Wafer accurate positioning method and device, electronic equipment and storage medium

Abstract

The application belongs to the technical field of wafer positioning, and discloses a wafer accurate positioning method and device, an electronic device and a storage medium. The method comprises the following steps: a spiral acquisition method of a high magnification objective lens is used to acquire viewpoint images of different positions in a target wafer; each acquired viewpoint image is subjected to image stitching; a template matching method is used to position a marked point of the stitched viewpoint image; at least two stitched images containing a preset marked point are obtained; an angle offset is calculated according to the position coordinates of the preset marked point to perform angle correction; then, the position offset of the wafer after angle correction is calculated to obtain an accurately positioned target wafer. The high resolution characteristic of the high magnification objective lens is used to improve the positioning accuracy, the spiral multi-viewpoint image acquisition method is used to expand the field of view range of the preset marked point search, the objective lens does not need to be switched, which is beneficial to simplifying the hardware of the visual imaging system and reducing the hardware cost of the positioning device.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wafer positioning, and in particular, to a wafer precise positioning method and device, an electronic device and a storage medium. BACKGROUND

[0002] In the field of semiconductor detection, for example, in the defect detection process of a MicroLED lamp bead array, due to the inevitable error of the feeding and discharging system when taking and placing the wafer, the wafer may not be in the ideal precise position after being placed. Therefore, before the subsequent defect detection, the wafer usually needs to be precisely positioned to ensure the accuracy of the detection.

[0003] The traditional wafer precise positioning method is usually based on a double objective switching mode. The low magnification objective has a larger field of view range but its spatial resolution is relatively low, which cannot meet the demand of high-precision positioning. In order to improve the positioning accuracy, the traditional double objective switching method needs to switch to a high magnification objective to collect the positioning mark point image after the preliminary positioning is completed using a low magnification objective. The high magnification objective has a higher spatial resolution, that is, the actual physical size corresponding to a single pixel in the image is smaller, which makes the image collected by the high magnification objective be able to provide more detailed mark point position information, thereby improving the final positioning accuracy. Although the double objective switching method can realize the precise positioning of the wafer, it has significant limitations. First, this method needs to rely on two different objectives and frequently switch the objectives during the positioning process. This switching mechanism makes the entire vision imaging system more complex, not only increasing the design and integration difficulty of the system, but also possibly introducing additional mechanical errors. Secondly, since two objectives and the corresponding switching mechanism need to be configured and maintained, the hardware cost of this traditional precise positioning method is usually high, which is a considerable burden for large-scale production and application.

[0004] Therefore, in order to solve the technical problems of the existing wafer precise positioning method in using the double objective switching mode, that is, the system is complex, the hardware cost is high and the mechanical error is easily triggered due to the frequent switching of the objectives, it is urgent to provide a wafer precise positioning method, device, electronic device and storage medium. SUMMARY

[0005] The purpose of the present application is to provide a wafer precise positioning method, device, electronic equipment and storage medium, at least two preset markers obtained by image stitching and marker positioning of the viewpoint image obtained by the spiral acquisition method are calculated to obtain the angle offset of the target wafer, so as to correct the target wafer and obtain the precisely positioned target wafer, solve the problem that the existing wafer precise positioning method uses the double objective lens switching mode, which leads to complex system, high hardware cost and mechanical error triggering due to frequent switching of the objective lens, only uses high magnification objective lens for spiral image acquisition, and does not need to configure and maintain two objective lenses and the corresponding switching mechanism, which significantly reduces the hardware cost and improves the positioning efficiency of the wafer.

[0006] In the first aspect, the present application provides a wafer precise positioning method for positioning a wafer, comprising the steps of:

[0007] The spiral acquisition method of high magnification objective lens is used to obtain viewpoint images at different positions in the target wafer in sequence; a plurality of preset markers for positioning are arranged in the target wafer;

[0008] Each time a viewpoint image is obtained, the viewpoint image obtained is stitched in the form of a nine-square grid, and the marker positioning is performed on the stitched viewpoint image by using a template matching method, so as to obtain at least two stitched images containing the preset markers;

[0009] According to the position coordinates of the preset markers in the stitched image, the angle offset of the target wafer is calculated;

[0010] Based on the angle offset, the target wafer is angle corrected, and the position offset of the angle corrected target wafer is calculated to obtain the precisely positioned target wafer.

[0011] The wafer precise positioning method provided by the present application can realize the positioning of the wafer, at least two preset markers obtained by image stitching and marker positioning of the viewpoint image obtained by the spiral acquisition method are calculated to obtain the angle offset of the target wafer, so as to correct the target wafer and obtain the precisely positioned target wafer. The present application only uses high magnification objective lens for spiral image acquisition, on the one hand, the high resolution characteristics of the high magnification objective lens are used to improve the positioning accuracy, on the other hand, the multi-viewpoint image acquisition method of spiral is used to expand the field of view range of the preset marker search, without switching the objective lens. The existing wafer precise positioning method uses the double objective lens switching mode, which leads to complex system, high hardware cost and mechanical error triggering due to frequent switching of the objective lens, and does not need to configure and maintain two objective lenses and the corresponding switching mechanism, which significantly reduces the hardware cost and improves the positioning efficiency of the wafer.

[0012] Optionally, a spiral acquisition method with a high magnification objective lens is adopted to sequentially acquire the viewpoint images of different positions in the target wafer, including:

[0013] Moving the high magnification objective lens to an ideal position corresponding to any preset marker point in the target wafer;

[0014] According to the preset moving step, the high magnification objective lens is controlled to move while sequentially capturing the target wafer by using the high magnification objective lens to acquire the viewpoint images of different positions in the target wafer.

[0015] The wafer precise positioning method provided in the application can position the wafer, and by controlling the high magnification objective lens to move spirally according to the preset moving step for capturing, the viewpoint images of different positions in the wafer can be comprehensively and efficiently acquired, thereby providing a complete data basis for subsequent image stitching and marker point positioning.

[0016] Optionally, each time a viewpoint image is acquired, the acquired viewpoint image is stitched, and a template matching method is used to position the marker points of the stitched viewpoint image to obtain at least two stitched images containing the preset marker points, including:

[0017] Each time a viewpoint image is acquired, the adjacent acquired viewpoint images are stitched in a nine-square grid stitching form with the currently acquired viewpoint image as the center to obtain the stitched viewpoint image;

[0018] By using the template matching method, the stitched viewpoint image each time is matched with the preset marker point template image to detect whether any of the preset marker points in the stitched viewpoint image each time is the same as the preset marker point template image;

[0019] When it is detected that any of the preset marker points in the currently stitched viewpoint image is the same as the preset marker point template image, the currently stitched viewpoint image is determined to be a stitched image containing the preset marker point, and the search for the current preset marker point is ended. The high magnification objective lens is moved to an ideal position corresponding to another preset marker point in the target wafer to acquire a stitched image containing another preset marker point by using the same spiral acquisition method, image stitching method and template matching method, thereby obtaining at least two stitched images containing the preset marker points.

[0020] The wafer accurate positioning method provided in the application can realize positioning of a wafer, through real-time splicing in a nine-square form and template matching, and taking detection of a preset mark point as a judgment basis, at least two spliced images containing the preset mark point are obtained, it can be ensured that the wafer spliced image containing sufficient positioning information is obtained in time in the image acquisition process, so that the positioning efficiency and accuracy are improved.

[0021] Optionally, each time a viewpoint image is acquired, the adjacent acquired viewpoint images are spliced in an image splicing manner with the current acquired viewpoint image as the center to obtain a spliced viewpoint image, comprising:

[0022] When each viewpoint image is acquired, adjacent images adjacent to the currently acquired viewpoint image in eight directions are extracted from the acquired viewpoint images according to the moving track of the high-magnification objective lens;

[0023] The current acquired viewpoint image is spliced with the adjacent images based on the positional relationship between the adjacent images and the current acquired viewpoint image with the current acquired viewpoint image as the center to obtain a spliced viewpoint image.

[0024] Optionally, through a template matching method, each spliced viewpoint image is matched with a preset mark point template image to detect whether any of the preset mark points in the preset mark point template image exists in each spliced viewpoint image, and the method further comprises:

[0025] When the number of acquired viewpoint images is greater than or equal to a preset maximum viewpoint number threshold, and any of the preset mark points in the preset mark point template image is not detected in each spliced viewpoint image, it is determined that the preset mark point finding is timed out, the finding of the preset mark point is terminated, and it is determined that the wafer positioning fails.

[0026] Optionally, the angle offset of the target wafer is calculated based on the position coordinates of the preset mark points in the spliced images, comprising:

[0027] The position coordinates of the preset mark points are calculated based on the offset of the preset mark points from the viewpoint center positions of the corresponding spliced images and the preset image space resolution;

[0028] The position coordinates of any two preset mark points are input into a preset angle offset calculation formula to calculate the angle offset of the target wafer.

[0029] Optionally, based on the angle offset, the target wafer is angle-corrected, and the position offset of the angle-corrected target wafer is calculated to obtain an accurately positioned target wafer, comprising:

[0030] correct the target wafer based on the angle offset to obtain an angle-corrected target wafer;

[0031] calculate a position offset between the position coordinates of the preset mark points in the angle-corrected target wafer and the preset target position coordinates, to provide an accurate position deviation compensation for subsequent detection or repair, and obtain an accurately positioned target wafer.

[0032] In a second aspect, the present application provides a wafer accurate positioning device for positioning a wafer, comprising:

[0033] The acquisition module is configured to acquire viewpoint images at different positions in a target wafer in sequence by using a spiral acquisition method of a high-magnification objective lens, and the target wafer is provided with a plurality of preset mark points for positioning.

[0034] The positioning module is configured to perform image stitching on the acquired viewpoint images each time a viewpoint image is acquired, and perform mark point positioning on the stitched viewpoint images by using a template matching method, to obtain at least two stitched images containing the preset mark points.

[0035] The calculation module is configured to calculate an angle offset of the target wafer according to the position coordinates of the preset mark points in the stitched images.

[0036] The correction module is configured to correct the target wafer based on the angle offset, and calculate a position offset of the angle-corrected target wafer, to obtain an accurately positioned target wafer.

[0037] The wafer accurate positioning device calculates an angle offset of the target wafer according to at least two preset mark points obtained by performing image stitching and mark point positioning on the viewpoint images acquired by using a spiral acquisition method, corrects the target wafer based on the angle offset, calculates a position offset of the angle-corrected target wafer, and obtains an accurately positioned target wafer. The wafer accurate positioning device solves the problems of complex system, high hardware cost and easy triggering of mechanical error caused by frequent switching of objective lenses in the existing wafer accurate positioning method using a double-objective lens switching mode. The wafer accurate positioning device only uses a high-magnification objective lens for spiral image acquisition, does not need to configure and maintain two objective lenses and corresponding switching mechanisms, significantly reduces the hardware cost, and improves the positioning efficiency of the wafer.

[0038] In a third aspect, the present application provides an electronic device comprising a processor and a memory, wherein the memory stores a computer program executable by the processor, and the processor executes the computer program to run the steps of the wafer accurate positioning method as described above.

[0039] In a fourth aspect, the present application provides a computer readable storage medium, which stores a computer program. When the computer program is executed by a processor, the steps of the wafer precise positioning method described above are performed. Advantages

[0040] The wafer precise positioning method, device, electronic equipment and storage medium provided by the present application calculate the angle offset of the target wafer by using at least two preset marker points obtained by image stitching and marker point positioning on the viewpoint images obtained by the high magnification objective lens spiral acquisition method, so as to perform angle correction on the target wafer, and calculate the position offset of the target wafer after angle correction, so as to obtain the precisely positioned target wafer. Only high magnification objective lens is used for spiral image acquisition, on the one hand, the high resolution characteristics of the high magnification objective lens are used to improve the positioning accuracy, and on the other hand, the multi-viewpoint image acquisition method of spiral is used to expand the field of view range of the preset marker point search, without the need to switch the objective lens. The existing wafer precise positioning method solves the problems of complex system, high hardware cost and easy triggering of mechanical error caused by frequent switching of the objective lens in the double objective lens switching mode, and does not need to configure and maintain two objective lenses and the corresponding switching mechanism, which significantly reduces the hardware cost and improves the positioning efficiency of the wafer. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 The flowchart of the wafer precise positioning method provided by the embodiment of the present application.

[0042] Figure 2 The structure diagram of the wafer precise positioning device provided by the embodiment of the present application.

[0043] Figure 3 The structure diagram of the electronic equipment provided by the embodiment of the present application.

[0044] Figure 4 The schematic diagram of the initial positioning of the preset marker point by the high magnification objective lens.

[0045] Figure 5 The schematic diagram of the spiral movement track in the spiral acquisition method.

[0046] Figure 6 The schematic diagram of the preset marker point in the spliced image.

[0047] Figure 7 The schematic diagram of the target wafer relative to the ideal position of the wafer.

[0048] Figure 8 The schematic diagram of the precisely positioned target wafer relative to the ideal position of the wafer.

[0049] Label explanation: 1, acquisition module; 2, positioning module; 3, calculation module; 4, correction module; 301, processor; 302, memory; 303, communication bus. DETAILED DESCRIPTION

[0050] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. The components of the embodiments of the present application described and shown in the drawings can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0051] It should be noted that: similar labels and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. At the same time, in the description of the present application, the terms "first", "second" and the like are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0052] Please refer to Figure 1 , Figure 1 is a wafer precise positioning method in some embodiments of the present application, which is used for positioning a wafer, comprising:

[0053] Step S101, using a spiral acquisition method of a high magnification objective, sequentially acquiring viewpoint images of different positions in the target wafer; a plurality of preset mark points for positioning are arranged in the target wafer;

[0054] Step S102, after acquiring each viewpoint image, the acquired viewpoint image is spliced in a nine-square grid splicing form, and the spliced viewpoint image is positioned by a template matching method, to obtain at least two spliced images containing the preset mark points;

[0055] Step S103, according to the position coordinates of the preset mark points in the spliced image, the angle offset of the target wafer is calculated;

[0056] Step S104, based on the angle offset, the target wafer is angle-corrected, and the position offset of the angle-corrected target wafer is calculated, to obtain the precisely positioned target wafer.

[0057] This precise wafer positioning method involves stitching together images from viewpoint images acquired using a high-magnification objective lens in a spiral acquisition method, and then using at least two preset marker points to calculate the angular offset of the target wafer. This angular offset is then used to correct the target wafer's angle, and the positional offset of the corrected target wafer is calculated to obtain the precisely positioned target wafer. Using only a high-magnification objective lens for spiral image acquisition improves positioning accuracy by leveraging the high resolution of the lens and expands the field of view for searching preset marker points using a spiral multi-viewpoint image acquisition method, eliminating the need for objective lens switching. This method addresses the problems of system complexity, high hardware costs, and susceptibility to mechanical errors caused by frequent objective lens switching in existing precise wafer positioning methods using dual-objective lens switching. Furthermore, it eliminates the need to configure and maintain two objectives and their corresponding switching mechanisms, significantly reducing hardware costs and improving wafer positioning efficiency.

[0058] Specifically, in step S101, a spiral acquisition method using a high-magnification objective lens is employed to sequentially acquire viewpoint images at different locations on the target wafer, including:

[0059] Move the high-magnification objective lens to the ideal position corresponding to any preset mark point on the target wafer;

[0060] A spiral acquisition method is adopted. The high-magnification objective lens is moved according to a preset movement step size, and the high-magnification objective lens is used to take pictures of the target wafer in sequence to obtain viewpoint images of different positions in the target wafer.

[0061] In step S101, the high-magnification objective lens is precisely moved to the ideal position corresponding to any preset marker point on the target wafer (i.e., the position of the preset marker point when the target wafer is in the ideal position), ensuring that the starting point for subsequent image acquisition has a clear reference benchmark. For example... Figure 4 As shown, Figure 4 This diagram illustrates the positioning of preset marker points for a high-magnification objective lens. In the diagram, d represents the preset marker point, circle e represents the target wafer, rectangle L within circle e represents the LED array, f represents the high-magnification objective lens, g represents the imaging lens, h represents the image sensor, and arrow k indicates the imaging direction. The high-magnification objective lens f, imaging lens g, and image sensor h constitute the visual imaging system, as shown below. Figure 4 As shown, the high-magnification objective lens f is initially positioned at the ideal position of any preset marker point d as the starting point for data acquisition.

[0062] By controlling the high-magnification objective lens to move spirally according to the preset moving step (the preset moving step includes a horizontal coordinate moving step and a vertical coordinate moving step, the horizontal coordinate moving step is used for moving in the horizontal coordinate direction, the vertical coordinate moving step is used for moving in the vertical coordinate direction, the horizontal coordinate moving step and the vertical coordinate moving step can be moved according to actual needs, and the horizontal coordinate moving step and the vertical coordinate moving step can be set to the same or different values according to the number of pixels in the image width and height directions multiplied by the spatial resolution, that is , , , the horizontal coordinate moving step is N, N is the number of width pixels of the image shot by the high-magnification objective lens, and R is the spatial resolution of the image shot by the high-magnification objective lens, the vertical coordinate moving step is M, and M is the number of height pixels of the image shot by the high-magnification objective lens) and synchronously shooting (as shown in Figure 5 , Figure 5 is a schematic diagram of a moving track of the spiral movement in the spiral acquisition method, the circles a1, …, and a25 are optical centers when the high-magnification objective lens moves each time (the number after a represents the moving order), the line segment b is a moving track of the high-magnification objective lens, and the dashed rectangle c is a view point area of an unacquired image), which can systematically and comprehensively cover each area of the target wafer and ensure that a sufficient number and quality of view point images are acquired, which are crucial for subsequent image stitching and marker positioning.

[0063] Before moving the high-magnification objective lens relative to the target wafer, the target wafer needs to be placed on the base of the three-axis motion table, a global coordinate system is established with a coordinate where the center of the target wafer in the ideal position (i.e., the position after accurate positioning) as the origin, the z-axis of the global coordinate system coincides with the rotation axis of the motion table, and the plane where the x-axis and the y-axis of the global coordinate system are located is parallel to the target wafer on the base of the three-axis motion table. When positioning the target wafer, the three-axis motion table can drive the target wafer to rotate along the z-axis, or can translate along the x-axis direction and the y-axis direction to change the position coordinate of the target wafer.

[0064] The spiral acquisition method refers to that the high-magnification objective lens moves in a spiral path in the clockwise or counterclockwise direction above the target wafer according to the preset moving step, and simultaneously intermittently shoots the target wafer (i.e., shoots once each time the high-magnification objective lens moves once), so as to acquire view point images covering different areas of the target wafer.

[0065] The preset marker refers to a specific pattern or structure pre-set on the target wafer for assisting positioning, which can be a cross marker, a circular marker, or a two-dimensional code, and the ideal position and characteristics thereof are known.

[0066] Specifically, in step S102, each time a viewpoint image is acquired, the acquired viewpoint image is stitched in a nine-square grid stitching manner, and a marker point positioning is performed on the stitched viewpoint image by a template matching method, to obtain at least two stitched images containing the preset marker points, including:

[0067] Each time a viewpoint image is acquired, the adjacent acquired viewpoint images are stitched in a nine-square grid stitching manner with the currently acquired viewpoint image as the center, to obtain the stitched viewpoint image.

[0068] By the template matching method, the stitched viewpoint image each time is matched with the preset marker point template image to detect whether any preset marker point identical to the preset marker point template image exists in the stitched viewpoint image each time.

[0069] When it is detected that any preset marker point identical to the preset marker point template image exists in the currently stitched viewpoint image, it is determined that the currently stitched viewpoint image is a stitched image containing the preset marker point, and the search for the current preset marker point is ended. The high-magnification objective lens is moved to an ideal position corresponding to another preset marker point in the target wafer, to acquire a stitched image containing another preset marker point by the same spiral acquisition method, image stitching method and template matching method, to obtain at least two stitched images containing the preset marker points.

[0070] Specifically, in step S102, each time a viewpoint image is acquired, the adjacent acquired viewpoint images are stitched in a nine-square grid stitching manner with the currently acquired viewpoint image as the center, to obtain the stitched viewpoint image, including:

[0071] At each time of acquiring a viewpoint image, the adjacent images adjacent to the currently acquired viewpoint image in eight directions are extracted from the acquired viewpoint images according to the moving track of the high-magnification objective lens.

[0072] The currently acquired viewpoint image and the adjacent images are stitched based on the positional relationship between the adjacent images and the currently acquired viewpoint image with the currently acquired viewpoint image as the center, to obtain the stitched viewpoint image.

[0073] In step S102, in the wafer positioning process, since a single viewpoint image can not completely cover the preset marker point, the field of view needs to be expanded by image stitching to ensure that the preset marker point can be completely captured. Each time a new viewpoint image is generated, the images having a spatial adjacency relationship with the currently acquired viewpoint image in eight directions are selected from the acquired viewpoint images as the adjacent images according to the moving direction and the historical track of the high-magnification objective lens.

[0074] The current acquired viewpoint image is taken as the center, and the current acquired viewpoint image and the adjacent images are spliced based on the positional relationship between the adjacent images and the current acquired viewpoint image to form a larger spliced image, and the spliced viewpoint image is obtained. Through this splicing method, only the current viewpoint image and the determined adjacent images are spliced locally each time, instead of globally splicing all the collected images, so that the purpose of reducing the calculation complexity and improving the real-time splicing is achieved.

[0075] In some optional embodiments, when splicing images, not only the nine-square splicing form can be used, but also other matrix arrangement methods can be used for splicing, such as QxQ or QxP (Q and P are positive integers) splicing forms. The current acquired viewpoint image is taken as the center, and the nearby acquired images are spliced to obtain the spliced viewpoint image.

[0076] In step S102, whenever a new viewpoint image is acquired and spliced to obtain a spliced viewpoint image, a template matching (for example, a correlation coefficient method based on normalized cross-correlation, a recognition algorithm based on contour shape, a local feature point matching algorithm (such as SIFT, ORB), or a target detection method driven by machine learning) is performed immediately to match the preset marker point template image with the spliced viewpoint image each time, so as to detect the occurrence of the preset marker point in the spliced viewpoint image in real time. This real-time detection mechanism ensures that once the condition of the occurrence of the preset marker point is met during the image splicing process, the current spliced viewpoint image can be determined as the target image, that is, the spliced image containing the preset marker point, and the search for the current preset marker point is ended, thereby avoiding unnecessary image acquisition and splicing and improving the efficiency. The existing matching calculation method is prior art, which will not be described in detail here.

[0077] Through the above method, only a high-magnification objective lens is used, images are sequentially acquired at multiple viewpoints around the ideal position of the preset marker point according to the multi-viewpoint image acquisition strategy, and the multi-viewpoint images are spliced and fused. The method of fusing “small images (viewpoint images) ” into a large image (spliced image) enables the preset marker point to enter the field of view, fully utilizes the high spatial resolution of the high-magnification objective lens, acquires high-precision positioning data of the preset marker point and the wafer, and can simplify the hardware of the visual imaging system while maintaining high positioning accuracy, thereby reducing the hardware cost of the positioning device.

[0078] Specifically, in step S102, after the marker point matching between the spliced viewpoint image each time and the preset marker point template image is performed by the template matching method to detect whether any preset marker point identical to the preset marker point template image exists in the spliced viewpoint image each time, the method further includes:

[0079] When the number of acquired viewpoint images is greater than or equal to the preset maximum viewpoint number threshold, and it is not detected that any preset marker point in the viewpoint image after each splicing is the same as the preset marker point template image, it is determined that the preset marker point search is timed out, the search for the preset marker point is terminated, and it is determined that the wafer positioning fails,

[0080] In step S102, the number of acquired viewpoint images is counted in real time during the image acquisition process. When the number of viewpoint images reaches the preset maximum viewpoint number threshold, and the preset marker point is not detected, it is determined that the current wafer positioning process has exceeded the normal time consumption range, the marker point search process is terminated, and invalid resource consumption is avoided.

[0081] In some optional embodiments, after a wafer positioning fails once, another preset marker point can be selected for repositioning. If positioning failures occur continuously, a worker is notified in time for abnormal handling.

[0082] In step S102, after the first preset marker point is detected, the position of the high-magnification objective lens is adjusted to the ideal position of another preset marker point, and the spiral acquisition method, the image splicing method, and the template matching method are repeated to quickly lock the position of the other preset marker point (if the number of acquired viewpoint images is greater than or equal to the preset maximum viewpoint number threshold, the other preset marker point is not found, and other preset marker points can be selected for repositioning). At least two spliced images containing the preset marker points are obtained.

[0083] Specifically, in step S103, the angle offset of the target wafer is calculated according to the position coordinates of the preset marker points in the spliced images, including:

[0084] The position coordinates of the preset marker points are calculated according to the offset of the preset marker points from the viewpoint center position of the corresponding spliced image and the preset image spatial resolution.

[0085] The position coordinates of any two preset marker points are input into a preset angle offset calculation formula, and the angle offset of the target wafer is calculated.

[0086] In step S103, the pixel offset of the preset marker point relative to the viewpoint center position is determined according to the pixel number difference of the preset marker point from the viewpoint center position in the horizontal coordinate direction and the pixel number difference in the vertical coordinate direction in the spliced image. Subsequently, the pixel offset is multiplied by the preset image spatial resolution to calculate the offset coordinates of the preset marker point relative to the viewpoint center position. The offset coordinates and the coordinates of the viewpoint center position are combined to calculate the accurate position coordinates of the preset marker point on the wafer plane. That is, the position coordinates of the preset marker point can be calculated by the following marker point coordinate formula:

[0087] ;

[0088] ;

[0089] in, The x-coordinate of the preset marker point; is the x-coordinate of the viewpoint center position of the stitched image corresponding to the preset marker point; n is the pixel offset of the preset marker point relative to the viewpoint center position in the x-coordinate direction; R is the preset image spatial resolution; The ordinate of the preset marker point; is the ordinate of the viewpoint center position of the stitched image corresponding to the preset marker point; m is the pixel offset of the preset marker point relative to the viewpoint center position in the ordinate direction.

[0090] like Figure 6 As shown, Figure 6 This diagram illustrates the preset marker points in the stitched image. Circles a1, a4, a5, a6, a7, a8, a18, a19, and a20 represent the optical centers of the high-magnification objective lens during each movement. The solid line area p represents the stitched image of the acquired viewpoint region, while circle a6 represents the viewpoint center position of the stitched image. The dashed rectangle c represents the viewpoint region where no image was acquired (in the 3x3 grid image stitching, if images of adjacent viewpoints are not acquired, all pixels in the corresponding viewpoint region are assigned a value of 0). d represents the preset marker point, x1 is the abscissa of the preset marker point's offset relative to the viewpoint center position, and y1 is the ordinate of the preset marker point's offset relative to the viewpoint center position. Figure 6 It can be seen that the x-coordinate x1 and y-coordinate y1 calculated by pixel offset and image spatial resolution, combined with the actual coordinates of the viewpoint center position of the stitched image, can be used to calculate the x-coordinate and y-coordinate of the preset marker point d.

[0091] Based on the calculated position coordinates of the preset marker points, the position coordinates of any two preset marker points are input into the preset angle offset calculation formula to calculate the angle offset of the target wafer.

[0092] The preset angle offset calculation formula is as follows:

[0093] ;

[0094] in, This is the angular offset. It is a two-parameter arctangent function, and its angle output range is... ; Let x be the x-coordinate of one of the preset marker points; is a longitudinal coordinate of one of the preset mark points; is a longitudinal coordinate of one of the preset mark points; is a longitudinal coordinate of one of the preset mark points; is an angle formed by a line connecting the two preset mark points and a positive direction axis of the horizontal coordinate axis when the target wafer is in the ideal position, that is, , is a longitudinal coordinate of one of the preset mark points in the ideal position, is a longitudinal coordinate of one of the preset mark points in the ideal position, is a longitudinal coordinate of one of the preset mark points in the ideal position, is a longitudinal coordinate of one of the preset mark points in the ideal position.

[0095] Specifically, in step S104, based on the angle offset, the target wafer is angle-corrected, and the position offset of the angle-corrected target wafer is calculated, to obtain the accurately positioned target wafer, including:

[0096] Based on the angle offset, the target wafer is angle-corrected to obtain the angle-corrected target wafer;

[0097] The position offset between the position coordinates of the preset mark points in the angle-corrected target wafer and the preset target position coordinates is calculated, to provide accurate position deviation compensation for subsequent detection or repair, and obtain the accurately positioned target wafer.

[0098] In step S104, the three-axis motion platform is rotated angle (counterclockwise rotation is positive, clockwise rotation is negative) relative to the vision imaging system based on the previously calculated angle offset, to adjust the target wafer, so that the overall angle of the target wafer is aligned with the ideal state (ideal position), to obtain the angle-corrected target wafer, wherein the position coordinates of the preset mark points are angle-corrected following the rotation of the target wafer, and the position coordinates of the preset mark points after angle correction are:

[0099] ;

[0100] ;

[0101] wherein, is a longitudinal coordinate of one of the preset mark points in the ideal position, is a longitudinal coordinate of one of the preset mark points in the ideal position, is a longitudinal coordinate of one of the preset mark points in the ideal position, is a longitudinal coordinate of one of the preset mark points in the ideal position.

[0102] As Figure 7 shown, Figure 7 is a schematic diagram of the target wafer relative to the ideal position of the wafer, wherein, is the angle offset, the solid circle e is the target wafer, the dashed line e' is the ideal position of the wafer, d1 is one of the preset mark points, and d2 is another preset mark point. From Figure 7 it can be known that the target wafer is rotated by an angle, that is, the angle of the target wafer e can be corrected.

[0103] After the angle correction is completed, by comparing the actual position coordinates of the preset mark points after the angle correction with the ideal position coordinates thereof, the position offset of the target wafer in the X and Y directions is calculated, and the target wafer with accurate positioning is obtained. For example, if the actual position of the preset mark points after the angle correction is (x', y'), the ideal position is (x t , y t ), and the position offset is (Δx, Δy) = (x t -x', y t -y'). The position offset can provide an accurate position offset compensation for subsequent detection or repair, and ensure the accuracy of the detection or repair. When the subsequent detection equipment or repair equipment performs an operation, the motion track or action point thereof can be fine-tuned according to the compensation, so as to ensure that the operation can accurately align with the target region on the wafer.

[0104] As Figure 8 shown, Figure 8 is a schematic diagram of the target wafer after the angle correction relative to the ideal position thereof, wherein the solid circle e is the target wafer, the dashed line e' is the ideal position of the wafer, d3 is one of the preset mark points, d4 is another preset mark point, d3' is the ideal position of one of the preset mark points, and d4' is the ideal position of another preset mark point. From Figure 8 it can be known that the offset of the target wafer e and the ideal position e' of the wafer can be determined according to the offset of the actual position coordinates of the preset mark points and the ideal position thereof.

[0105] ​As can be known from the above, the wafer accurate positioning method acquires the viewpoint images at different positions in the target wafer in sequence by adopting the spiral acquisition method of the high-power objective lens, the target wafer is provided with a plurality of preset mark points for positioning, each time a viewpoint image is acquired, the acquired viewpoint image is spliced in the form of a nine-square grid, and the mark point positioning is performed on the spliced viewpoint image by the template matching method, at least two spliced images containing the preset mark points are obtained, the angle offset of the target wafer is calculated according to the position coordinates of the preset mark points in the spliced images, the angle correction is performed on the target wafer based on the angle offset, the position offset of the target wafer after the angle correction is calculated, and the accurately positioned target wafer is obtained. Only the high-power objective lens is used for spiral image acquisition, on the one hand, the high resolution characteristics of the high-power objective lens are used to improve the positioning accuracy, and on the other hand, the multi-viewpoint image acquisition method of the spiral type is used to expand the field of view range of the preset mark point search, without the need to switch the objective lens. The existing wafer accurate positioning method solves the problems of complex system, high hardware cost and easy triggering of mechanical error caused by frequent switching of the objective lens when the double-objective lens switching mode is used, and does not need to configure and maintain two objective lenses and the corresponding switching mechanism, thereby significantly reducing the hardware cost and improving the positioning efficiency of the wafer.

[0106] Reference Figure 2 The present application provides a wafer accurate positioning device for positioning a wafer, comprising:

[0107] The acquisition module 1 is configured to acquire viewpoint images at different positions in the target wafer in sequence by adopting the spiral acquisition method of the high-power objective lens, and the target wafer is provided with a plurality of preset mark points for positioning.

[0108] The positioning module 2 is configured to, each time a viewpoint image is acquired, splice the acquired viewpoint image in the form of a nine-square grid, and perform mark point positioning on the spliced viewpoint image by the template matching method, to obtain at least two spliced images containing the preset mark points.

[0109] The calculation module 3 is configured to calculate the angle offset of the target wafer according to the position coordinates of the preset mark points in the spliced images.

[0110] The correction module 4 is configured to perform angle correction on the target wafer based on the angle offset, calculate the position offset of the target wafer after the angle correction, and obtain the accurately positioned target wafer.

[0111] The wafer precise positioning device obtains at least two preset mark points through image splicing and mark point positioning of the view point images obtained by the high magnification objective lens spiral acquisition method, calculates the angle offset of the target wafer, performs angle correction on the target wafer, calculates the position offset of the target wafer after the angle correction, and obtains the precisely positioned target wafer. Only the high magnification objective lens is used for spiral image acquisition, on the one hand, the high resolution characteristics of the high magnification objective lens are used to improve the positioning precision, and on the other hand, the multi-viewpoint image acquisition method of the spiral is used to expand the field of view range of the preset mark point search, without switching the objective lens. The existing wafer precise positioning method solves the problems of complex system, high hardware cost and easy triggering of mechanical error caused by frequent switching of the objective lens in the double objective lens switching mode, and does not need to configure and maintain two objective lenses and the corresponding switching mechanism, significantly reduces the hardware cost, and improves the positioning efficiency of the wafer.

[0112] Specifically, when the acquisition module 1 acquires the view point images of different positions in the target wafer in turn by using the spiral acquisition method of the high magnification objective lens, the following is performed:

[0113] moving the high magnification objective lens to an ideal position corresponding to any preset mark point in the target wafer;

[0114] controlling the high magnification objective lens to move according to a preset moving step, and using the high magnification objective lens to sequentially shoot the target wafer to acquire the view point images of different positions in the target wafer.

[0115] When the acquisition module 1 is executed, the high magnification objective lens is accurately moved to an ideal position corresponding to any preset mark point on the target wafer (i.e. the position of the preset mark point when the target wafer is in the ideal position), which ensures that the starting point of the subsequent image acquisition has a clear reference. As shown in Figure 4 , the preset mark point positioning diagram of the high magnification objective lens is shown in Figure 4 , wherein d is the preset mark point, e is the target wafer, f is the high magnification objective lens, g is the imaging lens, h is the image sensor, and arrow k is the imaging direction. Among them, the high magnification objective lens f, the imaging lens g and the image sensor h constitute a vision imaging system, as shown in Figure 4 , the high magnification objective lens f is initially positioned to the ideal position of any preset mark point d as the acquisition starting point.

[0116] The high-magnification objective lens is controlled to move in a spiral manner according to a preset movement step (the preset movement step includes a horizontal coordinate movement step and a vertical coordinate movement step, the horizontal coordinate movement step is used for movement in the horizontal coordinate direction, the vertical coordinate movement step is used for movement in the vertical coordinate direction, the horizontal coordinate movement step and the vertical coordinate movement step can be moved according to actual needs, and the horizontal coordinate movement step and the vertical coordinate movement step can be set to the same or different values according to the number of pixels in the image width and height directions multiplied by the spatial resolution, that is , , , wherein, is the horizontal coordinate movement step, N is the number of width pixels of the image captured by the high-magnification objective lens, and R is the spatial resolution of the image captured by the high-magnification objective lens, Figure 5 is the vertical coordinate movement step, and M is the number of height pixels of the image captured by the high-magnification objective lens) and is synchronously photographed (as shown in Figure 5 is a schematic diagram of the movement trajectory of the spiral movement in the spiral acquisition method, wherein the circles a1, …, a25 are the optical centers of the high-magnification objective lens at each movement, the line segment b is the movement trajectory of the high-magnification objective lens, and the dashed rectangle c is a view point area of which the image is not acquired), which can systematically and comprehensively cover each area of the target wafer and ensure that a sufficient number and quality of view point images are acquired, which are crucial for subsequent image stitching and marker positioning.

[0117] Before moving the high-magnification objective lens relative to the target wafer, the target wafer needs to be placed on the base of the three-axis motion platform, and a global coordinate system is established with the coordinate of the center of the target wafer in the ideal position (i.e. the position after accurate positioning) as the origin. The z-axis of the global coordinate system coincides with the rotation axis of the motion platform, and the plane in which the x-axis and y-axis of the global coordinate system lie is parallel to the target wafer on the base of the three-axis motion platform. When positioning the target wafer, the three-axis motion platform can rotate the target wafer along the z-axis, or translate the target wafer along the x-axis and y-axis to change the position coordinate of the target wafer.

[0118] The spiral acquisition method refers to that the high-magnification objective lens moves in a spiral path in the clockwise or counterclockwise direction above the target wafer according to the preset movement step, and simultaneously intermittently photographs the target wafer (i.e. once for each movement), thereby acquiring view point images covering different areas of the target wafer.

[0119] The preset marker refers to a specific pattern or structure pre-set on the target wafer for assisting positioning, which can be a cross marker, a circular marker or a two-dimensional code, and the ideal position and characteristics thereof are known.

[0120] Specifically, the positioning module 2 performs the following operations when obtaining each view point image, performing image stitching on the obtained view point image in a nine-square grid stitching form, and obtaining at least two stitched images containing the preset marker point by performing marker point positioning on the stitched view point image through a template matching method:

[0121] performing image stitching on the obtained view point image in a nine-square grid stitching form, taking the currently obtained view point image as the center, to obtain the stitched view point image;

[0122] performing marker point matching on each stitched view point image and the preset marker point template image through a template matching method to detect whether any preset marker point identical to the preset marker point template image exists in each stitched view point image;

[0123] when detecting that any preset marker point identical to the preset marker point template image exists in the currently stitched view point image, determining that the currently stitched view point image is a stitched image containing the preset marker point, ending the search for the current preset marker point, moving the high-magnification objective lens to an ideal position corresponding to another preset marker point in the target wafer, and obtaining a stitched image containing another preset marker point through the same spiral acquisition method, image stitching method and template matching method to obtain at least two stitched images containing the preset marker point.

[0124] Specifically, the positioning module 2 performs the following operations when obtaining each view point image, performing image stitching on the obtained view point image in a nine-square grid stitching form, taking the currently obtained view point image as the center, to obtain the stitched view point image:

[0125] extracting, from the obtained view point image, adjacent images adjacent to the currently obtained view point image in eight directions according to the movement trajectory of the high-magnification objective lens when obtaining each view point image;

[0126] performing stitching on the currently obtained view point image and the adjacent images based on the positional relationship between the adjacent images and the currently obtained view point image, taking the currently obtained view point image as the center, to obtain the stitched view point image.

[0127] When the positioning module 2 is executed, in the wafer positioning process, a single view point image may not be able to completely cover the preset marker point, so it is necessary to expand the field of view through image stitching to ensure that the preset marker point can be completely captured. Each time a new view point image is generated, the images adjacent to the currently obtained view point image in eight directions are selected as adjacent images from the obtained view point image according to the movement direction and historical trajectory of the high-magnification objective lens.

[0128] The current acquired viewpoint image is taken as the center, and based on the positional relationship between the adjacent images and the current acquired viewpoint image, the current acquired viewpoint image and the adjacent images are spliced to form a larger spliced image, and a spliced viewpoint image is obtained. Through this splicing method, only the current viewpoint image and the determined adjacent images are spliced locally each time, instead of globally splicing all the collected images, so as to reduce the calculation complexity and improve the real-time splicing.

[0129] In some optional embodiments, when splicing images, not only the nine-square splicing form can be used, but also other matrix arrangement methods can be used for splicing, such as QxQ or QxP (Q and P are positive integers) splicing forms. The current acquired viewpoint image is taken as the center, and the nearby acquired images are spliced to obtain a spliced viewpoint image.

[0130] When the positioning module 2 is executed, whenever a new viewpoint image is acquired and spliced to obtain a spliced viewpoint image, template matching (for example, existing matching calculation methods such as a correlation coefficient method based on normalized cross-correlation, a recognition algorithm based on contour shape, a local feature point matching algorithm (such as SIFT or ORB), or a target detection method driven by machine learning) is performed immediately, the spliced viewpoint image each time is matched with the preset marker point template image for marker point matching, so as to detect the occurrence of the preset marker point in the spliced viewpoint image in real time. This real-time detection mechanism ensures that once the condition of the occurrence of the preset marker point is met during the image splicing process, the current spliced viewpoint image can be immediately determined as the target image, that is, the spliced image containing the preset marker point, and the search for the current preset marker point is ended, thereby avoiding unnecessary image acquisition and splicing and improving the efficiency. The existing matching calculation method is prior art, which will not be described in detail here.

[0131] Through the above method, only a high-magnification objective lens is used, images are sequentially acquired at multiple viewpoints around the ideal position of the preset marker point according to the multi-viewpoint image acquisition strategy, and the multi-viewpoint images are spliced and fused, so that the preset marker point enters the field of view range by fusing “small images (viewpoint images) ” into a large image (spliced image), and the high spatial resolution characteristics of the high-magnification objective lens are fully utilized to acquire high-precision positioning data of the preset marker point and the wafer. The high-precision positioning data can simplify the hardware of the visual imaging system while maintaining high positioning accuracy, and reduce the hardware cost of the positioning device.

[0132] Specifically, after the positioning module 2 matches each spliced viewpoint image with the preset marker point template image for marker point matching by the template matching method to detect whether any preset marker point identical to the preset marker point template image exists in each spliced viewpoint image, the positioning module 2 further performs:

[0133] When the number of acquired viewpoint images is greater than or equal to the preset maximum viewpoint number threshold, and it is not detected that any preset marker point of the viewpoint image after each splicing is the same as the preset marker point template image, it is determined that the preset marker point search is timed out, the search for the preset marker point is terminated, and it is determined that the wafer positioning fails,

[0134] The positioning module 2, when executed, counts the number of acquired viewpoint images in real time during the image acquisition process. When the number of viewpoint images reaches the preset maximum viewpoint number threshold, and the preset marker point is not detected, it is determined that the current wafer positioning process has exceeded the normal time consumption range, the marker point search process is terminated, and invalid resource consumption is avoided.

[0135] In some optional embodiments, after a wafer positioning fails once, another preset marker point can be selected for repositioning. If positioning fails continuously, a worker is notified in time for abnormal handling.

[0136] The positioning module 2, when executed, adjusts the position of the high-magnification objective lens to the ideal position of another preset marker point immediately after detecting the first preset marker point, and quickly locks the position of another preset marker point (if the number of acquired viewpoint images is greater than or equal to the preset maximum viewpoint number threshold, another preset marker point is selected for repositioning) by repeating the spiral acquisition method, the image splicing method, and the template matching method, to obtain at least two spliced images containing the preset marker point.

[0137] Specifically, the calculation module 3, when calculating the angle offset of the target wafer according to the position coordinates of the preset marker point in the spliced image, performs:

[0138] According to the offset of the preset marker point from the viewpoint center position of the corresponding spliced image in the spliced image, and in combination with the preset image spatial resolution, the position coordinates of the preset marker point are calculated.

[0139] The position coordinates of any two preset marker points are input into a preset angle offset calculation formula, and the angle offset of the target wafer is calculated.

[0140] The calculation module 3, when executed, determines the pixel offset of the preset marker point relative to the viewpoint center position according to the pixel number difference of the preset marker point from the viewpoint center position in the horizontal coordinate direction and the pixel number difference in the vertical coordinate direction in the spliced image in which the preset marker point is located. Subsequently, the pixel offset is multiplied by the preset image spatial resolution to calculate the offset coordinates of the preset marker point relative to the viewpoint center position. The offset coordinates and the coordinates of the viewpoint center position are combined, and the accurate position coordinates of the preset marker point on the wafer plane are calculated. That is, the position coordinates of the preset marker point can be calculated by the following marker point coordinate formula:

[0141] ;

[0142] ;

[0143] in, The x-coordinate of the preset marker point; is the x-coordinate of the viewpoint center position of the stitched image corresponding to the preset marker point; n is the pixel offset of the preset marker point relative to the viewpoint center position in the x-coordinate direction; R is the preset image spatial resolution; The ordinate of the preset marker point; is the ordinate of the viewpoint center position of the stitched image corresponding to the preset marker point; m is the pixel offset of the preset marker point relative to the viewpoint center position in the ordinate direction.

[0144] like Figure 6 As shown, Figure 6 This diagram illustrates the preset marker points in the stitched image. Circles a1, a4, a5, a6, a7, a8, a18, a19, and a20 represent the optical centers of the high-magnification objective lens during each movement. The solid line area p represents the stitched image of the acquired viewpoint region, while circle a6 represents the viewpoint center position of the stitched image. The dashed rectangle c represents the viewpoint region where no image was acquired (in the 3x3 grid image stitching, if images of adjacent viewpoints are not acquired, all pixels in the corresponding viewpoint region are assigned a value of 0). d represents the preset marker point, x1 is the abscissa of the preset marker point's offset relative to the viewpoint center position, and y1 is the ordinate of the preset marker point's offset relative to the viewpoint center position. Figure 6 It can be seen that the x-coordinate x1 and y-coordinate y1 calculated by pixel offset and image spatial resolution, combined with the actual coordinates of the viewpoint center position of the stitched image, can be used to calculate the x-coordinate and y-coordinate of the preset marker point d.

[0145] Based on the calculated position coordinates of the preset marker points, the position coordinates of any two preset marker points are input into the preset angle offset calculation formula to calculate the angle offset of the target wafer.

[0146] The preset angle offset calculation formula is as follows:

[0147] ;

[0148] in, This is the angular offset. It is a two-parameter arctangent function, and its angle output range is... ; Let x be the x-coordinate of one of the preset marker points; is a longitudinal coordinate of one of the preset mark points; is a longitudinal coordinate of one of the preset mark points; is a longitudinal coordinate of one of the preset mark points; is an angle formed by a line connecting the two preset mark points and a positive direction axis of the horizontal coordinate axis when the target wafer is located at the ideal position, i.e. , is a longitudinal coordinate of one of the preset mark points at the ideal position, is a longitudinal coordinate of one of the preset mark points at the ideal position, is a longitudinal coordinate of one of the preset mark points at the ideal position, is a longitudinal coordinate of one of the preset mark points at the ideal position.

[0149] Specifically, the correction module 4 performs the following when the target wafer is accurately positioned based on the angle offset and the position offset of the target wafer after the angle correction:

[0150] correcting the angle of the target wafer based on the angle offset to obtain the target wafer after the angle correction;

[0151] calculating the position offset between the position coordinate of the preset mark point in the target wafer after the angle correction and the preset target position coordinate, to provide an accurate position deviation compensation for subsequent detection or repair, and to obtain the target wafer after the accurate positioning.

[0152] When the correction module 4 is executed, the three-axis motion platform is rotated by angle (counterclockwise rotation is positive and clockwise rotation is negative) relative to the vision imaging system based on the previously calculated angle offset, to adjust the rotation of the target wafer, so that the overall angle of the target wafer is aligned with the ideal state (ideal position), and the target wafer after the angle correction is obtained, wherein the position coordinate of the preset mark point is adjusted with the rotation of the target wafer, and the position coordinate of the preset mark point after the angle correction is:

[0153] ;

[0154] ;

[0155] wherein, is a longitudinal coordinate of one of the preset mark points at the ideal position, is a longitudinal coordinate of one of the preset mark points at the ideal position, is a longitudinal coordinate of one of the preset mark points at the ideal position, is a longitudinal coordinate of one of the preset mark points at the ideal position.

[0156] As Figure 7 shown, Figure 7 is a schematic diagram of the target wafer relative to the ideal position of the wafer, wherein, is the angle offset, the solid circle e is the target wafer, the dashed line e' is the ideal position of the wafer, d1 is one of the preset mark points, and d2 is another preset mark point. From Figure 7 it can be known that the target wafer is rotated by an angle, that is, the angle of the target wafer e' can be corrected.

[0157] After the angle correction is completed, by comparing the actual position coordinates of the preset mark points after the angle correction with the ideal position coordinates thereof, the position offset of the target wafer in the X and Y directions is calculated, and the target wafer with accurate positioning is obtained. For example, if the actual position of the preset mark points after the angle correction is (x', y'), the ideal position is (x t ,y t ), and the position offset is (Δx, Δy) = (x t -x', y t -y'). This position offset can provide an accurate position offset compensation for subsequent detection or repair, and ensure the accuracy of the detection or repair. When the subsequent detection equipment or repair equipment performs an operation, the motion track or action point thereof can be fine-tuned according to the compensation, so as to ensure that the operation can accurately align with the target region on the wafer.

[0158] As Figure 8 shown, Figure 8 is a schematic diagram of the target wafer relative to the ideal position of the wafer, wherein, the solid circle e is the target wafer, the dashed line e' is the ideal position of the wafer, d3 is one of the preset mark points, d4 is another preset mark point, d3' is the ideal position of one of the preset mark points, and d4' is the ideal position of another preset mark point. From Figure 8 it can be known that the offset between the target wafer e and the ideal position e' of the wafer can be determined according to the offset between the actual position coordinates of the preset mark points and the ideal positions thereof.

[0159] ​As can be known from the above, the wafer precise positioning device obtains the viewpoint images at different positions in the target wafer in sequence by adopting the spiral acquisition method of the high-magnification objective lens, the target wafer is provided with a plurality of preset mark points for positioning, after each viewpoint image is obtained, the obtained viewpoint image is spliced in the form of a nine-square grid, and the mark point positioning is performed on the spliced viewpoint image by the template matching method, at least two spliced images containing the preset mark points are obtained, the angle offset of the target wafer is calculated according to the position coordinates of the preset mark points in the spliced images, the angle correction is performed on the target wafer based on the angle offset, the position offset of the target wafer after the angle correction is calculated, and the precisely positioned target wafer is obtained. Therefore, the angle offset of the target wafer is calculated by using at least two preset mark points obtained by performing the image splicing and the mark point positioning on the viewpoint images obtained by the spiral acquisition method, the angle correction is performed on the target wafer, the position offset of the target wafer after the angle correction is calculated, and the precisely positioned target wafer is obtained. Only the spiral image acquisition is performed by using the high-magnification objective lens, on the one hand, the high resolution characteristic of the high-magnification objective lens is used to improve the positioning precision, and on the other hand, the multi-viewpoint image acquisition method of the spiral is used to expand the field of view range of the preset mark point search, and the objective lens does not need to be switched. The existing wafer precise positioning method solves the problems that the system is complex, the hardware cost is high, and the mechanical error is easy to trigger when the double-objective lens switching mode is used, and two objective lenses and the corresponding switching mechanism do not need to be configured and maintained, the hardware cost is significantly reduced, and the positioning efficiency of the wafer is improved.

[0160] Please refer to Figure 3 , Figure 3 A structural schematic diagram of an electronic device provided by an embodiment of the present application is provided, and the present application provides an electronic device, which comprises a processor 301 and a memory 302. The processor 301 and the memory 302 are interconnected and communicate with each other through a communication bus 303 and / or other forms of connection mechanism (not marked). The memory 302 stores a computer program executable by the processor 301. When the electronic device is running, the processor 301 executes the computer program to perform the wafer precise positioning method in any optional implementation manner of the above-mentioned embodiments to realize the following functions: the spiral acquisition method of the high-magnification objective lens is adopted to obtain viewpoint images at different positions in the target wafer in sequence, the target wafer is provided with a plurality of preset mark points for positioning, after each viewpoint image is obtained, the obtained viewpoint image is spliced in the form of a nine-square grid, and the mark point positioning is performed on the spliced viewpoint image by the template matching method, at least two spliced images containing the preset mark points are obtained, the angle offset of the target wafer is calculated according to the position coordinates of the preset mark points in the spliced images, the angle correction is performed on the target wafer based on the angle offset, the position offset of the target wafer after the angle correction is calculated, and the precisely positioned target wafer is obtained.

[0161] The computer readable storage medium provided by the embodiments of the present application stores a computer program, and the computer program is executed by a processor to implement the wafer precise positioning method in any optional implementation manner of the above embodiments to realize the following functions: a spiral acquisition method of a high magnification objective lens is adopted to sequentially acquire viewpoint images at different positions in a target wafer, a plurality of preset mark points for positioning are arranged in the target wafer, each time a viewpoint image is acquired, the acquired viewpoint image is spliced in a nine-square grid splicing form, and a mark point positioning is performed on the spliced viewpoint image by a template matching method, at least two spliced images containing the preset mark points are obtained, an angle offset of the target wafer is calculated according to the position coordinates of the preset mark points in the spliced images, an angle correction is performed on the target wafer based on the angle offset, a position offset of the target wafer after the angle correction is calculated, and the precisely positioned target wafer is obtained. The storage medium can be realized by any type of volatile or non-volatile storage device or a combination thereof, such as a static random access memory (SRAM), an electrically erasable programmable read-only memory (EEPROM), an erasable programmable read-only memory (EPROM), a programmable read-only memory (PROM), a read-only memory (ROM), a magnetic memory, a flash memory, a magnetic disk or an optical disk.

[0162] In the embodiments provided by the present application, it should be understood that the disclosed device and method can be implemented in other ways. The device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There can be another division during actual implementation. For example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections between the units can be indirect couplings or communication connections through some communication interfaces, devices or units, and can be electrical, mechanical or in other forms.

[0163] In addition, the units described as separate components may or may not be physically separate, and the components displayed as units may or may not be physical units, and may be located in one place, or distributed on multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiment scheme.

[0164] Furthermore, the functional modules in various embodiments of the present application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0165] In this paper, the relationship terms such as first and second 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 the entities or operations.

[0166] The above is only an embodiment of the present application and is not used to limit the protection scope of the present application. For those skilled in the art, the present application can have various changes and variations. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for precisely positioning a wafer, for positioning a wafer, characterized by, The method comprises the steps of: a spiral acquisition method using a high magnification objective lens is used to sequentially acquire viewpoint images at different positions in a target wafer; a plurality of preset marker points for positioning are arranged in the target wafer; each time a viewpoint image is acquired, the acquired viewpoint image is spliced in a nine-square grid splicing manner, and a marker point positioning is performed on the spliced viewpoint image by using a template matching method, to obtain at least two spliced images containing the preset marker points; an angle offset of the target wafer is calculated according to the position coordinates of the preset marker points in the spliced images; based on the angle offset, an angle correction is performed on the target wafer, and a position offset of the target wafer after the angle correction is calculated, to obtain a precisely positioned target wafer; a spiral acquisition method using a high magnification objective lens is used to sequentially acquire viewpoint images at different positions in a target wafer, comprising: moving the high magnification objective lens to an ideal position corresponding to any preset marker point in the target wafer; using the spiral acquisition method, controlling the high magnification objective lens to move while sequentially photographing the target wafer by using the high magnification objective lens according to a preset moving step, to acquire viewpoint images at different positions in the target wafer; each time a viewpoint image is acquired, the acquired viewpoint image is spliced in a nine-square grid splicing manner, and a marker point positioning is performed on the spliced viewpoint image by using a template matching method, to obtain at least two spliced images containing the preset marker points, comprising: each time a viewpoint image is acquired, the acquired viewpoint image is spliced in a nine-square grid splicing manner, and a marker point positioning is performed on the spliced viewpoint image by using a template matching method, to obtain at least two spliced images containing the preset marker points, comprising: each time a viewpoint image is acquired, the acquired viewpoint image is spliced in a nine-square grid splicing manner, and a marker point positioning is performed on the spliced viewpoint image by using a template matching method, to obtain at least two spliced images containing the preset marker points, comprising: each time a viewpoint image is acquired, the acquired viewpoint image is spliced in a nine-square grid splicing manner, and a marker point positioning is performed on the spliced viewpoint image by using a template matching method, to obtain at least two spliced images containing the preset marker points, comprising:

2. The wafer precise positioning method according to claim 1, wherein, each time a viewpoint image is acquired, the acquired viewpoint image is spliced in a nine-square grid splicing manner, and a marker point positioning is performed on the spliced viewpoint image by using a template matching method, to obtain at least two spliced images containing the preset marker points, comprising: each time a viewpoint image is acquired, the acquired viewpoint image is spliced in a nine-square grid splicing manner, and a marker point positioning is performed on the spliced viewpoint image by using a template matching method, to obtain at least two spliced images containing the preset marker points, comprising: each time a viewpoint image is acquired, the acquired viewpoint image is spliced in a nine-square grid splicing manner, and a marker point positioning is performed on the spliced viewpoint image by using a template matching method, to obtain at least two spliced images containing the preset marker points, comprising: each time a viewpoint image is acquired, the acquired viewpoint image is spliced in a nine-square grid splicing manner, and a marker point positioning is performed on the spliced viewpoint image by using a template matching method, to obtain at least two spliced images containing the preset marker points, comprising: each time a viewpoint image is acquired, the acquired viewpoint image is spliced in a nine-square grid splicing manner, and a marker point positioning is performed on the spliced viewpoint image by using a template matching method, to obtain at least two spliced images containing the preset marker points, comprising: each time a viewpoint image is acquired, the acquired viewpoint image is spliced in a nine-square grid splicing manner, and a marker point positioning is performed on the spliced viewpoint image by using a template matching method, to obtain at least two spliced images containing the preset marker points, comprising: each time a viewpoint image is acquired, the acquired viewpoint image is spliced in a nine-square grid splicing manner, and a marker point positioning is performed on the spliced viewpoint image by using a template matching method, to obtain at least two spliced images containing the preset marker points, comprising: each time a viewpoint image is acquired, the acquired viewpoint image is spliced in a nine-square grid splicing manner, and a marker point positioning is performed on the spliced viewpoint image by using a template matching method, to obtain at least two spliced images containing the preset marker points, comprising: each time a viewpoint image is acquired, the acquired viewpoint image is spliced in a nine-square grid splicing manner, and a marker point positioning is performed on the spliced viewpoint image by using a template matching method, to obtain at least two spliced images containing the preset marker points, comprising: each time a viewpoint image is acquired, the acquired viewpoint image is spliced in a nine-square grid splicing manner, and a marker point positioning is performed on the spliced viewpoint image by using a template matching method, to obtain at least two spliced images containing the preset marker points, comprising: each time a viewpoint image is acquired, the acquired viewpoint image is spliced in a nine-square grid splicing manner, and a marker point positioning is performed on the spliced viewpoint image by using a template matching method, to obtain at least two spliced images containing the preset marker points, comprising: The current acquired viewpoint image is spliced with the adjacent images based on the positional relationship between the adjacent images and the current acquired viewpoint image, to obtain a spliced viewpoint image.

3. The wafer precise positioning method of claim 1, wherein, After the viewpoint image is spliced each time, a preset marker point template image is matched with the marker point through a template matching method, to detect whether any preset marker point in the preset marker point template image exists in the viewpoint image spliced each time. When the number of acquired viewpoint images is greater than or equal to a preset maximum viewpoint number threshold, and it is detected that no preset marker point in the preset marker point template image exists in the viewpoint image spliced each time, it is determined that the preset marker point search is timed out, the search for the preset marker point is terminated, and wafer positioning fails.

4. The wafer precise positioning method of claim 1, wherein, The angle offset of the target wafer is calculated according to the positional coordinates of the preset marker points in the spliced image, including: The positional coordinates of the preset marker points are calculated according to the offset of the preset marker points from the viewpoint center position of the corresponding spliced image, in combination with a preset image space resolution. The angle offset of the target wafer is calculated by inputting the positional coordinates of any two preset marker points into a preset angle offset calculation formula.

5. The wafer precise positioning method of claim 1, wherein, The target wafer is angle-corrected based on the angle offset, and the positional offset of the angle-corrected target wafer is calculated, to obtain a precisely positioned target wafer, including: The target wafer is angle-corrected based on the angle offset, to obtain an angle-corrected target wafer. The positional offset between the positional coordinates of the preset marker points in the angle-corrected target wafer and the preset target positional coordinates is calculated, to provide an accurate positional deviation compensation for subsequent detection or repair, to obtain a precisely positioned target wafer.

6. A wafer precision positioning device for positioning wafers, characterized in that, including: The acquisition module is configured to acquire viewpoint images at different positions in the target wafer in sequence by using a spiral acquisition method of a high-magnification objective lens. The target wafer is provided with a plurality of preset marker points for positioning. The positioning module is configured to perform image splicing on the acquired viewpoint images each time a viewpoint image is acquired, and perform marker point positioning on the spliced viewpoint images by using a template matching method, to obtain at least two spliced images containing the preset marker points. The calculation module is configured to calculate the angle offset of the target wafer according to the positional coordinates of the preset marker points in the spliced image. The correction module is configured to perform angle correction on the target wafer based on the angle offset, and calculate the positional offset of the angle-corrected target wafer, to obtain a precisely positioned target wafer. The acquisition module is configured to acquire viewpoint images at different positions in the target wafer in sequence by using a spiral acquisition method of a high-magnification objective lens, including: The high-magnification objective lens is moved to an ideal position corresponding to any preset marker point in the target wafer. The high-magnification objective lens is controlled to move according to a preset moving step, and the high-magnification objective lens is used to sequentially capture the target wafer to obtain the viewpoint images at different positions in the target wafer. The positioning module is configured to perform image stitching on the acquired viewpoint images in a nine-grid stitching manner, and perform mark point positioning on the stitched viewpoint images by a template matching method to obtain at least two stitched images containing the preset mark points, including: The viewpoint images are stitched in a nine-grid stitching manner with the currently acquired viewpoint image as the center, and the adjacent acquired viewpoint images are stitched to obtain the stitched viewpoint images. The template matching method is used to match the preset mark point template image with the viewpoint images after each stitching to detect whether any of the preset mark points in the preset mark point template image exists in the viewpoint images after each stitching. When it is detected that any of the preset mark points in the preset mark point template image exists in the viewpoint images after the current stitching, the viewpoint images after the current stitching are determined as the stitched images containing the preset mark points, and the search for the current preset mark point is ended. The high-magnification objective lens is moved to an ideal position corresponding to another preset mark point in the target wafer, and the same spiral acquisition method, image stitching method and template matching method are used to acquire the stitched images containing another preset mark point, thereby obtaining at least two stitched images containing the preset mark points.

7. An electronic device, comprising: The computer program is executed by the processor to run the steps in the wafer precise positioning method of any one of claims 1-5.

8. A computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to run the steps in the wafer precise positioning method of any one of claims 1-5.

Images