Wafer movement control method, device and system

Abstract

The application discloses a wafer movement control method, device and system, and relates to the field of semiconductor processes. The wafer movement control method comprises the following steps: acquiring a plurality of position information corresponding to a plurality of overlay patterns, so that the position of each overlay pattern on the wafer can be accurately acquired; determining a scanning mode with the shortest time from a first scanning mode and a second scanning mode according to the plurality of position information; and controlling the wafer to move according to the scanning mode with the shortest time, so as to reduce the movement time of the wafer, improve the measurement efficiency of the wafer, and further improve the measurement efficiency of the overlay error.

Description

Technical Field

[0001] This application relates to the field of semiconductor processes, and in particular to a wafer movement control method, apparatus and system. Background Technology

[0002] In the semiconductor wafer manufacturing process, the wafer surface is typically provided with multiple dicing channels to separate the wafer and accommodate overlay patterns. These dicing channels are distributed along a first extension direction and a second extension direction, and the overlay patterns set inside them are key references for wafer alignment and defect detection.

[0003] In existing technologies, to acquire overlay patterns, wafer movement needs to be controlled so that each overlay pattern is within the field of view of the image sensor above the wafer. Currently, the wafer scanning mode (including the wafer's movement path and direction) is usually set based on fixed rules or manual experience. As the number of overlay patterns continues to increase, improper scanning mode configuration can easily lead to a significant increase in wafer movement time, thereby adversely affecting the wafer measurement efficiency. Summary of the Invention

[0004] This application provides a wafer movement control method, apparatus, and system. By setting the overlay patterns on the wafer to be located on the dicing tracks, and having multiple dicing tracks with different directions, multiple scanning modes can be planned according to the positions and different extension directions of all overlay patterns on the wafer surface. The wafer is then controlled to move along the scanning mode with the shortest time among the multiple scanning modes, saving wafer movement time and improving the measurement efficiency of overlay errors. At the same time, it ensures that as many overlay patterns as possible on the wafer surface can be scanned.

[0005] In a first aspect, the wafer movement control method provided in this application is used to acquire overlay patterns on the wafer surface dicing, including acquiring multiple position information corresponding to multiple overlay patterns; determining the scanning mode with the shortest time among a first scanning mode and a second scanning mode based on the multiple position information, wherein the first scanning mode is a mode of performing multiple scans along a first extension direction, and the second scanning mode is a mode of performing multiple scans along a second extension direction; controlling the wafer movement according to the determined scanning mode so that the image sensor acquires image information of each overlay pattern.

[0006] The wafer movement control method provided in this application includes first acquiring multiple position information corresponding to multiple overlay patterns to ensure that the position of each overlay pattern on the wafer can be accurately acquired, and determining the scanning mode with the shortest time among the first scanning mode and the second scanning mode based on the multiple position information, and then controlling the wafer movement according to the shortest scanning mode. This helps to reduce the wafer movement time, improve the wafer measurement efficiency, and thus improve the measurement efficiency of overlay error.

[0007] In some possible implementations, determining the scanning mode with the shortest time among the first and second scanning modes based on multiple location information includes: planning a first scanning path based on multiple location information and a first extension direction; planning a second scanning path based on multiple location information and a second extension direction; and determining the scanning mode with the shortest time among the first and second scanning modes based on the first and second scanning paths. In the embodiments of this application, generating scanning modes based on multiple location information and different extension directions (such as the first / second extension directions) can dynamically adapt to the distribution characteristics of the wafer surface pattern, reduce invalid movement paths, and determine the scanning mode with the shortest time among the two scanning modes by comparing the two scanning paths. This reduces idle travel and repetitive positioning time during wafer movement and avoids the efficiency loss caused by fixed paths in traditional static planning.

[0008] In some possible implementations, determining the scanning mode with the shortest time among the first and second scanning modes based on the first and second scanning paths includes: determining a first scanning time based on the first scanning path and a second scanning time based on the second scanning path; comparing the first and second scanning times to determine the scanning mode with the shortest time among the first and second scanning modes. In the embodiments of this application, generating scanning modes based on multiple positional information and different extension directions (such as the first / second extension directions) can dynamically adapt to the distribution characteristics of the wafer surface pattern, reduce invalid movement paths, and quickly select the optimal scanning path by comparing the time differences between the two scanning modes, thereby improving the wafer movement efficiency.

[0009] In some possible implementations, the scanning mode with the shortest time among the first and second scanning modes is determined based on the first and second scanning paths. This includes: determining the number of rows and / or length and / or number of turns of the first scanning path based on the first scanning path; and determining the number of rows and / or length and / or number of turns of the second scanning path based on the second scanning path; comparing the number of rows and / or length and / or number of turns of the first and second scanning paths to determine the scanning mode with the shortest time among the first and second scanning modes. In the embodiments of this application, by extracting the number of rows and / or length and / or number of turns of the first and second scanning paths (e.g., the number of rows reflects the number of steps of the driving device, / or length corresponds to the moving distance, / or number of turns is related to the servo motor response time), a multi-dimensional efficiency evaluation model is constructed to dynamically calculate the total time of the two scanning modes, thus avoiding redundant movement caused by traditional fixed path planning.

[0010] In some possible implementations, planning a first scanning path based on multiple location information and a first extension direction includes: obtaining multiple first path segments passing through the overlay pattern based on the multiple location information and the first extension direction, and extending each first path segment; planning a first scanning path based on the extended first path segments; and planning a second scanning path based on multiple location information and a second extension direction includes: obtaining multiple second path segments passing through the overlay pattern based on the multiple location information and the second extension direction, extending each second path segment; and planning a second scanning path based on the extended second path segments. In the embodiments of this application, by extending each path segment, acceleration and deceleration paths are provided for the drive device controlling wafer movement, ensuring that the drive device can smoothly accelerate and decelerate at the beginning and end of each scan line, reducing mechanical vibration and errors, and improving the stability of wafer movement.

[0011] In some possible implementations, determining the scanning mode with the shortest time among the first and second scanning modes based on multiple location information includes: determining a first density of the overprinted pattern distributed along the first extension direction based on multiple location information and a first extension direction; determining a second density of the overprinted pattern distributed along the second extension direction based on multiple location information and a second extension direction; and determining the scanning mode with the shortest time among the first and second scanning modes based on the first and second densities. In the embodiments of this application, by calculating the difference between the first density and the second density of the overprinted pattern along the first extension direction and along the second extension direction, and employing a region division and statistical averaging mechanism, accurate quantification of spatial distribution characteristics is achieved, effectively avoiding local noise interference and significantly improving the accuracy of density calculation.

[0012] In some possible implementations, before controlling the wafer movement according to the determined scanning mode, the process includes: determining whether the preset movement direction of the wafer is the scanning direction of the scanning mode; if the preset movement direction of the wafer is not the scanning direction of the scanning mode, controlling the wafer to rotate so that the preset movement direction of the wafer becomes the scanning direction of the scanning mode. By determining and adjusting the wafer's movement direction in advance before the wafer moves according to the scanning mode, it is ensured that the wafer's movement direction is consistent with the movement direction corresponding to the scanning mode. This allows the field of view of the image sensor to cover all overlay patterns on the wafer, reducing measurement errors introduced by directional deviations and improving the accuracy and reliability of overlay error measurement.

[0013] In some possible implementations, before controlling wafer movement according to a determined scanning mode, the process includes: determining whether the wafer's movement starting point is at the scanning starting point of the scanning mode; if the wafer's movement starting point is not at the scanning starting point of the scanning mode, controlling wafer movement to make the wafer's movement starting point coincide with the scanning starting point of the scanning mode. In the embodiments of this application, by precisely controlling the wafer's movement starting point, it is ensured that the scanning start position is consistent with the scanning starting point of the scanning mode, avoiding the inability to acquire some overlay patterns due to starting position deviation, reducing measurement errors introduced by position deviation, and improving the accuracy and reliability of overlay error measurement.

[0014] In some possible implementations, after aligning the wafer's movement starting point with the scanning starting point of the scanning mode, the process includes: determining whether the wafer's movement starting point is located at the center of the image sensor's field of view; if the wafer's movement starting point is not located at the center of the image sensor's field of view, controlling the wafer and / or the image sensor to move so that the wafer's movement starting point is located at the center of the image sensor's field of view. In the embodiments of this application, by precisely controlling the wafer to align the wafer's movement starting point with the center of the image sensor's field of view, it is ensured that all overlay patterns can be completely acquired by the image sensor, avoiding the inability to detect some overlay patterns due to positional deviations, reducing measurement errors introduced by positional deviations, and improving the accuracy and reliability of overlay error measurement.

[0015] In some possible implementations, wafer movement is controlled according to a defined scanning mode, including: controlling the wafer to move at a constant speed in path segments where the image sensor can capture the wafer image, and controlling the wafer to move at a variable speed in path segments where the image sensor cannot capture the wafer image. By controlling the wafer to move at a constant speed in path segments where the image sensor can capture the wafer image, the image sensor can successfully acquire all overlay patterns located on the path of that scanning mode, avoiding incomplete acquisition of multiple overlay patterns on the wafer due to unstable wafer movement speed. By controlling the wafer to accelerate or decelerate in path segments where the image sensor cannot capture the wafer image, the wafer movement speed conforms to the movement logic of that path segment, and the wafer can quickly pass through that path segment, which helps to reduce wafer movement time and thus improve the measurement efficiency of overlay errors.

[0016] In some possible implementations, the process of controlling the wafer to move at a constant speed includes: determining whether the wafer has moved to a position where the image sensor can capture the overlay pattern; if the wafer has moved to a position where the image sensor can capture the overlay pattern, controlling the image sensor to acquire an image. In the embodiments of this application, when the overlay pattern does not appear in the field of view of the image sensor, the image sensor will not acquire an image at that position; only when the overlay pattern appears in the field of view of the image sensor will the image at that position be acquired. Since real-time image acquisition is not required, and since the image sensor only acquires images when the overlay pattern appears in the field of view, the real-time acquisition and processing of meaningless images are avoided, significantly reducing the amount of data and lowering the burden of data processing and storage.

[0017] In some possible implementations, after the image sensor acquires an image, the process includes: determining whether the image meets preset conditions; if the image does not meet the preset conditions, discarding the image so that it is not used for measuring overlay error. By discarding images that do not meet the preset conditions, in this embodiment of the application, by determining whether the image meets the preset conditions and discarding images that do not meet the conditions, it is ensured that the images used for overlay error measurement are all high-quality and valid data, thereby significantly improving the accuracy of the measurement results.

[0018] Secondly, the wafer movement control device provided in this application is used to implement the wafer movement control method in the above embodiments. The device includes: an acquisition module for acquiring multiple position information corresponding to multiple overlay patterns; a processing module for determining the scanning mode with the shortest time among a first scanning mode and a second scanning mode based on the multiple position information, wherein the first scanning mode is a mode of performing multiple scans along a first extension direction, and the second scanning mode is a mode of performing multiple scans along a second extension direction; and a control module for controlling wafer movement according to the determined scanning mode.

[0019] The wafer movement control device provided in this application includes an acquisition module, a processing module, and a control module. The acquisition module is used to acquire multiple position information corresponding to multiple overlay patterns and plan a first scanning mode and a second scanning mode, so that the wafer has two movement modes to choose from. The processing module is used to determine the scanning mode with the shortest time among the first scanning mode and the second scanning mode based on the multiple position information, thereby determining the scanning mode for wafer movement to ensure wafer movement efficiency. The control module is used to control wafer movement according to the determined scanning mode, reducing wafer movement time, improving wafer movement efficiency, and thus ensuring the measurement efficiency of overlay error.

[0020] In some possible implementations, the acquisition module is used to determine a first scanning mode based on multiple positional information and a first extension direction; and to determine a second scanning mode based on multiple positional information and a second extension direction. The acquisition module is electrically connected to the processing module, which compares the scanning times of the first and second scanning modes and determines the scanning mode with the shortest time. By electrically connecting the acquisition module to the processing module, the processing module can receive the first and second scanning modes determined by the acquisition module, compare their scanning times, and thus determine the scanning mode with the shortest time. This helps to reduce the movement time of the wafer when moving according to the scanning mode, thereby ensuring the measurement efficiency of overlay error.

[0021] In some possible implementations, the wafer movement control device further includes a path planning module, and the acquisition module and the path planning module are electrically connected. The acquisition module is used to acquire multiple first path segments passing through the overlay pattern based on multiple position information and a first extension direction. The path planning module is used to plan the wafer movement path based on the multiple first path segments and determine a first scanning mode based on the movement path. Alternatively, the acquisition module is used to acquire multiple second path segments passing through the overlay pattern based on multiple position information and a second extension direction. The path planning module is used to plan the wafer movement path based on the multiple second path segments and determine a second scanning mode based on the movement path. By enabling the acquisition module to acquire multiple first path segments passing through the overlay pattern and enabling the path planning module to plan the first path segments to determine the first scanning mode, the path of the first scanning mode is made continuous, thereby improving the smoothness of wafer movement according to the first scanning mode and thus improving wafer movement efficiency. By having the acquisition module acquire multiple second path segments passing through the overlay pattern and the path planning module plan the second path segments to determine the second scanning mode, the path of the second scanning mode is made to be a continuous path, thereby improving the smoothness of wafer movement according to the second scanning mode and thus improving wafer movement efficiency.

[0022] In some possible implementations, the path planning module is used to extend multiple first path segments based on multiple first path segments, and obtain the extended multiple first path segments to plan the wafer's movement path; or, the path planning module is used to extend multiple second path segments based on multiple second path segments, and obtain the extended multiple second path segments to plan the wafer's movement path. By having the path planning module extend multiple first path segments and plan the wafer's movement path, or by having the path planning module extend multiple second path segments and plan the wafer's movement path, it is ensured that the wafer accelerates and decelerates along its extended path segments, thereby ensuring that the image sensor can stably acquire all overlay patterns, while also helping to ensure wafer movement efficiency and overlay error measurement efficiency.

[0023] In some possible implementations, the acquisition module acquires the preset scanning direction of the wafer before controlling wafer movement according to the scanning mode. The control module is electrically connected to the acquisition module and determines whether the preset scanning direction of the wafer is the scanning direction of the scanning mode, and controls the preset scanning direction of the wafer to be the scanning direction of the scanning mode. By having the acquisition module acquire the preset scanning direction of the wafer, the control module controls the wafer to move to the scanning direction of the scanning mode, ensuring that the wafer's movement direction is consistent with the movement direction corresponding to the scanning mode. This allows the field of view of the image sensor to cover all overlay patterns on the wafer, improving the accuracy and reliability of overlay error measurement.

[0024] In some possible implementations, the acquisition module acquires the actual position of the wafer before controlling wafer movement according to the scanning mode. The control module is electrically connected to the processing module. The control module determines whether the wafer is at the scan start point of the scanning mode and controls the wafer to move to the scan start point of the scanning mode. By having the control module control the wafer to move to the scan start point of the scanning mode, it ensures that the starting position of the scan is consistent with the scan start point of the scanning mode, so that the wafer can move strictly according to the movement path corresponding to the scanning mode, thereby improving the accuracy and reliability of overlay error measurement.

[0025] In some possible implementations, the wafer movement control device further includes an image sensor having a field of view. The image sensor and an acquisition module are electrically connected. The acquisition module acquires the field of view of the image sensor, and the control module determines whether the scanning start point of the scanning mode is located at the center of the field of view of the image sensor and controls the wafer to move to the center of the field of view of the image sensor. By controlling the wafer to move to the center of the field of view of the image sensor, when the wafer moves according to the scanning mode, all overlay patterns located on the path of that scanning mode can sequentially pass through the center of the field of view of the image sensor. This ensures that all overlay patterns can be completely acquired by the image sensor, avoiding the inability to detect some overlay patterns due to positional deviations, reducing measurement errors introduced by positional deviations, and improving the accuracy and reliability of overlay error measurement.

[0026] In some possible implementations, the wafer movement control device further includes an image sensor capable of capturing a path segment of the wafer image. A control module is electrically connected to the image sensor. The control module controls the wafer to move at a constant speed within the path segment where the image sensor can capture the wafer image, and also controls the wafer to move at a variable speed within the path segment where the image sensor cannot capture the wafer image. By controlling the wafer to move at a constant speed within the path segment where the image sensor can capture the wafer image, the image sensor can successfully acquire all overlay patterns on the wafer, avoiding incomplete acquisition of multiple overlay patterns due to unstable wafer movement speed. Furthermore, by controlling the wafer to move at a variable speed within the path segment where the image sensor cannot capture the wafer image, the wafer's movement speed conforms to the movement logic of that path segment, which helps ensure the stability of wafer movement. Simultaneously, it allows the wafer to quickly pass through the path segment, reducing wafer movement time and thus improving the measurement efficiency of overlay errors.

[0027] In some possible implementations, the wafer movement control device further includes an acquisition module. An image sensor is used to acquire the overlay pattern. The acquisition module and the image sensor are electrically connected. The acquisition module determines whether the wafer has moved to a position where the image sensor can capture the overlay pattern, and controls the image sensor to acquire an image when it can capture the overlay pattern. By including the acquisition module in the wafer movement control device, the acquisition module can control the image sensor to acquire images based on the wafer's movement position, thereby ensuring that the image sensor can accurately acquire the overlay pattern, improving the image sensor's efficiency in acquiring valid images, avoiding the real-time acquisition and processing of meaningless images, significantly reducing the amount of data, and lowering the burden of data processing and storage.

[0028] In some possible implementations, the acquisition module stores preset conditions. The acquisition module determines whether the images acquired by the image sensor meet the preset conditions and discards images that do not meet the preset conditions. By enabling the acquisition module to store preset conditions and selectively extract or retain images based on these conditions, it ensures that the images used for overlay error measurement are all high-quality and valid data, thereby significantly improving the accuracy of the measurement results.

[0029] Thirdly, the wafer movement control device provided in this application is used to implement the wafer movement control method or the wafer movement control device in any of the above embodiments. The device includes: a memory for storing multiple position information corresponding to multiple overlay patterns; a processor for determining the scanning mode with the shortest time among a first scanning mode and a second scanning mode based on the multiple position information, wherein the first scanning mode is a mode of performing multiple scans along a first extension direction, and the second scanning mode is a mode of performing multiple scans along a second extension direction; and a controller for controlling wafer movement according to the determined scanning mode.

[0030] The wafer movement control device provided in this application includes a memory, a processor, and a controller. The memory is used to acquire multiple position information corresponding to multiple overlay patterns and plan a first scanning mode and a second scanning mode, such that all overlay patterns on the first dicing track are located on the path of the first scanning mode, and all overlay patterns on the second dicing track are located on the path of the second scanning mode, thereby ensuring the measurement efficiency of the wafer when it moves according to the first scanning mode or the second scanning mode. The processor is used to determine the scanning mode with the shortest time among the first scanning mode and the second scanning mode based on the multiple position information, thereby determining the scanning mode for wafer movement to ensure wafer movement efficiency. The controller is used to control the wafer movement according to the determined scanning mode, reducing the wafer movement time, improving the wafer movement efficiency, and thus ensuring the measurement efficiency of overlay errors.

[0031] Fourthly, the wafer movement control system provided in this application includes a base for supporting the wafer, the wafer surface having multiple dicing channels intersecting along a first extension direction and a second extension direction, and multiple overlay patterns disposed on the dicing channels; a multi-axis drive unit for driving the base to move along the first extension direction or the second extension direction; an optical positioning unit for optically scanning the multiple overlay patterns to obtain multiple position information corresponding to the multiple overlay patterns; a processing unit for performing the following operations: determining the scanning mode with the shortest time among a first scanning mode and a second scanning mode based on the multiple position information, wherein the first scanning mode is a mode of multi-line scanning along the first extension direction, and the second scanning mode is a mode of multi-line scanning along the second extension direction; and a control unit for controlling the wafer movement according to the determined scanning mode.

[0032] The wafer movement control system provided in this application includes a base, a multi-axis drive unit, an optical positioning unit, a processing unit, and a control unit. The base supports the wafer, and the multi-axis drive unit can drive the base to move stably, thereby driving the wafer to move stably. The wafer has overlay patterns, and these patterns are all set on the dicing ridges, avoiding the overlay patterns occupying the functional area of ​​the wafer and making the distribution of marking points on the wafer more regular. The optical positioning unit has a field of view, which can acquire the position information of the overlay patterns entering the field of view and transmit it to the processing unit. The processing unit selects the scanning mode with the shortest time according to the position information corresponding to all overlay patterns on the wafer, so that the time taken for the base to move according to the scanning mode is minimized. The control unit controls the wafer movement according to the scanning mode with the shortest time, reducing the movement time of the base and improving the measurement efficiency of overlay error.

[0033] In some possible implementations, the wafer movement control system further includes an imaging unit, with the base moving relative to the imaging unit. The imaging unit is used to acquire multiple overlay patterns on the wafer surface. By including an imaging unit in the wafer movement control system, and having the imaging unit acquire multiple overlay patterns on the wafer surface, the overlay patterns can be transferred to the optical positioning unit via the imaging unit, while simultaneously improving the clarity of the overlay patterns acquired by the optical positioning unit.

[0034] In some possible implementations, the wafer movement control system further includes a focus detection unit. The imaging unit includes a second beam splitter and a moving lens. The second beam splitter is located on the image side of the moving lens and is used to transmit the overlay pattern acquired by the optical positioning unit to the focus detection lens. By positioning the second beam splitter on the image side of the moving lens and transmitting the overlay pattern acquired by the optical positioning unit to the focus detection lens through the second beam splitter, the focus detection unit can smoothly measure the focus status of the moving lens and the base based on the overlay pattern.

[0035] In some possible implementations, the wafer movement control system further includes a focus control unit electrically connected to both the focus detection unit and the moving lens. The focus control unit controls the spacing between the moving lens and the base based on the detection results from the focus detection unit. By electrically connecting the focus control unit to both the focus detection unit and the moving lens, the focus control unit can control the movement of the moving lens based on the detection results from the focus detection unit, thereby achieving focus between the moving lens and the base and ensuring improved image sharpness. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the structure of the wafer movement control system provided in the embodiments of this application;

[0037] Figure 2This is a schematic diagram of the motion control system of the imaging unit with a wedge and a relay lens assembly provided in the embodiments of this application.

[0038] Figure 3 This is a schematic diagram of a motion control system with an imaging unit provided in an embodiment of this application;

[0039] Figure 4 This is a top view of a wafer with multiple dicing channels provided in an embodiment of this application;

[0040] Figure 5 This is a flowchart of a wafer movement control method provided in an embodiment of this application;

[0041] Figure 6 This is a top view of a wafer whose overlay patterns are all located on multiple first dicing tracks, as provided in the embodiments of this application.

[0042] Figure 7 This is a top view of a wafer whose overlay patterns are all located on multiple second dicing tracks, as provided in the embodiments of this application.

[0043] Figure 8 This is a flowchart of the first method for determining the scanning mode with the shortest time provided in the embodiments of this application;

[0044] Figure 9 This is a flowchart of a second method for determining the scanning mode with the shortest scanning time provided in the embodiments of this application;

[0045] Figure 10 This is a flowchart of a third method for determining the scanning mode with the shortest time, provided in the embodiments of this application;

[0046] Figure 11 This is a flowchart of a method for planning a scanning path provided in an embodiment of this application;

[0047] Figure 12 This is a top view of a wafer with three dicing channels provided in an embodiment of this application;

[0048] Figure 13 This is a flowchart of the fourth method for determining the scanning mode with the shortest time provided in the embodiments of this application;

[0049] Figure 14 This is a flowchart of a wafer movement control method for determining whether a preset scanning direction of a wafer is the direction of a scanning mode, provided in an embodiment of this application.

[0050] Figure 15 This is a flowchart of a wafer movement control method provided in this application for determining whether the starting point of wafer movement is located at the starting point of a scanning mode;

[0051] Figure 16 This is a flowchart of a wafer movement control method provided in this application for determining whether the starting point of wafer movement is located at the center of the field of view of an image sensor;

[0052] Figure 17 This is a flowchart of a wafer movement control method for controlling the movement speed of a wafer, provided in an embodiment of this application.

[0053] Figure 18 This is a top view of a wafer with a single dicing track provided in an embodiment of this application;

[0054] Figure 19 This is a flowchart of a wafer movement control method for controlling image acquisition by an image sensor, provided in an embodiment of this application.

[0055] Figure 20 This is a flowchart of a wafer movement control method for determining whether an image meets preset conditions, provided in an embodiment of this application.

[0056] Figure 21 This is a schematic diagram of a wafer movement control device provided in an embodiment of this application;

[0057] Figure 22 This is a schematic diagram of a wafer movement control device with a path planning module provided in an embodiment of this application;

[0058] Figure 23 This is a schematic diagram of a mobile control device provided in an embodiment of this application, in which the control module and the processing module are connected.

[0059] Figure 24 This is a schematic diagram of a motion control device connected to an image sensor and an acquisition module, as provided in an embodiment of this application.

[0060] Figure 25 This is a schematic diagram of a motion control device that connects an image sensor and a control module according to an embodiment of this application;

[0061] Figure 26 This is a schematic diagram of a wafer movement control device with a data acquisition module provided in an embodiment of this application;

[0062] Figure 27 This is a schematic diagram of a wafer movement control device provided in an embodiment of this application.

[0063] Explanation of reference numerals in the attached figures:

[0064] 10-Wafer;

[0065] 11- Cutting marks; 12- Overlay pattern;

[0066] 111 - First cutting track; 112 - Second cutting track;

[0067] 1111 - First extension direction; 1112 - First turning path; 1113 - First movement direction; 1121 - Second extension direction; 1122 - Second turning path;

[0068] 20-Wafer Motion Control System;

[0069] 21-Base; 22-Optical positioning unit; 23-Multi-axis drive unit; 24-Processing unit; 25-Control unit; 26-Imaging unit; 27-Focus detection unit; 28-Focus control unit;

[0070] 261-Moving lens; 262-First beam splitter; 263-Second beam splitter; 264-Relay lens group; 265-Wedge plate; 266-Imaging lens group;

[0071] 2631 - First optical path; 2632 - Second optical path;

[0072] 30 - Wafer movement control device;

[0073] 31-Processing module; 32-Acquisition module; 33-Control module; 34-Path planning module; 35-Image sensor; 36-Acquisition module;

[0074] 41-Processor; 42-Memory; 43-Controller. Detailed Implementation

[0075] The embodiments of this application are described below with reference to the accompanying drawings.

[0076] For ease of understanding, the English abbreviations and related technical terms used in the embodiments of this application will be explained and described below.

[0077] It should be understood that the described embodiments are merely some, not all, of the embodiments in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0078] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0079] It should be understood that the term "and / or" used in this document is merely a description of the same field in the related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0080] Depending on the context, the word "if" as used herein can be interpreted as "when," "when," "in response to determination," or "in response to detection." Similarly, depending on the context, the phrase "if determination" or "if detection (of the stated condition or event)" can be interpreted as "when determination," "in response to determination," "when detection (of the stated condition or event)," or "in response to detection (of the stated condition or event)."

[0081] It should be understood that the terms "first," "second," etc., used in this application are for distinguishing purposes only and should not be construed as indicating or implying relative importance or order. "At least one" means "one or more."

[0082] In the description of this application, the terms “center,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0083] In the description of this application, it should be noted that due to manufacturing or assembly errors, there may be slight angular deviations in the design that should be perpendicular or parallel. For example, a deviation within 15 degrees is also considered perpendicular or parallel as described in this embodiment.

[0084] The phrase "within the range" used in this application, unless otherwise specified, includes both endpoints of the range by default. For example, in the range of 1 to 5, it includes the values ​​1 and 5.

[0085] It should be understood that in this application, "electrical connection" can be understood as physical contact and electrical conduction between components; it can also be understood as the form in which different components in a circuit structure are connected through physical lines that can transmit signals, such as copper foil or wires on a printed circuit board (PCB).

[0086] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0087] In the semiconductor manufacturing process, the wafer serves as the fundamental carrier of integrated circuits, and its processing precision and efficiency directly affect the performance and cost of the final product. With technological advancements, the size of integrated circuits continues to shrink, and the requirements for alignment precision during wafer processing are increasingly stringent. Overlay error is one of the most critical errors that needs to be controlled. It refers to the pattern alignment error between the previous and current layers. Large overlay errors can easily reduce the alignment precision of the wafer, leading to a decrease in the performance of subsequent products and reducing manufacturing yield. Overlay errors exhibit a certain distribution pattern on the wafer. To ensure that the overlay error remains within a certain threshold range, it is necessary to measure the overlay pattern on the wafer, identify its distribution pattern, and then feed this pattern back to the mask alignment exposure machine to control the wafer's overlay error.

[0088] For a single wafer, the more overlay patterns there are, the more accurate the measurement results of the overlay error obtained based on the overlay patterns will be. However, a greater number of overlay patterns means more measurements of the overlay patterns, requiring movement between more overlay patterns during the measurement process, which increases the measurement time for overlay error. Therefore, it is necessary to determine the wafer scanning mode so that the wafer moves according to the determined scanning mode, thereby reducing the wafer movement time and improving the wafer measurement efficiency.

[0089] Overlay error measurement systems are primarily used in wafer manufacturing and packaging processes. These systems are electrically connected to mask alignment and exposure machines to measure and control overlay errors, preventing excessive errors from causing circuit pattern errors. Overlay error measurement systems typically employ image-plane collecting diffraction overlay measurement technology and image overlay measurement technology to detect overlay errors. Since a single wafer usually has multiple overlay patterns, each pattern needs to be inspected individually to ensure the accuracy and reliability of the results. To ensure the individual inspection of all overlay patterns, image-plane collecting diffraction overlay measurement technology and image overlay measurement technology typically use a step-stop detection method. This involves decelerating before reaching a marker point, stopping at that point for inspection, and then accelerating to move to another overlay pattern, repeating this process. However, as the number of overprinted patterns increases, the time spent moving between different overprinted patterns in the above-mentioned step-stop detection method increases, resulting in an increase in the detection time of the entire overprinting error. Moreover, the ratio of the time spent moving between different overprinted patterns to the total detection time of the overprinting error increases, while the proportion of time used to detect the overprinted patterns decreases, leading to a decrease in the detection efficiency of the overprinting error, which is not conducive to industrial applications.

[0090] The wafer movement control system, method, and apparatus of this application can be used for various wafer measurements, such as film thickness measurement and optical critical dimension (OCD) measurement.

[0091] This application provides a wafer movement control system 20. Please refer to [link / reference]. Figure 1 , Figure 1 A schematic diagram of the wafer movement control system 20 provided in this application embodiment is shown. It can be understood that the wafer movement control system includes a base 21, which supports the wafer 10, enabling the wafer 10 to move along with the base 21 and ensuring the stability of the wafer 10's position during movement. Exemplarily, the base 21 can be a mechanical guide rail motion stage, an air-bearing motion stage, or a magnetic levitation motion stage to ensure that the base 21 can drive the wafer 10 to move stably.

[0092] Please see Figure 1 and Figure 4 , Figure 4This illustration shows a top view of a wafer 10 with multiple dicing channels 11 according to an embodiment of this application. The wafer is provided with dicing channels 11, and the wafer movement control system 20 further includes an optical positioning unit 22 (including an image sensor 35). The optical positioning unit 22 can be fixedly installed to ensure the stability of the optical positioning unit 22 structure. The optical positioning unit 22 is used to optically scan multiple overlay patterns 12 to obtain multiple position information corresponding to the multiple overlay patterns 12. As can be seen from the above, the acquisition path of the overlay patterns 12 can extend along the extension direction of the multiple dicing channels 11. Therefore, the optical positioning unit 22 can scan the overlay patterns 12 along the extension direction of the dicing channels 11. The optical positioning unit 22 has a field of view and can acquire the overlay pattern 12 that enters the field of view of the optical positioning unit 22. When the wafer movement control system 20 measures the overlay pattern 12, the base 21 drives the wafer 10 to move under the field of view of the optical positioning unit 22, so that the overlay pattern 12 on the wafer 10 can pass through the field of view of the optical positioning unit 22 in sequence, thus realizing the successful acquisition of all the overlay patterns 12 on the wafer 10.

[0093] Please see Figure 1 and Figure 4 The wafer movement control system 20 also includes a processing unit 24, which can be electrically connected to the optical positioning unit 22. The processing unit 24 is used to determine the scanning mode with the shortest time among the first and second scanning modes based on multiple position information, providing the shortest movement path for the wafer 10 and avoiding excessive wafer 10 movement time that would reduce the efficiency of overlay error measurement. It can be understood that the first scanning mode is along the first extension direction 1111 (e.g., ...). Figure 1 The first scanning mode is a multi-line scanning mode (shown in the X direction), and the second scanning mode is along the second extension direction 1121 (as shown). Figure 1 The optical positioning unit 22 performs a multi-line scanning mode (as shown in the Y direction) so that when the base 21 moves the wafer 10 according to the first scanning mode or the second scanning mode, all the overlay patterns 12 on the wafer 10 can be scanned by the optical positioning unit 22.

[0094] Please see Figure 1 and Figure 4The wafer movement control system 20 also includes a control unit 25 and a multi-axis drive unit 23. It is understood that the multi-axis drive unit 23 corresponds to the drive device mentioned above. The multi-axis drive unit 23 can be electrically connected to the base 21. The multi-axis drive unit 23 is used to drive the base 21 to move along the first extension direction 1111 or the second extension direction 1121, providing the base 21 with a driving force that can move the wafer 10. At the same time, the multi-axis drive unit 23 can also drive the base 21 to accelerate, decelerate or move at a constant speed, so that the moving speed of the base 21 matches the moving path, thereby ensuring the stability of the base 21 and improving the moving efficiency of the base 21. The control unit 25 can be electrically connected to both the processing unit 24 and the base 21. The control unit 25 is used to acquire the scanning mode determined in the processing unit 24 and control the base 21 to move according to the determined scanning mode. This causes the base 21 to move the wafer 10 relative to the optical positioning unit 22 according to the determined scanning mode, thereby enabling all the overlay patterns 12 on the wafer 10 to pass through the field of view of the optical positioning unit 22 in sequence under the determined scanning mode, thus achieving successful acquisition of all the overlay patterns 12 on the wafer 10. It can be understood that the control unit 25 and the multi-axis drive unit 23 can also control the optical positioning unit 22 to move relative to the base 21 so that the optical positioning unit 22 can acquire the overlay patterns 12 on the wafer 10. The optical positioning unit 22 can acquire the overlay pattern 12 on the wafer 10 by means of aerial photography or scanning imaging. For example, the optical positioning unit 22 may include a time delay integration camera, a line scan camera and an area scan camera, so that the optical positioning unit 22 can successfully acquire the moving overlay pattern 12 through the above three cameras, ensuring the clarity of the overlay pattern 12 acquired by the optical positioning unit 22.

[0095] The wafer movement control system provided in this application includes a base 21, an optical positioning unit 22, a multi-axis drive unit 23, a processing unit 24, and a control unit 25. The base 21 supports the wafer 10, and the multi-axis drive unit 23 can drive the base 21 to move stably, thereby driving the wafer 10 to move stably. The wafer 10 has overlay patterns 12, and the overlay patterns 12 are all set on the dicing ridges, avoiding the overlay patterns 12 occupying the functional area of ​​the wafer, and also making the distribution of the marking points on the wafer 10 more regular. The optical positioning unit 22 has a field of view, which can acquire the position information of the overlay patterns 12 entering the field of view and transmit it to the processing unit 24. The processing unit 24 selects the scanning mode with the shortest time according to the position information corresponding to all overlay patterns 12 on the wafer 10, so that the time taken for the base 21 to move according to the scanning mode is the shortest. The control unit 25 controls the movement of the wafer 10 according to the scanning mode with the shortest time, reducing the movement time of the base 21 and improving the measurement efficiency of overlay error.

[0096] For some possible implementations, please refer to Figure 2 and Figure 3 , Figure 2 This paper shows a schematic diagram of the motion control system for the imaging unit 26, which includes a wedge plate 265 and a relay lens group 264, according to an embodiment of this application. Figure 3 A schematic diagram of a motion control system with an imaging unit 26 provided in an embodiment of this application is shown. The wafer motion control system 20 further includes an imaging unit 26, which is used to acquire multiple overlay patterns 12 on the surface of the wafer 10. The base 21 moves relative to the imaging unit 26 so that the multiple overlay patterns 12 on the wafer 10 can pass through the imaging unit 26 in sequence. The imaging unit 26 can also transmit the multiple overlay patterns 12 on the wafer 10 to the optical positioning unit 22, ensuring that the optical positioning unit 22 can acquire the overlay patterns 12 completely, and improving the clarity of the overlay patterns 12 acquired by the optical positioning unit 22.

[0097] Since the optical positioning unit 22 acquires data in two ways, the optical positioning unit 22 needs to be configured with an imaging unit 26 according to these two acquisition methods to ensure that the optical positioning unit 22 can successfully acquire the overlay pattern 12 on the wafer 10. The following will combine... Figures 22 to 23 The embodiment shown provides a detailed explanation of the specific structure of the imaging unit 26.

[0098] In one embodiment, please refer to Figure 2 The imaging unit 26 includes an imaging lens group 266, a wedge plate 265, a relay lens group 264, a second beam splitter 263, a first beam splitter 262, and a moving lens 261. The imaging lens group 266, the wedge plate 265, the relay lens group 264, the second beam splitter 263, the first beam splitter 262, and the moving lens 261 are arranged sequentially from the image side to the object side. The wedge plate 265 is used to separate light signals of different intensities to facilitate subsequent measurement of overlay error. By setting the imaging unit 26, the overlay pattern 12 on the wafer 10 is successfully transmitted to the image sensor 35, thereby enabling the optical positioning unit 22 to acquire a complete and clear overlay pattern 12.

[0099] In one embodiment, please refer to Figure 3The imaging unit 26 includes an imaging lens group 266, a second beam splitter 263, a first beam splitter 262, and a moving lens 261. These components are arranged sequentially from the image side to the object side. The second beam splitter 263 and the first beam splitter 262 are used to change the direction of the light signal and transmit it. The imaging lens group 266 is used to collect the image. By configuring the imaging unit 26, the overlay pattern 12 on the wafer 10 is successfully transmitted to the optical positioning unit 22, thereby enabling the optical positioning unit 22 to acquire a complete and clear overlay pattern 12.

[0100] For some possible implementations, please refer to Figure 2 and Figure 3 The wafer motion control system 20 also includes a focus detection unit 27, and an imaging unit 26 includes a second beam splitter 263 and a moving lens 261. The second beam splitter 263 is located on the image side of the moving lens 261. The moving lens 261 is used to focus the light source and transmit the image acquired by the optical positioning unit 22 to the second beam splitter 263. The second beam splitter 263 is used to direct the overlay pattern 12 acquired by the optical positioning unit 22 along the first optical path 2631 (e.g., ...). Figures 1 to 3 The image is transmitted to the focus detection unit 27 in the X direction (as shown). The second beam splitter 263 and the focus detection unit 27 can be arranged opposite each other, or other image transmission mirrors can be arranged between the second beam splitter 263 and the focus detection unit 27, so that the focus detection unit 27 can detect the overlay pattern 12 acquired by the optical positioning unit 22, and can analyze the focus situation between the optical positioning unit 22 and the base 21 based on the overlay pattern 12. If the optical positioning unit 22 and the base 21 are not in focus, the focus detection unit 27 sends a signal. For example, the second beam splitter 263 can be the first beam splitter 262, so that after the image passes through the first beam splitter 262, it can be transmitted along the first optical path 2631 (as shown). Figures 1 to 3 The image (in the X direction) is transmitted to the focus detection unit 27 and also to the image side of the optical positioning unit 22 relative to the first beam splitter 262, so as to realize the detection of the overlay pattern 12 by the focus detection unit 27 and the acquisition of the overlay pattern 12 by the optical positioning unit 22. The detection method of the focus detection unit 27 can be white light interference, eccentric mask, differential confocal, chopper method or laser triangulation method, so that the focus detection unit 27 can detect the focusing status of the moving lens 261 and the base 21.

[0101] Please see Figure 2 and Figure 3The wafer movement control system 20 also includes a focus control unit 28, which is electrically connected to both the focus detection unit 27 and the moving lens 261. This allows the focus control unit 28 to control the moving lens 261 along the second optical path 2632 (e.g., based on the detection result of the focus detection unit 27) according to the detection result of the focus detection unit 27. Figures 1 to 3 The optical positioning unit 22 and the base 21 move in the Z direction (as shown), thereby keeping the optical positioning unit 22 and the base 21 in focus in real time, which helps improve the clarity of the image acquired by the optical positioning unit 22. When the optical positioning unit 22 and the base 21 are not in focus, the focus detection unit 27 detects the overlay pattern 12 acquired by the optical positioning unit 22 and transmits it to the focus control unit 28. The focus control unit 28 controls the moving lens 261 to move along the second optical path 2632 (as shown in the Z direction). Figure 2 and Figure 3 The moving lens 261 and the base 21 are focused, thereby ensuring improved image sharpness.

[0102] In one embodiment, please refer to Figure 2 and Figure 3 The focusing control unit 28 can be electrically connected to the acquisition control unit 25. The focusing control unit 28 is used to feed back the focusing status of the moving lens 261 and the base 21 to the acquisition control unit 25. When the moving objective lens and the base 21 are in focus, the focusing control unit 28 transmits a signal to the acquisition control unit 25, and the acquisition control unit 25 controls the optical positioning unit 22 to acquire the image of the overprinted pattern 12.

[0103] This application provides a wafer movement control method, which is specifically applied to the wafer movement control system described in the above embodiments. Please refer to [link to relevant documentation]. Figure 4 The dicing track 11 is used to divide the wafer 10. The surface of the wafer 10 has multiple overlay patterns 12, and the multiple overlay patterns 12 are all located on multiple dicing tracks 11, which ensures the setting of overlay patterns 12 on the wafer 10 and avoids the overlay patterns 12 occupying the functional area of ​​the wafer, providing sufficient area for the setting of functional areas on the wafer.

[0104] The positions of multiple overlay patterns 12 can be set according to the position of the dicing track 11 to ensure that all overlay patterns 12 on the wafer 10 are located on the dicing track 11, and at the same time, the image sensor 35 can acquire the overlay patterns 12 on the dicing track 11 when the wafer 10 moves along the dicing track 11 for overlay error measurement.

[0105] Please see Figure 4 The multiple cutting channels 11 include multiple first cutting channels 111 and multiple second cutting channels 112, the first cutting channels 111 being along a first extending direction 1111 (e.g., Figure 4The second cutting channel 112 extends along the second extending direction 1121 (as shown in the X direction). Figure 4 The wafer 10 extends along the Y direction (as shown), allowing it to move along the first extension direction 1111 to obtain the overlay pattern 12 on the first dicing 111, and to move along the second extension direction 1121 to obtain the overlay pattern 12 on the second dicing 112. The first dicing 111 and the second dicing 112 form a grid on the wafer 10, thereby matching the arrangement of the dicing 11 with the layout of the wafer's functional areas.

[0106] Understandably, please refer to Figure 4 The distribution of the overprinted pattern 12 on the cutting channel 11 has the following three cases: (1) the overprinted pattern 12 is only located on the first cutting channel 111 and not on the second cutting channel 112; (2) the overprinted pattern 12 is only located on the second cutting channel 112 and not on the first cutting channel 111; (3) the overprinted pattern 12 is located on both the first cutting channel 111 and the second cutting channel 112. In this case, there are five situations: ① a part of the overprinted pattern 12 is only located on the first cutting channel 111 and a part of the overprinted pattern 12 is located at the intersection of the first cutting channel 111 and the second cutting channel 112; ② a part of the overprinted pattern 12 is located on the second cutting channel 112. Pattern 12 is located only at the second cutting channel 112, and a portion of the overprinted pattern 12 is located at the intersection of the first cutting channel 111 and the second cutting channel 112; ③ All overprinted patterns 12 are located at the intersection of the first cutting channel 111 and the second cutting channel 112; ④ A portion of the overprinted pattern 12 is located only at the first cutting channel 111, and a portion of the overprinted pattern 12 is located only at the second cutting channel 112; ⑤ A portion of the overprinted pattern 12 is located only at the first cutting channel 111, a portion of the overprinted pattern 12 is located only at the second cutting channel 112, and a portion of the overprinted pattern 12 is located at the intersection of the first cutting channel 111 and the second cutting channel 112.

[0107] Please see Figure 5 , Figure 5 The flowchart illustrates a method for controlling the movement of a wafer 10 according to an embodiment of this application. The method for controlling the movement of the wafer 10 includes:

[0108] Step S01: Obtain multiple positional information corresponding to multiple overprinted patterns;

[0109] Step S02: Determine the scanning mode with the shortest time among the first scanning mode and the second scanning mode based on multiple location information, wherein the first scanning mode is a mode of performing multi-line scanning along the first extension direction, and the second scanning mode is a mode of performing multi-line scanning along the second extension direction 1121.

[0110] Step S03: Control the wafer movement according to the determined scanning mode so that the image sensor can acquire image information of each overlay pattern.

[0111] In step S01, the position information corresponding to each overlay pattern 12 on the wafer 10 is first measured to obtain multiple position information corresponding to multiple overlay patterns 12. In some embodiments, scanning electron microscope images can be used to obtain the coordinate values ​​of the overlay patterns 12. For example, the coordinate values ​​of each overlay pattern 12 can be obtained through a single electron microscope image. In other embodiments, the coordinate values ​​of the overlay patterns 12 can be provided by the manufacturing process that forms the overlay patterns 12. It is understood that the position information corresponding to each overlay pattern 12 on the wafer 10 is unique, so that the position of each overlay pattern 12 on the wafer 10 can be accurately obtained, thereby improving the accuracy of the measurement of the overlay patterns 12 on the wafer 10 and helping to improve the accuracy of overlay error measurement.

[0112] Please see Figure 6 and Figure 7 , Figure 6 This is a top view of a wafer 10, where the overlay patterns 12 provided in this embodiment are all located on multiple first dicing tracks 111. Figure 7 This illustration shows a top view of a wafer 10, where the overlay patterns 12 provided in this embodiment are all located on multiple second dicing tracks 112. In step S02, the movement path of the wafer 10 is first planned according to the multiple position information corresponding to the multiple overlay patterns 12 on the wafer 10, so that the scanning mode of the wafer 10 can be set according to the extension direction of the first dicing track 111 and the second dicing track 112, to ensure that the wafer 10 moves along the first extension direction 1111 (e.g., ...). Figure 6 and Figure 7 (as shown in the X direction) or the second extension direction 1121 (e.g.) Figure 6 and Figure 7When moving along the Y direction (as shown), each overlay pattern 12 can be acquired by the image sensor 35. Specifically, the wafer 10 can perform multiple scans along the first extension direction 1111 to form a first scan mode, and the wafer 10 can also perform multiple scans along the second extension direction 1121 to form a second scan mode, thereby ensuring that the wafer 10 has two scan modes, which is beneficial for subsequent selection of the two different scan modes. It can be understood that the first scan mode and the second scan mode have different scan paths. The scan mode of the wafer 10 can be set according to actual needs, so that the wafer 10 has a shorter scan path, which is beneficial for improving the efficiency of the wafer 10 when moving along its scan mode. At the same time, it ensures that all overlay patterns 12 on the wafer 10 are located on the scan path of the first scan mode or the scan path of the second scan mode, thereby ensuring the accuracy of the wafer 10 measurement and improving the accuracy of overlay error measurement. It is understood that the parameters included in each scanning mode include, but are not limited to, the scanning path, the scanning speed, and the scanning direction. All parameters required for the image sensor 35 to acquire the overlaid pattern 12 on the wafer are included in the scope of each scanning mode and are not limited here.

[0113] In one embodiment, please refer to Figure 6 and Figure 7 In step S02, the moving time of wafer 10 is related to the moving speed of wafer 10 and the length of the moving path of wafer 10. When the moving speed of wafer 10 remains constant, the shorter the moving path of wafer 10, the shorter the time taken for wafer 10 to move. In order to improve the measurement accuracy of overlay error, it is necessary to pass through all overlay patterns 12. Therefore, the scanning mode of wafer 10 movement can be determined according to the position of the overlay patterns 12 of the first dicing track 111 and the second dicing track 112 and the extension direction of the first dicing track 111 and the second dicing track 112. This helps to reduce the moving time of wafer 10, thereby ensuring that the moving efficiency of wafer 10 is high when moving according to the scanning mode, and ensuring the accuracy of overlay error measurement.

[0114] In step S02, it is also necessary to calculate the time required for each scanning mode to complete the scanning of all overlay patterns 12, compare the scanning times required for the two scanning modes, and select the scanning mode with the shortest time as the wafer scanning mode. When calculating the time required for each scanning mode to complete the scanning of all overlay patterns 12, factors such as the movement speed of the scanning stage, acceleration / deceleration time, and the time required to switch between different positions need to be considered. It can be understood that the scanning stage is used to support the wafer 10 and move the wafer 10.

[0115] For example, please refer to Figure 6If the multiple overlay patterns 12 on the wafer 10 are located only in the first dicing track 111 but not in the second dicing track 112, it can be understood that in this mode, if the movement path in the first scanning mode coincides with the first dicing track 111, and the movement path in the second scanning mode is parallel to the second dicing track 112 but does not coincide, then the total length of the movement path in the first scanning mode is less than the total length of the movement path in the second scanning mode. The first scanning mode takes the least time, so the first scanning mode can be determined as the scanning mode with the shortest time.

[0116] For example, please refer to Figure 7 If the multiple overlay patterns 12 on the wafer 10 are located only in the second dicing track 112 and not in the first dicing track 111, it can be understood that in this mode, if the moving path of the wafer 10 in the first scanning mode is parallel to the first dicing track 111 and does not coincide, and the moving path of the wafer in the second scanning mode coincides with the second dicing track 112, then the total length of the moving path in the first scanning mode is greater than the total length of the moving path in the second scanning mode. The second scanning mode takes the least time, so the second scanning mode can be determined as the scanning mode with the shortest time.

[0117] For example, please refer to Figure 4 If a portion of the overprinted pattern 12 is located only on the first cutting channel 111, a portion of the overprinted pattern 12 is located only on the second cutting channel 112, and a portion of the overprinted pattern 12 is located at the intersection of the first cutting channel 111 and the second cutting channel 112, it can be understood that in this mode, if the movement path in the first scanning mode coincides with and is parallel to the first cutting channel 111, and the movement path in the second scanning mode coincides with and is parallel to the second cutting channel 112, by comparing the total length of the movement path in the first scanning mode with the total length of the movement path in the second scanning mode, the scanning mode with the shortest time can be obtained.

[0118] In step S03, after determining the scanning mode with the shortest time, the wafer 10 is moved according to the determined scanning mode, which saves the moving time of the wafer 10 and helps to improve the measurement efficiency of overlay error.

[0119] In this embodiment, multiple position information corresponding to multiple overlay patterns 12 is first obtained to ensure that the position of each overlay pattern 12 on the wafer can be accurately obtained. Based on the multiple position information, the scanning mode with the shortest time among the first scanning mode and the second scanning mode is determined. Then, the wafer movement is controlled according to the shortest scanning mode, which helps to reduce the wafer movement time, improve the wafer measurement efficiency, and thus improve the measurement efficiency of overlay error.

[0120] For some possible implementations, please refer to Figure 8 , Figure 8The flowchart illustrates a first method for determining the scanning mode with the shortest scanning time according to an embodiment of this application. Step S02 includes:

[0121] Step S021: Plan a first scanning path based on multiple location information and a first extension direction; plan a second scanning path based on multiple location information and a second extension direction.

[0122] Step S022: Based on the first scan path and the second scan path, determine the scan mode with the shortest time among the first scan mode and the second scan mode.

[0123] Please see Figure 6 and Figure 8 In step S021, the coordinate data (X, Y) of all overlay patterns 12 on the wafer are obtained based on multiple positional information of the overlay pattern 12, and the first extension direction 1111 is marked (e.g., Figure 6 The X direction shown) and the perpendicular direction of the first extension direction 1111 (as shown) Figure 6 (As shown in the Y direction), the overlay patterns 12 with the same Y-axis coordinates are grouped together, and the coverage area of ​​each group of overlay patterns 12 in the X-axis direction is calculated (i.e., the maximum value and minimum value of the X-coordinate of the overlay pattern 12). The line connecting the maximum value and the minimum value of the X-coordinate of each group of overlay patterns 12 is taken as the first path segment, and the first path segments are connected to form the first scanning path.

[0124] For example, please refer to Figure 6 Assuming the first extension direction 1111 is the X direction and the perpendicular direction of the first extension direction 1111 is the Y direction, the coordinates of each overlaid pattern 12 are C1, C2, C3, C4, C5, and C6, respectively. Specifically, C1, C2, C3, C4, C5, and C6 can be (1, 2), (1, 3), (2, 4), (2, 3), (4, 2), and (4, 4). Grouping the overlaid patterns 12 with the same Y-axis coordinates into a group results in (1, 2) and (4, 2) being the first overlaid pattern 12. Group 1 consists of (1,3) and (2,3), Group 2 consists of (2,4) and (4,4) consists of (4,4). The maximum X-coordinate value of Group 1 is 4 and the minimum X-coordinate value is 1. The maximum X-coordinate value of Group 2 is 2 and the minimum X-coordinate value is 1. The maximum X-coordinate value of Group 3 is 4 and the minimum X-coordinate value is 2. Therefore, the first scan path includes path segments with Y-coordinates of 2 and X-coordinates between 1 and 4, path segments with Y-coordinates of 3 and X-coordinates between 1 and 2, and path segments with Y-coordinates of 4 and X-coordinates between 2 and 4. The connection between these processed and unprocessed path segments is used as the first scan path.

[0125] Please see Figure 7 and Figure 8In step S021, the coordinate data (X, Y) of all overlay patterns 12 on the wafer are obtained based on multiple positional information of the overlay pattern 12, and the second extension direction 1121 is marked (e.g., Figure 7 The Y-direction shown) and the perpendicular direction of the second extension direction 1121 (as shown) Figure 7 (As shown in the X direction), the overlay patterns 12 with the same X-axis coordinates are grouped together, and the coverage area of ​​each group of overlay patterns 12 in the Y-axis direction is calculated (i.e., the maximum value of the Y coordinate of the overlay pattern 12 and the minimum value of the X coordinate of the overlay pattern 12). The line connecting the maximum value of the Y coordinate of each group of overlay patterns 12 and the minimum value of the Y coordinate of the overlay pattern 12 is used as the second scanning path.

[0126] For example, please refer to Figure 7 Assuming the second extension direction 1121 is the Y direction and its perpendicular direction is the X direction, the coordinates of each overlaid pattern 12 are C1, C2, C3, C4, C5, and C6, respectively. Specifically, C1, C2, C3, C4, C5, and C6 can be (1, 2), (1, 3), (2, 4), (2, 3), (4, 2), and (4, 4). Grouping overlaid patterns 12 with the same X-axis coordinates into a group results in (1, 2) and (1, 3) being the... Group 1 consists of (2, 4) and (2, 3) as the second group, and (4, 2) and (4, 4) as the third group. The maximum Y-coordinate value of the first group is 3, and the minimum is 2. The maximum Y-coordinate value of the second group is 4, and the minimum is 3. The maximum Y-coordinate value of the third group is 4, and the minimum is 2. Therefore, the third scan path includes path segments with X-coordinates all at 1 and Y-coordinates between 2 and 3, path segments with X-coordinates all at 2 and Y-coordinates between 3 and 4, and path segments with X-coordinates all at 4 and Y-coordinates between 2 and 4. The connection between each path segment, whether processed or not, is used as the second scan path.

[0127] The parameters included in the first scan path are the number of rows, length, number of turns, and moving speed. Based on these parameters, the time taken for the wafer to move along the first scan path and the second scan path is calculated respectively. Therefore, the scan mode with the shortest time among the first and second scan modes is determined based on the time taken.

[0128] In this embodiment, a scanning pattern is generated based on multiple location information and different extension directions (such as the first / second extension direction), which can dynamically adapt to the distribution characteristics of the wafer surface pattern, reduce invalid movement paths, and determine the scanning pattern with the shortest time among the two scanning patterns by comparing the two scanning paths, thereby reducing the idle travel and repeated positioning time during the wafer movement process and avoiding the efficiency loss caused by fixed paths in traditional static planning.

[0129] For some possible implementations, please refer to Figure 9, Figure 9 A flowchart of a second method for determining the scanning mode with the shortest scanning time, provided in an embodiment of this application, is shown. Step S022 includes:

[0130] Step S0221: Determine the first scan time according to the first scan path, and determine the second scan time according to the second scan path;

[0131] Step S0222: Compare the first scan time and the second scan time to determine the scan mode corresponding to the smaller of the first scan time and the second scan time.

[0132] In step S0221, the first scan time required for the wafer to move along the first scan path and the second scan time required for the wafer to move along the second scan path can be obtained using the following formulas:

[0133]

[0134] Where n is the number of rows in the first scan path or the number of rows in the second scan path, L i Let v be the path segment scanned at a constant speed in each row, and t be the scanning speed. 加速 For the acceleration time of each row, t 减速 For the deceleration time of each row, t 行间移动 Let i be the line switching time. i = 1, 2, 3, ..., n.

[0135] In step S0222, after obtaining the first scan time and the second scan time, the scan times of the first scan mode and the second scan mode are compared, and the scan mode corresponding to the shortest scan time is determined as the scan mode of wafer 10. For example, if the first scan time is 5s and the second scan time is 7s, the first scan mode corresponding to the first scan time is determined as the scan mode of wafer 10. 加速 t 减速 and t 行间移动 All of these can be set to fixed values, meaning that the acceleration path segments for each row are the same, the deceleration path segments for each row are the same, and the path segments between rows are the same. Of course, t 加速 t 减速 and t 行间移动 Different lines may have different rules; no restrictions are set here.

[0136] In this embodiment, a scanning pattern is generated based on multiple location information and different extension directions (such as the first extension direction 1111 / the second extension direction 1121), which can dynamically adapt to the distribution characteristics of the wafer surface pattern, reduce invalid movement paths, and quickly select the optimal scanning path by comparing the time difference between the two scanning patterns, thus avoiding the efficiency loss caused by the fixed path in traditional static planning.

[0137] For some possible implementations, please refer to Figure 10 , Figure 10 A flowchart of a third method for determining the scanning mode with the shortest scanning time provided in an embodiment of this application is shown. Step S022 includes:

[0138] Step S0223: Based on the first scan path, determine the number of rows, and / or length, and / or number of turns of the first scan path; and based on the second scan path, determine the number of rows, and / or length, and / or number of turns of the second scan path;

[0139] Step S0224: Compare the number of rows, and / or length, and / or number of turns of the first scan path with the number of rows, and / or length, and / or number of turns of the second scan path to determine the scan mode with the shortest time among the first scan mode and the second scan mode.

[0140] In some embodiments, if the time taken for the wafer to move along the first scan path and the second scan path is calculated based on the number of rows in the first scan path and the number of rows in the second scan path, let the number of rows in the first scan path be N1 and the number of rows in the second scan path be N2. If the length of each row in the first scan path and the second scan path is L and the wafer's moving speed is V, then the total time taken for the first scan path is (L×N1) / V, and the total time taken for the second scan path is (L×N2) / V. If the total time taken for the first scan mode is less than the total time taken for the second scan mode, then the first scan mode is selected. If the difference is within a threshold (e.g., ±5%), then a path with higher fault tolerance (e.g., fewer turns and shorter length) is preferred. If the total time taken for the first scan mode is greater than the total time taken for the second scan mode, then the second scan mode is selected. By adopting a dynamic decision-making mechanism that prioritizes quantization efficiency based on row number, the system solves the problem of insufficient stability caused by single parameter optimization in traditional wafer movement control. At the same time, it takes into account the compatibility of multiple devices and the requirements of complex processes, significantly improving the efficiency and reliability of wafer scanning in semiconductor processes.

[0141] In some embodiments, if the time taken for the wafer to move along the first scan path and the second scan path is calculated based on the total length of the first scan path and the second scan path, and the total length of the first scan path is L1, the total length of the second scan path is L2, and the wafer's moving speed is V, then the total time taken for the first scan path = L1 / V, and the total time taken for the second scan path = L2 / V. If the total time taken for the first scan mode is less than the total time taken for the second scan mode, then the first scan mode is selected. If the difference is within a threshold, then a path with higher fault tolerance (such as fewer turns or fewer rows) is preferred. If the total time taken for the first scan mode is greater than the total time taken for the second scan mode, then the second scan mode is selected. This technical solution solves the problem of balancing efficiency and stability in traditional scan mode selection through a path length-driven efficiency optimization decision mechanism. It also supports multi-device parameter adaptation and process requirement expansion, significantly improving the accuracy, efficiency, and anti-interference capability of wafer scanning in semiconductor processes.

[0142] In some embodiments, if the time spent moving the wafer along the first scan path and along the second scan path is calculated based on the number of turns in the first scan path and the second scan path, let the number of turns in the first scan path be S1 and the number of turns in the second scan path be S2. If the time for a single turn is TS, then the total turn time of the first scan path = S1 * TS, and the total turn time of the second scan path = S2 * TS. If the total turn time of the first scan mode is less than the total turn time of the second scan mode, then the first scan mode is selected. If the difference is within a threshold, then a path with higher fault tolerance (such as shorter length and fewer rows) is preferentially selected. If the total turn time of the first scan mode is greater than the total turn time of the second scan mode, then the second scan mode is selected. This scheme solves the problem of difficulty in balancing efficiency and stability in traditional path selection through an efficiency optimization mechanism driven by the number of turns. It also adapts to various types of hardware devices and complex process requirements, significantly improving the accuracy, anti-interference capability, and equipment lifespan of the wafer scanning process.

[0143] It is understood that, based on the above embodiments, at least two of the number of rows, length, and number of turns of the first scan path can be combined to calculate the time consumption of the first scan path and the second scan path, which is not limited here.

[0144] In this embodiment, by extracting the number of rows, and / or length, and / or number of turns of the first and second scanning paths (e.g., the number of rows reflects the number of steps of the driving device, and / or the length corresponds to the moving distance, and / or the number of turns is related to the response time of the servo motor), a multi-dimensional efficiency evaluation model is constructed to dynamically calculate the total time consumption of the two scanning modes, thus avoiding redundant movement caused by traditional fixed path planning.

[0145] In one embodiment, please refer to Figure 11 , Figure 11 The flowchart illustrates a method for planning a scanning path according to an embodiment of this application. Step S021 may include:

[0146] Step S0211: Based on multiple location information and the first extension direction, obtain multiple first path segments passing through the overprinted pattern, and perform extension processing on each first path segment;

[0147] Step S0212: Based on the extended first path segments, plan the first scan path:

[0148] Step S0213: Based on multiple location information and the second extension direction, obtain multiple second path segments passing through the overprinted pattern, and perform extension processing on each first path segment;

[0149] Step S0214: Plan the second scanning path based on the extended second path segments.

[0150] In step S0211, the acquisition of multiple first path segments passing through the overprinted pattern 12 has been described in detail in step S021 and will not be repeated here. The method for extending each first path segment can be as follows: the path segment formed by extending a preset distance from one endpoint of each first path segment in a first direction (one of the first extension directions 1111) is taken as the first acceleration path segment of each row; the path segment formed by extending a preset distance from the other endpoint of each first path segment in a second direction (the other of the first extension directions 1111) is taken as the first deceleration path segment. The lengths of the first acceleration path segment and the first deceleration path segment can be the same or different, and are not limited here.

[0151] Similarly, in step S0214, the acquisition of multiple second path segments passing through the overprinted pattern 12 has been described in detail in step S021 and will not be repeated here. The method for extending each second path segment can be as follows: the path segment formed by extending a preset distance from one endpoint of each second path segment in a third direction (one of the directions in the second extension direction 1121) is used as the second acceleration path segment for each row; the path segment formed by extending a preset distance from the other endpoint of each second path segment in a fourth direction (another direction in the second extension direction 1121) is used as the second deceleration path segment. The lengths of the second acceleration path segment and the second deceleration path segment can be the same or different, and are not limited here.

[0152] For example, please see Figure 12 , Figure 12This diagram shows a top view of a wafer with three dicing channels according to an embodiment of this application. Overlay patterns 12 exist in three rows of first path segments extending along a first direction or second path segments extending along a second direction, labeled L1, L2, and L3, respectively. For the first row L1, the first scan row A1-L1-D1 is formed by extending 10 mm to the left from the left endpoint of L1, with the endpoint labeled A1, and extending 10 mm to the right from the right endpoint of L1, with the endpoint labeled D1. For the second row L2, the second scan row A2-L2-D2 is formed by extending 10 mm to the left from the left endpoint of L2, with the endpoint labeled A2, and extending 10 mm to the right from the right endpoint of L2, with the endpoint labeled D2. For the third row L3, the third scan row A3-L3-D3 is formed by extending 10 mm to the left from the left endpoint of L3, with the endpoint labeled A3, and extending 10 mm to the right from the right endpoint of L3, with the endpoint labeled D3.

[0153] In step S0212, please refer to Figure 12 It is also necessary to determine the first movement direction 1113 of each extended first path segment, the first movement direction 1113 (e.g. Figure 12 The arrows (indicated by the direction of the movement) indicate the direction in which the wafer moves along the defined scanning mode. The wafer's movement path is planned based on the first movement direction 1113 and the extended first path segments to enable the wafer to move within the defined scanning mode. In some embodiments, the wafer moves in opposite directions in adjacent extended first path segments, connecting the extended first path segments end-to-end to form a bow-shaped first scanning path. Similarly, the first scanning path segment can also be S-shaped, V-shaped, or U-shaped; no limitation is made here.

[0154] In steps S0212 and S0214, it is also necessary to determine the second movement direction of each extended second path segment, and plan the movement path based on the second movement direction and the extended second path segments. In some embodiments, the movement directions of adjacent extended second path segments are opposite, and the extended second path segments are connected end to end to form a bow-shaped second scanning path. Similarly, the second scanning path segment can also be S-shaped, V-shaped, or U-shaped, and is not limited here.

[0155] For example, please see Figure 12 If A1 is taken as the starting point of the path movement, and D1 and D2 are connected to form the first turning path 1112, and then A2 and A3 are connected to form the second turning path 1122, a complete bow-shaped scanning path is finally generated.

[0156] In the embodiments of this application, by extending each path segment, acceleration and deceleration paths are provided for the drive device that controls wafer movement, ensuring that the drive device can smoothly accelerate and decelerate at the beginning and end of each scan line, reducing mechanical vibration and errors, and improving the stability of wafer movement.

[0157] In some possible implementations, please refer to Figure 13 , Figure 13 which shows a flowchart of the fourth method for determining the scanning mode with the shortest time provided by the embodiments of the present application, and step S02 includes:

[0158] Step S0225: Determine the first density of the overlay patterns distributed along the first extension direction according to the plurality of position information and the first extension direction, and determine the second density of the overlay patterns distributed along the second extension direction according to the plurality of position information and the second extension direction;

[0159] Step S0226: Determine the scanning mode with the shortest time among the first scanning mode and the second scanning mode according to the first density and the second density.

[0160] In step S0225, a plurality of position information and the first extension direction 1111 are first acquired. The target area is divided into several sub-areas of equal width (such as strips with a width of W) along the first extension direction 1111. The number of overlay patterns 12 in each sub-area is counted (for example, the belonging area is judged by the coordinates of the center point of the pattern). The density of the overlay patterns 12 in each sub-area is equal to the number of overlay patterns 12 in each sub-area divided by the width of each sub-area. The average value or weighted average value (for example, weighted according to the area of the sub-areas) of the densities of all sub-areas is taken to obtain the first density. Similarly, if the second extension direction 1121 is involved, the target area can also be divided and calculated along the second extension direction 1121 in the above manner to obtain the second density. It can be understood that the formula for calculating the second density is similar to that for the first density, and details are not described herein again.

[0161] In step S0226, the proportionality coefficient k needs to be calibrated in advance, for example, the scanning time under unit density is measured through experiments. Assuming that the scanning time is proportional to the density, the first scanning time can be obtained: T3 == k × first density, and the second scanning time: T4 == k × second density; the values of T3 and T4 are directly compared. If T3 < T4, the first scanning mode is better; otherwise, the second scanning mode is selected.

[0162] In the embodiments of the present application, through differentiated calculation of the first density of the overlay patterns 12 along the first extension direction 1111 and the second density thereof along the second extension direction 1121, and adoption of a region division and statistical averaging mechanism, the precise quantification of spatial distribution features is realized, local noise interference is effectively avoided, and the accuracy of density calculation is significantly improved.

[0163] In some possible implementations, please refer to Figure 14 , Figure 14A flowchart of a wafer 10 movement control method provided in this application for determining whether the preset scanning direction of the wafer 10 is the direction of the scanning mode is shown. When the wafer 10 moves according to the determined scanning mode, the preset scanning direction of the wafer 10 may deviate from the scanning direction of the determined scanning mode. Since the overlay pattern 12 on the wafer 10 is small and the field of view of the image sensor 35 is limited, this deviation can easily cause some overlay patterns 12 to be unable to be acquired by the image sensor 35, thereby affecting the accuracy of overlay error measurement. Therefore, the scanning direction of the wafer 10 can be controlled before the wafer 10 moves according to the determined scanning mode to ensure that the scanning direction of the wafer 10 is consistent with the scanning direction of the determined scanning mode, thereby ensuring that the wafer 10 can move according to the determined scanning mode. Therefore, before step S03, the method further includes:

[0164] Step S04: Determine whether the preset movement direction of the wafer is the scanning direction of the scanning mode;

[0165] Step S05: If the preset movement direction of the wafer is not the scanning direction of the scanning mode, control the wafer to rotate so that the preset movement direction of the wafer is the scanning direction of the scanning mode.

[0166] In step S04, the preset scanning direction can be obtained by controlling the wafer to move a preset distance (such as the diameter of the wafer). For example, the preset distance the wafer moves can be controlled to be the diameter of the wafer, and the scanning direction of the wafer can be preset by the diameter of the wafer.

[0167] In steps S04 and S05, the movement of wafer 10 can be simulated first, and then the preset scanning direction of wafer 10 can be obtained, that is, the direction preset before the wafer moves. Then it is determined whether the preset scanning direction of wafer 10 is the scanning direction of the scanning mode. If the preset scanning direction of wafer 10 is the same as the scanning direction of the scanning mode, wafer 10 can move along that direction. If the preset scanning direction of wafer 10 is different from the scanning direction of the scanning mode, wafer 10 needs to be controlled to move to the scanning direction of the scanning mode to ensure that the moving direction of the wafer is consistent with the moving direction corresponding to the scanning mode, so that the field of view of image sensor 35 can cover all the overlay patterns 12 on the wafer, reduce the measurement error introduced by the direction deviation, and improve the accuracy and reliability of overlay error measurement.

[0168] For some possible implementations, please refer to Figure 15 , Figure 15The flowchart illustrates a method for controlling the movement of wafer 10 according to an embodiment of this application, which determines whether the starting point of the movement of wafer 10 is located at the starting point of the scanning mode. To ensure that all overlay patterns 12 can be scanned under the determined scanning mode, the actual position of wafer 10 needs to be controlled before controlling the movement of wafer 10 according to the determined scanning mode, so that the starting point of the movement of wafer 10 is located at the starting point of the scanning mode. Therefore, before step S03, the method further includes:

[0169] Step S06: Determine whether the wafer's movement start point is at the scan start point of the scan mode.

[0170] Step S07: If the wafer's movement starting point is not at the scanning starting point of the scanning mode, control the wafer to move so that the wafer's movement starting point coincides with the scanning starting point of the scanning mode.

[0171] In steps S06 and S07, the starting point of the movement of wafer 10 can be obtained first, and then it can be determined whether the starting point of the movement of wafer 10 is at the starting point of the scanning mode. If wafer 10 is at the starting point of the scanning mode, wafer 10 can move according to the scanning mode. If wafer 10 is not at the starting point of the scanning mode, it is also necessary to determine the distance between the starting point of the scanning mode and the starting point of the movement of wafer 10, as well as the specific direction in which the starting point of the scanning mode is located on wafer 10. Then, the starting point of the movement of wafer 10 is controlled to move along that direction to the starting point of the scanning mode, ensuring that the scanning start position is consistent with the scanning start point of the scanning mode, so that wafer 10 can move strictly according to the movement path corresponding to the scanning mode, avoiding the inability to acquire some patterns due to the deviation of the starting position, reducing the measurement error introduced by the position deviation, and improving the accuracy and reliability of overlay error measurement.

[0172] In this embodiment, by precisely controlling the starting point of wafer movement, the scanning start position is ensured to be consistent with the scanning start point of the scanning mode, avoiding the inability to acquire some overlay patterns due to starting position deviation, reducing measurement errors introduced by position deviation, and improving the accuracy and reliability of overlay error measurement.

[0173] For some possible implementations, please refer to Figure 16 , Figure 16 The flowchart illustrates a method for controlling the movement of a wafer 10 according to an embodiment of this application, which determines whether the starting point of movement of the wafer 10 is located at the center of the field of view of the image sensor 35. The image sensor 35 can acquire the overlay pattern 12 located at the center of the field of view. To ensure that all overlay patterns 12 in the determined scanning mode can pass through the center of the field of view of the image sensor 35 during the movement of the wafer 10, the method further includes the following steps after step S07:

[0174] Step S071: Determine whether the starting point of the wafer's movement is located at the center of the image sensor's field of view;

[0175] Step S072: If the starting point of the wafer's movement is not located at the center of the image sensor's field of view, control the wafer and / or the image sensor to move so that the starting point of the wafer's movement is located at the center of the image sensor's field of view.

[0176] In step S071, the position information of the wafer's starting point of movement is acquired in real time by the image sensor 35 and compared with the position of the center of the field of view of the image sensor 35. If the two positions are consistent, it is determined that the wafer's starting point of movement is located at the center of the field of view and no adjustment is required; if they are inconsistent, the process proceeds to step S072 for adjustment.

[0177] In step S072, if the wafer movement starting point deviates from the center of the field of view, the wafer is moved by the driving device to align its movement starting point with the center of the field of view. It can be understood that if the position of the image sensor 35 is adjustable, the image sensor 35 is moved by the driving device to align its field of view with the wafer movement starting point. After adjustment, the image sensor 35 is used again to verify whether the wafer movement starting point is located at the center of the field of view, ensuring accurate adjustment.

[0178] In this embodiment, by precisely controlling the alignment of the wafer movement starting point with the center of the field of view of the image sensor 35, it is ensured that all overlay patterns 12 can be completely acquired by the image sensor 35, avoiding the inability to detect some patterns due to positional deviation, reducing the measurement error introduced by positional deviation, and improving the accuracy and reliability of overlay error measurement.

[0179] To improve the movement efficiency of wafer 10, the movement speed of wafer 10 needs to be controlled. For some possible implementations, please refer to... Figure 17 , Figure 17 A flowchart of a wafer 10 movement control method for controlling the movement speed of wafer 10 according to an embodiment of this application is shown. Step S03 further includes:

[0180] Step S031: According to the determined scanning mode, in the path segment where the image sensor can capture the wafer image, control the wafer to move at a constant speed; in the path segment where the image sensor cannot capture the wafer image, control the wafer to move at a variable speed, so that the image sensor can acquire image information of each overlay pattern.

[0181] In step S031, the relative positions of the wafer 10 and the field of view of the image sensor 35 are first obtained. Then, it is determined whether the image sensor 35 can capture the wafer 10. It can be understood that the image sensor 35 can capture images within its field of view; that is, if the wafer 10 is within the field of view of the image sensor 35, then the image sensor 35 can capture the wafer 10. If the wafer 10 is not within the field of view of the image sensor 35, then the image sensor 35 cannot capture the wafer 10. When the wafer 10 moves into the field of view of the image sensor 35, it is necessary to control the wafer 10 to move at a constant speed along that path segment to ensure that the image sensor 35... 5. The stability of wafer 10 is obtained, which avoids the blurring of the image acquired by image sensor 35 due to the unstable moving speed of wafer 10, and helps to improve the clarity of the image acquired by image sensor 35. When wafer 10 moves to a position that is not within the field of view of image sensor 35, image sensor 35 cannot capture wafer 10 on that path segment. That is, it is not necessary to ensure the stability of wafer 10 relative to image sensor 35. Therefore, wafer 10 can be controlled to accelerate or decelerate on that path segment so that the moving speed of wafer 10 can adapt to that path segment. This helps to reduce the moving time of wafer 10 and thus ensure the moving efficiency of wafer 10.

[0182] For example, please refer to Figure 18 , Figure 18 The diagram shows a top view of a wafer with a dicing track 11 provided in an embodiment of this application. If P1 is a path segment on the wafer and B1 and B2 are path segments outside the wafer, and B1 is taken as the starting path segment, then the wafer 10 is controlled to accelerate in the B1 path segment, the wafer 10 is controlled to move at a constant speed in the P1 path segment, and the wafer 10 is controlled to decelerate in the B2 path segment.

[0183] It is understandable that when the wafer 10 moves to a path segment where the image sensor 35 cannot acquire an image of the wafer 10, since the image sensor 35 does not need to acquire an image of the wafer 10, the wafer 10 can accelerate or decelerate according to the actual situation to ensure the moving efficiency of the wafer 10, which is conducive to reducing the moving time of the wafer 10, and thus conducive to improving the measurement efficiency of overlay error.

[0184] During the process of controlling the uniform movement of wafer 10, it is necessary to acquire images of the overlay pattern 12 on wafer 10 for subsequent calculation of overlay error. In one embodiment, please refer to... Figure 19 , Figure 19 A flowchart of a method for controlling the movement of a wafer 10 that controls the image sensor 35 to acquire images, according to an embodiment of this application, is shown. Step S031 further includes:

[0185] Step S0311: Determine whether the wafer has moved to a position where the image sensor can capture the overlay pattern;

[0186] Step S0312: If the wafer moves to a position where the image sensor can capture the overlay pattern, control the image sensor to acquire an image.

[0187] In steps S0311 and S0312, during the process of controlling the wafer 10 to move at a constant speed, the driving device provides real-time feedback on the moving position of the wafer 10 and compares it with the preset capture position of the overlay pattern 12. If the position of the wafer 10 matches the preset position, it is determined that it has moved to a position where the image sensor 35 can capture the overlay pattern 12; otherwise, the wafer 10 is controlled to continue moving. After confirming that the wafer 10 has moved to a position where the image sensor 35 can capture the overlay pattern 12, the acquisition function of the image sensor 35 is activated. The image sensor 35 is controlled to perform high-resolution image acquisition of the overlay pattern 12 on the wafer 10 to ensure the integrity and clarity of the pattern. After acquisition, the image is initially verified to ensure that the overlay pattern 12 is completely captured, and the image data is stored in a designated location for subsequent analysis.

[0188] In this embodiment, when the overprinted pattern 12 does not appear in the field of view of the image sensor 35, the image sensor 35 will not acquire an image at that location. Only when the overprinted pattern 12 appears in the field of view of the image sensor 35 will the image at that location be acquired. Since real-time image acquisition is not required, and since the image sensor 35 only acquires images when the overprinted pattern 12 appears in the field of view, the real-time acquisition and processing of meaningless images are avoided, significantly reducing the amount of data and lowering the burden of data processing and storage.

[0189] During the image acquisition process of the image sensor 35 on the overprinted pattern 12, the image sensor 35 may acquire some useless images. In order to ensure that the stored images are all valid images with the overprinted pattern 12, in one embodiment, please refer to Figure 20 , Figure 20 A flowchart of a wafer 10 movement control method for determining whether an image meets preset conditions, provided in an embodiment of this application, is shown. After step S0312, the method further includes:

[0190] Step S03121: Determine whether the image meets the preset conditions.

[0191] Step S03122: If the image does not meet the preset conditions, the image is discarded so that it is not used for measuring overlay error.

[0192] In steps S03121 and S03122, preset conditions are obtained in advance, and then each image acquired by the image sensor 35 is judged to see if it meets the preset conditions. If the image meets the preset conditions, the image is stored for subsequent calculation of overlay error. If the image does not meet the preset conditions, the image is discarded to ensure that the images used for overlay error measurement are all high-quality and valid data, thereby significantly improving the accuracy of the measurement results.

[0193] This application also provides a wafer movement control device 30, please refer to [link to relevant documentation]. Figure 1 and Figure 21 , Figure 21 A schematic diagram of a wafer movement control device 30 provided in an embodiment of this application is shown. It can be understood that the wafer movement control device 30 is used to implement the wafer 10 movement control method in the above embodiment. The wafer movement control device 30 is used to measure the overlay error of the wafer 10 in the above embodiment. The surface of the wafer 10 has multiple dicing channels 11, and the multiple dicing channels 11 include multiple first dicing channels 111 and multiple second dicing channels 112. The first dicing channels 111 extend along a first extension direction 1111, and the second dicing channels 112 extend along a second extension direction 1121, so that the wafer 10 can move along different extension directions. Part or all of the overlay patterns 12 on the wafer 10 are located on the first dicing channel 111, and part or all of the overlay patterns 12 on the wafer 10 are located on the second dicing channels 112, so that the scanning mode of the wafer 10 can be set according to the extension directions of the first dicing channels 111 and the second dicing channels 112.

[0194] Please see Figure 1 and Figure 4 The dicing 11 on the wafer 10 typically extends in a straight line to simplify the setting of the dicing 11 and the subsequent processing of the wafer 10. Since the overlay patterns 12 are all set on the dicing 11, the overlay patterns 12 can be acquired along the extension direction of the dicing 11 to ensure that all overlay patterns 12 on the wafer 10 are fully acquired and to simplify the acquisition path of the overlay patterns 12, thus avoiding the increase in overlay error measurement time caused by an overly complex acquisition path.

[0195] Please see Figure 21The wafer movement control device 30 includes an acquisition module 32 and a processing module 31. The acquisition module 32 is used to acquire the position information corresponding to the overlay pattern 12. As mentioned above, the overlay pattern 12 is set on the dicing track 11. Therefore, the acquisition module 32 can acquire the position information corresponding to the overlay pattern 12 along the extension direction of the dicing track 11. The processing module 31 is used to receive multiple position information acquired by the acquisition module 32 and determine the scanning mode with the shortest time in the first scanning mode and the second scanning mode according to the extension direction of the dicing track 11. This helps to reduce the movement time of the wafer 10 and thus improve the movement efficiency of the wafer 10.

[0196] Specifically, the acquisition module 32 can acquire all the overlay patterns 12 of the first dicing channel 111 and all the overlay patterns 12 of the second dicing channel 112. The acquisition module 32 determines a first scanning mode based on the position of the overlay patterns 12 of the first dicing channel 111 and the extension direction of the first dicing channel 111, and determines a second scanning mode based on the position of the overlay patterns 12 of the second dicing channel 112 and the extension direction of the second dicing channel 112. Then, the processing module 31 compares the first scanning mode and the second scanning mode based on the number of overlay patterns 12 of the two types of dicing channels 11 and the total length of the two types of dicing channels 11, and selects the scanning mode with more overlay patterns 12 and shorter total length of dicing channels 11 as the determined scanning mode. This allows the wafer 10 to move according to its scanning mode, thereby shortening the movement time of the wafer 10 and ensuring the measurement accuracy of the wafer 10, thus improving the measurement efficiency of overlay error.

[0197] Please see Figure 21 The wafer movement control device 30 also includes a control module 33, which controls the movement of the wafer 10 according to the scan mode with the shortest time determined above, thereby shortening the movement time of the wafer 10, improving the measurement efficiency of the wafer 10, and ensuring the measurement efficiency of overlay error. For example, the control module 33 can determine the scan mode with the shortest time by being electrically connected to the processing module 31.

[0198] The wafer movement control device provided in this application includes an acquisition module, a processing module, and a control module. The acquisition module is used to acquire multiple position information corresponding to multiple overlay patterns and plan a first scanning mode and a second scanning mode, so that the wafer has two movement modes to choose from. The processing module is used to determine the scanning mode with the shortest time among the first scanning mode and the second scanning mode based on the multiple position information, thereby determining the scanning mode for wafer movement to ensure wafer movement efficiency. The control module is used to control wafer movement according to the determined scanning mode, reducing wafer movement time, improving wafer movement efficiency, and thus ensuring the measurement efficiency of overlay error.

[0199] In one embodiment, please refer to Figure 21 The processing module 31 can be electrically connected to the acquisition module 32. The acquisition module 32 is used to plan a first scanning path based on the first extension direction 1111 of the first dicing track 111 on the wafer 10 and the position information of multiple overlay patterns 12, and to plan a second scanning path based on the second extension direction 1121 of the second dicing track 112 on the wafer and the position information of multiple overlay patterns 12, so as to ensure that each overlay pattern 12 can be acquired by the image sensor 35 when the wafer moves along the first extension direction 1111 or the second extension direction 1121, thereby ensuring the accuracy of overlay error measurement. At the same time, the acquisition module 32 can also acquire the scanning time of the first scanning path and the scanning time of the second scanning path. The processing module 31 can receive the scanning times of the two scanning paths acquired by the acquisition module 32, and select the scanning time with the shortest time between the first scanning path and the second scanning path as the scanning mode for the movement of the wafer 10, so that when the wafer 10 moves according to the scanning mode, the movement time of the wafer 10 is reduced, thereby ensuring the measurement efficiency of overlay error. It is understandable that the distribution of the overlay pattern 12 can be set according to actual needs, thereby avoiding invalid movement paths and affecting the wafer movement efficiency.

[0200] To improve the stability of wafer movement, some possible implementation methods are described in the following references. Figure 1 and Figure 22 , Figure 22 This illustration shows a system schematic of a wafer movement control device 30 with a path planning module 34 provided in an embodiment of this application. The acquisition module 32 is used to obtain information based on multiple positional information and a first extension direction 1111 (e.g., ...). Figure 1 (As shown in the X direction), the image sensor 35 acquires multiple first path segments passing through the overlay pattern 12 and their extended paths, enabling the wafer to accelerate or decelerate along the extended path segments. This buffers the wafer's movement along the multiple first path segments, ensuring stability during movement and preventing the image sensor 35 from missing overlay patterns 12 due to wafer instability. The wafer movement control device 30 also includes a path planning module 34. The acquisition module 32 can be electrically connected to the path planning module 34. The path planning module 34 plans the multiple first path segments and their extended paths to connect them end-to-end, forming a complete movement path. This ensures the wafer 10's movement adapts to the path, guaranteeing smooth wafer movement and efficiency, which is beneficial for measuring overlay errors.

[0201] Similarly, the acquisition module 32 can also acquire information based on multiple location parameters and the second extension direction 1121 (e.g., ...). Figure 1(As shown in the Y direction), multiple second path segments and their extended paths passing through the overlay pattern 12 are obtained to ensure that the wafer can accelerate or decelerate on the extended path, thereby improving the stability of the wafer on the second path segment. The path planning module 34 receives information on multiple second path segments and their extended paths, and plans the movement path of the wafer 10 according to the multiple second path segments and their extended paths, so that the movement of the wafer 10 can adapt to the movement path, thereby ensuring the smoothness of the wafer movement, thereby ensuring the wafer movement efficiency, which is beneficial to ensuring the measurement efficiency of overlay error.

[0202] In one embodiment, since the overlay patterns 12 on the wafer 10 are all located on multiple first path segments, and no overlay patterns 12 are set between one first path segment and another, the wafer 10 moves slowly when it moves on multiple first path segments to ensure that the image sensor 35 can accurately capture all the overlay patterns 12 on the multiple path segments. When the wafer 10 moves from one first path segment to another, the wafer 10 needs a certain distance of extension path to accelerate, so that the wafer 10 can quickly pass through the area where no overlay patterns 12 are set, in order to ensure the moving efficiency of the wafer 10. When the wafer is about to reach another first path segment, the wafer needs to decelerate, so that the wafer enters the first path segment at a slower speed, in order to ensure the stability of the image sensor 35 in capturing the overlay patterns 12. Similarly, the second path segment also needs to be set with an extension path segment to ensure that the wafer moves with acceleration and deceleration on its extension path segment, thereby ensuring that the image sensor 35 can stably acquire all the overlay patterns 12, while also helping to ensure the wafer's movement efficiency and the measurement efficiency of overlay errors.

[0203] During the movement of wafer 10 according to the determined scanning mode, the preset movement direction and the starting point of wafer 10 may deviate from the direction and the position of the scanning starting point of the scanning mode. Since the overlay pattern 12 on wafer 10 is small and the field of view of image sensor 35 is limited, this deviation can easily cause some overlay patterns 12 to be missed, thus affecting the accuracy of overlay error measurement. Therefore, before wafer 10 moves, the preset scanning direction and the movement position of wafer 10 can be controlled according to the following two embodiments to make the preset scanning direction of wafer 10 consistent with the scanning direction of the determined scanning mode, and at the same time make the movement position of wafer 10 located at the scanning starting point of the scanning mode, so as to ensure that all overlay patterns 12 can be acquired, which is beneficial to ensuring the accuracy of overlay error measurement.

[0204] In one embodiment, please refer to Figure 23 , Figure 23This diagram illustrates a motion control device with a control module 33 connected to a processing module 31, as provided in an embodiment of this application. The acquisition module 32 acquires the preset scanning direction of the wafer 10 before controlling the wafer 10 to move according to a determined scanning mode. The control module 33 is electrically connected to the acquisition module 32. The control module 33 receives the preset scanning direction of the wafer 10 acquired by the acquisition module 32 and determines whether the preset scanning direction of the wafer 10 is the scanning direction of the scanning mode. When the preset scanning direction of the wafer 10 is the same as the scanning direction of the scanning mode, the wafer 10 can move along that direction. When the preset scanning direction of the wafer 10 is different from the scanning direction of the scanning mode, the control module 33 controls the wafer 10 to move to the scanning direction of the scanning mode to ensure that the moving direction of the wafer is consistent with the moving direction corresponding to the scanning mode. This allows the field of view of the image sensor 35 to cover all the overlay patterns 12 on the wafer, reducing measurement errors caused by directional deviations and improving the accuracy and reliability of overlay error measurement.

[0205] In one embodiment, please refer to Figure 24 The acquisition module 32 is used to acquire the moving position of the wafer 10 before controlling the movement of the wafer 10 according to the determined scanning mode. The control module 33 is electrically connected to the processing module 31. The control module 33 is used to receive the moving position of the wafer 10 and the scanning start point of the scanning mode. At the same time, it determines whether the wafer 10 is at the scanning start point of the scanning mode. When the wafer 10 is at the scanning start point of the scanning mode, the wafer 10 can move according to the scanning mode. When the wafer 10 is not at the scanning start point of the scanning mode, the control module 33 controls the wafer 10 to move to the scanning start point of the scanning mode, thereby ensuring that the starting position of the scan is consistent with the scanning start point of the scanning mode, so that the wafer 10 can move strictly according to the moving path corresponding to the scanning mode, avoiding the inability to acquire some patterns due to the deviation of the starting position, reducing the measurement error introduced by the position deviation, and improving the accuracy and reliability of the overlay error measurement.

[0206] For some possible implementations, please refer to Figure 24 , Figure 24 This diagram illustrates a system schematic of a motion control device connected to an image sensor 35 and an acquisition module 32, as provided in an embodiment of this application. The wafer motion control device 30 further includes an image sensor 35, which has a field of view. The image sensor 35 can acquire an image located at the center of its field of view. It is understood that when the overlay pattern 12 on the wafer 10 is located at the center of the field of view of the image sensor 35, the image of the overlay pattern 12 can be acquired by the image sensor 35. Therefore, before the wafer 10 moves, it is necessary to determine whether the starting point of the wafer's movement is located at the center of the field of view of the image sensor 35, thereby ensuring that all overlay patterns 12 can sequentially pass through the center of the field of view of the image sensor 35, ensuring the accuracy and reliability of the overlay error measurement.

[0207] For details, please refer to Figure 24 The image sensor 35 and the acquisition module 32 are electrically connected. The acquisition module 32 is used to acquire the field of view of the image sensor 35. The control module 33 receives the moving position of the wafer 10 and determines whether the starting point of the wafer 10 is located at the center of the field of view of the image sensor 35. When the starting point of the wafer 10 is located at the center of the field of view of the image sensor 35, the wafer 10 can move according to the determined scanning mode. When the starting point of the wafer 10 is not located at the center of the field of view of the image sensor 35, the control module 33 controls the wafer 10 to move to the center of the field of view of the image sensor 35, thereby ensuring that the scanning starting point of the scanning mode is located at the center of the field of view of the image sensor 35, so that all the overlay patterns 12 on the path of the scanning mode when the wafer 10 moves can be acquired by the image sensor 35, which helps to ensure the accuracy of the overlay error measurement.

[0208] To avoid incomplete acquisition of the overlay pattern 12 on the wafer 10 by the image sensor 35, and to ensure the moving efficiency of the wafer 10, the moving speed of the wafer 10 needs to be controlled according to its moving path. For some possible implementations, please refer to... Figure 25 , Figure 25 The diagram shows a system schematic of a motion control device connected to an image sensor 35 and a control module 33 according to an embodiment of this application. The control module 33 and the image sensor 35 are electrically connected. The image sensor 35 can capture the path segment of the image of the wafer 10. When the wafer 10 moves to a position where the image sensor 35 can capture the image of the wafer 10, the control module 33 controls the wafer 10 to move at a constant speed along the path segment to ensure that the image sensor 35 can successfully acquire all the overlay patterns 12 on the wafer 10. When the wafer 10 moves to a path segment where the image sensor 35 cannot capture the image of the wafer 10, the control module 33 controls the image wafer 10 to move at a variable speed along the path segment so that the moving speed of the wafer 10 can adapt to the path segment, which helps to reduce the moving time of the wafer 10 and thus improve the measurement efficiency of overlay error. It is understandable that when the wafer 10 moves to a path segment where the image sensor 35 cannot acquire an image of the wafer 10, since the image sensor 35 does not need to acquire an image of the wafer 10, the wafer 10 can accelerate or decelerate according to the actual situation to ensure the moving efficiency of the wafer 10, which is conducive to reducing the moving time of the wafer 10, and thus conducive to improving the measurement efficiency of overlay error.

[0209] For example, wafer 10 can first move at a constant speed along a path segment so that image sensor 35 can successfully capture all overlay patterns 12 on that path segment. Then, it can accelerate along the extended path of that path segment, providing a buffer area for wafer 10 to smoothly enter another path segment. Wafer 10 then turns so that the direction of movement of wafer 10 is in the scanning direction of the scanning mode. It should be noted that wafer 10 can decelerate during the turning process to make the movement of wafer 10 more in line with the logic of the turning process, so as to ensure that the movement process of wafer 10 is more stable, and thus ensure that wafer 10 can move stably according to the determined scanning mode. Wafer 10 then decelerates along the direction after the turn, so that when another path segment enters the field of view of image sensor 35, image sensor 35 can stably capture all overlay patterns 12 on wafer, so that wafer 10 can ensure a shorter movement time and good stability, which is beneficial to improving the measurement efficiency of overlay error. Understandably, the movement path of wafer 10 when turning can be U-shaped or V-shaped, which helps to ensure the stability of the movement process of wafer 10.

[0210] During the movement of wafer 10, it is necessary to acquire images of the overlay pattern 12 on wafer 10 for subsequent analysis and use. In one embodiment, please refer to... Figure 26 , Figure 26 This diagram illustrates a system schematic of a wafer movement control device 30 with an acquisition module 36 provided in an embodiment of this application. The wafer movement control device 30 further includes an acquisition module 36 and an image sensor 35 for real-time feedback of the wafer's movement position and a preset position for capturing the overlay pattern 12. The acquisition module 36 and the image sensor 35 are electrically connected. The acquisition module 36 determines whether the movement position of the wafer 10 is consistent with the preset position for capturing the overlay pattern 12. When the movement position of the wafer is consistent with the preset position for capturing the overlay pattern 12, the acquisition module 36 controls the image sensor 35 to perform high-resolution image acquisition of the overlay pattern 12 on the wafer. When the movement position of the wafer is inconsistent with the position for capturing the overlay pattern 12, the acquisition module 36 does not control the image sensor 35, and the image sensor 35 does not acquire the image at that position. This ensures that the image sensor 35 can accurately acquire the overlay pattern 12, improves the efficiency of the image sensor 35 in acquiring effective images, avoids the real-time acquisition and processing of meaningless images, significantly reduces the amount of data, and reduces the burden of data processing and storage.

[0211] In one embodiment, after the acquisition is completed, the image can be preliminarily verified by the acquisition module 32 to ensure that the overprinted pattern 12 is completely captured, and the image data is stored in the acquisition module 32 for subsequent analysis.

[0212] During the process of image sensor 35 acquiring images of overlay pattern 12, image sensor 35 may acquire some low-quality images, which may reduce the accuracy of subsequent overlay error measurement results. In order to ensure that the images stored by acquisition module 32 are all high-quality images that can be used for accurate calculation of overlay error, in some possible implementations, acquisition module 32 stores preset conditions. Acquisition module 32 can compare its stored images with the preset conditions one by one, and then determine whether the image acquired by image sensor 35 meets the preset conditions. If the image meets the preset conditions, the image is stored for subsequent processing and calculation of overlay error. If the image does not meet the preset conditions, acquisition module 32 discards the image, thereby ensuring that the images used for overlay error measurement are all high-quality and valid data, thereby significantly improving the accuracy of measurement results.

[0213] This application also provides a wafer movement control device 30, please refer to [link to relevant documentation]. Figure 27 , Figure 27 A schematic diagram of a wafer movement control device provided in an embodiment of this application is shown. It can be understood that the wafer movement control device is used to implement the wafer 10 movement control method or the wafer movement control device in the above embodiments. The wafer movement control device includes a memory 42, a processor 41, and a controller 43. The memory 42 is used to store multiple position information corresponding to multiple overlay patterns 12. The memory 42 can be electrically connected to the processor 41. The processor 41 acquires the multiple position information corresponding to the multiple overlay patterns 12 and determines the scanning mode with the shortest time among the first scanning mode and the second scanning mode based on the multiple position information, thereby determining the scanning mode of the wafer 10. The controller 43 can be electrically connected to the processor 41 and is used to control the movement of the wafer 10 according to the determined scanning mode, thereby reducing the movement time of the wafer 10, improving the movement efficiency of the wafer 10, and thus helping to improve the measurement efficiency of overlay error.

[0214] The memory 42, processor 41, and controller 43 provided in this application establish data interaction and control connections with the aforementioned virtual modules through a bus interface. For example, the acquisition module 32 is connected to the memory 42 and writes the coordinate data of the acquired overprinted pattern 12 into the cache area of ​​the memory 42 in real time through a first communication protocol; the processing module 31 receives the configuration parameters (scanning mode selection algorithm) from the processor 41 through a second communication protocol and writes the optimization result (shortest scanning mode) into the shared memory area of ​​the memory 42; the control module 33 is connected to the controller 43 and drives the multi-axis drive unit 23 to control the scanning movement of the base 21 along the first extension direction or the second extension direction through a third communication protocol.

[0215] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A method for controlling the movement of a wafer, wherein the wafer surface is provided with a plurality of dicing channels, the plurality of dicing channels having a first extending direction and a second extending direction, and the wafer surface is provided with a plurality of overlay patterns, the plurality of overlay patterns being disposed on the plurality of dicing channels, characterized in that, The method includes: Obtain multiple positional information corresponding to the multiple overprinted patterns; The scanning mode with the shortest time among the first scanning mode and the second scanning mode is determined based on the multiple location information, wherein the first scanning mode is a mode of performing multiple scans along the first extension direction, and the second scanning mode is a mode of performing multiple scans along the second extension direction. The wafer is moved according to the determined scanning mode so that the image sensor acquires image information of each of the overlay patterns.

2. The wafer movement control method according to claim 1, characterized in that, The step of determining the scanning mode with the shortest time among the first scanning mode and the second scanning mode based on the multiple location information includes: A first scanning path is planned based on the plurality of location information and the first extension direction, and a second scanning path is planned based on the plurality of location information and the second extension direction; Based on the first scan path and the second scan path, determine the scan mode with the shortest time among the first scan mode and the second scan mode.

3. The wafer movement control method according to claim 2, characterized in that, The step of determining the scanning mode with the shortest time among the first scanning mode and the second scanning mode based on the first scanning path and the second scanning path includes: The first scan time is determined based on the first scan path, and the second scan time is determined based on the second scan path; Compare the first scan time and the second scan time to determine the scan mode corresponding to the smaller of the first scan time and the second scan time.

4. The wafer movement control method according to claim 2, characterized in that, The step of determining the scanning mode with the shortest time among the first scanning mode and the second scanning mode based on the first scanning path and the second scanning path includes: Based on the first scanning path, determine the number of rows, and / or length, and / or number of turns of the first scanning path; and based on the second scanning path, determine the number of rows, and / or length, and / or number of turns of the second scanning path; By comparing the number of rows, and / or length, and / or number of turns of the first scan path with the number of rows, and / or length, and / or number of turns of the second scan path, the scan mode with the shortest time among the first scan mode and the second scan mode is determined.

5. The wafer movement control method according to any one of claims 2 to 4, characterized in that, The step of planning the first scanning path based on the multiple location information and the first extension direction includes: The method involves obtaining multiple first path segments passing through the overprinted pattern based on the multiple location information and the first extension direction, and performing extension processing on each of the first path segments. Based on the extended first path segments, plan the first scan path; and The step of planning the second scanning path based on the multiple location information and the second extension direction includes: The step involves obtaining multiple second path segments passing through the overprinted pattern based on the multiple position information and the second extension direction, and performing extension processing on each of the second path segments; Based on the extended second path segments, plan the second scanning path.

6. The wafer movement control method according to claim 1, characterized in that, The step of determining the scanning mode with the shortest time among the first scanning mode and the second scanning mode based on the multiple location information includes: Based on the plurality of positional information and the first extension direction, a first density of the overlay pattern distributed along the first extension direction is determined; and based on the plurality of positional information and the second extension direction, a second density of the overlay pattern distributed along the second extension direction is determined; Based on the first density and the second density, determine the scanning mode with the shortest time among the first scanning mode and the second scanning mode.

7. The wafer movement control method according to any one of claims 1 to 6, characterized in that, Before controlling the wafer movement according to the determined scanning mode, the process includes: Determine whether the preset movement direction of the wafer is the scanning direction of the scanning mode; If the preset movement direction of the wafer is not the scanning direction of the scanning mode, the wafer is controlled to rotate so that the preset movement direction of the wafer becomes the scanning direction of the scanning mode.

8. The wafer movement control method according to any one of claims 1 to 7, characterized in that, Before controlling the wafer movement according to the determined scanning mode, the process includes: Determine whether the starting point of the wafer's movement is at the starting point of the scan mode; If the starting point of the wafer's movement is not at the starting point of the scan mode, control the wafer to move so that the starting point of the wafer's movement coincides with the starting point of the scan mode.

9. The wafer movement control method according to claim 8, characterized in that, After the starting point of the wafer movement coincides with the starting point of the scan mode, the process includes: Determine whether the starting point of the wafer's movement is located at the center of the image sensor's field of view; If the starting point of the wafer's movement is not located at the center of the image sensor's field of view, control the wafer and / or the image sensor to move so that the starting point of the wafer's movement is located at the center of the image sensor's field of view.

10. The wafer movement control method according to any one of claims 1 to 9, characterized in that, The step of controlling the wafer movement according to the determined scanning mode includes: According to the determined scanning mode, the wafer is controlled to move at a constant speed when the image sensor can capture the wafer image on the path segment, and the wafer is controlled to move at a variable speed when the image sensor cannot capture the wafer image on the path segment.

11. The wafer movement control method according to any one of claims 1 to 10, characterized in that, The process of controlling the uniform movement of the wafer includes: Determine whether the wafer has moved to a position where the image sensor can capture the overlay pattern; If the wafer moves to a position where the image sensor can capture the overlay pattern, the image sensor is controlled to acquire an image.

12. The wafer movement control method according to claim 11, characterized in that, After the image sensor is controlled to acquire an image, the following steps are included: Determine whether the image meets the preset conditions; If the image does not meet the preset conditions, the image is discarded so that it is not used for measuring overlay error.

13. A wafer movement control device for implementing the wafer movement control method according to any one of claims 1 to 12, wherein the plurality of dicing channels have a first extending direction and a second extending direction, and the wafer surface is provided with a plurality of overlay patterns, the plurality of overlay patterns being disposed on the plurality of dicing channels, characterized in that, The device includes: The acquisition module is used to acquire multiple positional information corresponding to the multiple overprinted patterns; The processing module is used to determine the scanning mode with the shortest time among the first scanning mode and the second scanning mode based on the multiple location information, wherein the first scanning mode is a mode of performing multi-line scanning along the first extension direction, and the second scanning mode is a mode of performing multi-line scanning along the second extension direction. The control module is used to control the movement of the wafer according to the determined scanning mode, so that the image sensor can acquire image information of each of the overlay patterns.

14. A wafer movement control device, characterized in that, include: A memory is used to store multiple positional information corresponding to the multiple overprinted patterns; The processor is configured to determine the scanning mode with the shortest time among the first scanning mode and the second scanning mode based on the plurality of position information, wherein the first scanning mode is a mode of performing multi-line scanning along the first extension direction, and the second scanning mode is a mode of performing multi-line scanning along the second extension direction. A controller is used to control the movement of the wafer according to the determined scanning mode, so that the image sensor can acquire image information of each of the overlay patterns.

15. A wafer movement control system, characterized in that, include: A base for supporting a wafer, the wafer surface having a plurality of dicing channels intersecting along a first extension direction and a second extension direction, and a plurality of overlay patterns being provided on the dicing channels; A multi-axis drive unit is used to drive the base to move along the first extension direction or the second extension direction; An optical positioning unit is used to perform optical scanning on the plurality of overlaid patterns to obtain multiple positional information corresponding to the plurality of overlaid patterns; Processing unit, used to perform the following operations: The scanning mode with the shortest time among the first scanning mode and the second scanning mode is determined based on the multiple location information, wherein the first scanning mode is a mode of performing multiple scans along the first extension direction, and the second scanning mode is a mode of performing multiple scans along the second extension direction. A control unit is configured to control the movement of the wafer according to the determined scanning mode, so that the image sensor acquires image information of each of the overlay patterns.

Images