Wafer positioning compensation value measuring method and device and wafer positioning compensation system

Abstract

The application relates to a wafer positioning compensation value calculation method and device and a wafer positioning compensation system. In one embodiment, an image of a wafer is obtained by a camera, a displacement coordinate system is established according to the image and taking the camera as a reference, a conversion matrix can be established by combining a reference image of the wafer in a driving coordinate system, and then a compensation value required for positioning can be obtained by calculation. In this way, the camera can be arranged above a wafer working space, the wafer position can be obtained by the camera, and a light sensor does not need to be installed in the wafer working space, so that the wafer is more convenient to take, place and carry. In addition, the wafer position can be confirmed by one-time acquisition of the camera, the wafer does not need to be rotated, the time for single positioning compensation is saved, subsequent positioning compensation of other wafers can be realized according to the position of the wafer in the camera coordinate system and the conversion matrix, the time for subsequent wafer positioning compensation is further shortened, the work efficiency is greatly improved, and the time cost is reduced.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the field of semiconductor processing, and in particular, to a wafer positioning compensation value calculation method and device and a wafer positioning compensation system. BACKGROUND

[0002] A semiconductor element is manufactured on a semiconductor wafer using a plurality of different processing steps, each step involving different processing procedures and devices. In these procedures, the accuracy of the placement position of each wafer is highly required to ensure the quality of the wafer. Moreover, in procedures such as liquid coating, wafer cleaning, and the like, the wafer itself may also vibrate slightly, causing a change in position, and if the wafer position is not corrected, it may easily affect the subsequent process flow.

[0003] Therefore, semiconductor manufacturing and processing equipment usually has wafer compensation equipment and corresponding compensation value calculation methods to confirm the correct position of the wafer. However, the existing wafer compensation equipment adopts an optical sensing method to confirm the boundary position of the wafer, which requires optical sensors to be arranged above and below the wafer. However, in many cases in the process flow, the space around the wafer is arranged tightly, and the optical sensors on the upper and lower sides will greatly interfere with the handling process of the wafer. In addition, the existing optical sensing compensation method needs to control the rotation of the wafer to determine the position of the wafer positioning groove. In order to ensure accuracy, each wafer rotation positioning takes a considerable amount of time, and when the number of wafers reaches a certain amount, the time consumed for compensation value calculation will be longer. SUMMARY

[0004] Therefore, in view of the above technical problems, a wafer positioning compensation value calculation method, device and wafer positioning compensation system are provided. The technical solutions of the present disclosure are as follows:

[0005] According to an aspect of an embodiment of the present disclosure, a wafer positioning compensation value calculation method is provided, comprising:

[0006] controlling a positioning camera to capture a first wafer to be measured to obtain a first image; wherein the first wafer to be measured includes a positioning groove;

[0007] establishing a displacement coordinate system according to the position of the positioning groove in the first image;

[0008] obtaining a reference image of a wafer to be measured in a preset driving coordinate system; wherein the positioning groove of the wafer to be measured is located at a specified position in the reference image;

[0009] generating a target conversion matrix according to the first image and the reference image; the target conversion matrix is used to represent the coordinate conversion relationship between the displacement coordinate system and the driving coordinate system;

[0010] According to the target conversion matrix, a compensation coordinate value of the first wafer to be measured is calculated, and the compensation coordinate value is used to control a preset driving mechanism to move the first wafer to be measured to a target position.

[0011] In one of the embodiments, the control positioning camera photographs the first wafer to be measured to obtain a first image, which includes:

[0012] The preset backlight light source is controlled to light the first wafer to be measured.

[0013] The positioning camera is moved until the optical axis of the positioning camera is aligned with the center point of the first wafer to be measured, and the first wafer to be measured is photographed to obtain a first image.

[0014] In one of the embodiments, the positioning groove is a V-shaped groove, and the variable position coordinate system is established according to the position of the positioning groove in the first image, which includes:

[0015] The center point of the first wafer to be measured is taken as a variable position origin.

[0016] A straight line where the variable position origin and the V-shaped groove are connected is taken as a first coordinate axis.

[0017] A straight line that passes through the variable position origin and is perpendicular to the first coordinate axis is taken as a second coordinate axis.

[0018] The variable position coordinate system is established according to the variable position origin, the first coordinate axis and the second coordinate axis.

[0019] In one of the embodiments, the target conversion matrix is generated according to the first image and the reference image, which includes:

[0020] According to the positional relationship between the optical axis of the positioning camera and the driving coordinate system, a first variable position coordinate of the center point of the first wafer to be measured in the driving coordinate system is obtained.

[0021] The first image is converted into the driving coordinate system according to the first variable position coordinate.

[0022] The target conversion matrix is established according to the positional relationship between the first image and the reference image in the driving coordinate system.

[0023] In one of the embodiments, after the compensation coordinate value of the first wafer to be measured is calculated according to the target conversion matrix, the method further includes:

[0024] The positioning camera is controlled to photograph a second wafer to be measured to obtain a second image.

[0025] According to a preset algorithm, the second image is calculated and processed to obtain an additional offset value of the second wafer to be measured in the displacement coordinate system;

[0026] According to the additional offset value and the compensation coordinate value, a second compensation coordinate value is obtained; the second compensation coordinate value is used to control the driving mechanism to move the second wafer to be measured to the target position.

[0027] In one of the embodiments, the additional offset value includes a displacement coordinate of a center point of the second wafer to be measured in the displacement coordinate system.

[0028] In one of the embodiments, the displacement coordinate system includes two coordinate axes, and the additional offset value further includes a displacement angle between a positioning slot of the second wafer to be measured and one of the coordinate axes of the displacement coordinate system.

[0029] According to another aspect of the embodiments of the present disclosure, a wafer positioning compensation value measuring device is provided, which includes:

[0030] An image acquisition module is configured to control a positioning camera to capture a first wafer to be measured to obtain a first image; wherein the first wafer to be measured includes a positioning slot;

[0031] A coordinate system processing module is configured to establish a displacement coordinate system according to a position of the positioning slot in the first image;

[0032] A reference image acquisition module is configured to acquire a reference image of a wafer to be measured in a preset driving coordinate system; wherein a positioning slot of the wafer to be measured is located at a specified position in the reference image;

[0033] A conversion module is configured to generate a target conversion matrix according to the first image and the reference image; the target conversion matrix is used to represent a coordinate conversion relationship between the displacement coordinate system and the driving coordinate system;

[0034] A calculation module is configured to calculate a compensation coordinate value of the first wafer to be measured according to the target conversion matrix; the compensation coordinate value is used to control a preset driving mechanism to move the first wafer to be measured to a target position.

[0035] According to another aspect of the embodiments of the present disclosure, a wafer positioning compensation system is further provided, which includes a host computer, a driving mechanism, and a positioning camera;

[0036] The host computer stores a computer program; when the host computer executes the computer program, the steps of the above method are realized.

[0037] The driving mechanism is electrically connected with the host computer; the driving mechanism further comprises a carrier, a driving shaft and a driving controller, and the driving controller is connected with the carrier through the driving shaft;

[0038] The positioning camera is connected with the host computer.

[0039] According to another aspect of the embodiments of the present disclosure, a computer device is further provided, comprising a memory and a processor, the memory stores a computer program, and the processor implements the steps of the above method when executing the computer program.

[0040] According to another aspect of the embodiments of the present disclosure, a computer readable storage medium is further provided, which stores a computer program, and the computer program is executed by a processor to implement the steps of the above method.

[0041] In the technical solution provided by the embodiments of the present disclosure, a first image containing the current position of the wafer can be obtained by the camera, and a displacement coordinate system is established based on the camera according to the image, and then a conversion matrix between the displacement coordinate system and the driving coordinate system containing the current position can be established by combining the reference image of the wafer in the driving coordinate system, and then the compensation value required for positioning can be calculated. In this way, the camera can be arranged above the wafer workspace, and the wafer position can be obtained by the camera, without the need to install a light sensor in the wafer workspace, which is more convenient for wafer picking and handling. In addition, the wafer position can be confirmed by one-time camera acquisition, without the need to rotate the wafer, thereby saving the time for single positioning compensation, and the conversion matrix can also be used for compensation value calculation of other wafers, further shortening the time for subsequent wafer positioning compensation, greatly improving the work efficiency, and reducing the time cost.

[0042] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present disclosure. BRIEF DESCRIPTION OF DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments described in the present disclosure, and other drawings can also be obtained by those skilled in the art without creative labor.

[0044] Figure 1 Fig. 1 is a schematic diagram of an application scene of a positioning compensation scheme in an embodiment;

[0045] Figure 2 Fig. 2 is a flowchart of a compensation value calculation method for wafer positioning in an embodiment;

[0046] Figure 3 FIG. 1 is a flowchart illustrating a process of controlling a positioning camera to capture a first wafer to be measured in an embodiment;

[0047] Figure 4 FIG. 1 is a flowchart illustrating a process of controlling a positioning camera to capture a first wafer to be measured in an embodiment;

[0048] Figure 5 FIG. 1 is a flowchart illustrating a process of controlling a positioning camera to capture a first wafer to be measured in an embodiment;

[0049] Figure 6 FIG. 1 is a flowchart illustrating a process of controlling a positioning camera to capture a first wafer to be measured in an embodiment;

[0050] Figure 7 FIG. 1 is a flowchart illustrating a process of controlling a positioning camera to capture a first wafer to be measured in an embodiment;

[0051] Figure 8 FIG. 1 is a flowchart illustrating a process of controlling a positioning camera to capture a first wafer to be measured in an embodiment;

[0052] Figure 9 FIG. 1 is a flowchart illustrating a process of controlling a positioning camera to capture a first wafer to be measured in an embodiment;

[0053] Figure 10 FIG. 1 is a flowchart illustrating a process of controlling a positioning camera to capture a first wafer to be measured in an embodiment;

[0054] Figure 11 FIG. 1 is a flowchart illustrating a process of controlling a positioning camera to capture a first wafer to be measured in an embodiment;

[0055] Figure 12 FIG. 1 is a flowchart illustrating a process of controlling a positioning camera to capture a first wafer to be measured in an embodiment;

[0056] Reference Signs:

[0057] 10 - drive mechanism; 20 - host computer; 30 - positioning camera; 102 - object table; 104 - drive shaft; 106 - drive controller. DETAILED DESCRIPTION

[0058] In order to make the ordinary person skilled in the art better understand the technical solutions of the present disclosure, the technical solutions in the embodiments of the present disclosure will be described clearly and completely below with reference to the drawings.

[0059] It is to be understood that the terms "first", "second", and the like, used in the description and the claims of the present disclosure as well as the foregoing drawings should not be construed as necessarily implying a specific order or sequence. It is to be understood that the data thus used are interchangeable such that the embodiments of the present disclosure described herein can operate in other sequences than those described or illustrated herein. The embodiments described in the following examples do not represent all of the embodiments consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with some aspects of the present disclosure as detailed in the appended claims. The terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. Exclusion of such elements is only present if it is explicitly stated that these elements are excluded. For example, if a first, second, or the like is used to refer to a name, it is not to be construed as indicating any particular order or sequence.

[0060] The terms "vertical", "horizontal", "left", "right", "upper", "lower", "front", "rear", "circumferential", "direction of travel", and similar terms as used herein are based on the orientations or positional relationships shown in the drawings, and are used only for the purpose of facilitating the description of the present disclosure and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present disclosure.

[0061] Unless otherwise defined, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used in the description of the present disclosure herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising", or "includes" and / or "including" when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be noted that the connections between devices described in the present disclosure can be direct connections through interfaces or pins between devices, can be connections through leads, or can be wireless connections (communication connections).

[0062] Generally, a wafer includes a positioning groove (also referred to as a positioning edge), which is added as a crystal orientation mark during the manufacturing process of the wafer to indicate the crystal orientation of the wafer. In existing processes, the positioning groove of the wafer is usually a flat groove or a V-shaped groove. The positioning groove can help determine the crystal orientation, which is of great significance to subsequent processing and testing. Therefore, the positioning of the wafer includes two aspects: first, the wafer as a whole needs to be moved to the correct position; second, the positioning groove of the wafer needs to be ensured to be in the correct position.

[0063] Existing wafer positioning compensation schemes usually use an optical sensor to measure the movement compensation value of wafer positioning. Not only does the edge of the wafer need to be located within the sensing range of the optical sensor, but the wafer also needs to be controlled to rotate continuously to make the light pass through the positioning groove in order to determine the position of the positioning groove. This method is time-consuming and labor-intensive, and it also causes certain restrictions on the handling of the wafer.

[0064] To solve the above problems, the present disclosure provides a scheme that does not require the use of an optical sensor and can quickly perform positioning compensation.

[0065] Figure 1 is a schematic diagram of an application scenario of the positioning compensation scheme in an embodiment of the present disclosure, as shown in Figure 1 The driving mechanism 10 can be used for the movement and positioning of the wafer, and includes a stage 102, a driving shaft 104, and a driving controller 106. The host computer 20 can be used to control the positioning camera 30 to take pictures of the wafer, can receive the images taken by the positioning camera 30 and perform image processing and data calculation, and can also send corresponding control instructions to the driving mechanism 10.

[0066] The stage 102 is a platform for placing the wafer. The driving controller 106 can receive the control instructions sent by the host computer 20 and control the stage 102 to rotate and move linearly through the driving shaft 104. The host computer 20 can be a computer, a single-chip microcomputer, or other electronic devices with data processing and control functions connected to programmable logic controllers and test equipment. The positioning camera 30 can be an industrial camera or an industrial camera, etc. The positioning camera 30 can be electrically connected to the host computer 20 or can be connected to the host computer 20 wirelessly.

[0067] Figure 2 is a flowchart of a method for measuring a compensation value of wafer positioning in an embodiment, which can be used in the host computer 20 in the application scenario as shown in Figure 1 The method includes the following steps:

[0068] In step S202, the positioning camera 30 is controlled to take pictures of a first wafer to be measured, and a first image is obtained. The first wafer to be measured includes a positioning groove.

[0069] Specifically, one of the to-be-tested wafers can be selected as a first to-be-tested wafer, the first to-be-tested wafer is placed on the object table 102, the positioning camera 30 is controlled to move to a specified position to take a picture of the wafer, and a wafer image returned by the positioning camera 30 is received. For example, the positioning camera 30 can be controlled to move so that the wafer is at the center of the lens, and the first to-be-tested wafer is at the center of the first image.

[0070] In step S204, a displacement coordinate system is established according to the position of the positioning groove in the first image.

[0071] The position of the positioning groove in the first image refers to the orientation of the positioning groove of the wafer relative to the center point of the wafer in the image. The displacement coordinate system obtained according to the first image is a coordinate system with the positioning camera 30 as the perspective, and can be used to represent the position of the to-be-tested wafer in the camera coordinate system.

[0072] Specifically, the host computer 20 can analyze the first image by using image processing software or algorithm, confirm the relative position of the positioning groove and the center of the wafer, and establish a displacement coordinate system according to the relative position. For example, when the positioning groove is a flat groove, the center point of the wafer can be taken as the origin of the displacement coordinate system, a straight line parallel to the flat groove and passing through the origin can be taken as the horizontal axis, and a straight line perpendicular to the horizontal axis and passing through the origin can be taken as the vertical axis, and the displacement coordinate system can be established according to the origin, the horizontal axis and the vertical axis. When the positioning groove is a V-shaped groove, the line connecting the center of the wafer and the V-shaped groove can be taken as the coordinate axis, and the coordinate system can be established based on the line. In some other embodiments, the displacement coordinate system can not only be the Cartesian coordinate system described above, but also be a polar coordinate system or other coordinate system suitable for mathematical calculation.

[0073] In step S206, a reference image of the to-be-tested wafer in a preset driving coordinate system is obtained. The positioning groove of the to-be-tested wafer is located at a specified position in the reference image.

[0074] The preset driving coordinate system can be the control coordinate system of the driving mechanism 10, and the host computer 20 can control the driving mechanism 10 to perform corresponding actions according to the coordinates of the control coordinate system. The reference image is formed according to the driving coordinate system, and the reference image contains the correct position to which the to-be-tested wafer should be positioned finally. The correct position includes that the positioning groove of the to-be-tested wafer is at a correct orientation. For example, when the positioning groove is a V-shaped groove and the driving coordinate system is a Cartesian coordinate system, in the reference image, the center point of the to-be-tested wafer is at the origin of the driving coordinate system, and the V-shaped groove of the wafer is located in the negative half of the Y-axis of the driving coordinate system.

[0075] Specifically, a reference image can be formed in the drive coordinate system according to the final correct position and shape of the wafer to be measured. For example, when the correct placement position of the wafer does not change, the final placement image of the last batch of wafers on the drive mechanism 10 can be used as the reference image; or the reference image can be generated in the drive coordinate system according to the final correct positioning position of the wafer and the size of the wafer, the type of positioning groove and other parameter information. The reference image can be used to represent the position information of the wafer after the final positioning is completed, which includes the positions of the wafer center and the positioning groove.

[0076] In step S208, a target conversion matrix is generated according to the first image and the reference image; the target conversion matrix is used to represent the coordinate conversion relationship between the displacement coordinate system and the drive coordinate system.

[0077] Specifically, the first image and the reference image can be uniformly represented in a coordinate system, and a conversion matrix can be established according to the positional relationship between the first image and the reference image in the coordinate system. The coordinate system can be the displacement coordinate system in which the first image is located, or the drive coordinate system in which the reference image is located, or a third-party coordinate system that can be converted. The target conversion matrix can be a homogeneous transformation matrix.

[0078] It should be understood that in the present embodiment, the first image is used to represent the current position of the wafer to be measured, and the reference image is used to represent the correct position of the wafer to be measured after the final positioning compensation. In the present embodiment, the center point of the wafer refers to the center of the wafer.

[0079] In step S210, a compensation coordinate value of the first wafer to be measured is calculated according to the target conversion matrix; the compensation coordinate value is used to control the pre-set drive mechanism to move the first wafer to be measured to a target position.

[0080] The target position can be the final correct placement position of the wafer that needs to be positioned and compensated.

[0081] Specifically, according to the coordinates of the first wafer to be measured in the displacement coordinate system and the target conversion matrix, the compensation coordinate value required to move the first wafer to be measured from the current position to the position represented by the reference image in the drive coordinate system can be calculated. According to the compensation coordinate value, the host computer 20 can control the drive mechanism 10 to complete the corresponding operation, so that the first wafer to be measured is finally located at the target position in the drive coordinate system.

[0082] In the technical scheme provided by the embodiments of the present disclosure, a first image containing the current position of the wafer can be obtained by the camera, and a displacement coordinate system is established based on the camera according to the image, and then, in combination with a reference image of the wafer in a driving coordinate system, a conversion matrix between the displacement coordinate system containing the current position and the driving coordinate system can be established, and then a compensation value required for positioning can be obtained by calculation. In this way, the camera can be arranged above the wafer workspace, and the wafer position can be obtained by the camera, without the need to install a light sensor in the wafer workspace, which is more convenient for wafer picking and handling. In addition, the wafer position can be confirmed by one-time acquisition of the camera, without the need to rotate the wafer, thereby saving the time for single positioning compensation, and the conversion matrix can also be used for calculation of the positioning compensation value of other wafers, thereby further shortening the time for subsequent wafer positioning compensation, greatly improving the work efficiency, and reducing the time cost.

[0083] In one embodiment, as shown in FIG. 1, the control positioning camera 30 photographs the first wafer to be measured to obtain a first image, including: Figure 3

[0084] In step S2022, the preset backlight light source is controlled to light the first wafer to be measured.

[0085] Specifically, the backlight light source can be provided below the first wafer to be measured to light the first wafer to be measured. In some implementations, the light source can be arranged below the stage 102, and the stage 102 can also be modified to arrange the light source around or below the wafer. Figure 1

[0086] In step S2024, the positioning camera 30 is moved until the optical axis of the positioning camera 30 is aligned with the center point of the first wafer to be measured, and the first wafer to be measured is photographed to obtain a first image.

[0087] Specifically, the host computer 20 can control the positioning camera 30 to move until the optical axis of the camera is aligned with the center point of the first wafer to be measured, stop moving the positioning camera 30, and photograph the first wafer to be measured.

[0088] In the above embodiments, the current position image of the wafer can be clearly obtained by setting the backlight, effectively eliminating the adverse effects of insufficient illumination of the wafer processing environment on the image. In addition, after aligning the camera optical axis with the wafer center, the wafer center and the camera optical axis are coincident in the obtained image, which is more convenient for subsequent coordinate calculation, and is beneficial to improve the operation efficiency of the positioning compensation process.

[0089] In one embodiment, the positioning slot is a V-shaped slot, and the displacement coordinate system is established according to the position of the positioning slot in the first image, including:

[0090] ​​The center point of the first wafer to be tested is taken as the origin of the displacement.

[0091] The straight line connecting the displacement origin and the V-groove is taken as the first coordinate axis;

[0092] The straight line passing through the origin of the displacement and perpendicular to the first coordinate axis is taken as the second coordinate axis;

[0093] A displacement coordinate system is established based on the displacement origin, the first coordinate axis, and the second coordinate axis.

[0094] Specifically, the first image can be obtained according to step S2024, and the center point of the wafer is the optical axis of the positioning camera 30. This point is used as the origin of the displacement coordinate system. Further, the first coordinate axis can be established according to the origin and the V-groove, and the second coordinate axis can be established according to the origin and the first coordinate axis, thereby forming the displacement coordinate system.

[0095] Figure 4 This is a schematic diagram illustrating the result of establishing a displacement coordinate system based on the position of the positioning slot in one embodiment. For example... Figure 4 As shown, the positioning groove is a V-shaped groove, located in the fourth quadrant of the circle. The origin of the displacement is P, with the center of the wafer as the origin. The vertical axis (M axis) is established based on the line connecting the center of the circle and the V-shaped groove. The horizontal axis (N axis) is then obtained based on the center of the circle and the vertical axis. Finally, the displacement coordinate system is obtained.

[0096] In the above embodiments, the origin is taken after the camera optical axis coincides with the center of the wafer. A coordinate axis is established in conjunction with the positioning slot. The position of the wafer can be represented by the camera optical axis according to the obtained displacement coordinate system. The position information of the positioning slot can also be obtained, which makes the calculation process of the positioning compensation value simpler and saves the calculation time.

[0097] In one embodiment, such as Figure 5 As shown, generating the target transformation matrix based on the first image and the reference image includes:

[0098] Step S2082: Based on the positional relationship between the optical axis of the positioning camera 30 and the driving coordinate system, the first displacement coordinate of the center point of the first wafer under test in the driving coordinate system is obtained.

[0099] In this image, the optical axis of the positioning camera 30 coincides with the center point of the first wafer under test in the first image. The first image is used to represent the current position of the first wafer under test.

[0100] Specifically, after the positioning camera 30 stops moving, the coordinates of the optical axis of the camera in the driving coordinate system can be obtained by the host computer 20. These coordinates are the first displacement coordinates of the center point of the first wafer to be tested in the first image in the driving coordinate system.

[0101] Step S2084, converting the first image into the driving coordinate system according to the first displacement coordinates.

[0102] Specifically, the first image is obtained by photographing the first wafer to be measured, and the first displacement coordinates obtained in step S2082 can be used to represent the first image in the driving coordinate system.

[0103] Step S2086, establishing a target conversion matrix according to the positional relationship between the first image and the reference image in the driving coordinate system.

[0104] Specifically, the first image and the reference image can be represented in the driving coordinate system at the same time, and a homogeneous transformation matrix can be established according to the coordinate relationship between the first image and the reference image. For example, the center of the wafer in the reference image can be placed at the origin of the driving coordinate system, the angle between the line connecting the center of the wafer in the first image and the origin and the coordinate axis can be obtained, and a homogeneous transformation matrix can be established according to the first displacement coordinates and the corresponding angle.

[0105] Figure 6 FIG. 1 is a schematic diagram of converting the first image into the driving coordinate system according to steps S2082-S2084 in an embodiment, as shown in FIG. 1: point O represents the origin of the driving coordinate system, and the center point of the wafer in the reference image is located at point O; point P represents the origin of the displacement coordinate system, which is also the center point of the first wafer to be measured in the first image; the host computer 20 can obtain the position of the camera optical axis after the positioning camera 30 stops moving, and represent the position of the camera optical axis in the driving coordinate system with coordinates, which are the coordinates P(x, y) of point P in the driving coordinate system, and obtain the first image in the driving coordinate system according to the coordinates of point P. Figure 6

[0106] FIG. 2 is a schematic diagram of calculating the compensation value according to the target conversion matrix in an embodiment, as shown in FIG. 2: the first wafer to be measured is currently located at point P of the driving coordinate system, in order to move the first wafer to be measured to point O in the reference image and ensure the correct position of the positioning groove, the following method can be used to establish a homogeneous transformation matrix and calculate a compensation coordinate value: Figure 7 Figure 7 The angle between the line connecting points O and P and the horizontal axis (N-axis) of the first image is θ1, the angle between the line connecting points O and P and the X-axis of the reference image is θ2, and the coordinates of points O and P can be used to obtain the following transformation formula:

[0107]

[0108]

[0109]

[0110] ​​

[0111] Where Rot represents the rotation of the coordinate system, and Trans represents the translation of the coordinate system. Combining the above formulas (1) to (3), we can obtain the homogeneous transformation matrix T for moving the first image from point P to the reference image at point O. T can be expressed as the following transformation formula:

[0112]

[0113] The compensation value required for the positioning compensation process of the first wafer under test can be calculated using the above formula. The host computer 20 controls the drive mechanism 10 to rotate the first wafer under test based on the value of θ2, moving the first wafer under test from the first position to the middle position; then, according to... The value of θ1 is used to translate the first wafer under test from the middle position to the reference position; finally, while keeping the overall position of the first wafer under test unchanged, the rotation is completed according to the value of θ1 to put the positioning groove in the correct position.

[0114] In the above embodiments, both the first image and the reference image are represented in the driving coordinate system. By establishing a homogeneous transformation matrix that includes two dimensions—the wafer coordinate position and the positioning slot angle—the positioning compensation value, encompassing both the overall wafer and the positioning slot, can be calculated. Furthermore, based on this compensated positioning value, accurate wafer positioning can be achieved through the rotation and movement of its own driving mechanism without the need for other auxiliary positioning devices such as robotic arms. This simplifies the positioning compensation process and significantly improves overall efficiency.

[0115] In one embodiment, such as Figure 8 As shown, after calculating the compensation coordinate values ​​of the first wafer under test based on the target transformation matrix, the method further includes:

[0116] Step S212: Control the positioning camera 30 to take a picture of the second wafer under test to obtain a second image.

[0117] The second wafer under test is another wafer under test whose positioning compensation value is calculated after the first wafer under test has been positioned; the second image is used to represent the current position of the second wafer under test.

[0118] Step S214: Perform calculation processing on the second image according to the preset algorithm to obtain the additional offset value of the second wafer under test in the displacement coordinate system.

[0119] Since the position of the positioning camera 30 remains unchanged, the displacement coordinate system is still a coordinate system with the camera's optical axis as the origin. The additional offset value can be the coordinates of the center point of the second wafer under test in the displacement coordinate system.

[0120] Specifically, the host computer 20 can calculate the additional offset value of the second wafer to be measured in the displacement coordinate system relative to the displacement origin by using a preset algorithm.

[0121] In step S216, a second compensation coordinate value is obtained according to the additional offset value and the compensation coordinate value; the second compensation coordinate value is used to control the driving mechanism to move the second wafer to be measured to the target position.

[0122] The compensation coordinate value can be used to transfer from the origin of the displacement coordinate system to the origin of the driving coordinate system, and the additional offset value can be used to transfer from the center point of the second wafer to be measured to the origin of the displacement coordinate system.

[0123] Specifically, according to the additional offset value and the compensation coordinate value, an algorithm can be used to obtain the second compensation coordinate value for moving the second wafer to be measured to the origin of the driving coordinate system.

[0124] In the above embodiment, the second wafer to be measured can be photographed without moving the camera, and the second compensation coordinate value required by the second wafer to be measured can be quickly calculated according to the obtained second image and the parameters obtained according to the first wafer to be measured, thereby further improving the calculation speed of the positioning compensation value of the subsequent wafer to be measured.

[0125] Figure 9 is a schematic diagram of the second image in the displacement coordinate system in an embodiment, as Figure 9 shown: M and N are coordinate axes of the displacement coordinate system, P is the origin of the displacement coordinate system, and U(m, n) is the coordinate of the center point of the second wafer to be measured in the displacement coordinate system.

[0126] In an embodiment, the additional offset value includes a displacement coordinate of the center point of the second wafer to be measured in the displacement coordinate system.

[0127] Specifically, when the current overall position of the second wafer to be measured is different from the position before the positioning of the first wafer to be measured, but the direction of the positioning slot is consistent with that before the positioning of the first wafer to be measured, the displacement coordinate can be the coordinate U(m, n) in Figure 9 .

[0128] In an embodiment, the displacement coordinate system includes two coordinate axes, and the additional offset value further includes a displacement included angle between the positioning slot of the second wafer to be measured and one of the coordinate axes of the displacement coordinate system.

[0129] Specifically, when the current position of the second wafer to be measured is different from that before the positioning of the first wafer to be measured, and the direction of the positioning slot is also different, after the displacement coordinate U(m, n) is obtained as shown in Figure 9 , the included angle θ3 between the line connecting the point U and the positioning slot and the N axis can be further obtained, and θ3 is taken as the displacement included angle to comprehensively calculate the additional offset value.

[0130] In the above embodiments, solutions are provided for measuring and calculating the positioning compensation value according to different conditions of other to-be-measured wafers, without moving the camera, and the positioning compensation value can be quickly calculated through the algorithm throughout the whole process, thereby saving operation time.

[0131] It should be understood that the method in the above embodiments is only one solution provided by the present disclosure for measuring and calculating the positioning compensation value of other to-be-measured wafers. In other embodiments, the measurement method of the first to-be-measured wafer can also be used for the second to-be-measured wafer, for example, the positioning camera 30 is controlled to align the camera optical axis with the center point of the second to-be-measured wafer, a second image is obtained after shooting, a corresponding second displacement coordinate system is established, and then the compensation coordinate value of the second to-be-measured wafer is calculated.

[0132] It should be understood that although each step in the flowchart involved in each of the above embodiments is displayed in sequence according to the arrow, these steps are not necessarily executed in the order indicated by the arrow. Unless otherwise specified herein, the execution of these steps is not strictly limited in sequence, and these steps can be executed in other orders. Moreover, at least part of the steps in the flowchart involved in each of the above embodiments can include multiple steps or stages, which are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily sequential, but can be executed in rotation or alternation with at least part of other steps or steps or stages in other steps.

[0133] In one embodiment, as shown in FIG. 1, a device for measuring and calculating a compensation value of wafer positioning is provided, comprising: Figure 10

[0134] The image acquisition module 502 is configured to control the positioning camera to shoot the first to-be-measured wafer to obtain a first image, wherein the first to-be-measured wafer comprises a positioning groove.

[0135] The coordinate system processing module 504 is configured to establish a displacement coordinate system according to the position of the positioning groove in the first image.

[0136] The reference image acquisition module 506 is configured to acquire a reference image of a to-be-measured wafer in a preset driving coordinate system, wherein the positioning groove of the to-be-measured wafer is located at a specified position in the reference image.

[0137] The conversion module 508 is configured to generate a target conversion matrix according to the first image and the reference image, wherein the target conversion matrix is used to represent the coordinate conversion relationship between the displacement coordinate system and the driving coordinate system.

[0138] ​The computing module 510 is configured to calculate a compensation coordinate value of the first wafer to be tested according to the target transformation matrix; and the compensation coordinate value is used to control a preset driving mechanism to move the first wafer to be tested to a target position.

[0139] The specific limitations of the above measuring device can refer to the above limitations of the above measuring method. According to the above measuring method, the measuring device can add a first module, a second module, and the like to implement the steps in the corresponding method embodiments. Each module in the above measuring device can be implemented by software, hardware, and a combination thereof in whole or in part. The above modules can be embedded in or independent of the processor in the computer device in hardware form, or can be stored in the memory in the computer device in software form, so as to be called and executed by the processor to perform the operations corresponding to each of the above modules.

[0140] According to another aspect of the embodiments of the present disclosure, as shown in Figure 11 A wafer positioning compensation system is provided, which includes a host computer 20, a driving mechanism 10, and a positioning camera 30.

[0141] The host computer 20 stores a computer program, and the host computer 20 implements the steps in the above method embodiments when executing the computer program.

[0142] The driving mechanism 10 is electrically connected to the host computer 20. The driving mechanism 10 further includes a carrier table 102, a driving shaft 104, and a driving controller 106. The driving controller 106 is connected to the carrier table 102 through the driving shaft 104.

[0143] The positioning camera 30 is connected to the host computer 20.

[0144] The driving shaft 104 can complete corresponding rotation, movement, and the like according to the instructions of the driving controller 106. The positioning camera 30 is arranged above the driving mechanism 10 at a position that does not affect the wafer process flow, and the positioning camera 30 can capture a wafer image that meets the clarity requirement.

[0145] According to another aspect of the embodiments of the present disclosure, a computer device is provided, which can be a terminal. The internal structure diagram of the computer device can be as shown in Figure 12As shown in the figure. The computer device includes a processor, a memory, a communication interface, a display screen and an input device connected through a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operating system and the computer program in the non-volatile storage medium to run. The communication interface of the computer device is used to communicate with external terminals in a wired or wireless manner. Wireless mode can be achieved through WIFI, operator network, NFC (near field communication) or other technologies. The computer program is executed by the processor to implement the above measurement method. The display screen of the computer device can be a liquid crystal display screen or an electronic ink display screen. The input device of the computer device can be a touch layer overlaid on the display screen, or a key, trackball or touchpad arranged on the shell of the computer device. It can also be an external keyboard, touchpad or mouse, etc.

[0146] Those skilled in the art can understand that Figure 12 The skilled in the art can understand that

[0147] In one embodiment, a computer device is also provided, including a memory and a processor, the memory stores a computer program, and the processor executes the computer program to implement the steps in the above method embodiments.

[0148] According to another aspect of the embodiments of the present disclosure, a computer readable storage medium is provided, which stores a computer program, and the computer program is executed by a processor to implement the steps in the above method embodiments.

[0149] According to another aspect of the embodiments of the present disclosure, a computer program product is provided, which includes a computer program, and the computer program is executed by a processor to implement the steps in the above method embodiments.

[0150] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer readable storage medium, and when the computer program is executed, the processes of the above-mentioned embodiments of the methods can be included. Any reference to memory, storage, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (Read-Only Memory, ROM), magnetic tape, floppy disk, flash memory or optical memory, etc. Volatile memory can include random access memory (Random Access Memory, RAM) or external cache memory. As an illustration but not limitation, RAM can be in various forms, such as static random access memory (Static Random Access Memory, SRAM) or dynamic random access memory (Dynamic Random Access Memory, DRAM), etc. The database involved in the embodiments provided in the present application can include at least one of a relational database and a non-relational database. The non-relational database can include a distributed database based on a block chain, etc., and is not limited thereto. The processor involved in the embodiments provided in the present application can be a general-purpose processor, a central processing unit, a graphics processing unit, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., and is not limited thereto.

[0151] Any combination of the technical features of the above embodiments can be made. In order to make the description simple, all possible combinations of the technical features in the above embodiments are not described, however, as long as the combination of the technical features does not exist contradictory, it should be considered as the scope of the present disclosure.

[0152] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent of the present application. It should be pointed out that those skilled in the art will easily think of other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. The present disclosure is intended to cover any variations, uses or adaptations of the present disclosure, which follow the general principles of the present disclosure and include common knowledge or conventional technical means in the technical field which are not disclosed in the present disclosure. The specification and embodiments are only regarded as exemplary, and the true scope and spirit of the present disclosure are indicated by the claims.

[0153] It should be understood that the present disclosure is not limited to the precise structures described and shown in the drawings, and various modifications and changes can be made without departing from the scope thereof.

Claims

1. A method for calculating compensation values ​​for wafer positioning, characterized in that, include: The positioning camera is controlled to capture a first image of the first wafer under test, thereby obtaining a first image; wherein the first wafer under test includes a positioning groove. Establish a displacement coordinate system based on the position of the positioning groove in the first image; A reference image of the wafer under test in a preset driving coordinate system is obtained; wherein the positioning groove of the wafer under test is located at a specified position in the reference image; A target transformation matrix is ​​generated based on the first image and the reference image; the target transformation matrix is ​​used to represent the coordinate transformation relationship between the displacement coordinate system and the driving coordinate system. The compensation coordinate value of the first wafer under test is calculated based on the target transformation matrix; the compensation coordinate value is used to control the preset drive mechanism to move the first wafer under test to the target position; After calculating the compensated coordinate values ​​of the first wafer under test based on the target transformation matrix, the method further includes: The positioning camera is controlled to capture an image of the second wafer under test, thereby obtaining a second image; The second image is processed according to a preset algorithm to obtain the additional offset value of the second wafer under test in the displacement coordinate system. A second compensation coordinate value is obtained based on the additional offset value and the compensation coordinate value; the second compensation coordinate value is used to control the drive mechanism to move the second wafer under test to the target position.

2. The calculation method according to claim 1, characterized in that, The controlled positioning camera captures an image of the first wafer under test, obtaining a first image, including: The preset backlight source is controlled to illuminate the first wafer under test; Move the positioning camera until its optical axis is aligned with the center point of the first wafer under test, and take a picture of the first wafer under test to obtain a first image.

3. The calculation method according to claim 2, characterized in that, The positioning groove is a V-shaped groove. Establishing a displacement coordinate system based on the position of the positioning groove in the first image includes: The center point of the first wafer to be tested is taken as the origin of the displacement. The straight line connecting the displacement origin and the V-groove is taken as the first coordinate axis; The straight line passing through the origin of the displacement and perpendicular to the first coordinate axis is taken as the second coordinate axis; A displacement coordinate system is established based on the displacement origin, the first coordinate axis, and the second coordinate axis.

4. The calculation method according to claim 2, characterized in that, The step of generating the target transformation matrix based on the first image and the reference image includes: Based on the positional relationship between the optical axis of the positioning camera and the driving coordinate system, the first displacement coordinate of the center point of the first wafer under test in the driving coordinate system is obtained; The first image is transformed into the driving coordinate system based on the first displacement coordinates; A target transformation matrix is ​​established based on the positional relationship between the first image and the reference image in the driving coordinate system.

5. The calculation method according to claim 1, characterized in that, The compensated coordinate values ​​are used to transfer from the origin of the displacement coordinate system to the origin of the driving coordinate system.

6. The calculation method according to claim 1, characterized in that, The additional offset value includes the offset coordinates of the center point of the second wafer under test in the displacement coordinate system.

7. The calculation method according to claim 6, characterized in that, The displacement coordinate system includes two coordinate axes, and the additional offset value also includes the offset angle between the positioning groove of the second wafer under test and one of the coordinate axes of the displacement coordinate system.

8. A device for calculating compensation values ​​for wafer positioning, characterized in that, include: An image acquisition module is used to control a positioning camera to capture a first image of a first wafer under test; wherein the first wafer under test includes a positioning groove. The coordinate system processing module is used to establish a displacement coordinate system based on the position of the positioning groove in the first image; A reference image acquisition module is used to acquire a reference image of the wafer under test in a preset driving coordinate system; wherein the positioning groove of the wafer under test is located at a specified position in the reference image; A transformation module is used to generate a target transformation matrix based on the first image and the reference image; the target transformation matrix is ​​used to represent the coordinate transformation relationship between the displacement coordinate system and the driving coordinate system. The calculation module is used to calculate the compensation coordinate value of the first wafer under test based on the target transformation matrix; the compensation coordinate value is used to control the preset drive mechanism to move the first wafer under test to the target position; After calculating the compensated coordinate values ​​of the first wafer under test based on the target transformation matrix, the method further includes: The positioning camera is controlled to capture an image of the second wafer under test, thereby obtaining a second image; The second image is processed according to a preset algorithm to obtain the additional offset value of the second wafer under test in the displacement coordinate system. A second compensation coordinate value is obtained based on the additional offset value and the compensation coordinate value; the second compensation coordinate value is used to control the drive mechanism to move the second wafer under test to the target position.

9. A wafer positioning compensation system, characterized in that, include: Host computer, drive mechanism, positioning camera; The host computer stores a computer program, and when the host computer executes the computer program, it implements the steps of the method according to any one of claims 1 to 7. The drive mechanism is electrically connected to the host electromechanical unit; the drive mechanism also includes a stage, a drive shaft, and a drive controller, the drive controller being connected to the stage via the drive shaft; The positioning camera is connected to the host computer.

10. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 7.

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