Marker positioning method and system based on object side telecentric lens

Abstract

The application provides a mark positioning method and system based on an object-side telecentric lens, wherein the method comprises the following steps: determining the mechanical pixel x-axis magnification, the mechanical pixel y-axis magnification, the x-axis telecentricity and the y-axis telecentricity corresponding to the image acquisition device based on the object-side telecentric lens; determining the target conversion matrix from the pixel coordinate system to the mechanical coordinate system according to the mechanical pixel x-axis magnification, the mechanical pixel y-axis magnification, the device center point mechanical x-axis coordinate, the y-axis coordinate and the z-axis coordinate, the image acquisition device focal length, the x-axis telecentricity and the y-axis telecentricity; acquiring and determining the mask worktable moving path according to the position of the reference mark plate mark, the position of the mask mark and the target conversion matrix from the pixel coordinate system to the mechanical coordinate system; and controlling the mask worktable to move. The application can realize the three-dimensional space accurate positioning of the target object with higher precision through the effective fusion of the telecentricity and the mechanical pixel magnification and other parameters for mark positioning.

Description

Technical Field

[0001] This application relates to the field of photolithography positioning technology, and more specifically, to a marking positioning method and system based on an object-side telecentric lens. Background Technology

[0002] Photolithography is a crucial step in the manufacturing of semiconductor integrated circuits. Specifically, it uses processes such as exposure to transfer patterns designed on a mask to a reference marking plate for fine processing. During the fabrication of the semiconductor reference marking plate, it is necessary to control the stage on which the mask is located to move to a specific position so that the mask markings and the semiconductor reference marking plate markings are aligned, thereby improving the overlay accuracy.

[0003] In the prior art, images of mask markings and semiconductor reference marking plates are acquired by a simple measuring camera, and field image alignment (FIA) technology is used to process the positioning of the camera image onto the real three-dimensional space based on the measuring camera's x-axis magnification, y-axis magnification, and the coordinates of the camera's field of view center point.

[0004] However, existing technologies do not effectively integrate the telecentricity of the measuring camera and the camera's intrinsic parameters during the alignment process, ignoring the mutual influence between the data, which makes it impossible to accurately locate the target object in three-dimensional space. Summary of the Invention

[0005] The purpose of this application is to provide a marker positioning method and system based on an object-side telecentric lens to address the shortcomings of the prior art, thereby solving the problem that the prior art cannot accurately locate the target object in three-dimensional space.

[0006] To achieve the above objectives, the technical solution adopted in this application is as follows:

[0007] In a first aspect, this application provides a marker positioning method based on an object-side telecentric lens, the method comprising:

[0008] Determine the mechanical pixel x-axis magnification, mechanical pixel y-axis magnification, x-axis telecentricity, and y-axis telecentricity corresponding to the image acquisition device based on the object-side telecentric lens;

[0009] Based on the mechanical pixel x-axis magnification, the mechanical pixel y-axis magnification, the preset mechanical x-axis coordinates of the device center point, the preset mechanical y-axis coordinates of the device center point, the preset mechanical z-axis coordinates of the device center point, the preset focal length of the image acquisition device, the x-axis telecentricity, and the y-axis telecentricity, determine the target transformation matrix from the pixel coordinate system to the mechanical coordinate system;

[0010] Acquire the positions of the reference markers and mask markers in the image of the object under test sent by the image acquisition device;

[0011] The mask stage movement path is determined based on the position of the reference mark plate, the position of the mask mark, and the target transformation matrix between the pixel coordinate system and the machine coordinate system.

[0012] The mask stage is moved according to the mask stage movement path so that the mask mark in the mask set on the mask stage is aligned with the reference mark in the reference mark plate.

[0013] Optionally, determining the target transformation matrix from the pixel coordinate system to the machine coordinate system based on the mechanical pixel x-axis magnification, the mechanical pixel y-axis magnification, the preset mechanical x-axis coordinates of the device center point, the preset mechanical y-axis coordinates of the device center point, the preset mechanical z-axis coordinates of the device center point, the preset focal length of the image acquisition device, the x-axis telecentricity, and the y-axis telecentricity includes:

[0014] Establish pixel coordinate system, image coordinate system, camera coordinate system, and machine coordinate system;

[0015] Establish a first transformation matrix from the image coordinate system to the pixel coordinate system;

[0016] Establish a second transformation matrix from the camera coordinate system to the image coordinate system;

[0017] Establish a third transformation matrix between the machine coordinate system and the camera coordinate system;

[0018] Based on the first transformation matrix, the second transformation matrix, and the third transformation matrix, determine the transformation matrix between the pixel coordinate system and the machine coordinate system;

[0019] The mechanical pixel x-axis magnification, the mechanical pixel y-axis magnification, the preset mechanical x-axis coordinates of the device center point, the preset mechanical y-axis coordinates of the device center point, the preset mechanical z-axis coordinates of the device center point, the preset focal length of the image acquisition device, the x-axis telecentricity, and the y-axis telecentricity are input into the transformation matrix between the pixel coordinate system and the mechanical coordinate system to obtain the target transformation matrix from the pixel coordinate system to the mechanical coordinate system.

[0020] Optionally, the first transformation matrix for establishing the image coordinate system to the pixel coordinate system includes:

[0021] The position coordinates of the origin of the image coordinate system in the pixel coordinate system are set to a preset value to obtain the first transformation matrix from the image coordinate system to the pixel coordinate system.

[0022] Optionally, determining the transformation matrix between the pixel coordinate system and the machine coordinate system based on the first transformation matrix, the second transformation matrix, and the third transformation matrix includes:

[0023] Determine the first transformation inverse matrix corresponding to the first transformation matrix;

[0024] Determine the second transformation inverse matrix corresponding to the second transformation matrix;

[0025] The transformation matrix between the pixel coordinate system and the machine coordinate system is determined based on the first transformation inverse matrix, the second transformation inverse matrix, and the third transformation matrix.

[0026] Optionally, determining the transformation matrix between the pixel coordinate system and the machine coordinate system based on the first transformation inverse matrix, the second transformation inverse matrix, and the third transformation matrix includes:

[0027] Multiply the third transformation matrix, the second transformation inverse matrix, and the first transformation matrix to obtain the transformation matrix between the pixel coordinate system and the machine coordinate system;

[0028] The transformation matrix between the pixel coordinate system and the machine coordinate system is as follows:

[0029]

[0030] in, The third transformation matrix, This is the inverse matrix of the second transformation. Let be the inverse of the first transformation matrix, α be the x-axis telecentrism, β be the y-axis telecentrism, and t be the inverse of the first transformation matrix. x Let t be the mechanical x-axis coordinate of the center point of the equipment. y Let z be the mechanical y-axis coordinate of the center point of the equipment, z M Let m be the mechanical z-axis coordinate of the center point of the device, m be the ratio of the focal length of the image acquisition device to the mechanical z-axis coordinate of the center point of the device, dx be the x-axis magnification of the mechanical pixel, and dy be the y-axis magnification of the mechanical pixel.

[0031] Optionally, determining the mask stage movement path based on the position of the reference mark plate, the position of the mask mark, and the target transformation matrix between the pixel coordinate system and the machine coordinate system includes:

[0032] The starting position of movement is determined based on the position of the mask mark in the image of the object under test and the target transformation matrix between the pixel coordinate system and the machine coordinate system.

[0033] The end position of the movement is determined based on the position of the reference marker in the image of the object under test and the target transformation matrix between the pixel coordinate system and the machine coordinate system.

[0034] The movement path of the mask worktable is determined based on the starting position and the ending position of the movement.

[0035] Optionally, determining the starting position of movement based on the position of the mask mark in the image of the object under test and the target transformation matrix between the pixel coordinate system and the machine coordinate system includes:

[0036] The starting position of the movement is obtained by multiplying the vector corresponding to the position of the mask mark with the target transformation matrix between the pixel coordinate system and the machine coordinate system.

[0037] Optionally, the method further includes:

[0038] Based on the first transformation matrix, the second transformation matrix, and the third transformation matrix, determine the transformation matrix from the machine coordinate system to the pixel coordinate system;

[0039] The marker position in the pixel coordinate system is determined based on the transformation matrix from the machine coordinate system to the pixel coordinate system, the x-axis magnification of the machine pixel, the y-axis magnification of the machine pixel, the preset machine x-axis coordinates of the device center point, the preset machine y-axis coordinates of the device center point, the preset focal length of the image acquisition device, the telecentricity of the x-axis and the telecentricity of the y-axis, and the marker position in the machine coordinate system.

[0040] Optionally, determining the transformation matrix from the machine coordinate system to the pixel coordinate system based on the first transformation matrix, the second transformation matrix, and the third transformation matrix includes:

[0041] Multiply the first transformation matrix, the second transformation matrix, and the third transformation matrix to obtain the transformation matrix from the machine coordinate system to the pixel coordinate system;

[0042] The transformation matrix from the machine coordinate system to the pixel coordinate system is as follows:

[0043]

[0044] in, Let be the first transformation matrix. This is the second transformation matrix. Let dx be the x-axis magnification of the mechanical pixel, dy be the y-axis magnification of the mechanical pixel, f be the focal length of the image acquisition device, α be the x-axis telecentricity, β be the y-axis telecentricity, and t be the focal length of the image acquisition device. x Let t be the mechanical x-axis coordinate of the center point of the equipment. y Let be the mechanical y-axis coordinate of the center point of the device.

[0045] Secondly, this application provides a marker positioning system based on an object-side telecentric lens. The marker positioning system based on an object-side telecentric lens includes a control module, an image acquisition device, a mask worktable, and a reduction projection lens. The image acquisition device is used to acquire an image of the object under test sequentially through the reduction projection lens and the object-side telecentric lens. The image of the object under test includes mask marks on the mask on the mask worktable and reference mark marks in the reference mark plate. The image of the object under test is then sent to the control module. The control module is used to execute the steps of the marker positioning method based on an object-side telecentric lens as described in the first aspect.

[0046] The beneficial effects of this application are as follows: First, the mechanical pixel x-axis magnification, mechanical pixel y-axis magnification, x-axis telecentricity, and y-axis telecentricity corresponding to the image acquisition device based on the object-side telecentric lens are determined. Since the image acquisition device uses an object-side telecentric lens, the measured x-axis and y-axis telecentricities deviate very little from the actual optical path and the telecentricity of the mask stage, thereby improving the three-dimensional spatial positioning of the target object. Then, based on the aforementioned mechanical pixel magnification, telecentricity, preset device center point coordinates, and preset image acquisition device focal length, the target transformation matrix from the pixel coordinate system to the mechanical coordinate system is determined. Next, the positions of the reference markers and mask markers sent by the image acquisition device are obtained, and the mask stage movement path is determined based on the target transformation matrix from the pixel coordinate system to the mechanical coordinate system, thereby controlling the movement of the mask stage. In the above method, by effectively fusing the telecentricity acquired by the image acquisition device and camera parameters such as the mechanical pixel x-axis magnification and mechanical pixel y-axis magnification for marker positioning, higher precision three-dimensional spatial positioning of the target object can be achieved. Attached Figure Description

[0047] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1 This is a schematic diagram illustrating an application scenario of a marker positioning method based on an object-side telecentric lens provided in an embodiment of this application;

[0049] Figure 2 This is a flowchart illustrating a marker positioning method based on an object-side telecentric lens provided in an embodiment of this application;

[0050] Figure 3 This is a schematic diagram illustrating the principle of telecentricity measurement provided in an embodiment of this application;

[0051] Figure 4 This is a schematic diagram of a reference mark plate marking and a mask marking provided in an embodiment of this application;

[0052] Figure 5 This is a flowchart illustrating the steps for determining a target transformation matrix from a pixel coordinate system to a machine coordinate system, as provided in an embodiment of this application.

[0053] Figure 6 This is a schematic diagram illustrating the imaging principle of an image acquisition device provided in an embodiment of this application;

[0054] Figure 7 This is a schematic diagram illustrating the relationship between a camera coordinate system and an image coordinate system provided in an embodiment of this application;

[0055] Figure 8 This is a schematic diagram illustrating the relationship between an image coordinate system and a pixel coordinate system provided in an embodiment of this application;

[0056] Figure 9 This is a flowchart illustrating a method for determining the transformation matrix between a pixel coordinate system and a machine coordinate system, provided in an embodiment of this application.

[0057] Figure 10 This is a flowchart illustrating a method for determining the moving path of a mask worktable, as provided in an embodiment of this application. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the accompanying drawings in this application are for illustrative and descriptive purposes only and are not intended to limit the scope of protection of this application. Furthermore, it should be understood that the schematic drawings are not drawn to scale. The flowcharts used in this application illustrate operations implemented according to some embodiments of this application. It should be understood that the operations in the flowcharts may not be implemented in sequence, and steps without logical contextual relationships may be reversed or implemented simultaneously. In addition, those skilled in the art, guided by the content of this application, may add one or more other operations to the flowcharts, or remove one or more operations from the flowcharts.

[0059] Furthermore, the described embodiments are merely some, not all, of the embodiments of this application. The components of the embodiments of this application described and illustrated herein can typically be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0060] It should be noted that the term "comprising" will be used in the embodiments of this application to indicate the presence of the features declared thereafter, but does not exclude the addition of other features.

[0061] In existing technologies, the FIA ​​method is used for image-based target localization. Specifically, it involves measuring the camera's x-axis magnification, y-axis magnification, and the coordinates of the camera's field of view center to locate the camera image in the real 3D space. However, existing technologies do not effectively fuse the camera's telecentricity and intrinsic parameters during alignment, ignoring the mutual influence between data, which results in the inability to accurately locate the target object in 3D space.

[0062] Based on this, this application proposes a marker positioning method based on an object-side telecentric lens. This method is applied in the control module of a marker positioning system. First, it determines the mechanical pixel magnification and telecentricity of the image acquisition device based on the object-side telecentric lens, and then determines the target transformation matrix from the pixel coordinate system to the mechanical coordinate system based on the mechanical coordinates of the device's center point. This target transformation matrix is ​​used to determine the movement of the mask stage in the mechanical coordinate system based on the pixel length of the image of the object under test acquired by the image acquisition device. During use, the positions of the reference marker and the mask marker in the image of the object under test sent by the image acquisition device are first obtained. Both the reference marker and the mask marker positions are coordinates in the pixel coordinate system. Then, the movement path of the mask stage is determined according to the target transformation matrix from the pixel coordinate system to the mechanical coordinate system. The movement of the mask stage is controlled according to this movement path, which is the path in the mechanical coordinate system. This application not only uses mechanical pixel magnification, telecentricity, and mechanical coordinates of the device center point during the transformation from pixel coordinate system to mechanical coordinate system to achieve accurate three-dimensional spatial positioning, but also utilizes an object-side telecentric lens to overcome the imaging characteristics of near-large and far-small, thereby improving the accuracy of target spatial positioning when the reference mark plate and mask mark are aligned.

[0063] Before introducing the specific implementation steps of the marker positioning method based on the object-side telecentric lens, we will first introduce the application scenarios of this method. Figure 1 This is a schematic diagram illustrating an application scenario of a marker positioning method based on an object-side telecentric lens provided in an embodiment of this application. For example... Figure 1As shown, the object-side telecentric lens-based marking and positioning method is applied in an object-side telecentric lens-based marking and positioning system. This system includes a control module, an image acquisition device, a mask stage, and a reduction projection lens. The image acquisition device has an object-side telecentric lens and is used to sequentially acquire images of the object under test through the reduction projection lens and the object-side telecentric lens, and then send these images to the control module. The control module receives the object under test images sent by the image acquisition device and controls the movement of the mask stage based on the positions of the reference markers and mask marks in the object under test images. One or more reference markers are set for each silicon wafer. The mask marks on the mask stage are aligned with the reference markers to enable photolithography on the silicon wafer. As an optional implementation, since a reference marker may have two or more markers, specifically including coarse alignment marks and fine alignment marks, multiple image acquisition devices with object-side telecentric lenses can be used to align the reference markers and mask marks.

[0064] Next, refer to Figure 2 The specific implementation process of the marker-based localization method using an object-side telecentric lens is introduced. Among other things, Figure 2 This is a flowchart illustrating a marker positioning method based on a telecentric lens provided in an embodiment of this application.

[0065] S201. Determine the mechanical pixel x-axis magnification, mechanical pixel y-axis magnification, x-axis telecentricity, and y-axis telecentricity of the image acquisition device based on the object-side telecentric lens.

[0066] In this context, the x-axis magnification of the mechanical pixels in the image acquisition device based on the object-side telecentric lens is the ratio of the unit pixel length on the x-axis of the image acquisition device to the mechanical movement length of the mask stage. The y-axis magnification of the mechanical pixels is the ratio of the unit pixel length on the y-axis of the image acquisition device to the mechanical movement length of the mask stage. The x-axis telecentricity is the rotational offset angle of the optical path relative to the mask stage along the x-axis, and the y-axis telecentricity is the rotational offset angle of the optical path relative to the mask stage along the y-axis.

[0067] As an optional implementation, the mechanical pixel x-axis magnification, mechanical pixel y-axis magnification, x-axis telecentricity, and y-axis telecentricity corresponding to the image acquisition device can be determined through a pre-adjustment process. This pre-adjustment process involves controlling the mask stage to translate and rotate along the x and y axes, thereby determining the mechanical pixel x-axis magnification, mechanical pixel y-axis magnification, x-axis telecentricity, and y-axis telecentricity based on the moved pixel distance and the mechanical movement distance.

[0068] As an optional implementation, the method for obtaining the mechanical pixel x-axis magnification and mechanical pixel y-axis magnification corresponding to the object-side telecentric lens is as follows: The mask stage is controlled to move horizontally according to a preset mechanical distance and preset mechanical direction based on a unit movement step, and the object-side telecentric lens is controlled to acquire an image of the object under test during the movement of the mask stage, wherein the mask stage is located within the field of view of the object-side telecentric lens. The quotient of the pixel distance the object under test moves along the x-axis in the image of the object under test and the mechanical distance the mask stage moves along the x-axis is taken as the mechanical pixel x-axis magnification, and the quotient of the pixel distance the object under test moves along the y-axis in the image of the object under test and the mechanical distance the mask stage moves along the y-axis is taken as the mechanical pixel y-axis magnification. The object under test can be a mask mark. Optionally, the steps of controlling the mask stage to move horizontally according to the preset mechanical distance and preset mechanical direction, and controlling the object-side telecentric lens to acquire an image of the object under test during the movement of the mask stage can be performed multiple times to obtain multiple candidate x-axis magnifications and candidate y-axis magnifications. After removing outliers using the three sigma method, the average of the selected x-axis magnification and y-axis magnification is calculated to obtain the mechanical pixel x-axis magnification and mechanical pixel y-axis magnification, so as to make the mechanical pixel x-axis magnification and mechanical pixel y-axis magnification more accurate.

[0069] As an optional implementation, the method for obtaining the x-axis and y-axis telecentricity corresponding to the object-side telecentric lens is as follows: The mask stage is controlled to move vertically along a preset mechanical distance and towards the mask stage, and the object-side telecentric lens is controlled to acquire an image of the object under test during the movement of the mask stage, wherein the mask stage is located within the field of view of the object-side telecentric lens. The ratio of the mechanical distance corresponding to the pixel distance along the x-axis of the object under test in the image of the object under test to the preset mechanical distance is used as the tangent value of the x-axis telecentricity, and the ratio of the mechanical distance corresponding to the pixel distance along the y-axis of the object under test in the image of the object under test to the preset mechanical distance is used as the tangent value of the y-axis telecentricity. The mechanical distance corresponding to the pixel distance can be calculated and determined based on the mechanical pixel x-axis magnification and mechanical pixel y-axis magnification.

[0070] For example, Figure 3 This is a schematic diagram illustrating the principle of telecentricity measurement provided in an embodiment of this application. Figure 3 As shown, the center position of the image of the object under test changes when the mask stage moves vertically. The centroid can be determined by the ratio of the preset mechanical distance to the mechanical distance corresponding to the pixel distance the object under test moves in the image of the object under test.

[0071] S202. Based on the mechanical pixel x-axis magnification, mechanical pixel y-axis magnification, preset mechanical x-axis coordinates of the device center point, preset mechanical y-axis coordinates of the device center point, preset mechanical z-axis coordinates of the device center point, preset focal length of the image acquisition device, x-axis telecentricity, and y-axis telecentricity, determine the target transformation matrix from the pixel coordinate system to the mechanical coordinate system.

[0072] The pixel coordinate system is used to characterize the projected coordinates of the object being measured on the discrete image plane. The coordinate axes of the pixel coordinate system can be represented by (u, v), and its unit scale is one pixel. The machine coordinate system is a reference system used to characterize the position of the object being measured, and its coordinate axes are (x, v). mcs y mcs , z mcs In this embodiment, the origin of the mechanical coordinate system can be set directly below the zoomed-out projection lens, where x... mcs axis and y mcs The axial direction is determined by the installation of the servo, and the specific position in the mechanical coordinate system can be determined by readings from a high-precision interferometer.

[0073] Optionally, the target transformation matrix from pixel coordinates to machine coordinates is specifically used to convert coordinates in the pixel coordinates to coordinates in the machine coordinates. Further, this target transformation matrix can convert the movement path in the pixel coordinates to the movement path in the machine coordinates, so that the mask stage can move according to the movement path in the machine coordinates converted from the movement path in the pixel coordinates.

[0074] As an optional implementation, the target transformation matrix from pixel coordinates to machine coordinates can be determined based on the transformation matrix from pixel coordinates to machine coordinates, as well as the mechanical pixel x-axis magnification, mechanical pixel y-axis magnification, preset mechanical x-axis coordinates of the device center point, preset mechanical y-axis coordinates of the device center point, preset mechanical z-axis coordinates of the device center point, preset focal length of the image acquisition device, and preset x-axis and y-axis telecentricity. The mechanical x-axis and y-axis coordinates of the device center point are both coordinates of the image acquisition device in the machine coordinate system. The mechanical z-axis coordinate of the device center point is preset based on the position of the object being measured. Specifically, by adjusting the z-axis coordinates of the device, the coordinates of the device center point on the mechanical z-axis when the image is clear are the mechanical z-axis coordinates of the device center point. During the marking and positioning process on the reference marker board, the mechanical x-axis, y-axis, and z-axis coordinates of the device center point are all preset and do not change during the marking and positioning process. The focal length of the image acquisition device is determined by the model of the image acquisition device.

[0075] As another optional implementation, the target transformation matrix from the mechanical coordinate system to the pixel coordinate system can be determined based on the mechanical pixel x-axis magnification, mechanical pixel y-axis magnification, preset mechanical x-axis coordinates of the device center point, preset mechanical y-axis coordinates of the device center point, preset mechanical z-axis coordinates of the device center point, preset focal length of the image acquisition device, x-axis telecentricity, and y-axis telecentricity. Then, based on the target transformation matrix from the mechanical coordinate system to the pixel coordinate system, the movement path in the pixel coordinate system corresponding to the movement path in the mechanical coordinate system can be determined.

[0076] It is worth noting that because the image acquisition device uses an object-side telecentric lens, the deviations between the x-axis and y-axis telecentricities and the actual optical path and mask stage telecentricity are very small. Therefore, the transformation relationship from the pixel coordinate system to the machine coordinate system determined based on the determined x-axis and y-axis telecentricities is more accurate, resulting in more precise movement of the mask stage.

[0077] S203. Obtain the position of the reference marker plate mark and the position of the mask mark in the image of the object under test sent by the image acquisition device.

[0078] In the image of the object being measured acquired by the image acquisition device, the reference mark plate is projected onto the photosensitive element of the device sequentially through a zoom projection lens and an object-side telecentric lens, while the mask mark is projected directly onto the photosensitive element of the image acquisition device through the object-side telecentric lens.

[0079] It is worth noting that the positions of the reference marker and the mask marker in the image of the object being measured sent by the image acquisition device are both in pixel coordinate system.

[0080] S204. Determine the mask stage movement path based on the position of the reference mark plate, the position of the mask mark, and the target transformation matrix between the pixel coordinate system and the machine coordinate system.

[0081] Specifically, since the positions of the reference mark plate and the mask mark are both in the pixel coordinate system, the positions of the reference mark plate and the mask mark in the mechanical coordinate system can be determined based on the target transformation matrix between the pixel coordinate system and the mechanical coordinate system. Thus, the mask stage moving path can be determined based on the positions of the reference mark plate and the mask mark.

[0082] S205. Control the mask stage to move according to the mask stage movement path so that the mask mark in the mask set on the mask stage is aligned with the reference mark plate mark in the reference mark plate.

[0083] The mask stage may include a mask carrier stage and a mask. The mask includes mask markings corresponding to markings on a reference marking plate, which is located on the silicon wafer carrier stage. After the mask stage's movement path is determined, the control module controls the mask carrier stage to move so that the mask markings on the mask on the mask stage are aligned with the reference markings on the reference marking plate. After aligning the reference markings with the mask markings, the silicon wafer on the silicon wafer carrier stage can be overlaid according to a user-preset path pattern and path scaling percentage.

[0084] As an alternative implementation method, Figure 4 This is a schematic diagram of a reference mark plate and a mask mark provided in an embodiment of this application. For example... Figure 4 As shown, the reference mark plate markings include: a first reference mark plate marking and a second reference mark plate marking.

[0085] The first reference mark plate is marked as a square hollow ring with an outer width of 70 micrometers and an inner width of 50 micrometers. The second reference mark plate is marked as a left part, a middle part, and a right part. The left part and the middle part are spaced 7 micrometers apart, and the middle part and the right part are spaced 7 micrometers apart. The left part includes three vertical lines with a width of 7 micrometers, a spacing of 7 micrometers, and a length of 80 micrometers. The right part includes three vertical lines with a width of 7 micrometers, a spacing of 7 micrometers, and a length of 80 micrometers. The middle part includes a horizontal line with a width of 7 micrometers, a spacing of 7 micrometers, and a length of 80 micrometers. The tops of the left part, the middle part, and the right part are flush. The mask markings include an upper part, a lower part, a left part, and a right part. The upper part includes two horizontal lines, each 20 micrometers wide and 20 micrometers apart. The lower part includes two horizontal lines, each 20 micrometers wide and 20 micrometers apart. The left part includes two vertical lines, each 20 micrometers wide and 20 micrometers apart. The right part includes two horizontal lines, each 20 micrometers wide and 20 micrometers apart. The bottom edge of the upper part is 5 micrometers away from the left and right parts, and the left and right parts are 5 micrometers apart from the lower part. Using the aforementioned reference marking plate and mask markings can improve calculation accuracy.

[0086] The first reference mark plate mark, the second reference mark plate mark, and the mask mark can be used for x-axis magnification and y-axis magnification measurement, and the second reference mark plate mark and the mask mark can be used for x-axis telecentricity and y-axis telecentricity measurement.

[0087] In this embodiment, the mechanical pixel x-axis magnification, mechanical pixel y-axis magnification, x-axis telecentricity, and y-axis telecentricity corresponding to the image acquisition device based on the object-side telecentric lens are first determined. Since the image acquisition device uses an object-side telecentric lens, the measured x-axis and y-axis telecentricities deviate very little from the actual optical path and the telecentricity of the mask stage, thereby improving the three-dimensional spatial positioning of the target object. Then, based on the aforementioned mechanical pixel magnification, telecentricity, preset device center point coordinates, and preset image acquisition device focal length, a target transformation matrix from the pixel coordinate system to the mechanical coordinate system is determined. Next, the positions of the reference markers and mask markers sent by the image acquisition device are obtained, and the mask stage movement path is determined based on the target transformation matrix from the pixel coordinate system to the mechanical coordinate system, thereby controlling the movement of the mask stage. In the above method, by effectively fusing the telecentricity acquired by the image acquisition device and camera parameters such as the mechanical pixel x-axis magnification and mechanical pixel y-axis magnification for marker positioning, higher precision three-dimensional spatial positioning of the target object can be achieved.

[0088] Next, refer to Figure 5 The following explanation addresses the step S202 above, which involves determining the target transformation matrix from the pixel coordinate system to the machine coordinate system based on the mechanical pixel x-axis magnification, mechanical pixel y-axis magnification, preset mechanical x-axis coordinates of the device center point, preset mechanical y-axis coordinates of the device center point, preset mechanical z-axis coordinates of the device center point, preset focal length of the image acquisition device, x-axis telecentricity, and y-axis telecentricity. Figure 5 This is a flowchart illustrating the steps for determining a target transformation matrix from a pixel coordinate system to a machine coordinate system, as provided in an embodiment of this application.

[0089] S501. Establish pixel coordinate system, image coordinate system, camera coordinate system and machine coordinate system.

[0090] The image coordinate system is established with the intersection of the image's diagonals as the origin, and its unit is meters or millimeters. The coordinate axes of the image coordinate system are (x...). p y p The camera coordinate system is a coordinate system based on the image acquisition device's own angles, with its coordinate axes being (x, y, y). M y M , z M ). Figure 6 This is a schematic diagram illustrating the imaging principle of an image acquisition device provided in an embodiment of this application. Figure 7 This is a schematic diagram illustrating the relationship between a camera coordinate system and an image coordinate system provided in an embodiment of this application. For example... Figure 6 and Figure 7As shown, in an image acquisition device, the lens is equivalent to a convex lens, and the photosensitive element forms an image at the focal point of the convex lens that is opposite to the actual object being measured. In actual shooting, when the object distance is much greater than twice the focal length of the image acquisition device, the image formed by the image acquisition device is as follows: Figure 6 As shown, this approximates pinhole imaging at the focal length. The pinhole surface in the imaging structure lies between the imaging plane and the object plane containing the measured object. (As shown...) Figure 7 As shown, a camera coordinate system is established at the origin of the pinhole surface, and an image coordinate system is established on the object point plane side of the pinhole surface. The distance between the origin of the image coordinate system and the camera coordinate system is the focal length of the image acquisition device. The x-axis of the camera coordinate system... M The x-axis and the x-axis in the image coordinate system p The axes are in the same direction, and the y-axis of the camera coordinate system is the same. M The axes and the y-axis in the image coordinate system p The axes are in the same direction, and the z-axis of the camera coordinate system is the same. M The axis is the direction from the origin to the origin of the image coordinate system.

[0091] exist Figure 7 In the above, assume there exists a point M(x) in the camera coordinate system. M y M , z M If ), then there exists a point P(x) in the image coordinate system. p y p Based on the principle of similarity, we can obtain the following equation (1):

[0092]

[0093] Among them, f p That is, the focal length f of the image acquisition device.

[0094] S502. Establish the first transformation matrix from the image coordinate system to the pixel coordinate system.

[0095] Optionally, Figure 8 This is a schematic diagram illustrating the relationship between an image coordinate system and a pixel coordinate system provided in an embodiment of this application. For example... Figure 8 As shown, the origin of the pixel coordinate system is located to the lower left of the origin of the image coordinate system, and the pixel coordinate system and the image coordinate system have a translational relationship. Let (u0, v0) represent the coordinates of the origin of the image coordinate system in the pixel coordinate system. Specifically, the u-axis of the pixel coordinate system represents the column of the pixel, and the v-axis represents the row of the pixel. The u-axis of the pixel coordinate system is parallel to the x-axis of the image coordinate system. p The axes are parallel and in the same direction; the v-axis of the pixel coordinate system is parallel to the y-axis of the image coordinate system. p The axes are parallel and in the same direction.

[0096] Alternatively, the transformation relationship from the image coordinate system to the pixel coordinate system can be as follows (2):

[0097]

[0098] Where dx is the x-axis of a single pixel in the image coordinate system. p The physical length on the axis. dy is the y-axis of a single pixel in the image coordinate system. p The physical length on the axis.

[0099] As an optional implementation, the specific process of establishing the first transformation matrix from the image coordinate system to the pixel coordinate system in step S502 includes the following steps.

[0100] Optionally, the position coordinates of the origin of the image coordinate system in the pixel coordinate system are set to a preset value to obtain the first transformation matrix from the image coordinate system to the pixel coordinate system.

[0101] The preset value can be (0, 0).

[0102] Specifically, the origin of the pixel coordinate system is set as the image center, which is also the geometric center of the pixel arrangement. Therefore, (u0, v0) can be set as a preset value. Optionally, (u0, v0) can be set to (0, 0). Therefore, the transformation relationship from the image coordinate system to the pixel coordinate system can be as follows (3):

[0103]

[0104] in, This is the first transformation matrix.

[0105] This embodiment achieves higher-speed calculation and simplifies the number of calculation parameters by setting the position coordinates of the origin of the image coordinate system in the pixel coordinate system to a preset value.

[0106] S503. Establish the second transformation matrix from the camera coordinate system to the image coordinate system.

[0107] Optionally, based on the relationship between the camera coordinate system and the image coordinate system, as shown in equation (1), the transformation relationship from the camera coordinate system to the image coordinate system can be obtained, as shown in equation (4) below:

[0108]

[0109] Among them, (x p y p ,1) are the homogeneous coordinates of a point in the image coordinate system, (x M y M , z M , 1) are the homogeneous coordinates of the point in the camera coordinate system.

[0110] To simplify the transformation relation, let z be normalized according to the principle. MIf the value is 1, then according to the above equation (3), we can obtain equation (5):

[0111]

[0112] in, This is the second transformation matrix.

[0113] S504. Establish the third transformation matrix between the machine coordinate system and the camera coordinate system.

[0114] In practical applications, both the camera coordinate system and the machine coordinate system are three-dimensional coordinates. Therefore, they can be translated and rotated to be converted to each other. For example, the conversion relationship between the machine coordinate system and the camera coordinate system can be shown in equation (6):

[0115]

[0116] in, This is the third transformation matrix, where R represents the rotation matrix and T represents the translation matrix.

[0117] For example, R can be Where α is the x-axis telecentrism, β is the y-axis telecentrism, and T can be... Indicates that at x mcs axis, y mcs axis and z mcs The distance translated along the axis. Since the distance between the lens and the measured object within the depth of field does not affect the magnification of the image when using a telecentric lens for imaging, t... z If it can be 0, then T can be... In this embodiment, t x Let t be the mechanical x-axis coordinate of the equipment's center point. y Let y be the mechanical y-axis coordinate of each point in the equipment.

[0118] S505. Based on the first transformation matrix, the second transformation matrix, and the third transformation matrix, determine the transformation matrix between the pixel coordinate system and the machine coordinate system.

[0119] Optionally, since the first transformation matrix represents the transformation matrix from the image coordinate system to the pixel coordinate system, the second transformation matrix represents the transformation matrix from the camera coordinate system to the image coordinate system, and the third transformation matrix represents the transformation matrix between the machine coordinate system and the camera coordinate system, it is necessary to perform inverse transformations on the first and second transformation matrices respectively, and determine the transformation matrix between the pixel coordinate system and the machine coordinate system based on the inversely transformed matrix and the third transformation matrix.

[0120] S506. Input the mechanical pixel x-axis magnification, mechanical pixel y-axis magnification, preset mechanical x-axis coordinates of the device center point, preset mechanical y-axis coordinates of the device center point, preset mechanical z-axis coordinates of the device center point, preset image acquisition device focal length, x-axis telecentricity, and y-axis telecentricity into the transformation matrix between the pixel coordinate system and the mechanical coordinate system to obtain the target transformation matrix from the pixel coordinate system to the mechanical coordinate system.

[0121] Specifically, the target transformation matrix from pixel coordinates to machine coordinates is used to convert the coordinates in the pixel coordinates to the coordinates in the machine coordinates.

[0122] In this embodiment, the transformation matrix between the pixel coordinate system and the machine coordinate system is determined based on the first transformation matrix from the image coordinate system to the pixel coordinate system, the second transformation matrix from the camera coordinate system to the image coordinate system, and the third transformation matrix between the machine coordinate system and the camera coordinate system. Multiple parameters are then input into the transformation matrix between the pixel coordinate system and the machine coordinate system to obtain the target transformation matrix between the pixel coordinate system and the machine coordinate system. This allows for the control of object movement in the machine coordinate system based on the target transformation matrix between the pixel coordinate system and the machine coordinate system, thereby achieving more precise target spatial positioning and movement control.

[0123] Furthermore, such as Figure 9 As shown, the step S505 above, which determines the transformation matrix between the pixel coordinate system and the machine coordinate system based on the first transformation matrix, the second transformation matrix, and the third transformation matrix, is as follows. Wherein, Figure 9 This is a schematic flowchart of a method for determining the transformation matrix between the pixel coordinate system and the machine coordinate system provided in an embodiment of this application.

[0124] S901. Determine the first transformation inverse matrix corresponding to the first transformation matrix.

[0125] Optionally, for the first transformation matrix Perform the inverse transformation to obtain the first transformation inverse matrix. The first transformation inverse matrix represents the transformation matrix from the pixel coordinate system to the image coordinate system.

[0126] S902. Determine the second transformation inverse matrix corresponding to the second transformation matrix.

[0127] Alternatively, because of the telecentric lens, changes in the distance between the lens and the measured object within the depth of field do not affect the camera's magnification of the image during imaging. Therefore, refer to... Figure 7 There exists a point M(x) in the camera coordinate system. M y M , z M There exists a point p(x) in the image coordinate system. p y pThe second transformation matrix can be converted into equation (7):

[0128]

[0129] in, This is the second transformation matrix under a telecentric lens, where m represents the focal length f and z of the image acquisition device. M The ratio. Performing an inverse transformation on the second transformation matrix under the telecentric lens, we obtain the second transformation inverse matrix as follows:

[0130] S903. Based on the first transformation inverse matrix, the second transformation inverse matrix, and the third transformation matrix, determine the transformation matrix between the pixel coordinate system and the machine coordinate system.

[0131] Optionally, since the first inverse transformation matrix is ​​the transformation matrix from the pixel coordinate system to the image coordinate system, the second inverse transformation matrix is ​​the transformation matrix from the image coordinate system to the camera coordinate system, and the third transformation matrix is ​​the transformation matrix between the camera coordinate system and the machine coordinate system, the transformation matrix between the pixel coordinate system and the machine coordinate system can be determined based on the first inverse transformation matrix, the second inverse transformation matrix, and the third transformation matrix.

[0132] In this embodiment, by determining the first and second inverse transformation matrices, and by determining the transformation matrix from the pixel coordinate system to the machine coordinate system based on the first, second, and third transformation matrices, the transformation between pixel coordinates and machine coordinates is realized.

[0133] Furthermore, the specific process of determining the transformation matrix between the pixel coordinate system and the machine coordinate system based on the first transformation inverse matrix, the second transformation inverse matrix, and the third transformation matrix in step S903 above is as follows.

[0134] Optionally, the third transformation matrix, the second transformation inverse matrix, and the first transformation matrix are multiplied together to obtain the transformation matrix between the pixel coordinate system and the machine coordinate system.

[0135] Specifically, the transformation matrix is ​​obtained by left-multiplying the third transformation matrix, the inverse of the second transformation matrix, and the first transformation matrix in sequence to obtain the transformation matrix between the pixel coordinate system and the machine coordinate system.

[0136] The transformation matrix between the pixel coordinate system and the machine coordinate system is given by the following equation (8):

[0137]

[0138] in, This is the third transformation matrix. This is the inverse matrix of the second transformation. Let x be the inverse matrix of the first transformation. mcs y mcs , z mcs() represents the mechanical coordinates, α represents the x-axis telecentricity, β represents the y-axis telecentricity, and t represents the y-axis telecentricity. x It is the mechanical x-axis coordinate of the equipment center point, t y It is the mechanical y-axis coordinate of the equipment center point, z M Let be the mechanical z-axis coordinate of the device center point, m be the ratio of the focal length of the image acquisition device to the mechanical z-axis coordinate of the device center point, dx be the mechanical pixel x-axis magnification, dy be the mechanical pixel y-axis magnification, and (u, v) be the pixel coordinates.

[0139] In this embodiment, the transformation matrix between the pixel coordinate system and the machine coordinate system is obtained by multiplying the first transformation inverse matrix, the second transformation inverse matrix and the third transformation matrix. This allows for precise positioning of the object in the machine coordinate system by combining the imaging principle of the object-side telecentric lens and the camera's intrinsic parameters.

[0140] As an optional implementation method, refer to Figure 10 As shown, the specific process of determining the mask stage movement path in step S204 above, based on the position of the reference mark plate, the position of the mask mark, and the target transformation matrix between the pixel coordinate system and the machine coordinate system, is as follows. Wherein, Figure 10 This is a flowchart illustrating a method for determining the moving path of a mask worktable, as provided in an embodiment of this application.

[0141] S1001. Determine the starting position of the movement based on the position of the mask mark in the image of the object being measured and the target transformation matrix between the pixel coordinate system and the machine coordinate system.

[0142] The starting position of the movement is the starting position of the mask worktable's movement path.

[0143] S1002. Determine the end position of the movement based on the position of the reference mark plate in the image of the object being measured and the target transformation matrix between the pixel coordinate system and the machine coordinate system.

[0144] The starting position of the movement is the starting position of the mask worktable's movement path.

[0145] S1003. Determine the mask stage movement path based on the start and end positions of the movement.

[0146] As an optional implementation, the mask stage movement path can be determined according to the preset path pattern and path scaling percentage, based on the start and end positions of the movement.

[0147] As an optional implementation, to ensure that the reference markers do not move out of the field of view of the image acquisition device during the movement of the mask stage, the movement boundary of the mask stage can be determined by combining the actual field of view of the image acquisition device, the actual size of the reference markers, and the mechanical coordinates of the mask stage. The movement boundary is the position in the mechanical coordinate system. Based on the starting position, ending position, and movement boundary, the movement path of the mask stage is determined.

[0148] In this embodiment, the starting and ending positions of the movement are determined based on the positions of the mask markings, the reference markings, and the target transformation matrix between the pixel coordinate system and the machine coordinate system. Then, the movement path of the mask stage is determined based on these positions. Because the target transformation matrix between the pixel coordinate system and the machine coordinate system effectively fuses the imaging principle of the object-side telecentric lens and the camera parameters, the movement path of the mask stage is made more precise.

[0149] The specific steps for determining the starting position of movement in step S1001 above, based on the position of the mask mark in the image of the object under test and the target transformation matrix between the pixel coordinate system and the machine coordinate system, are as follows.

[0150] Optionally, the starting position of the movement is obtained by multiplying the vector corresponding to the position of the mask mark with the target transformation matrix between the pixel coordinate system and the machine coordinate system.

[0151] Alternatively, the formula for calculating the starting position of the move can be as follows (9):

[0152]

[0153] Among them, (x mcs1 y mcs1 , z mcs1 (u1, v1) represents the mechanical coordinates of the starting position of the movement, (u1, v1) represents the pixel coordinates of the mask mark position, α represents the x-axis telecentricity, β represents the y-axis telecentricity, and t represents the position of the mask mark. x Let t be the mechanical x-axis coordinate of the equipment's center point. y Let z be the mechanical y-axis coordinate of the equipment center point, z M Let be the mechanical z-axis coordinate of the device's center point, m be the ratio of the image acquisition device's focal length to the mechanical z-axis coordinate of the device's center point, dx be the mechanical pixel x-axis magnification, and dy be the mechanical pixel y-axis magnification. α, β, t x t y z M m, dx, and dy are all known values.

[0154] In this embodiment, the starting position of movement is obtained by multiplying the vector corresponding to the position of the mask mark with the transformation matrix between the pixel coordinate system and the machine coordinate system. Since the transformation matrix between the pixel coordinate system and the machine coordinate system realizes the imaging principle of the object-side telecentric lens and the effective fusion of camera parameters, the starting position of movement in the machine coordinate system is more accurate.

[0155] As an optional implementation method, in actual implementation, when it is necessary to determine the object position in the pixel coordinate system based on the object position in the mechanical coordinate system, the following steps can be performed.

[0156] Optionally, the transformation matrix from the machine coordinate system to the pixel coordinate system is determined based on the first transformation matrix, the second transformation matrix, and the third transformation matrix.

[0157] The first transformation matrix is ​​the transformation matrix from the image coordinate system to the pixel coordinate system, the second transformation matrix is ​​the transformation matrix from the camera coordinate system to the image coordinate system, and the third transformation matrix is ​​the transformation matrix between the camera coordinate system and the machine coordinate system. Therefore, the transformation matrix from the machine coordinate system to the pixel coordinate system can be determined based on the transformation relationship between the first, second, and third transformation matrices.

[0158] Optionally, the marker position in the pixel coordinate system is determined based on the transformation matrix from the machine coordinate system to the pixel coordinate system, the mechanical pixel x-axis magnification, the mechanical pixel y-axis magnification, the preset mechanical x-axis coordinates of the device center point, the preset mechanical y-axis coordinates of the device center point, the preset focal length of the image acquisition device, the x-axis telecentricity and y-axis telecentricity, and the marker position in the machine coordinate system.

[0159] Specifically, the mechanical pixel x-axis magnification, mechanical pixel y-axis magnification, preset mechanical x-axis coordinates of the device center point, preset mechanical y-axis coordinates of the device center point, preset image acquisition device focal length, x-axis telecentricity, and y-axis telecentricity are input into the transformation matrix from the mechanical coordinate system to the pixel coordinate system to obtain the target transformation matrix from the mechanical coordinate system to the pixel coordinate system. Based on the target transformation matrix from the mechanical coordinate system to the pixel coordinate system and the marker position in the mechanical coordinate system, the marker position in the pixel coordinate system is determined.

[0160] Specifically, the vector corresponding to the mark position in the machine coordinate system is multiplied by the target transformation matrix from the machine coordinate system to the pixel coordinate system to obtain the mark position in the pixel coordinate system.

[0161] In this embodiment, the transformation matrix from the machine coordinate system to the pixel coordinate system is determined based on the first transformation matrix, the second transformation matrix, and the third transformation matrix. Then, the marker position in the pixel coordinate system is determined based on multiple parameters such as telecentricity and the marker position in the machine coordinate system, thereby realizing the transformation between the object position in the machine coordinate system and the object position in the pixel coordinate system.

[0162] Furthermore, the specific process of determining the transformation matrix from the machine coordinate system to the pixel coordinate system based on the first transformation matrix, the second transformation matrix, and the third transformation matrix in the above steps is as follows.

[0163] Optionally, the first transformation matrix, the second transformation matrix, and the third transformation matrix are multiplied together to obtain the transformation matrix from the machine coordinate system to the pixel coordinate system.

[0164] Specifically, the first transformation matrix, the second transformation matrix, and the third transformation matrix are multiplied on the left in sequence to obtain the transformation matrix from the machine coordinate system to the pixel coordinate system.

[0165] The transformation matrix from the machine coordinate system to the pixel coordinate system is shown in equation (10) below:

[0166]

[0167] in, This is the first transformation matrix. This is the second transformation matrix. The third transformation matrix is ​​given, where dx is the x-axis magnification of the mechanical pixels, dy is the y-axis magnification of the mechanical pixels, f is the focal length of the image acquisition device, α is the x-axis telecentricity, β is the y-axis telecentricity, and t... x It is the mechanical x-axis coordinate of the equipment center point, t y It is the mechanical y-axis coordinate of the equipment's center point.

[0168] In this embodiment, by multiplying the first transformation matrix, the second transformation matrix, and the third transformation matrix, a transformation matrix from the machine coordinate system to the pixel coordinate system is obtained. Based on this transformation matrix, a more accurate positioning can be achieved by converting the position in the machine coordinate system to the position in the pixel coordinate system.

[0169] This application also provides a marker positioning system based on an object-side telecentric lens. The marker positioning system based on an object-side telecentric lens includes a control module, an image acquisition device, a mask worktable, and a reduction projection lens. The image acquisition device is used to acquire images of the object under test sequentially through the reduction projection lens and the object-side telecentric lens. The image of the object under test includes mask marks on the mask on the mask worktable and reference mark marks in the reference mark plate. The image of the object under test is then sent to the control module, which is used to execute the steps of the marker positioning method based on an object-side telecentric lens as described above.

[0170] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A marking and positioning method based on an object-side telecentric lens, characterized in that, The method includes: Determine the mechanical pixel x-axis magnification, mechanical pixel y-axis magnification, x-axis telecentricity, and y-axis telecentricity corresponding to the image acquisition device based on the object-side telecentric lens; Based on the mechanical pixel x-axis magnification, the mechanical pixel y-axis magnification, the preset mechanical x-axis coordinates of the device center point, the preset mechanical y-axis coordinates of the device center point, the preset mechanical z-axis coordinates of the device center point, the preset focal length of the image acquisition device, the x-axis telecentricity, and the y-axis telecentricity, determine the target transformation matrix from the pixel coordinate system to the mechanical coordinate system; Acquire the positions of the reference markers and mask markers in the image of the object under test sent by the image acquisition device; The mask stage movement path is determined based on the position of the reference mark plate, the position of the mask mark, and the target transformation matrix between the pixel coordinate system and the machine coordinate system. The mask stage is moved according to the mask stage movement path so that the mask mark in the mask set on the mask stage is aligned with the reference mark in the reference mark plate. The step of determining the target transformation matrix from the pixel coordinate system to the machine coordinate system based on the mechanical pixel x-axis magnification, the mechanical pixel y-axis magnification, the preset mechanical x-axis coordinates of the device center point, the preset mechanical y-axis coordinates of the device center point, the preset mechanical z-axis coordinates of the device center point, the preset focal length of the image acquisition device, the x-axis telecentricity, and the y-axis telecentricity includes: Establish pixel coordinate system, image coordinate system, camera coordinate system, and machine coordinate system; Establish a first transformation matrix from the image coordinate system to the pixel coordinate system; Establish a second transformation matrix from the camera coordinate system to the image coordinate system; Establish a third transformation matrix between the machine coordinate system and the camera coordinate system; Based on the first transformation matrix, the second transformation matrix, and the third transformation matrix, determine the transformation matrix between the pixel coordinate system and the machine coordinate system; The mechanical pixel x-axis magnification, the mechanical pixel y-axis magnification, the preset mechanical x-axis coordinates of the device center point, the preset mechanical y-axis coordinates of the device center point, the preset mechanical z-axis coordinates of the device center point, the preset focal length of the image acquisition device, the x-axis telecentricity, and the y-axis telecentricity are input into the transformation matrix between the pixel coordinate system and the mechanical coordinate system to obtain the target transformation matrix from the pixel coordinate system to the mechanical coordinate system.

2. The marking and positioning method based on an object-side telecentric lens according to claim 1, characterized in that, The first transformation matrix for establishing the image coordinate system to the pixel coordinate system includes: The position coordinates of the origin of the image coordinate system in the pixel coordinate system are set to a preset value to obtain the first transformation matrix from the image coordinate system to the pixel coordinate system.

3. The marking and positioning method based on an object-side telecentric lens according to claim 1, characterized in that, Determining the transformation matrix between the pixel coordinate system and the machine coordinate system based on the first transformation matrix, the second transformation matrix, and the third transformation matrix includes: Determine the first transformation inverse matrix corresponding to the first transformation matrix; Determine the second transformation inverse matrix corresponding to the second transformation matrix; The transformation matrix between the pixel coordinate system and the machine coordinate system is determined based on the first transformation inverse matrix, the second transformation inverse matrix, and the third transformation matrix.

4. The marking and positioning method based on an object-side telecentric lens according to claim 3, characterized in that, Determining the transformation matrix between the pixel coordinate system and the machine coordinate system based on the first transformation inverse matrix, the second transformation inverse matrix, and the third transformation matrix includes: Multiply the third transformation matrix, the second transformation inverse matrix, and the first transformation matrix to obtain the transformation matrix between the pixel coordinate system and the machine coordinate system; The transformation matrix between the pixel coordinate system and the machine coordinate system is as follows: in, The third transformation matrix, This is the inverse matrix of the second transformation. Let be the inverse of the first transformation matrix, α be the x-axis telecentrism, β be the y-axis telecentrism, and t be the inverse of the first transformation matrix. x Let t be the mechanical x-axis coordinate of the center point of the equipment. y Let z be the mechanical y-axis coordinate of the center point of the equipment, z M Let be the mechanical z-axis coordinate of the device's center point, m be the ratio of the focal length of the image acquisition device to the mechanical z-axis coordinate of the device's center point, dx be the mechanical pixel x-axis magnification, and dy be the mechanical pixel y-axis magnification. The value is 1.

5. The marking and positioning method based on an object-side telecentric lens according to claim 1, characterized in that, The step of determining the mask stage movement path based on the position of the reference marker plate, the position of the mask marker, and the target transformation matrix between the pixel coordinate system and the machine coordinate system includes: The starting position of movement is determined based on the position of the mask mark in the image of the object under test and the target transformation matrix between the pixel coordinate system and the machine coordinate system. The end position of the movement is determined based on the position of the reference marker in the image of the object under test and the target transformation matrix between the pixel coordinate system and the machine coordinate system. The movement path of the mask worktable is determined based on the starting position and the ending position of the movement.

6. The marking and positioning method based on an object-side telecentric lens according to claim 5, characterized in that, Determining the starting position of movement based on the position of the mask mark in the image of the object under test and the target transformation matrix between the pixel coordinate system and the machine coordinate system includes: The starting position of the movement is obtained by multiplying the vector corresponding to the position of the mask mark with the target transformation matrix between the pixel coordinate system and the machine coordinate system.

7. The marking and positioning method based on an object-side telecentric lens according to any one of claims 1-6, characterized in that, The method further includes: Based on the first transformation matrix, the second transformation matrix, and the third transformation matrix, determine the transformation matrix from the machine coordinate system to the pixel coordinate system; The marker position in the pixel coordinate system is determined based on the transformation matrix from the machine coordinate system to the pixel coordinate system, the x-axis magnification of the machine pixel, the y-axis magnification of the machine pixel, the preset machine x-axis coordinates of the device center point, the preset machine y-axis coordinates of the device center point, the preset focal length of the image acquisition device, the telecentricity of the x-axis and the telecentricity of the y-axis, and the marker position in the machine coordinate system.

8. The marking and positioning method based on an object-side telecentric lens according to claim 7, characterized in that, The step of determining the transformation matrix from the machine coordinate system to the pixel coordinate system based on the first transformation matrix, the second transformation matrix, and the third transformation matrix includes: Multiply the first transformation matrix, the second transformation matrix, and the third transformation matrix to obtain the transformation matrix from the machine coordinate system to the pixel coordinate system; The transformation matrix from the machine coordinate system to the pixel coordinate system is as follows: （10） in, Let be the first transformation matrix. This is the second transformation matrix. Let dx be the x-axis magnification of the mechanical pixel, dy be the y-axis magnification of the mechanical pixel, f be the focal length of the image acquisition device, α be the x-axis telecentricity, β be the y-axis telecentricity, and t be the focal length of the image acquisition device. x Let t be the mechanical x-axis coordinate of the center point of the equipment. y Let be the mechanical y-axis coordinate of the center point of the device.

9. A marking and positioning system based on an object-side telecentric lens, characterized in that, The object-side telecentric lens-based marking and positioning system includes a control module, an image acquisition device, a mask worktable, and a reduction projection lens. The image acquisition device is used to acquire images of the object under test sequentially through the reduction projection lens and the object-side telecentric lens. The image of the object under test includes mask marks on the mask worktable and reference mark marks in the reference mark plate. The image of the object under test is then sent to the control module. The control module is used to execute the steps of the object-side telecentric lens-based marking and positioning method as described in any one of claims 1-8.

Images