Image correction method, device, semiconductor quantity detection method, equipment, medium, product

Abstract

The present application relates to a method for correcting an image, including: setting a calibration object in the field of view of a line scan camera, the image collected by the line scan camera includes a valid image of the sample under test and a calibration image corresponding to the calibration object; based on the acceleration, initial velocity, frame rate and uniform speed in the uniform speed stage during the acquisition of the line scan camera, a deformation function is determined, the deformation function represents the relationship between the coordinates of the pixel points on the variable speed image and the coordinates of the corresponding pixel points on the corrected image; based on the calibration image and the deformation function, the actual initial velocity of the line scan camera is determined; based on the actual initial velocity, the deformation function, the coordinates of the pixel points on the variable speed image and the grayscale of the pixel points, the variable speed image is corrected to obtain the corrected image. The present application also relates to an image correction device, a semiconductor quantity detection method, equipment, medium and product.

Description

Technical Field

[0001] The present application relates to the field of semiconductor quantity detection, and in particular to an image correction method, device, semiconductor quantity detection method, equipment, medium, and product. Background Art

[0002] When using a testing device or a measuring device equipped with a line scan camera to measure the sample to be tested, the line scan camera and the sample to be tested are usually moved at a constant speed relative to each other to collect images, and the multiple images collected are spliced ​​to obtain a complete image. However, the line scan camera has acceleration and deceleration stages in the start and stop process of collecting images, which causes the collected images to be deformed, so that the speed-changing images collected in the speed-changing stage cannot reflect the true morphological data of the sample to be tested. Summary of the invention

[0003] In order to solve the problem of deformation of the images captured in the above-mentioned variable speed stage, the present application proposes an image correction method for correcting the image of the sample under test captured by a line scan camera. There are a variable speed stage and a uniform speed stage during the capture of the line scan camera, and the image of the sample under test includes a variable speed image captured in the variable speed stage and a uniform speed image captured in the uniform speed stage.

[0004] The method comprises the following steps: setting a calibration object in the field of view of the line scan camera, wherein the image acquired by the line scan camera comprises a valid image of the sample under test and a calibration image corresponding to the calibration object; determining a deformation function based on the acceleration, initial velocity, frame rate and uniform velocity in the uniform velocity stage during acquisition by the line scan camera, wherein the deformation function represents the relationship between the coordinates of the pixel points on the variable velocity image and the coordinates of the corresponding pixel points on the corrected image; determining the actual initial velocity of the line scan camera based on the calibration image and the deformation function; and correcting the variable velocity image based on the actual initial velocity, the deformation function, the coordinates of the pixel points on the variable velocity image and the grayscale of the pixel points to obtain the corrected image.

[0005] Optionally, the position of the calibration object is set so that all or part of the calibration image is aligned with the speed-shifted image in the effective image.

[0006] Optionally, the calibration object is arranged on a side of the sample to be measured, so that the line scan camera collects images of the sample to be measured and the calibration object at the same time.

[0007] Optionally, the calibration object is suitable for providing a plurality of periodically arranged calibration marks in the calibration image, and an arrangement direction of the calibration marks is parallel to a movement direction acquired by the line scan camera.

[0008] Optionally, based on the acceleration, initial velocity, frame rate and uniform speed in the uniform speed stage during acquisition by the line scan camera, determining the deformation function includes:

[0009] When the speed change stage is the acceleration stage:

[0010] The length coordinate of the speed-changing image is determined by the following formula:

[0011] ,

[0012] in, is the length coordinate of the speed-changing image, is the frame rate, is the acceleration during the acceleration phase, is the initial velocity, is the speed at any time point in the acceleration phase;

[0013] The speed at any time point in the acceleration phase is determined by the following formula for:

[0014] ,

[0015] in, is the initial velocity Speed ​​up to The acceleration time used when

[0016] The length coordinate of the variable speed image is converted into the length coordinate of the uniform speed image by the following formula:

[0017] ,

[0018] in, is the length coordinate of the uniform speed image, is the uniform speed;

[0019] Combining the above formulas, the deformation function can be obtained as follows:

[0020] .

[0021] Optionally, the calibration image and the deformation function include:

[0022] Determine the search range of the initial velocity, including the step size, traversal starting point and traversal end point of the initial velocity;

[0023] Applying the ergodic accumulation method to bring each initial velocity into the deformation function respectively, and calculating the length coordinate of the corresponding corrected image of the speed-varying image, and the periodic spacing of the calibration image in the corresponding corrected image;

[0024] The standard deviation of the periodic spacing of the calibration marks corresponding to different initial velocities is calculated, and the initial velocity corresponding to the minimum value of the standard deviation is determined as the actual initial velocity.

[0025] Optionally, based on the acceleration, initial velocity, frame rate and uniform speed in the uniform speed stage during acquisition by the line scan camera, determining the deformation function includes:

[0026] When the speed change stage is the deceleration stage:

[0027] The length coordinate of the speed-changing image is determined by the following formula:

[0028] ,

[0029] in, is the length coordinate of the speed-changing image, is the frame rate, is the acceleration during the deceleration phase, is the uniform speed, is the speed at any time point in the deceleration stage;

[0030] The speed at any time point in the deceleration phase is determined by the following formula v 2 is:

[0031] ,

[0032] in, is the uniform speed Slow down to The deceleration time used when

[0033] The length coordinate of the variable speed image is converted into the length coordinate of the uniform speed image by the following formula:

[0034] ,

[0035] in, is the length coordinate of the uniform speed image;

[0036] Combining the above formulas, the deformation function can be obtained as follows:

[0037] .

[0038] Optionally, the grayscale of the pixel is obtained by bilinear interpolation.

[0039] The present application also proposes an image correction device, which is used to correct the image of a sample under test acquired by a line scan camera. The line scan camera has a variable speed stage and a uniform speed stage during acquisition. The image of the sample under test includes a variable speed image acquired in the variable speed stage and a uniform speed image acquired in the uniform speed stage. The device includes:

[0040] A calibration image unit, used to set a calibration object in the field of view of the line scan camera, wherein the image collected by the line scan camera includes a valid image of the sample under test and a calibration image corresponding to the calibration object;

[0041] A deformation function unit, for determining a deformation function based on the acceleration, initial velocity, frame rate and uniform speed in the uniform speed stage during acquisition by the line scan camera, wherein the deformation function represents the relationship between the coordinates of the pixel points on the variable speed image and the coordinates of the corresponding pixel points on the corrected image;

[0042] an initial velocity acquisition unit, configured to determine an actual initial velocity of the line scan camera based on the calibration image and the deformation function;

[0043] An image correction unit is used to correct the speed-changing image based on the actual initial velocity, the deformation function, the coordinates of the pixel points on the speed-changing image and the grayscale of the pixel points to obtain the corrected image.

[0044] The present application also proposes a semiconductor quantity detection method, comprising:

[0045] Obtaining a corrected image of the speed-changing image by the image correction method as described above;

[0046] splicing the corrected image and the uniform speed image into a detection image of the tested sample;

[0047] Extracting the grayscale value of each pixel coordinate in the detection image;

[0048] The grayscale value of each pixel coordinate is analyzed and processed according to the detection standard to obtain the quantity detection result.

[0049] Optionally, a bilinear interpolation method is used to extract the grayscale of each pixel coordinate in the detection image.

[0050] The present application also proposes an electronic device, which includes a memory storing computer-executable instructions and a processor; when the instructions are executed by the processor, the device implements the aforementioned method.

[0051] The present application also proposes a computer-readable medium, which stores one or more programs. The one or more programs can be executed by one or more processors to implement the aforementioned method.

[0052] The present application also proposes a computer program product, comprising a computer program, wherein the computer program implements the aforementioned method when executed by a processor.

[0053] The image correction method proposed in the present application determines the initial velocity of the line scan camera during acquisition by setting a calibration object and a simple deformation function, and then can correct the image deformation caused by the acceleration and deceleration process of the line scan camera during image acquisition, so that the image acquired by the line scan camera in the acceleration and deceleration stage at the start and / or end stage is consistent with the image acquired in the uniform speed stage, that is, the ratio of the surface size of the sample under test represented by each pixel scanned by the camera is kept consistent, and the morphological data of the sample under test can be reflected at a uniform ratio.

[0054] Furthermore, in the implementation of the semiconductor quantity detection method of the present application, during the image acquisition stage of the sample to be tested, combined with the above-mentioned image correction method, it is equivalent to simultaneously performing the image pre-alignment and preprocessing process, thereby reducing the amount of calculation and time required for detecting objects using a line scan camera, and improving the efficiency of the entire process. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 is a flowchart of an image correction method according to an embodiment of the present application.

[0056] Figure 2 is a schematic diagram of a calibration object according to an embodiment of the present application.

[0057] Figure 3 It is a schematic diagram of the positions of the calibration object and the sample to be tested according to the implementation mode of the present application.

[0058] Figure 4 It is a flow chart of determining the actual initial velocity based on the calibration image and the deformation function according to an embodiment of the present application.

[0059] Figure 5 It is a corresponding relationship diagram between adjacent period spacing and initial velocity according to the implementation mode of the present application.

[0060] Figure 6 It is a corresponding relationship diagram between the standard deviation of the adjacent period intervals and the initial velocity according to the implementation mode of the present application.

[0061] Figure 7 These are the image before correction and the image after correction according to the embodiments of the present application.

[0062] Figure 8 It is a structural diagram of an image correction device according to an embodiment of the present application.

[0063] Fig. 9 is a flow chart of a semiconductor quantity detection method according to an embodiment of the present application.

[0064] Fig.10 is a structural diagram of an electronic device according to an embodiment of the present application. DETAILED DESCRIPTION

[0065] Next, the method and device proposed in this application will be described with reference to the accompanying drawings.

[0066] During the image acquisition process, the line scan camera only captures a single line of images each time, and each line of images has a fixed pixel width. For example, the width of a single acquired image may be 1 pixel, 3 pixels, 5 pixels, or 7 pixels, etc. Through relative movement with the sample under test along the width direction of the single line of images (i.e., the acquisition direction of the line scan camera), the line scan camera continuously performs n line-by-line scans to accumulate image data. These line-by-line acquired image data are eventually spliced ​​into a complete two-dimensional image. The length of the two-dimensional image is equal to the sum of the widths of the single line images acquired n times, and is proportional to the relative movement distance between the line scan camera and the sample under test. In some specific embodiments, the n times are thousands or tens of thousands of times.

[0067] In view of the acquisition characteristics of the line scan camera, this relative motion should maintain a uniform speed. Ensure that in the two-dimensional image acquired by the line scan camera, in the width direction of the single-line image (i.e. the acquisition direction of the line scan camera), the proportion of the surface size of the sample scanned by the camera represented by each pixel is consistent.

[0068] Furthermore, for a specific line scan camera with a certain resolution, its acquisition frequency (line frequency) must match the speed of the camera relative to the sample under test. In addition, its acquisition frequency (line frequency) also has an ideal value. The ideal acquisition frequency and the corresponding uniform motion state can ensure the consistency and uniformity of each acquired image line, so that in the final synthesized two-dimensional image, the ratio of the physical size of the plane where the actual sample under test is located represented by each pixel is consistent, and the morphological data of the sample under test can be reflected at a uniform ratio.

[0069] In a preferred embodiment, during the entire acquisition process, the line scan camera should have an ideal line frequency and a corresponding ideal speed, and maintain a uniform speed throughout the entire process to achieve high-quality image acquisition.

[0070] In actual applications, when a line scan camera with a specific determined resolution is used to capture images of the sample under test, after setting a suitable line frequency, there is a speed change stage when the formal acquisition begins and the speed is accelerated to the ideal speed corresponding to the line frequency, or when the acquisition is about to end and the speed is decelerated from the ideal speed.

[0071] In this embodiment, the acquisition speed in the variable speed stage is always lower than the speed corresponding to the uniform speed stage. Therefore, the acquired image is always stretched to a certain extent compared with the image acquired in the uniform speed state. That is, the final synthesized two-dimensional image includes the images acquired in the variable speed stage and the uniform speed stage. That is, the image acquired in the variable speed stage is deformed and has inconsistent proportions compared with the image acquired in the uniform speed stage.

[0072] In the preferred embodiment provided in the present application, the acquisition speed in the uniform speed stage is the ideal speed corresponding to the ideal line frequency of the line scan camera, and the acquired image is a uniform speed image that can truly reflect the morphological data of the sample under test. The image acquired in the variable speed stage is a variable speed image that is deformed and does not correspond to the actual sample under test.

[0073] Automated Optical Inspection (AOI) plays a vital role in the semiconductor industry by using high-resolution camera systems and advanced image processing technology to detect defects on the surface of wafers. These defects may include but are not limited to pattern defects, surface irregularities, foreign matter, cracks, etc., which have a direct impact on the performance and reliability of semiconductor devices.

[0074] In practice, due to the advantages of line scan cameras such as high resolution and high-speed acquisition, line scan cameras are often used to capture two-dimensional images of the surface of the wafer or other sample under test, and then the captured images are used for defect detection or dimensional measurement data analysis through image processing algorithms.

[0075] In the field of semiconductor inspection or measurement, it is necessary to identify and locate very small defects on the surface of the wafer or other sample being tested, such as scratches, contamination, oxidation and particles. The size of these defects may be only a few microns or even smaller. Therefore, it is necessary to use a very high-resolution line scan camera to capture images of semiconductor samples. With the development of semiconductor technology, AOI has higher and higher requirements for the ability to detect tiny defects or capture subtle features, and the requirements for image resolution and accuracy have also increased accordingly.

[0076] Since the line scan camera has acceleration and deceleration stages in the start and stop process of the above-mentioned image acquisition, the physical size of the actual object represented in each single-line image in the images acquired in the acceleration and deceleration stages is inconsistent with the physical size of the actual object represented in each single-line image in the images acquired in the uniform speed stage, resulting in different ratios between each pixel in the images acquired in the variable speed stage and the images acquired in the uniform speed stage and its corresponding physical size in the actual object.

[0077] Whether each pixel in the image represents the same and consistent physical size in the actual object is crucial for image analysis and measurement, because it ensures the consistency, accuracy and reliability of the image data. If in the detection or measurement process of the same batch of semiconductor samples to be tested, the proportions of the physical sizes of the actual objects represented by pixels in different images or different positions of the same image in the collected two-dimensional images of the same semiconductor sample to be tested or the same batch of semiconductor samples to be tested are different, it will affect the accuracy of the defect or measurement analysis results based on the two-dimensional image, and have an adverse effect on the quality control of the integrated circuit process, such as reducing the production yield and reducing the safety and reliability of electronic devices.

[0078] The image correction method proposed in the embodiment of the present application is used to correct the variable speed image so as to correct the variable speed image to be equal to or nearly equal to: the image obtained by collecting the corresponding part of the measured sample collected in the variable speed stage at the uniform speed of the uniform speed stage.

[0079] Furthermore, the semiconductor quantity detection method based on the image correction method provided in the embodiments of the present application can meet the detection or measurement needs with higher precision and accuracy brought about by the development of semiconductor technology.

[0080] Figure 1 That is the flowchart corresponding to the image correction method.

[0081] In step 101, a calibration object is set in the field of view of the line scan camera, and the image collected by the line scan camera includes the effective image of the sample under test and the calibration image corresponding to the calibration object. The calibration object can be suitable for providing a calibration mark including a plurality of periodic arrangements in the calibration image, and the arrangement direction of the calibration mark is parallel to the movement direction collected by the line scan camera. For example, the calibration object can be various graphics that are easy to distinguish and easy to determine the coordinates, such as calibration lines (such as stripes, lines, scales, etc.) arranged alternately in light and dark, calibration blocks (such as squares, circles, etc.), and are arranged at equal intervals. Figure 2 It is a preferred embodiment of the calibration object, that is, the calibration lines are arranged at equal intervals and alternate between light and dark. It can be understood that when the image is collected, whether the sample being measured moves or the line scan camera moves, the calibration object and the sample being measured always remain relatively still.

[0082] The effective image is the complete effective part used to reflect the morphology of the sample to be tested for quantity detection. The calibration image is used as a reference image to correct the speed-changing image. In order to make the calibration image accurately reflect the movement of the speed-changing stage and the degree of deformation of the speed-changing image, the calibration object is set so that all or part of the calibration image can be aligned with the speed-changing image part of the sample to be tested.

[0083] Preferably, the calibration object is placed on the side of the sample to be measured, so that the line scan camera can simultaneously capture images of the sample to be measured and the calibration object. Figure 3 As shown, multiple calibration objects are arranged on the side of the sample to be tested, so that calibration images A, B, and C exist on the side of the effective image VF of the sample to be tested (in practice, only one is required to achieve image correction, which is only for the convenience of explanation). Among them, the calibration image A is completely aligned with the effective image, that is, partially aligned with the variable speed image; the calibration image B is completely aligned with the variable speed image, and the range covers the entire variable speed image; the calibration image C is completely aligned with the variable speed image, and the range only corresponds to a part of the variable speed image. For the calibration image C, since the line scan camera is in uniform acceleration motion, as long as the velocity at the start of the acquisition of the calibration image C is obtained, the initial velocity of the line scan camera can be calculated through the acceleration, the distance between the calibration image C and the position where the effective image starts to be acquired, and the acquisition time.

[0084] In step 102, based on the acceleration, initial velocity, frame rate and uniform speed of the line scan camera during acquisition, a deformation function is determined, and the deformation function represents the relationship between the coordinates of the pixel points on the variable speed image and the coordinates of the corresponding pixel points on the corrected image. The deformation function is used to correspond the coordinates of the pixel points on the variable speed image and the corrected image, that is, the coordinate transformation can be performed through the deformation function. Since the line scan camera will experience variable speed and uniform speed stages during the acquisition process, these speed changes mainly affect the ratio of each pixel along the acquisition direction of the line scan camera to the size of the actually scanned sample, and the influencing factors in the direction perpendicular to the acquisition direction of the line scan camera are consistent. Therefore, in the embodiment provided in the present application, the deformation function described is specifically for the coordinate transformation along the length direction (i.e., the acquisition direction of the line scan camera) to correct this deformation. For example, the coordinate of the length direction of point P on the variable speed image is m1, and the coordinate of the length direction of point P on the corrected image becomes m2. The deformation function is the corresponding relationship between the coordinates m1 and m2. The coordinates m1 can be substituted into the deformation function to obtain the coordinates m2, and vice versa.

[0085] Generally, the speed change stage includes an acceleration stage from a stationary speed to a uniform speed when the line scan camera is started. The deformation function of the acceleration stage is determined through the following derivation process.

[0086] First, assume is the length coordinate of the speed-changing image in the acceleration phase, is the frame rate of the line scan camera when acquiring, is the acceleration during the acceleration phase, It is the initial velocity of the line scan camera when it starts to collect data and move. is the speed at any time point in the acceleration stage. The corresponding length coordinate on the speed-varying image acquired when the line scan camera accelerates to any speed can be obtained by the following formula (1):

[0087] ,

[0088] Then, the speed at any time point in the acceleration phase can be determined by formula (2): With initial velocity Relationship:

[0089] ,

[0090] The length coordinate of the variable speed image is converted into the length coordinate of the uniform speed image by formula (3): :

[0091] ,

[0092] It can be understood that the uniform speed image described here is an image obtained by assuming that the portion of the sample under test corresponding to the variable speed image is captured at a uniform speed in the uniform speed stage, and does not refer to the uniform speed image obtained during the actual quantity detection process.

[0093] By combining the above equations, the deformation function of the acceleration stage can be determined as formula (4):

[0094] ,

[0095] Normally, when the line scan camera reaches a uniform speed, the remaining acquisition process can be completed at a uniform speed. However, there are other situations. For example, when the detection space is not large enough, in order to avoid the line scan camera from stopping suddenly, the line scan camera may need to start decelerating during the acquisition process to reduce the distance the line scan camera needs to move. For this reason, the present application also proposes a method for determining the deformation function for the deceleration stage.

[0096] First, assume that is the length coordinate of the speed-changing image in the deceleration phase, is the frame rate of the line scan camera when acquiring, is the acceleration during the deceleration phase, is the uniform speed in the uniform speed stage, is the speed at any time point in the deceleration stage. Therefore, the length coordinate corresponding to the speed-varying image acquired when the line scan camera decelerates to any speed can be obtained by the following formula (5):

[0097] ,

[0098] Then, the speed at any time point in the deceleration phase can be determined by formula (6): With uniform speed Relationship:

[0099] ,

[0100] The length coordinate of the variable speed image is converted into the length coordinate of the uniform speed image by formula (7): :

[0101] ,

[0102] By combining the above equations, the deformation function of the deceleration stage can be determined as formula (8):

[0103] ,

[0104] It can be understood that each parameter in the above formula (1) to formula (8) is a scalar.

[0105] In step 103, the actual initial velocity of the line scan camera is determined based on the calibration image and the deformation function. Since the actual initial velocity of the line scan camera at startup is difficult to determine, the present application also proposes a method for determining the actual initial velocity of the line scan camera based on the calibration image and the deformation function, as shown in the process Figure 4 shown.

[0106] In step 401, the search range of the initial velocity is determined, including the step length of the initial velocity, the traversal starting point, and the traversal end point. For example, the step length is set to , the traversal starting point is 0, and the traversal end point is a uniform speed , so that the search range is .

[0107] In step 402, the traversal accumulation method is applied to bring each initial velocity into the deformation function respectively, and the length coordinate of the corrected image of the corresponding variable speed image and the periodic spacing of the calibration image in the corresponding corrected image are calculated. By bringing all the velocity values ​​and other known parameters in the search range into the deformation function, the length coordinate of the corrected image corresponding to each velocity value can be calculated. Then, the spacing between adjacent calibration lines or calibration blocks of the periodically arranged calibration image in the corrected image can be confirmed based on the coordinates of the pixel points of each corrected image. In the present application, each calibration line or calibration block is a period, and this step can obtain the periodic spacing between all adjacent periods corresponding to each initial velocity. For example, Figure 5 As shown, the horizontal axis is the initial velocity, the vertical axis is the length coordinate, and the period A, period B, and period C are three calibration lines arranged in sequence. By reading the data corresponding to the horizontal and vertical axes, the spacing between the corresponding periods at a certain initial velocity can be obtained. It can be understood that Figure 5Only three cycles are shown for illustration. In practice, the calibration object may include more calibration lines. If the scanning accuracy of the line scan camera is sufficient, the more and denser the calibration lines are, the better.

[0108] In step 403, the standard deviation of the period spacing of the calibration marks corresponding to different initial velocities is calculated, and the initial velocity corresponding to the minimum standard deviation is determined as the actual initial velocity. In step 402, the period spacing between all periods corresponding to each initial velocity is obtained, and the standard deviation of the adjacent period spacing corresponding to different initial velocities can be obtained respectively. The smaller the standard deviation, the closer the spacing between adjacent periods. Therefore, when using calibration objects with equal period spacing, the initial velocity corresponding to the minimum standard deviation can be confirmed as the actual initial velocity. For example, Figure 6 As shown, the horizontal axis is the speed, and the vertical axis is the standard deviation. When the standard deviation is 0, the value of the horizontal axis is 39, and 39 mm / s can be determined as the actual initial velocity required. Of course, calibration objects with unequal periodic spacing can also be used, and other mathematical calculations can be used to determine the correspondence between adjacent period spacings corresponding to different initial velocities and adjacent period spacings in the actual calibration object, which will not be repeated here.

[0109] In step 104, based on the actual initial velocity, the deformation function, the coordinates of the pixels on the speed-changing image, and the grayscale of the pixels, the speed-changing image is corrected to obtain a corrected image. It is understandable that since the speed-changing stage not only causes the shape of the speed-changing image to be deformed in the length direction, but also causes the grayscale of each pixel on the speed-changing image to be deformed, the image obtained by coordinate transformation using only the deformation function is not the final corrected image required, and the actual grayscale value of each pixel on the corrected image needs to be determined. According to the calculations in the previous steps, the length of the image can be The speed-shifted image is converted to a length of Assuming the image width is W, the coordinates of the pixel points in the image before transformation are , the coordinates of the pixels in the transformed image are , it can be seen that the width direction is not affected. In this step, the coordinates of the transformed image Corresponding to the coordinates before transformation .in, , In getting When the gray value is is not an integer, so bilinear interpolation is used to extract the grayscale. Thus, the speed change graph can be corrected in both length and grayscale to obtain an accurate corrected image. Figure 7This is an example of an image before and after correction. F1 is a partial calibration image in the image before correction, and F2 is a partial calibration image in the image after correction. It can be seen that the correction makes the spacing between adjacent periods in the image after correction equal. It can be understood that Figure 7 The part in the figure is cut out from the calibration image, so the period width of the calibration image shown in the image before and after correction seems to be different. On the surface of the actual measured sample, their period widths in physical size are the same.

[0110] This application also proposes an image correction device. Figure 8 As shown, the correction device comprises:

[0111] The calibration image unit 801 is used to set a calibration object in the field of view of the line scan camera. The image collected by the line scan camera includes a valid image of the sample under test and a calibration image corresponding to the calibration object.

[0112] A deformation function unit 802 is used to determine a deformation function based on the acceleration, initial velocity, frame rate and uniform speed of the uniform speed stage during the acquisition of the line scan camera, wherein the deformation function represents the relationship between the coordinates of the pixel points on the variable speed image and the coordinates of the corresponding pixel points on the corrected image;

[0113] An initial velocity acquisition unit 803, used to determine the actual initial velocity of the line scan camera based on the calibration image and the deformation function;

[0114] The image correction unit 804 is used to correct the speed-varying image based on the actual initial velocity, the deformation function, the coordinates of the pixels on the speed-varying image and the grayscale of the pixels to obtain a corrected image.

[0115] It is understandable that the device can be run on various computers and servers, and the aforementioned method can be used to correct the speed-changing image in the speed-changing stage to obtain a corrected image that is closest to the actual image of the measured sample.

[0116] This application also proposes a semiconductor quantity detection method, the steps of which are as follows: Fig. 9 shown.

[0117] In step 901, a corrected image of the speed-changing image is obtained by using the aforementioned image correction method.

[0118] In step 902, the corrected image and the uniform speed image are spliced ​​into a detection image of the sample under test. Due to the working principle of the line scan camera, multiple images may be collected during the measurement process. After all the images that need to be corrected are corrected, all the images are spliced ​​together to form a complete detection image of the sample under test.

[0119] In step 903, the grayscale value of each pixel coordinate in the detection image is extracted. The grayscale value of each pixel coordinate in the detection image can be extracted by using a bilinear interpolation method.

[0120] In step 904, the grayscale value of each pixel coordinate is analyzed and processed according to the detection standard to obtain the measurement result. The grayscale value can reflect the morphology of the sample under test, such as the concave and convex conditions, contaminants, defects, etc. of the surface of the sample under test. Therefore, by analyzing the grayscale value of each pixel coordinate, the required detection or measurement data can be obtained.

[0121] In an embodiment of the present application, the sample to be tested may be a product to be tested or a product of a process phase in the field of integrated circuits / semiconductors / electronic components such as PCBs, display panels, and semiconductor chips. It covers the front-end and back-end processes of semiconductor manufacturing, including multiple process links such as lithography, etching, and deposition. The semiconductor quantity detection method provided in this application plays a key role in these links to ensure product quality and production efficiency. Specifically, the semiconductor measurement / detection includes one or more of: film thickness measurement (Film Metrology), critical dimension measurement (Optical Critical Dimension OCD), overlay alignment measurement (Overlay Metrology), and reticle inspection (Reticle Inspection). Preferably, in this embodiment, the sample to be tested may be a patternless wafer or a patterned wafer. The material of the wafer may be one or more of silicon, germanium, silicon carbide, gallium arsenide, sapphire, lithium tantalate, lithium niobate, and the like.

[0122] Specifically, the process of traditional semiconductor measurement / inspection using AOI technology includes: 1. Image acquisition: Use a high-resolution camera (a line scan camera in this embodiment) to shoot the sample to be tested to obtain a clear image. 2. Image pre-alignment and preprocessing: Align the acquired images to keep all images processed under the same standard to keep the image coordinate system, scale, direction, etc. in subsequent processing steps consistent; 3. Image preprocessing: Perform image denoising, filtering and other preprocessing operations on the preprocessed images to improve image quality. 4. Feature extraction: Extract key features such as solder joints, pins, etc. from the preprocessed images. 5. Defect detection: Use image processing algorithms to detect potential defects and problems based on the extracted features. 6. Result analysis: Analyze the test results to determine whether repair or re-production is required.

[0123] The semiconductor quantity detection method proposed in this application is particularly suitable for the application of line scan cameras in detection or measurement equipment. This method can automatically capture multiple frames of images during the start-stop acceleration and deceleration stages when the camera acquires images. Using the aforementioned image correction technology, these images that are deformed due to speed changes are accurately calibrated and corrected. The corrected images can be directly used for subsequent measurement and detection work. In addition, pre-alignment and preprocessing can be performed on the corrected images to further improve detection efficiency and accuracy.

[0124] In the method of the present application, the images collected by the line scan camera are calibrated and corrected during the collection process, effectively correcting the image deformation caused by speed changes. Subsequently, these corrected images are seamlessly spliced ​​with the images collected at a uniform speed to form a complete test image of the sample under test. This complete test image will be used in the subsequent quantity detection steps to ensure the integrity and accuracy of the test results.

[0125] In the semiconductor quantity detection method provided by the present application, the image correction method at this stage plays the same effect as the pre-alignment and pre-processing steps in the traditional semiconductor measurement / detection method using AOI technology. In this way, the semiconductor quantity detection method provided by the present application can reduce the process of the traditional semiconductor quantity detection method and reduce the calculation amount and time consumption of the overall detection / measurement.

[0126] Furthermore, the corrected and stitched images are highly consistent with the actual samples being tested, and can effectively detect tiny defects on the surface of the samples being tested, which is sufficient to meet various testing / measurement needs, greatly improving the accuracy of the testing process and the yield rate of semiconductor processes, thereby improving the safety and reliability of electronic devices.

[0127] Reference now Fig.10 , which is a block diagram of an electronic device 1000 according to an embodiment of the present application. The electronic device 1000 may include one or more processors 1002, a system control logic 1008 connected to at least one of the processors 1002, a system memory 1004 connected to the system control logic 1008, a non-volatile memory (NVM) 1006 connected to the system control logic 1008, and a network interface 1010 connected to the system control logic 1008.

[0128] The processor 1002 may include one or more single-core or multi-core processors. The processor 1002 may include any combination of a general-purpose processor and a dedicated processor (e.g., a graphics processor, an application processor, a baseband processor, etc.). In the embodiments of this document, the processor 1002 may be configured to execute one or more embodiments of the various embodiments proposed in this application.

[0129] In some embodiments, system control logic 1008 may include any suitable interface controller to provide any suitable interface to at least one of processors 1002 and / or any suitable device or component in communication with system control logic 1008 .

[0130] In some embodiments, the system control logic 1008 may include one or more memory controllers to provide an interface to the system memory 1004. The system memory 1004 may be used to load and store data and / or instructions. In some embodiments, the system memory 1004 of the electronic device 1000 may include any suitable volatile memory, such as a suitable dynamic random access memory (DRAM).

[0131] The non-volatile memory 1006 may include one or more tangible, non-transitory computer-readable media for storing data and / or instructions. In some embodiments, the non-volatile memory 1006 may include any suitable non-volatile memory such as flash memory and / or any suitable non-volatile storage device, such as at least one of a HDD (Hard Disk Drive), a CD (Compact Disc) drive, and a DVD (Digital Versatile Disc) drive.

[0132] The non-volatile memory 1006 may include a portion of storage resources installed on a device of the electronic device 1000, or it may be accessible by the device but not necessarily a portion of the device. For example, the non-volatile memory 1006 may be accessed over a network via the network interface 1010.

[0133] In particular, the system memory 1004 and the non-volatile memory 1006 may include: a temporary copy and a permanent copy of the instruction 1020, respectively. The instruction 1020 may include: instructions that, when executed by at least one of the processors 1002, cause the electronic device 1000 to implement the method provided by the present application. In some embodiments, the instruction 1020, hardware, firmware and / or software components thereof may be additionally / alternatively placed in the system control logic 1008, the network interface 1010 and / or the processor 1002.

[0134] In some embodiments, the network interface 1010 may be integrated with other components of the electronic device 1000. For example, the network interface 1010 may be integrated with at least one of the processor 1002, the system memory 1004, the non-volatile memory 1006, and a firmware device (not shown) having instructions, and when at least one of the processors 1002 executes the instructions, the electronic device 1000 implements one or more of the various embodiments described herein. The network interface 1010 may further include any suitable hardware and / or firmware to provide a multiple-input multiple-output radio interface.

[0135] In one embodiment, at least one of the processors 1002 may be packaged together with logic for one or more controllers of the system control logic 1008 to form a system in package (SiP). In one embodiment, at least one of the processors 1002 may be integrated on the same die with logic for one or more controllers of the system control logic 1008 to form a system on chip (SoC).

[0136] The electronic device 1000 may further include an input / output (I / O) device 1012. The input / output (I / O) device 1012 may include a user interface to enable a user to interact with the device 1000; the design of a peripheral component interface enables peripheral components to interact with the electronic device 1000.

[0137] In some embodiments, the user interface may include, but is not limited to, a display (e.g., an LCD display, a touch screen display, etc.), a speaker, a microphone, one or more cameras (e.g., a still image camera and / or a video camera), a flashlight (e.g., an LED flash), and a keyboard.

[0138] In some embodiments, the peripheral component interface may include, but is not limited to, a non-volatile memory port, an audio jack, and a power interface.

[0139] It will be understood by those skilled in the art that the structure illustrated in the embodiment of the present invention does not constitute a specific limitation on the electronic device 1000. In other embodiments of the present application, the electronic device 1000 may include more or fewer components than shown in the figure, or combine some components, or split some components, or arrange the components differently. The components shown in the figure may be implemented in hardware, software, or a combination of software and hardware.

[0140] Program code can be applied to input instructions to perform each function described herein and generate output information. Output information can be applied to one or more output devices in a known manner. For purposes of this application, processing system includes any system with a processor such as, for example, a digital signal processor (DSP), a microcontroller, an application specific integrated circuit (ASIC) or a microprocessor.

[0141] Program code can be implemented with high-level programming language or object-oriented programming language to communicate with the processing system. When necessary, program code can also be implemented with assembly language or machine language. In fact, the mechanism described herein is not limited to the scope of any specific programming language. In either case, the language can be a compiled language or an interpreted language.

[0142] One or more aspects of at least one embodiment may be implemented by representative instructions stored on a computer-readable storage medium, which represent various logic in a processor, and when the instructions are read by a machine, cause the machine to fabricate logic for performing the techniques described herein. These representations, known as "IP cores," may be stored on a tangible computer-readable storage medium and supplied to multiple customers or manufacturing facilities to load into a manufacturing machine that actually manufactures the logic or processor.

[0143] An embodiment of the present application discloses a computer-readable medium storing one or more programs executable by one or more processors to implement the method of the present application.

[0144] An embodiment of the present application discloses a computer program product, including a computer program, which implements the method of the present application when executed by a processor.

[0145] The above specific embodiments illustrate the implementation of the present application, and those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in this specification. Although the description of the present application will be introduced in conjunction with the preferred embodiment, this does not mean that the features of this invention are limited to the implementation. In addition, in order to avoid confusion or blurring the focus of the present application, some specific details will be omitted in the description. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0146] Furthermore, various operations will be described as multiple discrete operations in a manner that is most helpful for understanding the illustrative embodiments; however, the order of description should not be construed as implying that these operations are necessarily order dependent. In particular, these operations do not need to be performed in the order presented.

[0147] Unless the context dictates otherwise, the terms "comprising," "having," and "including" are synonymous. The phrase "A / B" means "A or B." The phrase "A and / or B" means "(A and B) or (A or B)."

[0148] As used herein, the term "module" or "unit" may refer to, be or include: an application specific integrated circuit (ASIC), an electronic circuit, a (shared, dedicated or group) processor and / or memory that executes one or more software or firmware programs, a combinational logic circuit and / or other suitable components that provide the described functionality.

[0149] In the accompanying drawings, some structural or method features are shown in a specific arrangement and / or order. However, it should be understood that such specific arrangement and / or ordering may not be required. In some embodiments, these features may be arranged in a manner and / or order different from that shown in the illustrative drawings. In addition, the inclusion of structural or method features in a specific figure does not mean that such features are required in all embodiments, and in some embodiments, these features may not be included or may be combined with other features.

[0150] It should be understood that although the terms "first", "second", etc. may be used here to describe various units or data, these units or data should not be limited by these terms. These terms are used only to distinguish one feature from another. For example, without departing from the scope of the exemplary embodiment, a first feature may be referred to as a second feature, and similarly, a second feature may be referred to as a first feature.

Claims

1. An image correction method, used for correcting an image of a sample under test acquired by a line scan camera, wherein the line scan camera has a variable speed stage and a uniform speed stage during acquisition, and the image of the sample under test includes a variable speed image acquired in the variable speed stage and a uniform speed image acquired in the uniform speed stage, characterized in that: The method comprises: A calibration object is arranged in the field of view of the line scan camera, and the image acquired by the line scan camera includes a valid image of the sample under test and a calibration image corresponding to the calibration object, wherein the calibration object is suitable for providing a plurality of periodically arranged calibration marks in the calibration image; Determine a deformation function based on the acceleration, initial velocity, frame rate and uniform speed of the uniform speed stage during acquisition by the line scan camera, wherein the deformation function represents the relationship between the coordinates of the pixel points on the variable speed image and the coordinates of the corresponding pixel points on the corrected image; Determining the actual initial velocity of the line scan camera based on the calibration image and the deformation function includes: Determine the search range of the initial velocity, including the step size, traversal starting point and traversal end point of the initial velocity; Applying the ergodic accumulation method to bring each initial velocity into the deformation function respectively, and calculating the length coordinate of the corresponding corrected image of the speed-varying image, and the periodic spacing of the calibration image in the corresponding corrected image; Calculating the standard deviation of the periodic spacing of the calibration marks corresponding to different initial velocities, and determining the initial velocity corresponding to the minimum value of the standard deviation as the actual initial velocity; Based on the actual initial velocity, the deformation function, the coordinates of the pixels on the speed-varying image and the grayscale of the pixels, the speed-varying image is corrected to obtain the corrected image.

2. The method according to claim 1, characterized in that The position of the calibration object is set so that all or part of the calibration image is aligned with the speed-shifted image in the effective image.

3. The method according to claim 2, characterized in that The calibration object is arranged on the side of the sample to be measured, so that the line scan camera can collect images of the sample to be measured and the calibration object at the same time.

4. The method according to claim 3, characterized in that The arrangement direction of the calibration marks is parallel to the movement direction collected by the line scan camera.

5. The method according to claim 4, characterized in that Based on the acceleration, initial velocity, frame rate and uniform speed in the uniform speed stage during acquisition by the line scan camera, the deformation function is determined to include: When the speed change phase is the acceleration phase: The length coordinate of the speed-changing image is determined by the following formula: ， in, is the length coordinate of the speed-changing image, is the frame rate, is the acceleration during the acceleration phase, is the initial velocity, is the speed at any time point in the acceleration phase; The speed at any time point in the acceleration phase is determined by the following formula for: ， in, is the initial velocity Speed ​​up to The acceleration time used when The length coordinate of the variable speed image is converted into the length coordinate of the uniform speed image by the following formula: ， in, is the length coordinate of the uniform speed image, is the uniform speed; Combining the above formulas, the deformation function can be obtained as follows: 。 6. The method according to claim 4, characterized in that Based on the acceleration, initial velocity, frame rate and uniform speed in the uniform speed stage during acquisition by the line scan camera, the deformation function is determined to include: When the speed change stage is the deceleration stage: The length coordinate of the speed-changing image is determined by the following formula: ， in, is the length coordinate of the speed-changing image, is the frame rate, is the acceleration during the deceleration phase, is the uniform speed, is the speed at any time point in the deceleration stage; The speed at any time point in the deceleration phase is determined by the following formula v 2 is: ， in, is the uniform speed Slow down to The deceleration time used when The length coordinate of the variable speed image is converted into the length coordinate of the uniform speed image by the following formula: ， in, is the length coordinate of the uniform speed image; Combining the above formulas, the deformation function can be obtained as follows: 。 7. The method according to claim 1, characterized in that The grayscale of the pixel is obtained by bilinear interpolation.

8. An image correction device, used for correcting the image of a sample under test acquired by a line scan camera, wherein the line scan camera has a variable speed stage and a uniform speed stage during acquisition, and the image of the sample under test includes a variable speed image acquired in the variable speed stage and a uniform speed image acquired in the uniform speed stage, characterized in that: The device comprises: A calibration image unit, used to set a calibration object in the field of view of the line scan camera, wherein the image acquired by the line scan camera includes a valid image of the sample under test and a calibration image corresponding to the calibration object, wherein the calibration object is suitable for providing a plurality of periodically arranged calibration marks in the calibration image; A deformation function unit, for determining a deformation function based on the acceleration, initial velocity, frame rate and uniform speed in the uniform speed stage during acquisition by the line scan camera, wherein the deformation function represents the relationship between the coordinates of the pixel points on the variable speed image and the coordinates of the corresponding pixel points on the corrected image; An initial velocity acquisition unit, used to determine the actual initial velocity of the line scan camera based on the calibration image and the deformation function, comprising: Determine the search range of the initial velocity, including the step size, traversal starting point and traversal end point of the initial velocity; Applying the ergodic accumulation method to bring each initial velocity into the deformation function respectively, and calculating the length coordinate of the corresponding corrected image of the speed-varying image, and the periodic spacing of the calibration image in the corresponding corrected image; Calculating the standard deviation of the periodic spacing of the calibration marks corresponding to different initial velocities, and determining the initial velocity corresponding to the minimum value of the standard deviation as the actual initial velocity; An image correction unit is used to correct the speed-changing image based on the actual initial velocity, the deformation function, the coordinates of the pixel points on the speed-changing image and the grayscale of the pixel points to obtain the corrected image.

9. A semiconductor quantity detection method, characterized in that: include: Obtaining a corrected image of the speed-changing image by the image correction method according to any one of claims 1 to 7; splicing the corrected image and the uniform speed image into a detection image of the tested sample; Extracting the grayscale value of each pixel coordinate in the detection image; The grayscale value of each pixel coordinate is analyzed and processed according to the detection standard to obtain the quantity detection result.

10. The method according to claim 9, characterized in that A bilinear interpolation method is used to extract the grayscale of each pixel coordinate in the detection image.

11. An electronic device, characterized in that: The device comprises a memory storing computer executable instructions and a processor; when the instructions are executed by the processor, the device implements the method according to any one of claims 1 to 7, or 9 to 10.

12. A computer-readable medium, characterized in that The computer-readable medium stores one or more programs, and the one or more programs can be executed by one or more processors to implement the method of any one of claims 1 to 7 or 9 to 10.

13. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the method according to any one of claims 1 to 7 or 9 to 10 is implemented.

Images