameter sets is higher than the fitness of the processing parameter sets not selected in the first set of processing parameter sets.

[0019] In some embodiments, a second set of processing parameters is generated: a first set of processing parameters in the second set of processing parameter sets is generated by a combination operation of parameter values ​​in the first set of processing parameter sets; and a second set of processing parameters is generated as a part of the second set of processing parameter sets by changing at least a portion of the parameter values ​​in the first set of processing parameter sets.

[0020] In some embodiments, it also includes: updating the first measurement result based on the updated one or more image processing parameters; updating the measurement difference based on the second measurement result and the updated first measurement result; and in response to the updated measurement difference satisfying a predetermined condition, determining the target parameter value of the one or more image processing parameters based on the parameter value of the updated one or more image processing parameters.

[0021] In some embodiments, determining a first measurement result regarding a target size of a wafer pattern includes: determining a target contour of the wafer pattern based on a captured image and one or more image processing parameters; determining one or more measurement positions on the target contour according to measurement position parameters in the one or more image processing parameters; and determining the first measurement result based on measurement values ​​of the target size determined respectively for the one or more measurement positions.

[0022] In some embodiments, determining a target contour of a wafer pattern includes: determining an initial contour of the wafer pattern and one or more sampling points on the initial contour based on a captured image; for a given sampling point among the one or more sampling points, determining a contour point corresponding to the given sampling point in a first direction based on an edge threshold parameter and a contour point selection parameter among one or more image processing parameters, wherein the first direction is a normal direction of the initial contour, the edge threshold parameter indicates a grayscale value of the contour point, and the contour point selection parameter indicates a rate of change of grayscale value at the contour point; and determining a target contour based on one or more contour points corresponding to the one or more sampling points, respectively.

[0023] In some embodiments, determining a target profile of a wafer pattern includes: preprocessing the wafer pattern based on a captured image and preprocessing parameters in one or more image processing parameters to obtain an updated captured image; and determining a target profile of the wafer pattern based on the updated captured image.

[0024] In a third aspect of the present disclosure, an electronic device is provided. The device includes at least one processing unit; and at least one memory, the at least one memory is coupled to the at least one processing unit and stores instructions for execution by the at least one processing unit. When the instructions are executed by the at least one processing unit, the device executes the method of the first aspect.

[0025] In a fourth aspect of the present disclosure, a computer-readable storage medium is provided, wherein a computer program is stored on the computer-readable storage medium, and the computer program can be executed by a processor to implement the method of the first aspect.

[0026] According to an embodiment of the present disclosure, a first set of processing parameter sets is generated based on the corresponding initial values ​​of one or more image processing parameters of the captured image. A second set of processing parameter sets is generated at least by combining the parameter values ​​in the first set of processing parameter sets, and the image processing parameters are updated based on each processing parameter set in the second set of processing parameter sets. In this way, the accuracy of the image processing parameters is improved to further enable the user to obtain more accurate size information of the wafer pattern.

[0027] It should be understood that the contents described in this content section are not intended to limit the key features or important features of the embodiments of the present disclosure, nor are they intended to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The above and other features, advantages and aspects of the embodiments of the present disclosure will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. In the accompanying drawings, the same or similar reference numerals represent the same or similar elements, wherein: Figure 1 A schematic diagram showing an example environment in which embodiments according to the present disclosure may be implemented; Figure 2 A flow chart showing a first example process for parameter correction according to some embodiments of the present disclosure is shown; Figure 3 A schematic diagram showing an updated captured image of a wafer pattern according to some embodiments of the present disclosure; Figure 4 A schematic diagram showing a captured image of a wafer pattern according to some embodiments of the present disclosure; Figure 5 A schematic diagram showing grayscale values ​​of a wafer pattern according to some embodiments of the present disclosure; Figure 6 A schematic diagram showing contour points of a wafer pattern according to some embodiments of the present disclosure; Figure 7 A schematic diagram showing a target profile of a wafer pattern according to some embodiments of the present disclosure; Figure 8 A schematic diagram showing measurement locations according to some embodiments of the present disclosure; Fig. 9 A flowchart showing a second example process for parameter correction according to some embodiments of the present disclosure; and Fig.10A block diagram of an electronic device capable of implementing various embodiments of the present disclosure is shown. DETAILED DESCRIPTION

[0029] Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be construed as being limited to the embodiments described herein, which are instead provided for a more thorough and complete understanding of the present disclosure. It should be understood that the drawings and embodiments of the present disclosure are only for exemplary purposes and are not intended to limit the scope of protection of the present disclosure.

[0030] In the description of the embodiments of the present disclosure, the term "including" and similar terms should be understood as open inclusion, that is, "including but not limited to". The term "based on" should be understood as "based at least in part on". The term "one embodiment" or "the embodiment" should be understood as "at least one embodiment". The terms "first", "second", etc. may refer to different or the same objects. Other explicit and implicit definitions may also be included below.

[0031] Various example implementations of the scheme will be described in detail below with reference to the accompanying drawings.

[0032] See first Figure 1 , which shows a schematic diagram of an example environment 100 in which various embodiments of the present disclosure can be implemented. The example environment 100 may generally include an electronic device 110. The electronic device may be used to measure the captured image to obtain profile information of a wafer pattern (such as the size and profile of the wafer pattern). In some embodiments, the electronic device 110 may be used to evaluate the obtained profile information to improve the accuracy and reliability of the profile information.

[0033] In some embodiments, the electronic device 110 may be communicatively connected to a wafer processing platform. Exemplarily, the wafer processing platform may be a device or a lithography device for measuring wafer patterns. The electronic device 110 may be communicatively connected to one or more sensors at various locations on the wafer processing platform or adjacent to the wafer processing platform. The wafer processing platform may actually process the wafer and transmit a set of measurement parameter information to the electronic device 110.

[0034] The electronic device 110 obtains a captured image 120 for a target object as input. The target object may be a component in an integrated circuit or any other suitable type of electronic component. Examples of target objects include, but are not limited to, metal wires or electronic devices (such as transistors) in an integrated circuit. In some embodiments, the captured image 120 may be obtained by capturing the target object using a line width scanning electron microscope. It should be understood that the captured image 120 for the target object may also be obtained with the aid of any other suitable device, such as other types of microscopes. The captured image 120 includes at least one wafer pattern 130. The scope of the present disclosure is not limited in this respect.

[0035] In some embodiments, the captured image 120 may be input to the electronic device 110 by a user. In some embodiments, the captured image 120 may have been pre-stored in the electronic device 110. In some embodiments, the electronic device 110 may also be communicatively coupled to other devices to obtain the captured image 120 from the other devices. The scope of the present disclosure is not limited in this respect. In some embodiments, the electronic device 110 may process the captured image 120 to obtain a measurement result 140 for the wafer pattern 130. The measurement result 140 may include a measurement value of a target dimension, such as a measurement value of a critical dimension (CD). In the example environment 100, the electronic device 110 may be any type of device with computing capabilities, including a terminal device or a server device. The terminal device may be any type of mobile terminal, fixed terminal or portable terminal, including mobile phones, desktop computers, laptop computers, notebook computers, netbook computers, tablet computers, media computers, multimedia tablets, personal communication system (PCS) devices, personal navigation devices, personal digital assistants (PDAs), audio / video players, digital cameras / camcorders, positioning devices, television receivers, radio broadcast receivers, e-book devices, gaming devices or any combination of the foregoing, including accessories and peripherals of these devices or any combination thereof. The server device may include, for example, a computing system / server, such as a mainframe, an edge computing node, a computing device in a cloud environment, and the like.

[0036] As mentioned above, in the semiconductor chip manufacturing process, it may be necessary to use equipment such as line width scanning electron microscopes to measure the contour information of wafer patterns. Currently, most of the images taken by scanning electron microscopes are visually inspected to extract contour information from the captured images. By quantitatively analyzing the contour information, the scale measurement information of the wafer pattern (including sidewall angle, critical dimension, etc.) is determined.

[0037] In the process of visual inspection of captured images and quantitative analysis of contour information, it is necessary to determine the size information of the wafer pattern based on image processing parameters (e.g., image preprocessing parameters, edge detection parameters, etc.). Image processing parameters will directly affect the accuracy of scale measurement information. Currently, image processing parameters are mostly determined based on the experience of analysts, resulting in low accuracy of the size measurement information obtained.

[0038] In view of this, the present application provides a scheme for parameter correction. In an embodiment of the present disclosure, a first set of processing parameter sets is generated based on the corresponding initial values ​​of one or more image processing parameters of the captured image, and the processing parameter sets in the first set of processing parameter sets include corresponding parameter values ​​of one or more image processing parameters, and the one or more image processing parameters are used to determine a first measurement result of a target size of a wafer pattern. A second set of processing parameter sets is generated at least through a combination operation of the parameter values ​​in the first set of processing parameter sets, and the processing parameter sets in the second set of processing parameters include corresponding parameter values ​​of one or more image processing parameters. Based on the corresponding parameter values ​​in each processing parameter set in the second set of processing parameter sets, one or more image processing parameters are updated.

[0039] According to the solution of the present disclosure, a first set of processing parameter sets is generated based on the corresponding initial values ​​of one or more image processing parameters of the captured image. A second set of processing parameter sets is generated at least by combining the parameter values ​​in the first set of processing parameter sets, and the image processing parameters are updated based on each processing parameter set in the second set of processing parameter sets. In this way, the accuracy of the image processing parameters is improved to further enable the user to obtain more accurate size information of the wafer pattern.

[0040] Figure 2 FIG. 2 is a schematic diagram showing a first example process 200 for parameter correction according to some embodiments of the present disclosure. In some embodiments, the process 200 may be implemented or included in Figure 1 In the electronic device 110 shown. It should be understood that the process 200 may also include additional blocks not shown and / or may omit one (or some) of the blocks shown, and the scope of the present disclosure is not limited in this respect.

[0041] In some embodiments, the electronic device 110 generates a first set of processing parameter sets based on the corresponding initial values ​​of one or more image processing parameters for the captured image of the wafer pattern. The processing parameter set in the first set of processing parameter sets includes corresponding parameter values ​​of one or more image processing parameters, and the one or more image processing parameters are used to determine the first measurement result of the target size of the wafer pattern 130. The initial value of the image processing parameter can be a predetermined process parameter, or a value determined by the analyst based on his own experience. The wafer pattern 130 is formed on the wafer using a mask pattern. The target size of the wafer pattern 130 can refer to the width of the photoresist groove or line obtained at a specific exposure intensity threshold, which is used to measure the minimum controllable size of the semiconductor device or line. In some embodiments, the wafer pattern 130 can include multiple graphics. The outline in the embodiment of the present disclosure can be the outline of each graphic in the wafer pattern 130. The target size can refer to the size of the graphic in the wafer pattern 130, such as CD. Exemplarily, the target size can be the average value of the sizes of multiple outlines.

[0042] In some embodiments, for the wafer pattern 130 formed on the wafer, a line width scanning electron microscope is first used to obtain a captured image of the wafer pattern 130. The wafer pattern 130 is processed based on the captured image and one or more image processing parameters to determine the target contour of the wafer pattern 130. In some embodiments, the determined target contour can be used to determine the measured size of the wafer pattern 130. Since the captured images obtained by the scanning electron microscope often show characteristics such as high noise and low contrast, in some embodiments, the captured images can be preprocessed to improve the quality of the captured images. Thereby, the accuracy of the first measurement result obtained is further improved.

[0043] like Figure 2 As shown, in block 210, the captured image may be preprocessed based on the corresponding initial values ​​of the image preprocessing parameters in the first set of processing parameters to obtain an updated captured image. In some embodiments, preprocessing the captured image includes grayscale, noise reduction, and size adjustment. Accordingly, the image preprocessing parameters in the one or more image processing parameters may include a grayscale threshold, a parameter for noise reduction, and an adjusted size.

[0044] By preprocessing the captured images using different image preprocessing parameters, updated captured images with different accuracies can be obtained. Figure 3 FIG. 3 is a schematic diagram showing an updated captured image 300 of a wafer pattern according to some embodiments of the present disclosure. Figure 3As shown, the first captured image 310-1, the second captured image 310-2, the third captured image 310-3 and the fourth captured image 310-4 correspond to different image preprocessing parameters, which can be individually or collectively referred to as updated captured images 310. Exemplarily, corresponding low-pass filter parameters can be selected to perform high-frequency noise reduction processing on the captured images to obtain the updated captured image 310.

[0045] In box 220, feature extraction may be performed on the updated captured image 310 to determine the initial contour of the wafer pattern. In some embodiments, the electronic device 110 may determine a plurality of marking points based on the brightness feature of the updated captured image 310. The brightness feature is related to the pixel value of one or more pixels included in the updated captured image 310. In order to determine these marking points, the electronic device 110 may take the brightness feature into consideration in various ways. In some embodiments, the updated captured image 310 may be first binarized and the initial contour in the binarized image may be determined. Exemplarily, an edge detection algorithm (such as a Canny edge detection algorithm, a Sobel edge detection algorithm, etc.) may be used to identify the edge of the wafer pattern in the captured image. Subsequently, the edge points in the captured image where the grayscale value changes significantly are determined by extreme point detection. Based on the determined multiple edge points, the initial contour of the wafer pattern is determined. Figure 4 FIG. 4 is a schematic diagram showing a captured image 400 of a wafer pattern according to some embodiments of the present disclosure. Figure 4 As shown, based on the grayscale value, a target area 410 including the outline of the wafer pattern is determined in the updated captured image 310 .

[0046] In block 230, contour points of the wafer pattern may be determined based on the initial contour of the wafer pattern. In some embodiments, one or more sampling points may be determined on the initial contour. For a certain sampling point among the one or more sampling points, a contour point corresponding to the sampling point is determined in a first direction based on a corresponding initial value of an edge threshold parameter in a first set of processing parameters and a corresponding initial value of a contour point selection parameter. In some embodiments, the edge threshold parameter indicates a grayscale value of the contour point, the contour point selection parameter indicates a grayscale value change rate at the contour point, and the first direction is a normal direction of the initial contour. Figure 4 As shown, a first sampling point 420-1, a second sampling point 420-2, a third sampling point 420-3, and a fourth sampling point 420-4 are determined from the initial contour, which may be individually or collectively referred to as sampling points 420. Exemplarily, for the first sampling point 420-1, the normal of the initial contour at the first sampling point 420-1 is first determined. Subsequently, a contour point corresponding to the first sampling point 420-1 is determined in the normal direction.

[0047] Figure 5FIG. 5 is a schematic diagram showing grayscale values ​​500 of a wafer pattern according to some embodiments of the present disclosure. Figure 5 As shown, in the normal direction, the grayscale values ​​510 on both sides of the first sampling point 420-1 increase first and then decrease. At least two candidate contour points can be determined from a predetermined distance on both sides of the first sampling point 420-1 according to a predetermined edge threshold parameter 520 (i.e., the corresponding initial value of the contour point selection parameter in the first set of processing parameters). The grayscale values ​​of the candidate contour points are determined based on the edge threshold parameter 520. Usually, the two candidate contour points are located outside and inside the first sampling point 420-1, respectively, and the contour points can be determined from the candidate contour points based on the contour point selection parameters. In this way, the contour points corresponding to each sampling point 420 can be determined respectively.

[0048] At block 240 , a target contour may be determined based on the determined plurality of contour points. Figure 6 FIG. 6 is a schematic diagram showing contour points 600 of a wafer pattern according to some embodiments of the present disclosure. Figure 6 As shown, the "X"-shaped mark in the updated captured image 310 corresponds to the mark signal of the contour point. In some embodiments, the target contour can be determined by connecting multiple contour points. , connect the lines in the corresponding order of the layout to get the complete outline information The updated captured image 310 may include multiple patterns, and the extracted contour point set is denoted as , is the number of contours, is the contour point, For the A set of contour points of a pattern. Accordingly, the determined target contour may include a first target contour 610-1 and a second target contour 610-2, which may be individually or collectively referred to as a target contour 610. In this case, the more sampling points 420 determined for a certain target pattern, the more contour points are obtained, and the higher the accuracy of the target contour finally determined. In some embodiments, if there are multiple captured images corresponding to the wafer pattern 130 (that is, multiple images are captured for the same wafer or the same position on the wafer), the contour of the wafer pattern 130 in each captured image may be first determined. Subsequently, the average value of the contours in the multiple captured images is taken as the target contour of the wafer pattern 130.

[0049] Figure 7 FIG. 7 is a schematic diagram of a target profile 700 of a wafer pattern according to some embodiments of the present disclosure. Figure 7The first target contour 710-1 and the second target contour 710-2 in the layout size space may be individually or collectively referred to as the target contour 710. In some embodiments, the contour on the scale of the captured image may be mapped back to the layout size space to obtain Figure 7 The target contour is shown. The mapping formula is, for example:

[0050] in is the pixel size of the map mapped to the image, is the coordinate translation, is the first The coordinates of the contours, The first The coordinates of the contour.

[0051] In block 250, a first measurement result of a target size of the wafer pattern may be determined based on the determined target profile 710. For example, the distance between the left and right contour lines of the target profile may be determined as the measurement value of the target size. During the measurement process, the number and distribution of measurement positions directly affect the first measurement result obtained. Therefore, multiple measurement positions may be determined in the target profile 710, and the first measurement result may be determined by calculating the measurement values ​​corresponding to the multiple measurement line positions.

[0052] In some embodiments, one or more measurement locations on the target contour may be determined based on corresponding initial values ​​of measurement location parameters in the first set of image processing parameters. Figure 8 Schematic diagram of a measurement location 800 according to some embodiments of the present disclosure is shown. Figure 8 As shown, a first measurement position 810-1, a second measurement position 810-2, a third measurement position 810-3, and a fourth measurement position 810-4 can be determined in the target profile 710, which can be individually or collectively referred to as measurement positions 810. The dimensions of the target profile 710 are measured at multiple measurement positions 810 to obtain multiple measurement values. In some embodiments, outliers in the multiple measurement values ​​can be removed. An outlier refers to a measurement value with obvious errors, for example, a measurement value with an error greater than an error threshold from other measurement values ​​or other values ​​that do not meet data requirements. Based on the average value of the remaining multiple measurement values ​​after removing the outlier values As the first measurement result corresponding to the target profile 710. In this way, based on the measurement position parameters in the image processing parameters, the most accurate measurement value is determined through a plurality of different measurement positions.

[0053] In block 260, based on the determined first measurement result, it is determined whether the first measurement result satisfies a predetermined condition. If the predetermined condition is met, the image processing parameter is stopped from being updated. If the predetermined condition is not met, the process proceeds to block 270. In some embodiments, the predetermined condition may be that the number of iterations corresponding to the first measurement result exceeds a predetermined number threshold, the measurement difference between the first measurement result and the second measurement result is less than a predetermined threshold, or the measurement difference determined by the previous multiple iterations is stable.

[0054] The second measurement result is determined using a photolithography machine that forms a wafer pattern on a wafer. In some embodiments, if the wafer pattern includes multiple graphics, the first measurement result includes multiple measurement values ​​for the target size corresponding to the multiple graphics, and the second measurement result includes multiple reference values ​​for the target size corresponding to the multiple graphics. For each of the multiple graphics, determine the difference between the measurement value corresponding to the graphic and the reference value corresponding to the graphic. Based on the differences determined for the multiple graphics, the measurement difference is determined. The image processing parameters used in the process of determining the first measurement result are updated based on the measurement difference between the second measurement result determined by the photolithography machine and the first result. In this way, the consistency of the measurement value for the captured image and the measurement value of the photolithography machine is ensured to facilitate subsequent analysis of the measurement information.

[0055] In some embodiments, if the wafer pattern 130 includes multiple graphics, the measurement values ​​corresponding to the contours of the multiple graphics can be recorded as . is the number of patterns included in the wafer pattern 130, represents the measured value of the contour of the i-th figure in the wafer pattern 130. In this case, the measured difference for the wafer pattern 130 may be the sum of the differences corresponding to each figure in the wafer pattern 130, and the calculation formula of the measured difference cost is, for example:

[0056] in For the The second measurement result of the contour, For the The difference between the first and second measurements of a contour, is the number of contours.

[0057] In some embodiments, the average value of the differences corresponding to each graphic included in the wafer pattern 130 or the median value of multiple differences can be used as the measurement difference of the wafer pattern 130. The embodiments of the present disclosure are not limited to this. In some embodiments, if there are multiple captured images corresponding to the wafer pattern 130, the measurement difference corresponding to each captured image can be determined first. Subsequently, based on the sum of the multiple measurement differences obtained, the measurement difference of the wafer pattern 130 is determined.

[0058] In box 270, one or more image processing parameters may be updated based on the determined measurement difference. To this end, the operations in boxes 210 to 270 may be performed multiple times to iteratively update the image processing parameters. In each iteration, the first measurement result is updated based on the one or more image processing parameters updated in the previous iteration. The measurement difference is updated based on the second measurement result and the updated first measurement result. If it is detected that the first measurement result is updated, box 260 is executed (i.e., it is determined whether the updated first measurement result meets the predetermined condition). If the predetermined condition is met, the iteration process is terminated. The parameter values ​​of the one or more updated image processing parameters obtained in this iteration are used to determine the target parameter values ​​of the one or more image processing parameters. If the updated measurement difference cannot meet the predetermined condition, the image processing parameters are updated and the content in box 210 is executed again.

[0059] In some embodiments, the image processing parameters may be updated using a machine learning model (e.g., a genetic algorithm model). The electronic device 110 generates a second set of processing parameter sets by at least combining the parameter values ​​in the first set of processing parameter sets. The processing parameter set in the second set of processing parameters includes corresponding parameter values ​​of one or more image processing parameters.

[0060] Exemplarily, the second set of processing parameter sets can be generated by crossover and mutation operations of parameter values ​​in the first set of processing parameter sets. One or more image processing parameters are updated based on corresponding parameter values ​​in each processing parameter set in the second set of processing parameter sets. The second set of processing parameter sets refers to the offspring population generated during each iteration of the genetic algorithm model.

[0061] In some embodiments, multiple processing parameter sets are determined from the first set of processing parameter sets. Exemplarily, multiple processing parameter sets can be determined based on the fitness of each processing parameter set. Subsequently, at least one processing parameter set is generated as at least a part of the second set of processing parameter sets by combining the parameter values ​​in the multiple processing parameter sets (i.e., crossover operation). In some embodiments, the first processing parameter set in the second set of processing parameter sets is generated by combining the parameter values ​​in the first set of processing parameter sets. The second processing parameter set is generated as a part of the second set of processing parameter sets by changing at least a part of the parameter values ​​in the first processing parameter set (i.e., performing a mutation operation on at least a part of the parameter values).

[0062] In some embodiments, for each processing parameter set in the first set of processing parameter sets, a fitness of the processing parameter set is determined, the fitness indicating a measurement difference obtained using the processing parameter set. Based on the respective fitness of the first set of processing parameter sets, a plurality of processing parameter sets are selected from the first set of processing parameter sets, wherein the fitness of the selected plurality of processing parameter sets is higher than the fitness of the non-selected processing parameter sets in the first set of processing parameter sets. In some embodiments, the fitness of the parameter set is determined based on a measurement difference between the first measurement result and the second measurement result, for example, the fitness of the parameter set may be the inverse of the measurement difference.

[0063] Exemplarily, the parameters such as the initial population size, crossover probability and mutation probability of the genetic algorithm can be first defined, and the first set of processing parameter sets (i.e., the initial population) can be generated according to the corresponding initial values ​​and constraints of one or more image processing parameters. Exemplarily, the first set of processing parameter sets can be obtained by performing crossover, mutation and reproduction operations on the initial values ​​of the image processing parameters. The electronic device 110 generates the initial values ​​of the first set of processing parameter sets (i.e., the initial population) of the image processing parameters. Each processing parameter set in a set of processing parameter sets corresponds to an individual. The length of each individual is the same as the number of parameters to be optimized. Each individual includes the initial values ​​of all parameters to be optimized. As an example, the maximum number of iterations N and the population size Q of the genetic algorithm can be defined, and the parameters to be optimized, the fixed parameters and the mutual restriction relationship between the parameters can be defined. The range of values ​​of each parameter to be optimized is defined, assuming that there are a total of A parameters to be optimized. According to the previously defined A parameters to be optimized and their value ranges, each parameter is randomly selected once to obtain a vector of length A. Repeating this behavior Q times will result in a matrix of size [A,Q], which is the initial population, containing Q individuals, each of which has a length of A and contains the results of random initialization of A parameters.

[0064] For any one of the iterative generation steps of the plurality of image processing parameters, a crossover operation is performed on a portion of the processing parameter sets in the first group of processing parameter sets to generate at least one first processing parameter set. The obtained first processing parameter set is used as a part of the second group of processing parameter sets (i.e., the offspring population). Subsequently, a mutation operation is performed on a portion of the processing parameter sets in the second group of processing parameter sets to generate at least one second processing parameter set. The generated at least one second processing parameter set is used as a part of the second group of processing parameter sets. Based on the corresponding parameter values ​​in each processing parameter set in the second group of processing parameter sets, one or more image processing parameters are updated. Exemplarily, the fitness of each processing parameter set in the second group of processing parameter sets can be determined. Subsequently, the image processing parameters are updated based on the corresponding parameter values ​​in the processing parameter set with the highest fitness. If the measurement error corresponding to the second group of processing parameter sets meets a predetermined condition, the image processing parameters are stopped from being updated. Otherwise, the step of updating the image processing parameters is performed again by performing crossover and mutation operations on a portion of the processing parameter sets in the second group of processing parameter sets.

[0065] Fig. 9 FIG. 9 is a flowchart of a second example process 900 for parameter correction according to some embodiments of the present disclosure. The process 900 may be implemented at the electronic device 110. Figure 1 900 is described below.

[0066] like Fig. 9 As shown, in box 910, the electronic device 110 generates a first group of processing parameter sets based on corresponding initial values ​​of one or more image processing parameters of a captured image of a wafer pattern, and the processing parameter sets in the first group of processing parameter sets include corresponding parameter values ​​of one or more image processing parameters, and the one or more image processing parameters are used to determine a first measurement result regarding a target size of the wafer pattern.

[0067] In some embodiments, the first measurement result is determined by: determining a target contour of a wafer pattern based on a captured image and one or more image processing parameters; determining one or more measurement positions on the target contour according to the one or more image processing parameters; and determining the first measurement result based on measurement values ​​of target sizes respectively determined for the one or more measurement positions.

[0068] In some embodiments, the one or more image processing parameters include at least one of: a measurement position parameter, an object contour determination parameter, or an image pre-processing parameter.

[0069] At block 920, the electronic device 110 generates a second set of processing parameter sets by at least combining the parameter values ​​in the first set of processing parameter sets, wherein the processing parameter sets in the second set of processing parameter sets include corresponding parameter values ​​of one or more image processing parameters.

[0070] In some embodiments, a second set of processing parameters is generated: a first set of processing parameters in the second set of processing parameter sets is generated by a combination operation of parameter values ​​in the first set of processing parameter sets; and a second set of processing parameters is generated as a part of the second set of processing parameter sets by changing at least a portion of the parameter values ​​in the first set of processing parameter sets.

[0071] In some embodiments, generating the second set of processing parameter sets includes: determining multiple processing parameter sets from the first set of processing parameter sets; and generating at least one processing parameter set as at least a part of the second set of processing parameter sets by combining parameter values ​​in the multiple processing parameter sets.

[0072] In some embodiments, determining multiple processing parameter sets from a first group of processing parameter sets includes: determining, for each processing parameter set in the first group of processing parameter sets, a fitness of the processing parameter set, the fitness indicating a measurement error corresponding to the processing parameter set; and selecting multiple processing parameter sets from the first group of processing parameter sets based on the corresponding fitness of the first group of processing parameter sets, wherein the fitness of the selected multiple processing parameter sets is higher than the fitness of the processing parameter sets not selected in the first group of processing parameter sets.

[0073] In some embodiments, determining the fitness of the processing parameter set includes: for each processing parameter set in a first group of processing parameter sets, determining a first measurement result corresponding to the processing parameter set based on a corresponding parameter value of the processing parameter set; determining a measurement difference corresponding to the processing parameter set based on the first measurement result and a second measurement result about a target size, the second measurement result being determined using a lithography machine that forms a wafer pattern; and determining the fitness corresponding to the processing parameter set based on the measurement difference.

[0074] At block 930, the electronic device 110 updates one or more image processing parameters based on corresponding parameter values ​​in each processing parameter set in the second set of processing parameter sets.

[0075] In some embodiments, process 900 also includes updating the first measurement result based on the updated one or more image processing parameters; and in response to the updated first measurement result satisfying a predetermined condition, determining the target parameter values ​​of the one or more image processing parameters based on the parameter values ​​of the updated one or more image processing parameters.

[0076] In some embodiments, the predetermined condition includes at least one of the following: the number of updates of the first measurement result is greater than a threshold number, or the measurement difference corresponding to the first measurement result is less than a difference threshold, the measurement difference is determined based on the updated first measurement result and a second measurement result about the target size, and the second measurement result is determined using a lithography machine that forms a wafer pattern.

[0077] like Fig.10 As shown, the electronic device 1000 is in the form of a general electronic device. The components of the electronic device 1000 may include, but are not limited to, one or more processors or processing units 1010, a memory 1020, a storage device 1030, one or more communication units 1040, one or more input devices 1060, and one or more output devices 1060. The processing unit 1010 may be an actual or virtual processor and is capable of performing various processes according to a program stored in the memory 1020. In a multi-processor system, multiple processing units execute computer executable instructions in parallel to improve the parallel processing capability of the electronic device 1000.

[0078] The electronic device 1000 typically includes a plurality of computer storage media. Such media may be any accessible media that is accessible to the electronic device 1000, including but not limited to volatile and non-volatile media, removable and non-removable media. The memory 1020 may be a volatile memory (e.g., a register, a cache, a random access memory (RAM)), a non-volatile memory (e.g., a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), flash memory), or some combination thereof. The storage device 1030 may be a removable or non-removable medium, and may include a machine-readable medium, such as a flash drive, a disk, or any other medium, which may be capable of being used to store information and / or data and may be accessed within the electronic device 1000.

[0079] The electronic device 1000 may further include additional removable / non-removable, volatile / non-volatile storage media. Fig.10 As shown in , a disk drive for reading or writing from a removable, non-volatile disk (e.g., a "floppy disk") and an optical drive for reading or writing from a removable, non-volatile optical disk may be provided. In these cases, each drive may be connected to the bus (not shown) by one or more data media interfaces. Memory 1020 may include a computer program product 1025 having one or more program modules that are configured to perform various methods or actions of various embodiments of the present disclosure.

[0080] The communication unit 1040 implements communication with other electronic devices through a communication medium. Additionally, the functions of the components of the electronic device 1000 can be implemented in a single computing cluster or multiple computing machines that can communicate through a communication connection. Therefore, the electronic device 1000 can operate in a networked environment using a logical connection with one or more other servers, a network personal computer (PC), or another network node.

[0081] The input device 1050 may be one or more input devices, such as a mouse, a keyboard, a tracking ball, etc. The output device 1060 may be one or more output devices, such as a display, a speaker, a printer, etc. The electronic device 1000 may also communicate with one or more external devices (not shown) through the communication unit 1040 as needed, such as a storage device, a display device, etc., communicate with one or more devices that allow a user to interact with the electronic device 1000, or communicate with any device (e.g., a network card, a modem, etc.) that allows the electronic device 1000 to communicate with one or more other electronic devices. Such communication may be performed via an input / output (I / O) interface (not shown).

[0082] According to an exemplary implementation of the present disclosure, a computer-readable storage medium is provided, on which computer-executable instructions are stored, wherein the computer-executable instructions are executed by a processor to implement the method described above. According to an exemplary implementation of the present disclosure, a computer program product is also provided, which is tangibly stored on a non-transitory computer-readable medium and includes computer-executable instructions, and the computer-executable instructions are executed by a processor to implement the method described above.

[0083] Various aspects of the present disclosure are described herein with reference to the flowcharts and / or block diagrams of the methods, devices, and computer program products implemented according to the present disclosure. It should be understood that each box in the flowchart and / or block diagram and the combination of each box in the flowchart and / or block diagram can be implemented by computer-readable program instructions.

[0084] These computer-readable program instructions can be provided to a processing unit of a general-purpose computer, a special-purpose computer, or other programmable data processing device, thereby producing a machine, so that when these instructions are executed by the processing unit of the computer or other programmable data processing device, a device that implements the functions / actions specified in one or more boxes in the flowchart and / or block diagram is generated. These computer-readable program instructions can also be stored in a computer-readable storage medium, and these instructions cause the computer, programmable data processing device, and / or other equipment to work in a specific manner, so that the computer-readable medium storing the instructions includes a manufactured product, which includes instructions for implementing various aspects of the functions / actions specified in one or more boxes in the flowchart and / or block diagram.

[0085] Computer-readable program instructions can be loaded onto a computer, other programmable data processing apparatus, or other device so that a series of operational steps are performed on the computer, other programmable data processing apparatus, or other device to produce a computer-implemented process, so that the instructions executed on the computer, other programmable data processing apparatus, or other device implement the functions / actions specified in one or more boxes in the flowchart and / or block diagram.

[0086] The flow chart and block diagram in the accompanying drawings show the possible architecture, function and operation of the system, method and computer program product according to multiple implementations of the present disclosure. In this regard, each square box in the flow chart or block diagram can represent a part of a module, program segment or instruction, and a part of a module, program segment or instruction includes one or more executable instructions for realizing the logical function of the specification. In some implementations as replacements, the function marked in the square box can also occur in a sequence different from that marked in the accompanying drawings. For example, two continuous square boxes can actually be executed substantially in parallel, and they can sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each square box in the block diagram and / or flow chart, and the combination of the square boxes in the block diagram and / or flow chart can be realized by a special hardware-based system that performs the function or action of the specification, or can be realized by a combination of special hardware and computer instructions.

[0087] The above descriptions of various implementations of the present disclosure are exemplary, non-exhaustive, and not limited to the disclosed implementations. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described implementations. The selection of terms used herein is intended to best explain the principles of the implementations, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the various implementations disclosed herein.

Claims

1. A parameter correction method, comprising: generating a first set of processing parameter sets based on corresponding initial values ​​of one or more image processing parameters for a captured image of a wafer pattern, wherein the processing parameter sets in the first set of processing parameter sets include corresponding parameter values ​​of the one or more image processing parameters, the one or more image processing parameters being used to determine a first measurement result regarding a target dimension of the wafer pattern; generating a second set of processing parameters by at least combining the parameter values ​​in the first set of processing parameters, the processing parameter sets in the second set of processing parameters including corresponding parameter values ​​of the one or more image processing parameters; as well as The one or more image processing parameters are updated based on corresponding parameter values ​​in each processing parameter set in the second set of processing parameter sets.

2. The method according to claim 1, characterized in that Generating the second set of processing parameters includes: determining a plurality of processing parameter sets from said first set of processing parameter sets; and At least one processing parameter set is generated as at least a part of the second group of processing parameter sets by combining the parameter values ​​in the plurality of processing parameter sets.

3. The method according to claim 1, characterized in that Generate the second set of processing parameters: generating a first processing parameter set in the second processing parameter set by combining the parameter values ​​in the first processing parameter set; as well as A second processing parameter set is generated as a part of the second set of processing parameter sets by changing at least a portion of parameter values ​​in the first set of processing parameters.

4. The method according to claim 2, characterized in that Determining a plurality of processing parameter sets from the first set of processing parameter sets comprises: determining, for each processing parameter set in the first set of processing parameter sets, a fitness of the processing parameter set, the fitness indicating a measurement error corresponding to the processing parameter set; and The plurality of processing parameter sets are selected from the first set of processing parameter sets based on respective fitnesses of the first set of processing parameter sets, wherein fitnesses of the selected plurality of processing parameter sets are higher than fitnesses of processing parameter sets not selected from the first set of processing parameter sets.

5. The method according to claim 4, characterized in that Determining the fitness of the processing parameter set includes: For each processing parameter set in the first group of processing parameter sets, determining the first measurement result corresponding to the processing parameter set based on a corresponding parameter value of the processing parameter set; determining a measurement difference corresponding to the set of processing parameters based on the first measurement result and a second measurement result regarding the target size, the second measurement result being determined using a lithography stage that forms the wafer pattern; and Based on the measured differences, a fitness corresponding to the set of processing parameters is determined.

6. The method according to claim 1, further comprising: updating the first measurement result according to the updated one or more image processing parameters; And in response to the updated first measurement result satisfying a predetermined condition, determining target parameter values ​​of the one or more image processing parameters based on the parameter values ​​of the updated one or more image processing parameters.

7. The method according to claim 6, characterized in that The predetermined condition includes at least one of the following: The update number of the first measurement result is greater than a threshold number, or A measurement difference corresponding to the first measurement result is less than a difference threshold, and the measurement difference is determined based on the updated first measurement result and a second measurement result about the target size, and the second measurement result is determined using a lithography machine that forms the wafer pattern.

8. The method according to claim 1, characterized in that The first measurement result is determined by: determining a target profile of the wafer pattern based on the captured image and the one or more image processing parameters; determining one or more measurement locations on the target profile based on the one or more image processing parameters; as well as The first measurement result is determined based on the measured values ​​of the target size determined for the one or more measurement positions, respectively.

9. The method according to claim 1, characterized in that: The one or more image processing parameters include at least one of the following: Measuring position parameters, Target contour determination parameters, or Image preprocessing parameters.

10. An electronic device comprising: at least one processing unit; as well as At least one memory, the at least one memory being coupled to the at least one processing unit and storing instructions for execution by the at least one processing unit, the instructions causing the electronic device to perform the method according to any one of claims 1 to 9 when executed by the at least one processing unit.

11. A computer-readable storage medium having a computer program stored thereon, wherein the computer program can be executed by a processor to implement the method according to any one of claims 1 to 9.

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