Image alignment method and device, equipment, storage medium and program product
By automatically calculating the movement offset between the microscope image and the lithographic simulation image, the problems of low manual alignment efficiency and poor accuracy are solved, and efficient and accurate image alignment is achieved.
Patent Information
- Application Number
- CN202411300781.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-18
- Publication Date
- 2025-02-11
AI Technical Summary
During the chip manufacturing process, the manual alignment efficiency of photolithography simulation images and microscope images is low and the accuracy is poor, resulting in large errors in image alignment.
By acquiring the overlapping image composed of the photolithography simulation image and the microscope image, the spacing distance between the contour feature points in the microscope image and the matching feature points in the photolithography simulation image is determined, and the movement offset is solved based on the objective function, so as to automatically align it Microscope image.
It improves the efficiency and accuracy of image alignment, reduces the error caused by manual alignment, and realizes efficient alignment of lithographic simulation images and microscope images.
Smart Images
Figure CN119417874A_ABST
Abstract
Description
Technical Field
[0001] The present application belongs to the field of photolithography simulation technology, and in particular, relates to an image alignment method, device, equipment, storage medium and program product. Background Art
[0002] In the chip manufacturing process, as the line width continues to decrease, optical proximity effect correction based on lithography models has begun to be widely used. In the process of modeling the lithography model, in order to detect the accuracy of the lithography model, it is necessary to align the lithography simulation image of the lithography model with the corresponding microscope image generated by the scanning electron microscope and compare them to see if the two match.
[0003] In the existing method, the lithography simulation image is manually aligned with the corresponding microscope image.
[0004] However, due to the large number of images that need to be aligned and the large errors between manually aligned images, the efficiency of image alignment is low and the accuracy is poor. Summary of the invention
[0005] The embodiments of the present application provide an image alignment method, apparatus, device, storage medium and program product, which can improve the efficiency and accuracy of image alignment.
[0006] In one aspect of an embodiment of the present application, an image alignment method is provided, comprising:
[0007] Acquire a superimposed image consisting of a photolithography simulation image and a corresponding microscope image;
[0008] According to the superimposed image, respectively determine the spacing distances between different contour feature points in the microscope image and corresponding matching feature points in the lithography simulation image;
[0009] Based on multiple interval distances, solving the target movement offset corresponding to the microscope image when the objective function is minimum, the objective function is used to characterize the corresponding relationship between the movement offset of the microscope image and the distance accumulation value of the multiple interval distances;
[0010] The microscope image is moved according to the target movement offset so that the microscope image is aligned with the lithography simulation image.
[0011] In one aspect of an embodiment of the present application, an image alignment device is provided, comprising:
[0012] An image acquisition module, used to acquire an overlay image consisting of a photolithography simulation image and a corresponding microscope image;
[0013] A distance determination module, used to determine the interval distances between different contour feature points in the microscope image and corresponding matching feature points in the lithography simulation image, respectively, based on the overlay image;
[0014] An offset determination module is used to solve the target movement offset corresponding to the microscope image when the objective function is minimum based on multiple interval distances, and the objective function is used to characterize the corresponding relationship between the movement offset of the microscope image and the distance accumulation value of the multiple interval distances;
[0015] The image alignment module is used to move the microscope image according to the target movement offset so as to align the microscope image with the lithography simulation image.
[0016] In one aspect of an embodiment of the present application, an electronic device is provided, which includes: a memory and a program or instruction stored in the memory and executable on a processor, wherein when the program or instruction is executed by the processor, an image alignment method as provided in any aspect of the above-mentioned embodiment of the present application is implemented.
[0017] In one aspect of an embodiment of the present application, a readable storage medium is provided, on which a program or instruction is stored. When the program or instruction is executed by a processor, an image alignment method provided in any aspect of the above-mentioned embodiment of the present application is implemented.
[0018] In one aspect of an embodiment of the present application, a computer program product is provided. When instructions in the computer program product are executed by a processor of an electronic device, the electronic device executes an image alignment method provided in any aspect of the above-mentioned embodiment of the present application.
[0019] In the image alignment method provided by the embodiment of the present application, according to the stacked image composed of the lithography simulation image and the corresponding microscope image, the interval distance between different contour feature points in the microscope image and the corresponding matching feature points in the lithography simulation image is determined. Then, according to the objective function that characterizes the correspondence between the moving offset and the distance accumulation value of the corresponding multiple spacing distances, the moving offset corresponding to the minimum of the objective function is selected as the target moving offset, so that the alignment between the lithography simulation image and the corresponding microscope image in the stacked image can reach the highest. Finally, based on the target moving offset, the microscope image is automatically offset corrected, so that the microscope image is aligned with the lithography simulation image without manual image alignment. In this way, the embodiment of the present application calculates the target moving offset, and automatically performs offset correction processing on the stacked image according to the target moving offset, without manual alignment. At the same time, the target moving offset when the alignment of the stacked image is the highest is accurately determined by the objective function, overcoming the problem of large errors between aligned images caused by manual alignment, thereby improving the efficiency and accuracy of image alignment. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] In order to more clearly illustrate the technical solution of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.
[0021] Figure 1 is a flowchart of an image alignment method provided by an embodiment of the present application;
[0022] Figure 2 is a schematic diagram of an overlay image provided by an embodiment of the present application;
[0023] Figure 3 is a schematic diagram of a corrected overlay image provided by an embodiment of the present application;
[0024] Figure 4 It is a flowchart of a method for generating an overlay image provided by an embodiment of the present application;
[0025] Figure 5 This is a structural schematic diagram of the distance between the contour feature points and the matching feature points provided by an embodiment of the present application;
[0026] Figure 6 is a structural schematic diagram of an image alignment device provided by an embodiment of the present application;
[0027] Figure 7 It is a structural schematic diagram of an image alignment device provided by an embodiment of the present application. DETAILED DESCRIPTION
[0028] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, rather than to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by illustrating the examples of the present application.
[0029] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.
[0030] In the existing method, the lithography simulation image is manually aligned with the corresponding microscope image. However, due to the large number of images that need to be compared and the large errors between the manually aligned images, the efficiency and accuracy of the image alignment are low.
[0031] The purpose of the present application is to provide an image alignment method, device, equipment, storage medium and program product. In the image alignment method provided in the embodiment of the present application, according to the stacked image composed of the lithography simulation image and the corresponding microscope image, the interval distance between different contour feature points in the microscope image and the corresponding matching feature points in the lithography simulation image is determined. Then, according to the objective function that characterizes the correspondence between the moving offset and the distance accumulation value of the corresponding multiple spacing distances, the moving offset corresponding to the minimum of the objective function is selected as the target moving offset, so that the alignment between the lithography simulation image and the corresponding microscope image in the stacked image can reach the highest. Finally, based on the target moving offset, the microscope image is automatically offset corrected, so that the microscope image is aligned with the lithography simulation image without manual image alignment. In this way, the embodiment of the present application calculates the target moving offset, and automatically performs offset correction processing on the stacked image according to the target moving offset, without manual alignment. At the same time, the target moving offset when the alignment of the stacked image is the highest is accurately determined by the objective function, overcoming the problem of large errors between aligned images caused by manual alignment, thereby improving the efficiency and accuracy of image alignment.
[0032] The following describes specific embodiments of the image alignment method, device, equipment, storage medium, and program product provided by the embodiments of the present application. First, the image alignment method is introduced.
[0033] Figure 1 A flowchart of an image alignment method is provided. The image alignment method can be applied to a server. The image alignment method can include the following S101 to S104.
[0034] S101, obtaining a superimposed image consisting of a photolithography simulation image and a corresponding microscope image.
[0035] In this embodiment, the photolithography simulation image is an image obtained by inputting the mask pattern into a photolithography model for simulation. The photolithography model is a mathematical model for simulating the interaction between light, mask and photoresist in the photolithography process.
[0036] The microscope image is an image obtained by scanning the developed silicon wafer using a high-resolution electron microscope.
[0037] As an example, the server inputs the target mask pattern into the lithography model to obtain a lithography simulation image corresponding to the target mask pattern; and then uses a high-resolution electron microscope to obtain a microscope image after the actual lithography process is performed according to the target mask pattern.
[0038] Then the photolithography simulation image and the microscope image are superimposed to form a stacked image. Specifically, image processing software, such as Photoshop or MATLAB, can be used for the stacking operation. The stacked image can be the photolithography simulation image on top of the microscope image, or the microscope image on top of the photolithography simulation image.
[0039] Furthermore, in order to achieve better visual fusion of the two images, the brightness, contrast and color balance of the images may be adjusted.
[0040] like Figure 2 As shown, a schematic diagram of a superimposed image is provided. It can be clearly seen that the contour of the lithography simulation image and the contour of the microscope image are not aligned at this time, and there is a large deviation.
[0041] S102: Determine the spacing distances between different contour feature points in the microscope image and corresponding matching feature points in the lithography simulation image according to the overlay image.
[0042] In this embodiment, the contour feature points are feature points on the contour of the photoresist pattern. Different contour feature points can be identified by using an image processing algorithm. For example, the image processing algorithm may include an edge detection algorithm or a corner detection algorithm.
[0043] As an example, the server first identifies multiple different contour feature points in the microscope image through an edge detection algorithm. Then, through an image registration algorithm, matching feature points corresponding to the contour feature points identified in the microscope image are found in the lithography simulation image. Specifically, the image registration algorithm may include a feature point matching method or a transform domain matching method.
[0044] Then, for each pair of matched feature points, the coordinate difference between them in the microscope image and the lithography simulation image, i.e., the separation distance, is calculated.
[0045] S103, based on the multiple interval distances, solving the target movement offset corresponding to the microscope image when the objective function is minimum, the objective function is used to characterize the corresponding relationship between the movement offset of the microscope image and the distance accumulation value of the multiple interval distances.
[0046] In this embodiment, the objective function can be designed as a sum of squares of multiple interval distances, wherein the independent variable of the objective function is the movement offset, and the dependent variable of the objective function is the sum of squares of the interval distances.
[0047] As an example, after obtaining each interval distance, the server constructs an objective function according to each interval distance. Then, an optimization algorithm is used to solve the target movement offset of the microscope image corresponding to the minimum objective function. The optimization algorithm may be a gradient descent method or a Newton method.
[0048] S104, moving the microscope image according to the target movement offset, so as to align the microscope image with the photolithography simulation image.
[0049] In this embodiment, the server moves the microscope image according to the target movement offset obtained by solving, so that the microscope image and the lithography simulation image are aligned to the greatest extent. Specifically, the movement of the microscope image can be achieved by the translation transformation function in the image processing software to ensure that the microscope image maintains clarity and resolution during the movement.
[0050] like Figure 3 As shown, a schematic diagram of a corrected overlay image is provided. It can be clearly seen that after the microscope image is moved, the contour of the microscope image is basically aligned with the contour of the lithography simulation image, and the deviation between the two is small.
[0051] In the image alignment method provided in the present embodiment, according to the stacked image composed of the lithography simulation image and the corresponding microscope image, the interval distance between different contour feature points in the microscope image and the corresponding matching feature points in the lithography simulation image is determined. Then, according to the objective function that characterizes the correspondence between the moving offset and the distance accumulation value of the corresponding multiple spacing distances, the moving offset corresponding to the minimum of the objective function is selected as the target moving offset, so that the alignment between the lithography simulation image and the corresponding microscope image in the stacked image can reach the highest. Finally, based on the target moving offset, the microscope image is automatically offset corrected, so that the microscope image is aligned with the lithography simulation image without manual image alignment. In this way, the embodiment of the present application calculates the target moving offset, and automatically performs offset correction processing on the stacked image according to the target moving offset, without manual alignment. At the same time, the target moving offset when the alignment of the stacked image is the highest is accurately determined by the objective function, overcoming the problem of large errors between aligned images caused by manual alignment, thereby improving the efficiency and accuracy of image alignment.
[0052] As an optional embodiment, S101 may specifically include:
[0053] Acquire a mask image and a microscope image information file corresponding to the mask image;
[0054] Inputting the mask image into the lithography model to obtain a lithography simulation image corresponding to the mask image;
[0055] Generate a microscope image according to the microscope image information file;
[0056] The microscope image is superimposed on the lithography simulation image to obtain an overlay image corresponding to the mask image.
[0057] In this embodiment, the mask image is a binary image used to define the area that needs to be exposed during the photolithography process, wherein a pixel value other than 0 in the mask image indicates an area that needs to be exposed, and a pixel value of 0 indicates an area that does not need to be exposed.
[0058] The microscope image information file is a file for storing metadata information of the microscope image. For example, the microscope image information file may include information such as the path, resolution, and size of the microscope image.
[0059] The microscope image information file may be in various file formats such as a text file, a table file, and a compressed file. For example, the microscope image information file may be a text file in a txt format.
[0060] As an example, Figure 4 As shown, a schematic flow chart of a method for generating an overlay image is provided.
[0061] The server first obtains the mask image 410 and the microscope image information file 430 corresponding to the mask image 410. Then, the lithography model 420 is constructed using the lithography simulation software, and the parameters of the lithography machine are set in the lithography model 420. Specifically, the lithography simulation software can be TCAD or K-Layout, and the parameters of the lithography machine can include the wavelength of the light source, the exposure time, and the type of photoresist. The mask image 410 is input into the constructed lithography model 420, and the lithography model 420 performs simulation calculations based on the input mask image and the set parameters, thereby generating a lithography simulation image 440.
[0062] Then, the server reads the metadata stored in the microscope image information file 430 , and generates a microscope image 450 corresponding to the mask image 410 according to the metadata.
[0063] Then, the photolithography simulation image 440 and the microscope image 450 are superimposed using image processing software, and the brightness, contrast and color balance of the image are adjusted, thereby obtaining a superimposed image 460 corresponding to the mask image 410 .
[0064] Through this embodiment, the mask image is input into the lithography model to obtain a lithography simulation image corresponding to the mask image; and a microscope image corresponding to the mask image is generated according to the microscope image information file. Finally, the microscope image is superimposed on the lithography simulation image to obtain an overlay image corresponding to the mask image. In this way, by comparing the lithography simulation image and the overlay image through the overlay image, it is possible to intuitively observe whether the photoresist pattern contours of the two match, thereby being able to accurately identify the simulation accuracy of the lithography model.
[0065] As an optional embodiment, the microscope image information file includes pixel physical size, image storage address and image feature point coordinates;
[0066] Generate a microscope image according to the microscope image information file, which may specifically include:
[0067] Get the initial scanned image from the image storage address;
[0068] According to the physical size of pixels, the initial scanned image is corrected to obtain a microscope image;
[0069] Superimposing the microscope image onto the lithography simulation image to obtain an overlay image corresponding to the mask image may specifically include:
[0070] According to the coordinates of the image feature points, the microscope image is superimposed on the position corresponding to the coordinates of the image feature points in the lithography simulation image to obtain a superimposed image corresponding to the mask image.
[0071] In this embodiment, the initial scanned image is an image obtained by scanning with a high-resolution electron microscope in advance without any processing.
[0072] The physical size of a pixel is used to characterize the physical size that a microscope image can be expected to reach.
[0073] The image feature point coordinates are the coordinates of a position point with obvious features in the microscope image. For example, the image feature point coordinates may be the coordinates of the center point of the microscope image.
[0074] As shown in Table 1, a microscope image information file is provided. The first column in the microscope image information file is the image storage address of each microscope image. The second column in the microscope image information file is the X-axis coordinate in the image feature point coordinates of each microscope image, and the third column in the microscope image information file is the Y-axis coordinate in the image feature point coordinates of each microscope image. The fourth column in the microscope image information file is the X-axis size in the pixel physical size of each microscope image, and the fifth column in the microscope image information file is the Y-axis size in the pixel physical size of each microscope image.
[0075] Table 1 Microscope image information files
[0076] Image storage address X-axis coordinate Y-axis coordinate X-axis size Y-axis size / data / 100.jpg -274150 3214200 8 8 / data / 145.jpg -968350 -981020 8 8 / data / 206.jpg -1119850 -3010730 8 8 / data / 207.jpg -1051850 -3010770 8 8 / data / 224.jpg -1595850 -2710610 8 8 / data / 262.jpg -1459850 -2500250 8 8 / data / 374.jpg -1149650 1078610 8 8
[0077] As an example, the server uses the corresponding image processing library to load the initial image from the image storage address, and then adjusts the resolution or pixel density of the initial image according to the pixel physical size so that the initial image reaches the expected pixel physical size, thereby obtaining a microscope image.
[0078] Specifically, the resolution of the original image can be changed by resampling to achieve the expected physical size of pixels in the microscope image.
[0079] Then, when the microscope image is superimposed on the lithography simulation image, the center point coordinates of the microscope image are first determined according to the image feature point coordinates. Then, according to the center point coordinates of the microscope image, the microscope image is superimposed on the corresponding position in the lithography simulation image, thereby obtaining a superimposed image corresponding to the mask image.
[0080] Through this embodiment, the initial scanned image is first obtained according to the image storage address in the microscope image information file. Then, the initial scanned image is corrected according to the pixel physical size in the microscope image information file. In this way, it can be ensured that the microscope image finally obtained meets the expected requirements, so that it can be ensured that the simulation accuracy of the lithography model can be accurately identified by visually observing whether the photoresist pattern contour of the superimposed image matches.
[0081] As an optional embodiment, determining the spacing distances between different contour feature points in the microscope image and corresponding matching feature points in the lithography simulation image respectively according to the overlay image may specifically include:
[0082] According to the superimposed image, different contour feature points in the microscope image are obtained;
[0083] For each contour feature point, respectively obtain a first straight line and a second straight line where the contour feature point is located, the first straight line and the second straight line being perpendicular;
[0084] According to the first straight line and the second straight line where each contour feature point is located, respectively determine a first distance in the first direction and a second distance in the second direction between each contour feature point in the microscope image and a corresponding matching feature point in the lithography simulation image;
[0085] According to the first distance and the second distance corresponding to each contour feature point, the spacing distance between each contour feature point in the microscope image and the corresponding matching feature point in the lithography simulation image is determined respectively.
[0086] In this embodiment, the first straight line can be a straight line along the x-axis direction of the plane rectangular coordinate system, and the second straight line is a straight line along the y-axis direction of the plane rectangular coordinate system; the first straight line can also be a straight line along the y-axis direction of the plane rectangular coordinate system, and the second straight line is a straight line along the x-axis direction of the plane rectangular coordinate system.
[0087] As an example, Figure 5 As shown, a structural schematic diagram of the spacing distance between a contour feature point and a matching feature point is provided. The server constructs a first straight line along the x-axis direction and a second straight line along the y-axis direction for the contour feature point A on the microscope image 450. Then, on the first straight line along the x-axis direction, the first distance D1 between the contour feature point A in the microscope image 450 and the corresponding matching feature point B in the lithography simulation image 440 is measured in the x-axis direction; at the same time, on the second straight line along the y-axis direction, the second distance D2 between the contour feature point A in the microscope image 450 and the corresponding matching feature point B in the lithography simulation image 440 is measured in the y-axis direction.
[0088] Finally, according to the first distance D1 and the second distance D2, the actual spacing distance between the contour feature point A in the microscope image and the corresponding matching feature point B in the lithography simulation image is calculated. Specifically, the spacing distance can be calculated using the Euclidean distance formula or the Manhattan distance formula.
[0089] Through this embodiment, by constructing the first straight line and the second straight line, the first distance in the first direction and the second distance in the second direction between the contour feature point and the matching feature point are obtained. Finally, the interval distance between the contour feature point and the matching feature point can be accurately determined according to the first distance and the second distance. This helps to determine the optimal target movement offset of the microscope image according to the interval distance between the contour feature point and the matching feature point, thereby improving the accuracy of image alignment.
[0090] As an optional embodiment, determining the interval distance between each contour feature point in the microscope image and the corresponding matching feature point in the lithography simulation image according to the first distance and the second distance corresponding to each contour feature point may specifically include:
[0091] The following steps are executed repeatedly until the first distance and the second distance corresponding to each contour feature point are traversed:
[0092] According to the first distance and the second distance, a corresponding first distance square value and a corresponding second distance square value are obtained;
[0093] The first squared distance value and the second squared distance value are added and then square rooted to obtain the interval distance between the contour feature point in the microscope image and the corresponding matching feature point in the lithography simulation image.
[0094] In this embodiment, the interval distance between the contour feature point and the matching feature point can be specifically determined by the following formula 1:
[0095]
[0096] Where D represents the distance between the contour feature point and the corresponding matching feature point. Represents the square value of the distance between the contour feature point and the corresponding matching feature point in the x-axis direction. Indicates the square of the distance between the contour feature point and the corresponding matching feature point in the y-axis direction.
[0097] Among them, when the distance in the x-axis direction is larger, the interval distance between the contour feature point and the matching feature point is larger; when the distance in the y-axis direction is larger, the interval distance between the contour feature point and the matching feature point is also larger.
[0098] Through this embodiment, the Euclidean distance formula is used to accurately calculate the interval between the contour feature point and the matching feature point, which helps to determine the optimal target movement offset of the microscope image based on the interval between the contour feature point and the matching feature point, thereby improving the accuracy of image alignment.
[0099] In this embodiment, before S103, the image alignment method may further include:
[0100] Accumulate multiple interval distances to obtain a distance accumulation value;
[0101] The moving offset is used as the independent variable, the accumulated distance value is corrected, and the objective function is constructed.
[0102] In this embodiment, the movement offset is the independent variable of the function, and the distance accumulation value is the dependent variable of the function.
[0103] As an example, the objective function can be specifically determined by the following formula 2:
[0104]
[0105] In the formula, f(x,y) is the objective function, Indicates the movement offset in the x-axis direction. Indicates the movement offset in the y-axis direction. It represents the square value of the distance between the i-th contour feature point and the corresponding matching feature point in the x-axis direction. Represents the square value of the distance between the i-th contour feature point and the corresponding matching feature point in the y-axis direction. It means accumulation from the i-th to the n-th, where n is the total number of contour feature points.
[0106] in, That is, the corrected distance accumulation value. In this way, when the objective function value is minimum, it is the moment when the alignment degree between the microscope image and the photolithography simulation image is the highest. Therefore, the movement offset corresponding to the microscope image when the objective function is minimum is determined as the target movement offset.
[0107] Through this embodiment, the objective function is constructed, and the movement offset corresponding to the microscope image when the objective function is minimum is determined as the target movement offset. In this way, the alignment degree between the microscope image and the lithography simulation image can be maximized, thereby improving the accuracy of image alignment.
[0108] Based on the image alignment method, accordingly, the present application also provides a specific embodiment of the image alignment device.
[0109] like Figure 6 As shown, the image alignment device 600 provided in the embodiment of the present application includes an image acquisition module 610 , a distance determination module 620 , an offset determination module 630 and an image alignment module 640 .
[0110] An image acquisition module 610 is used to acquire an overlay image consisting of a photolithography simulation image and a corresponding microscope image;
[0111] A distance determination module 620 is used to determine the interval distances between different contour feature points in the microscope image and corresponding matching feature points in the lithography simulation image according to the overlay image;
[0112] An offset determination module 630 is used to solve the target movement offset corresponding to the microscope image when the objective function is minimized based on multiple interval distances, and the objective function is used to characterize the corresponding relationship between the movement offset of the microscope image and the distance accumulation value of the multiple interval distances;
[0113] The image alignment module 640 is used to move the microscope image according to the target movement offset so as to align the microscope image with the lithography simulation image.
[0114] As an optional embodiment, the image acquisition module 610 specifically includes the following units:
[0115] A file acquisition unit, used for acquiring a mask image and a microscope image information file corresponding to the mask image;
[0116] An image input unit, used to input the mask image into the lithography model to obtain a lithography simulation image corresponding to the mask image;
[0117] An image generating unit, used for generating a microscope image according to the microscope image information file;
[0118] The image superposition unit is used to superimpose the microscope image on the photolithography simulation image to obtain a superimposed image corresponding to the mask image.
[0119] As an optional embodiment, the microscope image information file includes pixel physical size, image storage address and image feature point coordinates;
[0120] The image generation unit specifically includes the following subunits:
[0121] An image acquisition subunit, used for acquiring an initial scanned image from an image storage address;
[0122] An image correction subunit, used to correct the initial scanned image according to the physical size of the pixels to obtain a microscope image;
[0123] The image overlay unit is specifically used for:
[0124] According to the coordinates of the image feature points, the microscope image is superimposed on the position corresponding to the coordinates of the image feature points in the lithography simulation image to obtain a superimposed image corresponding to the mask image.
[0125] As an optional embodiment, the distance determination module 620 specifically includes the following units:
[0126] A feature point acquisition unit, used for acquiring different contour feature points in the microscope image according to the superimposed image;
[0127] A straight line acquisition unit, used for respectively acquiring, for each contour feature point, a first straight line and a second straight line where the contour feature point is located, the first straight line and the second straight line being perpendicular;
[0128] A distance determination unit, for determining, according to the first straight line and the second straight line where each contour feature point is located, a first distance in the first direction and a second distance in the second direction between each contour feature point in the microscope image and a corresponding matching feature point in the lithography simulation image;
[0129] The distance determination unit is further used to determine the interval distance between each contour feature point in the microscope image and the corresponding matching feature point in the lithography simulation image according to the first distance and the second distance corresponding to each contour feature point.
[0130] As an optional embodiment, the distance determination unit specifically includes the following subunits:
[0131] The loop execution subunit is used to loop the following subunits until the first distance and the second distance corresponding to each contour feature point are traversed:
[0132] A distance calculation subunit, configured to obtain a first distance square value and a second distance square value corresponding to the first distance and the second distance;
[0133] The distance calculation subunit is further used to add the first distance square value and the second distance square value and then perform square root processing to obtain the interval distance between the contour feature point in the microscope image and the corresponding matching feature point in the lithography simulation image.
[0134] As an optional embodiment, based on multiple interval distances, before solving the target movement offset corresponding to the microscope image when the objective function is minimized, the image alignment device 600 may further include the following modules:
[0135] A distance accumulation module, used for accumulating a plurality of the interval distances to obtain the distance accumulation value;
[0136] The function construction module is used to correct the distance accumulation value with the moving offset as the independent variable to construct the target function.
[0137] Based on the image alignment method, accordingly, the present application also provides a specific embodiment of the image alignment device.
[0138] Figure 7 A schematic diagram of the hardware structure of the image alignment device provided in an embodiment of the present application is shown.
[0139] The image alignment device may include a processor 701 and a memory 702 storing computer program instructions.
[0140] Specifically, the processor 701 may include a central processing unit (CPU), or an application specific integrated circuit (ASIC), or may be configured to implement one or more integrated circuits of the embodiments of the present application.
[0141] The memory 702 may include a large capacity memory for data or instructions. By way of example and not limitation, the memory 702 may include a hard disk drive (HDD), a floppy disk drive, a flash memory, an optical disk, a magneto-optical disk, a magnetic tape, or a universal serial bus (USB) drive or a combination of two or more of these. In appropriate cases, the memory 702 may include a removable or non-removable (or fixed) medium. In appropriate cases, the memory 702 may be inside or outside the integrated gateway disaster recovery device. In a specific embodiment, the memory 702 is a non-volatile solid-state memory.
[0142] The processor 701 implements any one of the image alignment methods in the above embodiments by reading and executing computer program instructions stored in the memory 702 .
[0143] In one example, the image alignment device may further include a communication interface 703 and a bus 710. Figure 7 As shown, the processor 701, the memory 702, and the communication interface 703 are connected via a bus 710 and communicate with each other.
[0144] The communication interface 703 is mainly used to implement communication between various modules, devices, units and / or equipment in the embodiments of the present application.
[0145] Bus 710 includes hardware, software or both, and the components of image alignment device are coupled to each other. For example, but not limitation, bus may include accelerated graphics port (AGP) or other graphics bus, enhanced industrial standard architecture (EISA) bus, front side bus (FSB), hypertransport (HT) interconnection, industrial standard architecture (ISA) bus, infinite bandwidth interconnection, low pin count (LPC) bus, memory bus, micro channel architecture (MCA) bus, peripheral component interconnection (PCI) bus, PCI-Express (PCI-X) bus, serial advanced technology attachment (SATA) bus, video electronics standard association local (VLB) bus or other suitable bus or two or more of these combinations. In appropriate cases, bus 710 may include one or more buses. Although the present application embodiment describes and shows a specific bus, the present application considers any suitable bus or interconnection.
[0146] In addition, in combination with the image alignment method in the above embodiment, the embodiment of the present application can provide a computer storage medium for implementation. The computer storage medium stores computer program instructions; when the computer program instructions are executed by a processor, any one of the image alignment methods in the above embodiment is implemented.
[0147] In addition, in combination with the image alignment method in the above-mentioned embodiment, the embodiment of the present application may provide a computer program product for implementation. When the instructions in the computer program product are executed by a processor of an electronic device, the electronic device executes the image alignment method provided by any aspect of the above-mentioned embodiment of the present application.
[0148] It should be clear that the present application is not limited to the specific configuration and processing described above and shown in the figures. For the sake of simplicity, a detailed description of the known method is omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present application is not limited to the specific steps described and shown, and those skilled in the art can make various changes, modifications and additions, or change the order between the steps after understanding the spirit of the present application.
[0149] The functional blocks shown in the above-described block diagram can be implemented as hardware, software, firmware or a combination thereof. When implemented in hardware, it can be, for example, an electronic circuit, an application specific integrated circuit (ASIC), appropriate firmware, a plug-in, a function card, etc. When implemented in software, the elements of the present application are programs or code segments that are used to perform the required tasks. The program or code segment can be stored in a machine-readable medium, or transmitted on a transmission medium or a communication link by a data signal carried in a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, optical fiber media, radio frequency (RF) links, etc. The code segment can be downloaded via a computer network such as the Internet, an intranet, etc.
[0150] It should also be noted that the exemplary embodiments mentioned in this application describe some methods or systems based on a series of steps or devices. However, this application is not limited to the order of the above steps, that is, the steps can be performed in the order mentioned in the embodiment, or in a different order from the embodiment, or several steps can be performed simultaneously.
[0151] Aspects of the present disclosure are described above with reference to the flowchart and / or block diagram of the method, device (system) and computer program product according to the embodiment of 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 program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device to produce a machine so that these instructions executed by the processor of the computer or other programmable data processing device enable the implementation of the function / action specified in one or more boxes of the flowchart and / or block diagram. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field programmable logic circuit. It can also be understood that each box in the block diagram and / or flowchart and the combination of boxes in the block diagram and / or flowchart can also be implemented by dedicated hardware that performs a specified function or action, or can be implemented by a combination of dedicated hardware and computer instructions.
[0152] The above is only a specific implementation of the present application. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the systems, modules and units described above can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here. It should be understood that the protection scope of the present application is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in this application, and these modifications or replacements should be included in the protection scope of this application.
Claims
1. An image alignment method, characterized in that: include: Acquire a superimposed image consisting of a photolithography simulation image and a corresponding microscope image; According to the stacked image, respectively determining the spacing distances between different contour feature points in the microscope image and corresponding matching feature points in the lithography simulation image; Based on the multiple interval distances, solving the target movement offset corresponding to the microscope image when the objective function is minimum, the objective function is used to characterize the corresponding relationship between the movement offset of the microscope image and the distance accumulation value of the multiple interval distances; The microscope image is moved according to the target movement offset so as to align the microscope image with the photolithography simulation image.
2. The method according to claim 1, characterized in that: The step of obtaining a superimposed image of a lithography simulation image and a corresponding microscope image includes: Acquire a mask image and a microscope image information file corresponding to the mask image; Inputting the mask image into a lithography model to obtain the lithography simulation image corresponding to the mask image; generating the microscope image according to the microscope image information file; The microscope image is superimposed on the photolithography simulation image to obtain the superimposed image corresponding to the mask image.
3. The method according to claim 2, characterized in that The microscope image information file includes pixel physical size, image storage address and image feature point coordinates; Generating the microscope image according to the microscope image information file includes: Acquire an initial scanned image from the image storage address; According to the physical size of the pixel, the initial scanned image is corrected to obtain the microscope image; The step of superimposing the microscope image onto the photolithography simulation image to obtain the superimposed image corresponding to the mask image includes: According to the image feature point coordinates, the microscope image is superimposed on a position in the lithography simulation image corresponding to the image feature point coordinates to obtain the superimposed image corresponding to the mask image.
4. The method according to any one of claims 1 to 3, characterized in that: The step of respectively determining the spacing distances between different contour feature points in the microscope image and corresponding matching feature points in the lithography simulation image according to the overlay image comprises: According to the stacked image, different contour feature points in the microscope image are acquired; For each of the contour feature points, respectively obtain a first straight line and a second straight line where the contour feature point is located, the first straight line and the second straight line being perpendicular; Determine, according to the first straight line and the second straight line where each of the contour feature points is located, a first distance in the first direction and a second distance in the second direction between each of the contour feature points in the microscope image and a corresponding matching feature point in the lithography simulation image; According to the first distance and the second distance corresponding to each of the contour feature points, the interval distance between each contour feature point in the microscope image and the corresponding matching feature point in the lithography simulation image is determined respectively.
5. The method according to claim 4, characterized in that The determining, according to the first distance and the second distance corresponding to each of the contour feature points, respectively the spacing distance between each contour feature point in the microscope image and the corresponding matching feature point in the lithography simulation image comprises: The following steps are executed in a loop until the first distance and the second distance corresponding to each of the contour feature points are traversed: Obtaining a corresponding first distance square value and a second distance square value according to the first distance and the second distance; The first squared distance value and the second squared distance value are added and then square rooted to obtain the interval distance between the contour feature point in the microscope image and the corresponding matching feature point in the lithography simulation image.
6. The method according to any one of claims 1 to 3, characterized in that: Before solving the target movement offset corresponding to the microscope image when the objective function is minimized based on the multiple interval distances, the method further includes: Accumulate a plurality of the interval distances to obtain the distance accumulation value; The distance accumulation value is corrected with the movement offset as an independent variable to construct the objective function.
7. An image alignment device, characterized in that: include: An image acquisition module, used to acquire an overlay image consisting of a photolithography simulation image and a corresponding microscope image; A distance determination module, used to determine the interval distances between different contour feature points in the microscope image and corresponding matching feature points in the lithography simulation image, respectively, according to the overlay image; An offset determination module, used to solve the target movement offset corresponding to the microscope image when the objective function is minimized based on the multiple interval distances, wherein the objective function is used to characterize the corresponding relationship between the movement offset of the microscope image and the distance accumulation value of the multiple interval distances; The image alignment module is used to move the microscope image according to the target movement offset so as to align the microscope image with the photolithography simulation image.
8. An electronic device, characterized in that: The device comprises: a processor and a memory storing computer program instructions; When the processor executes the computer program instructions, the image alignment method according to any one of claims 1 to 6 is implemented.
9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer program instructions, and when the computer program instructions are executed by a processor, the image alignment method according to any one of claims 1 to 6 is implemented.
10. A computer program product, characterized in that When the instructions in the computer program product are executed by a processor of an electronic device, the electronic device executes the image alignment method as described in any one of claims 1 to 6.