Wafer detection control method, wafer detection system and storage medium

Abstract

The invention provides a wafer detection control method, a wafer detection system and a storage medium, and the method comprises the steps: controlling a first detection module to carry out the two-dimensional surface detection of a to-be-detected wafer disposed on a four-axis displacement platform, and determining a to-be-detected region needing the three-dimensional detection through a two-dimensional detection result of the first detection module; according to the relationship between the displacement required for switching each to-be-detected area from the current position to the second detection position and the switching stroke threshold value, the first movement mode or the second movement mode is flexibly selected to control the four-axis displacement table, and rapid switching between the detection positions is achieved; according to the method, rapid two-dimensional surface full-disc scanning and precise three-dimensional shape fixed-point detection are combined, and an intelligent motion mode decision-making mechanism based on a switching stroke threshold value is introduced, so that the positioning precision and the smoothness of a detection process are ensured, invalid motion and hardware wear are reduced, and the detection efficiency is remarkably improved.

Description

Technical Field

[0001] This application relates to the field of semiconductor inspection technology, specifically to a wafer inspection control method, a wafer inspection system, and a storage medium. Background Technology

[0002] As semiconductor process nodes continue to evolve towards smaller nanometer scales, the defect size on the wafer surface is constantly shrinking, and the requirements for controlling the microscopic three-dimensional morphology are becoming increasingly stringent. To meet the higher yield and performance requirements of chip products, multiple detection and measurement technologies need to work together to comprehensively and accurately evaluate the two-dimensional defects and three-dimensional morphology parameters of the wafer surface.

[0003] In traditional wafer inspection systems, inspection and measurement stations are typically arranged in a decentralized architecture, meaning that the equipment for two-dimensional defect inspection is separate from the equipment for three-dimensional topography measurement. While this decentralized architecture can improve the performance of individual inspection or measurement through equipment specialization, in practical applications, it also requires wafers to be transferred multiple times between independent inspection and measurement equipment, resulting in low inspection efficiency. More importantly, the independent optical systems and mechanical coordinate systems of different devices are difficult to keep consistent, causing the defect location found at the inspection station to be unable to be accurately reproduced at the measurement station. This leads to a failure in the correlation between two-dimensional and three-dimensional data, severely limiting the accuracy and reliability of the inspection results.

[0004] To achieve the integration of detection and measurement, existing technologies attempt to fix modules with different functions within the same equipment frame. However, due to the fixed positions of the modules, the optical paths and measurement reference points of the static integrated architecture are also fixed and cannot be dynamically adjusted. When precise alignment of the coordinate system is required, it often relies on software compensation or a limited electric translation stage for correction, which limits both accuracy and adaptability. Furthermore, it cannot achieve rapid and accurate physical switching between detection and measurement modes, essentially failing to solve the problem of coordinate system transformation between different detection stations. Summary of the Invention

[0005] The purpose of this application is to overcome the shortcomings of the prior art and provide a wafer inspection control method, a wafer inspection system and a storage medium, aiming to solve the technical problem of coordinate unification and rapid conversion between different inspection stations in an integrated wafer inspection system.

[0006] In a first aspect, embodiments of this application provide a wafer inspection control method applied to a wafer inspection system. The wafer inspection system includes a four-axis displacement stage for carrying a wafer to be inspected, a first inspection module for performing two-dimensional surface inspection on the wafer to be inspected, and a second inspection module for performing three-dimensional morphology inspection on the wafer to be inspected. The first inspection module and the second inspection module have corresponding first and second inspection positions.

[0007] The wafer inspection and control method includes:

[0008] The first detection module is controlled to perform two-dimensional surface detection on the wafer to be tested placed on the four-axis displacement stage, and one or more test areas on the wafer to be tested that need to be three-dimensionally detected are determined based on the two-dimensional detection results.

[0009] Based on the relative positional relationship between each of the test areas and the second detection position, it is determined whether the displacement required to switch each of the test areas from its current position to the second detection position exceeds a preset switching travel threshold.

[0010] Based on the judgment result, different motion modes are selected to control the movement of the four-axis displacement stage, so as to switch each of the areas to be tested to the second detection position;

[0011] The second detection module is controlled to perform three-dimensional shape detection on the area to be tested located at the second detection position, and a three-dimensional detection result is obtained.

[0012] In some embodiments, the switching travel threshold is configured to control the straight-line distance between the optical center of the first detection module and the optical center of the second detection module.

[0013] In some embodiments, the step of selecting different motion modes to control the movement of the four-axis displacement stage based on the judgment result includes:

[0014] When the displacement required for switching in the area to be tested does not exceed the switching stroke threshold, the first motion mode is selected to control the four-axis displacement stage.

[0015] When the displacement required for switching in the area to be tested exceeds the switching stroke threshold, the second motion mode is selected to control the four-axis displacement stage.

[0016] The first motion mode includes controlling the four-axis displacement stage to translate along the X-axis and / or Y-axis; the second motion mode includes controlling the four-axis displacement stage to rotate along the R-axis, and then to translate along the X-axis and / or Y-axis after rotation.

[0017] In some embodiments, determining whether the displacement required to switch each of the tested regions from its current position to the second detection position exceeds a preset switching travel threshold, based on the relative positional relationship between each tested region and the second detection position, includes:

[0018] Mark at least one target feature point in each of the regions to be tested, and determine the first coordinate information of the target feature points;

[0019] In the same coordinate system, for each area to be tested, the displacement required from the target feature point to the optical center of the second detection module is calculated based on the first coordinate information of the target feature point.

[0020] Determine whether the displacement required from the target feature point to the optical center of the second detection module exceeds the switching travel threshold.

[0021] In some embodiments, determining whether the displacement required from the target feature point to the optical center of the second detection module exceeds the switching travel threshold includes:

[0022] Compare the displacement required from the target feature point to the optical center of the second detection module with the magnitude of the switching travel threshold;

[0023] When the required displacement is less than or equal to the switching travel threshold, it is determined that the displacement required to switch the area to be tested from the current position to the second detection position does not exceed the switching travel threshold.

[0024] If the required displacement is greater than the switching travel threshold, it is determined that the displacement required to switch the area to be tested from the current position to the second detection position exceeds the switching travel threshold.

[0025] In some embodiments, determining whether the displacement required to switch each of the tested regions from its current position to the second detection position exceeds a preset switching travel threshold, based on the relative positional relationship between each tested region and the second detection position, includes:

[0026] Mark at least one target feature point in each of the regions to be tested, and determine the first coordinate information of the target feature points;

[0027] In the same coordinate system, the relative position of the target feature point and the preset reference line is determined based on the first coordinate information;

[0028] When the target feature point is located in the first region, it is determined that the displacement required to switch the region to be tested from the current position to the second detection position does not exceed the switching travel threshold.

[0029] When the target feature point is located in the second region, it is determined that the displacement required to switch the region to be tested from the current position to the second detection position exceeds the switching travel threshold.

[0030] The preset reference line is perpendicular to the line connecting the optical center of the first detection module and the optical center of the second detection module, and the preset reference line divides the wafer under test into a first region close to the second detection module and a second region far away from the second detection module.

[0031] In some embodiments, the target feature point is the geometric center point of the region to be tested, the centroid of the defect, or one of a plurality of key points determined according to the shape of the defect.

[0032] In some embodiments, selecting a second motion mode to control the movement of the four-axis displacement stage includes:

[0033] The four-axis displacement stage is controlled to rotate along the R-axis by a first angle so that the relative displacement between the target feature point and the optical center of the second detection module after rotation is less than or equal to the switching travel threshold, or the first coordinate information of the target feature point is located in the first region.

[0034] Control the four-axis displacement stage to translate along the X-axis and / or Y-axis.

[0035] In some embodiments, determining one or more regions on the wafer to be tested that require three-dimensional inspection based on the two-dimensional inspection results includes:

[0036] Extract the grayscale feature information and / or two-dimensional size information of all measured areas from the two-dimensional detection results;

[0037] The grayscale feature information is compared with a preset grayscale threshold, and / or the two-dimensional size information is compared with a preset size threshold;

[0038] Based on the comparison results, one or more areas to be tested that require 3D detection are identified.

[0039] In some embodiments, the method further includes, prior to performing two-dimensional inspection on the wafer under test:

[0040] Using the four-axis displacement stage as a reference, the optical center of the first detection module and the second detection module are calibrated sequentially.

[0041] In some embodiments, optical center correction is performed on the first detection module, including:

[0042] The four-axis displacement stage, on which the standard wafer is placed, is controlled to move to the first detection position;

[0043] Adjust the position of the first detection module so that the optical center of the first detection module is initially aligned with the mechanical center of the four-axis displacement stage;

[0044] The four-axis displacement stage is controlled to move along the X-axis, Y-axis and / or R-axis, and correction is performed based on an angle correction algorithm to make the optical center of the first detection module coincide with the mechanical center of the four-axis displacement stage.

[0045] In some embodiments, optical center correction is performed on the second detection module, including:

[0046] Select a marker point on the standard wafer;

[0047] The four-axis displacement stage is driven to move using either the first motion mode or the second motion mode, and the four-axis displacement stage is controlled to move to the second detection position;

[0048] Adjust the position of the second detection module so that the optical center of the second detection module coincides with the center of the marker point.

[0049] In some embodiments, driving the four-axis displacement stage to move using a first motion mode or a second motion mode, and controlling the four-axis displacement stage to move to the second detection position, includes:

[0050] Based on the relative position of the marker point and the second detection position, determine whether switching it to the second detection position exceeds a preset switching travel threshold.

[0051] When the displacement required for switching does not exceed the switching stroke threshold, the first motion mode is selected to control the movement of the four-axis displacement table;

[0052] When the displacement required for switching exceeds the switching stroke threshold, the second motion mode is selected to control the movement of the four-axis displacement table.

[0053] Secondly, embodiments of this application provide a wafer inspection system, comprising:

[0054] A four-axis displacement stage is used to support the wafer under test and can move along the X-axis, Y-axis and R-axis to move the wafer under test.

[0055] The first detection module is used to perform two-dimensional surface inspection on the wafer under test.

[0056] The second detection module is used to perform three-dimensional morphology detection on the wafer under test.

[0057] The processor is communicatively connected to the four-axis displacement stage, the first detection module, and the second detection module, respectively; the processor is configured to execute the wafer inspection control method as described in any embodiment of the first aspect.

[0058] Thirdly, embodiments of this application provide a computer-readable storage medium storing a computer-executable program or instructions, which, when executed by a processor, are used to implement the wafer inspection control method as described in any embodiment of the first aspect.

[0059] The wafer inspection control method and wafer inspection system provided in this application, after controlling the first inspection module to perform two-dimensional surface inspection on the wafer to be inspected placed on a four-axis displacement stage, firstly, the first inspection module accurately locates the area to be inspected in three dimensions through two-dimensional surface inspection, and then, based on the relationship between the displacement of the area to be inspected to the second inspection position and the switching stroke threshold, flexibly selects the first motion mode or the second motion mode to control the four-axis displacement stage, realizing rapid switching between inspection positions; by combining rapid two-dimensional full-disk scanning with precise three-dimensional topography pinpoint inspection, and introducing an intelligent motion mode decision mechanism based on the switching stroke threshold, this application not only ensures positioning accuracy and smoothness of the inspection process, but also reduces invalid movement and hardware wear, significantly improving inspection efficiency.

[0060] In addition, the computer-readable storage medium provided in the embodiments of this application has the same beneficial effects as the wafer inspection and control method described above. Attached Figure Description

[0061] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0062] Figure 1 This is a schematic diagram of the structure of a wafer inspection system provided in one embodiment of this application.

[0063] Figure 2 This is a flowchart of a wafer inspection control method provided in one embodiment of this application.

[0064] Figure 3 A flowchart of a wafer inspection control method provided in another embodiment of this application.

[0065] Figure 4 A flowchart of a wafer inspection control method provided in another embodiment of this application.

[0066] Figure 5 A flowchart of a wafer inspection control method provided in another embodiment of this application.

[0067] Figure 6 A flowchart of a wafer inspection control method provided in another embodiment of this application.

[0068] Figure 7 A flowchart of a wafer inspection control method provided in another embodiment of this application.

[0069] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0070] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments. Similar elements in different embodiments are referred to by related similar element reference numerals. In the following embodiments, many details are described to facilitate a better understanding of the present application. However, those skilled in the art will readily recognize that some features may be omitted in different situations, or may be replaced by other elements, materials, or methods. In some cases, certain operations related to the present application are not shown or described in the specification. This is to avoid obscuring the core parts of the present application with excessive description. For those skilled in the art, detailed description of these related operations is not necessary; they can fully understand the related operations based on the description in the specification and general technical knowledge in the art.

[0071] Furthermore, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various embodiments. At the same time, the steps or actions in the method description can be rearranged or adjusted in a manner obvious to those skilled in the art. Therefore, the various orders in the specification and drawings are only for the clear description of a particular embodiment and do not imply a necessary order, unless otherwise stated that a particular order must be followed.

[0072] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class, without limiting the number of objects; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship. Unless otherwise specified, the terms "connection" and "linkage" used in this application include both direct and indirect connections (linkages).

[0073] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0074] Figure 1 This is a schematic diagram of the structure of a wafer inspection system provided in one embodiment of this application. Figure 1As shown, the wafer inspection system provided in this embodiment includes a four-axis displacement stage 10, a first inspection module 20, a second inspection module 30, and a control module 40.

[0075] In this embodiment, the four-axis displacement stage 10 is used to support the wafer under test and can move along the X, Y, and R axes to move the wafer under test. The four-axis displacement stage 10 plays a fundamental role in supporting and precisely moving the wafer under test in the entire wafer inspection system. It directly supports and fixes the wafer under test through a robust mechanical body. The displacement stage integrates a motor and transmission device, which enables it to receive motion commands sent by the control module 40 and move the wafer under test to the appropriate position according to the commands, so that the first detection module 20 and the second detection module 30 can accurately inspect the wafer. Specifically, when different areas of the wafer under test need to be inspected, the four-axis displacement stage 10 can drive the wafer under test carried on it to translate along the X and Y axes in the horizontal plane according to the inspection requirements, so as to move any area under test on the wafer to the inspection position directly below the two inspection modules and align it with the optical center of the inspection module; it can also drive the wafer under test carried on it to rise and fall along the vertical Z axis, so as to adjust the focus distance during inspection and ensure clear imaging; in addition, it can also rotate around the axis (R axis) perpendicular to the surface of the wafer under test, so as to align the specific structural direction on the wafer under test with the scanning or illumination direction of the inspection module.

[0076] The first detection module 20 is used for two-dimensional surface inspection of the wafer under test, and it has one or more corresponding detection positions. The first detection module 20 works closely with the four-axis displacement stage 10. After the four-axis displacement stage 10 moves the wafer under test to the appropriate position of its detection position, the first detection module 20 focuses on the quality analysis of the two-dimensional surface of the wafer under test. In practice, the first detection module 20 consists of a high-resolution optical camera, a specific wavelength illumination source, and matching objective lenses and lens groups. It is rigidly mounted at a fixed position above the displacement stage, and its optical axis is vertically or tilted to the detection position. When the displacement stage moves a certain area of ​​the wafer into the field of view of the camera, the first detection module 20 emits light to illuminate the wafer and captures the reflected or transmitted light signals. Using specific optical or electronic inspection techniques, it generates a high-contrast two-dimensional planar image to identify and locate two-dimensional defects such as scratches, stains, and particles on the wafer surface, as well as two-dimensional feature information such as surface flatness. It is worth noting that during the testing process, the detection position of the first detection module 20 depends on the precise positioning of the wafer by the four-axis displacement stage 10. Only when the four-axis displacement stage 10 accurately moves the wafer into its detection range can the accuracy of the detection result be determined.

[0077] The second detection module 30 is used for three-dimensional morphology inspection of the wafer under test, and it also has one or more corresponding detection positions. Unlike the first detection module 20, the second detection module 30 focuses more on acquiring the three-dimensional information of the wafer. When the four-axis displacement stage 10 adjusts the wafer under test to the detection position corresponding to the second detection module 30, the second detection module 30 uses techniques such as laser scanning, confocal microscopy, and interferometry to accurately acquire three-dimensional data such as the height undulation and contour shape of the wafer surface by emitting detection signals and receiving signals reflected from different heights on the wafer surface. This allows for the reconstruction of a three-dimensional surface morphology map of the detection area, which is of great significance for evaluating the wafer's processing accuracy and structural integrity. Similar to the first detection module 20, the second detection module 30 also relies on the precise positioning of the four-axis displacement stage 10 to ensure the accuracy and comprehensiveness of the inspection. Only when the wafer is in the appropriate detection position can the second detection module 30 accurately acquire the wafer's three-dimensional morphology information.

[0078] The control module 40 is the command center of the entire wafer inspection system. It includes one or more high-performance processors and is electrically connected to the four-axis stage 10, the first inspection module 20, and the second inspection module 30 via a cable network. As the command center, it is responsible for planning and coordinating the entire inspection process. This includes sending motion control commands to the four-axis stage 10, precisely controlling the movement trajectory, speed, and displacement of the four-axis stage 10 along the X, Y, and R axes according to the preset inspection process and requirements. This ensures that the wafer under test can be accurately moved to the inspection positions of the first inspection module 20 and the second inspection module 30. It also receives the inspection data transmitted from the first inspection module 20 and the second inspection module 30, processes and analyzes this data using the powerful computing and analysis capabilities of the processors, and determines whether the quality of the wafer under test is qualified by comparing it with preset standard data.

[0079] The processor can be a general-purpose central processing unit (CPU) responsible for performing system-level task scheduling, logical judgment and flow control; or a digital signal processor (DSP), field-programmable gate array (FPGA) that focuses more on parallel computing and real-time signal processing; or even a graphics processing unit (GPU) dedicated to high-speed image processing to meet the complex computing needs of two-dimensional image analysis, three-dimensional point cloud data processing and multi-axis motion control.

[0080] It should be noted that the innovation of this application lies in how the processor in the control module 40 coordinates and switches between different detection positions (e.g., moving from the detection position of the first detection module 20 to the detection position of the second detection module 30). This control logic and process will be explained in detail below. Furthermore, the specific mechanical structure, implementation form, and detailed functions of the aforementioned modules are not rigidly defined or elaborated upon here, allowing for multiple possible implementation methods.

[0081] Figure 2 This is a flowchart illustrating a wafer inspection control method provided in one embodiment of this application. Figure 2 As shown, the wafer inspection control method provided in this embodiment is applied to the wafer inspection system provided in the above embodiment. The specific process is executed by the processor in the control module 40, and the control method specifically includes the following steps:

[0082] Step S210: Control the first detection module to perform two-dimensional surface detection on the wafer to be tested placed on the four-axis displacement stage, and determine one or more areas on the wafer to be tested that need to be three-dimensionally detected based on the two-dimensional detection results.

[0083] After the wafer inspection process is initiated, the processor first controls the four-axis displacement stage 10 to perform coordinated movement, causing the wafer under test to be scanned at the first inspection position located directly below the first inspection module 20. The first inspection module 20 uses optical or electronic inspection technology to comprehensively scan the surface of the wafer and quickly image the entire wafer surface or a designated area. At the same time, it collects data information on two-dimensional features such as whether there are scratches, stains, particles, and surface flatness, and generates two-dimensional images that are transmitted back to the processor of the control module 40. After scanning, the processor runs specific image processing and defect recognition algorithms to analyze the massive amount of two-dimensional images, accurately locate areas with abnormalities, and determine one or more "areas to be inspected" that need to be inspected in three dimensions. These areas to be inspected are often the parts where the two-dimensional inspection results show potential quality problems or where further in-depth investigation of their three-dimensional structural features is needed.

[0084] Step S220: Based on the relative positional relationship between each test area and the second detection position, determine whether the displacement required to switch each test area from its current position to the second detection position exceeds the preset switching travel threshold.

[0085] After identifying all test areas, the processor needs to issue motion commands to the four-axis stage 10 to move them one by one to the second detection position below the second detection module 30. Specifically, the processor considers the relative position of each test area on the four-axis stage 10 and the corresponding second detection position of the second detection module 30, calculates the total displacement that the four-axis stage 10 needs to perform when the center point of the test area is accurately moved to the center of the second detection position, and further compares the calculated required displacement distance with a pre-set switching travel threshold to determine whether the movement of the test area is within a controllable and reasonable range.

[0086] In some embodiments, the switching travel threshold is configured to control the linear distance between the optical center of the first detection module and the optical center of the second detection module.

[0087] The switching travel threshold is a safe and reasonable upper limit of displacement range determined by the system based on factors such as equipment performance, detection accuracy requirements, and actual detection process. This is used to determine whether moving the area to be tested to the second detection position is a "short-distance movement" that can be completed directly, or a "long-distance or complex path movement" that requires special processing.

[0088] In this embodiment, the switching travel threshold is specifically defined as the straight-line distance between the optical centers of the first detection module 20 and the second detection module 30 on the horizontal plane, representing the most direct and shortest theoretical movement path between the two detection stations. When the processor determines that the total displacement required for the current test area to move to the second detection station exceeds this threshold, it means that the system cannot complete the switching through simple XY plane linear motion. This is likely because the test area has a special position on the wafer, resulting in an excessively long movement path, or there is a risk related to the mechanical limits of the displacement stage, thus requiring the triggering of complex motion modes such as XY axis linear movement or R axis rotation. Conversely, if the displacement is less than or equal to the threshold, it indicates that efficient and direct planar movement can be performed directly.

[0089] Step S230: Select different motion modes to control the movement of the four-axis displacement stage according to the judgment result, so as to switch each area to be tested to the second detection position.

[0090] Based on the judgment result of step S220, the processor will make different decisions and select the corresponding motion mode to control the movement of the four-axis displacement stage 10. If the calculated displacement does not exceed the threshold, the processor will select an efficient motion mode, directing the four-axis displacement stage 10 to move smoothly and accurately to the second detection position by following a relatively simple path and method, such as controlling the displacement stage to perform direct, linear interpolation movement along the X and Y axes. Conversely, if the required displacement exceeds the switching stroke threshold, indicating that direct movement may encounter mechanical limitations or be inefficient, the processor will select another more complex and optimized motion mode, which may involve multiple coordinated movements of the four-axis displacement stage 10 in different axes, or the use of some special movement strategies to avoid obstacles or utilize a better trajectory, ultimately safely positioning the target area to the second detection position.

[0091] In some embodiments, different motion modes are selected to control the movement of the four-axis displacement stage based on the judgment result, including:

[0092] Step S2301: When the displacement required for switching in the area to be tested does not exceed the switching stroke threshold, select the first motion mode to control the four-axis displacement stage; wherein, the first motion mode includes controlling the four-axis displacement stage to translate along the X-axis and / or Y-axis.

[0093] When the processor determines that the displacement required to move a certain area under test to the second detection position does not exceed the preset switching travel threshold, it means that the distance between the area and the target position is short and within a range that can be directly and efficiently reached. At this time, the processor will select and execute the first motion mode. The first motion mode specifically refers to controlling the four-axis displacement stage 10 to move in the horizontal plane, and by driving the X-axis and Y-axis motors, the wafer being carried is precisely translated in a straight line or a small range. Through this translation method, the path is direct and the action is rapid, without any additional or unnecessary axial movements. It can accurately position the area under test below the optical center of the second detection module 30 in the shortest time and with the least mechanical complexity, thereby maximizing detection efficiency while ensuring positioning accuracy.

[0094] Step S2302: When the displacement required for switching in the area to be tested exceeds the switching stroke threshold, select the second motion mode to control the four-axis displacement stage; wherein, the second motion mode includes controlling the four-axis displacement stage to rotate along the R axis, and then to translate along the X axis and / or Y axis after rotation.

[0095] When the processor determines that the required displacement exceeds the switching travel threshold, it indicates that the distance between the area to be tested and the second detection position is too far. If a direct XY translation is used, it may be impossible to reach the target area due to the physical travel limitations of the stage, or there is a risk of interference with mechanical components along the movement path. Therefore, the processor will activate a relatively complex second motion mode. Specifically, the second motion mode first controls the four-axis stage 10 to rotate at a certain angle along the R-axis (i.e., the rotation axis perpendicular to the wafer surface). By rotating, the orientation of the wafer on the horizontal plane is readjusted. This allows the area to be tested, which was originally on a long-distance movement path, to be adjusted to a more advantageous position closer to the second detection position. After the orientation adjustment is completed, the stage is then controlled to perform subsequent translation along the X-axis and / or Y-axis, finally delivering the area to be tested to the second detection position. This "rotate first, then translate" strategy cleverly overcomes the mechanical limitations of long-distance movement by adding a rotational degree of freedom, ensuring the safety and feasibility of the entire switching process.

[0096] Step S240: Control the second detection module to perform three-dimensional shape detection on the area to be tested at the second detection position, and obtain the three-dimensional detection result.

[0097] When the test area of ​​the wafer under test is successfully switched and stabilized in the second detection position by controlling the four-axis displacement stage 10, the processor sends a trigger command to the second detection module 30. The second detection module 30, in response to the trigger command, utilizes its specialized three-dimensional detection technologies, such as laser scanning, confocal microscopy, and interferometry, to perform a comprehensive and detailed three-dimensional morphological inspection of the test area in the second detection position within its field of view, and collects three-dimensional data information such as the height undulations and contour shape of the test area surface. After the inspection is completed, the processor will perform in-depth analysis and processing of this three-dimensional inspection data, comparing and evaluating it with preset standard three-dimensional data, and finally obtaining detailed inspection results on the three-dimensional morphology of the test area to determine whether the three-dimensional structure of the area meets the quality requirements.

[0098] In summary, the wafer inspection control method provided in any of the above embodiments first uses a first inspection module to accurately locate the area to be inspected in three dimensions through two-dimensional surface inspection. Then, based on the relationship between the displacement of the area to be inspected from the second inspection position and the switching stroke threshold, it flexibly selects either the first motion mode or the second motion mode to control the four-axis displacement stage. By combining rapid two-dimensional full-disk scanning with precise three-dimensional topography pinpoint inspection and introducing an intelligent motion mode decision-making mechanism based on the switching stroke threshold, it not only ensures positioning accuracy and the smoothness of the inspection process, reduces invalid movement and hardware wear, but also ultimately constitutes a seamless automated process from preliminary screening to precise quantitative analysis. This significantly improves the overall inspection throughput and the level of intelligence in system operation while ensuring a high detection rate.

[0099] Figure 3 A flowchart illustrating a wafer inspection control method provided in another embodiment of this application. Figure 3 As shown, based on any of the above embodiments, step S210, determining one or more areas on the wafer to be tested that require three-dimensional testing based on the two-dimensional detection results, specifically includes the following steps:

[0100] Step S301: Extract grayscale feature information and / or two-dimensional size information of all measured areas from the two-dimensional detection results.

[0101] After the first detection module 20 performs two-dimensional surface inspection on the wafer under test placed on the four-axis displacement stage 10, the processor scans and analyzes the high-resolution two-dimensional image of the entire wafer acquired from the first detection module 20. For each measured area in the image, the processor calculates and extracts its key physical features. The measured area can be a pixel or a small block of a preset size. The acquired physical feature information includes at least grayscale feature information and two-dimensional size information. The grayscale feature information characterizes the average brightness, contrast, or specific texture pattern of the image of the measured area, reflecting differences in reflectivity of the wafer material, changes in film thickness, or minor contamination. The two-dimensional size information characterizes the geometric parameters of the measured area, such as area, length, and width. By extracting these quantitative features, the visual image is transformed into structured data that can be processed by the algorithm.

[0102] Step S302: Compare the grayscale feature information with a preset grayscale threshold, and / or compare the two-dimensional size information with a preset size threshold.

[0103] After acquiring the grayscale feature information and / or two-dimensional size information of all tested areas, the processor compares them with preset thresholds stored in the database. These thresholds are standards pre-defined based on extensive historical data and process specifications, primarily used to identify and determine whether any anomalies exist in the tested area. For example, the grayscale value of a region is compared with a preset grayscale threshold to determine if any brightness anomalies exist; simultaneously, the area of ​​the region is compared with a preset size threshold to filter out particles that are too small or meaningless.

[0104] Step S303: Based on the comparison results, determine one or more areas to be tested that require 3D detection.

[0105] Based on the comparison results, the processor will further determine whether the area to be tested needs more precise 3D re-inspection according to preset logical rules. The preset logical rules can be grayscale anomalies or size exceeding limits. For example, if at least one of the grayscale features and / or 2D size information of a certain area to be tested exceeds a preset threshold, it will be marked as an area to be tested that needs to be 3D detected. For these marked areas to be tested, the four-axis displacement stage 10 needs to be driven to switch from the current position to the detection position of the second detection module 30. Furthermore, the motion mode of the movement switching process needs to be determined to ensure that it can move and switch to the target position safely and reliably.

[0106] Figure 4 This is a flowchart illustrating a wafer inspection control method provided in another embodiment of this application. Figure 4 As shown, based on any of the above embodiments, step S220, determining whether the displacement required to switch each test area from its current position to the second detection position exceeds a preset switching travel threshold, based on the relative positional relationship between each test area and the second detection position, specifically includes the following steps:

[0107] Step S401: Mark at least one target feature point in each area to be tested, and determine the first coordinate information of the target feature point.

[0108] To accurately measure the positional relationship between the area to be tested and the second detection point, and thus determine the displacement, the processor automatically marks at least one representative "target feature point" within the identified area to be tested according to a preset strategy. Furthermore, the position of this target feature point, i.e., its "first coordinate information," is precisely measured and recorded in a high-precision wafer coordinate system, providing starting point data for subsequent path calculations.

[0109] In some embodiments, the target feature point is the geometric center of the region to be measured, the centroid of the defect, or one of a plurality of key points determined according to the shape of the defect.

[0110] The selection of target feature points is highly flexible. Selecting the geometric center point as the feature point can represent the approximate center position of the area on the plane, making it easier to ensure that the entire area can be covered. When there are defects in the area to be measured, using the centroid of the defect as the target feature point can focus more on the key parts. For complex defects with irregular shapes, one of the multiple key points determined by the shape of the defect can be selected to more accurately reflect the positional characteristics of the defect.

[0111] Step S402: In the same coordinate system, for each area to be measured, calculate the displacement required from the target feature point to the optical center of the second detection module based on the first coordinate information of the target feature point.

[0112] After determining the coordinates of all target feature points in the test area, the processor will transform the first coordinate information to ensure that the displacement required from the target feature point to the optical center of the second detection module 30 can be determined using the coordinates of the target feature point under the same coordinate system. Specifically, for each test area, the processor will call the first coordinate information of its target feature point and combine it with the fixed and known coordinate values ​​of the optical center of the second detection module 30 in the same coordinate system. Through spatial geometric calculations, it will calculate the synthetic displacement vector that the four-axis displacement stage 10 needs to complete when moving the target feature point directly from its current position to a certain detection position corresponding to the second detection module 30, such as the displacement from a certain detection position corresponding to the first detection module 20 to a certain detection position corresponding to the second detection module 30. This provides a basis for determining whether the switching travel threshold has been exceeded.

[0113] In some embodiments, the displacement required from the target feature point to the optical center of the second detection module can be the straight-line distance from the target feature point to the optical center of the second detection module or the cumulative translation amount.

[0114] On one hand, the required displacement refers to the straight-line distance from the target feature point to the optical center of the second detection module, representing the shortest interval between the two points in space. This distance can be directly compared with a preset switching travel threshold to theoretically determine the feasibility of direct movement. On the other hand, it can also refer to the cumulative translational amount required for the actual movement of the control stage. This typically refers to the total vector displacement synthesized from the components that the stage needs to move along the X and Y axes, more realistically reflecting the actual motion load of the actuator. In practical implementation, the processor can prioritize using the faster straight-line distance for initial feasibility screening, and then, after determining the motion mode, precisely calculate the cumulative translational amount guiding the motor's movement. These two methods complement each other, jointly ensuring the accuracy of movement judgment and the precision of motion control.

[0115] Step S403: Determine whether the displacement required for the target feature point to reach the optical center of the second detection module exceeds the switching travel threshold.

[0116] Furthermore, the processor calculates the required displacement for each area to be tested and compares it with a preset "switching travel threshold" in the system. The switching travel threshold defines the maximum allowable distance that the system considers safe and direct linear movement. If the calculated displacement is less than or equal to this threshold, a relatively simple motion mode can be used to complete the position switch; if the displacement exceeds this threshold, direct movement is considered risky or infeasible, and a special motion mode is required. The judgment result will directly serve as the decision basis for selecting the "first motion mode" or "second motion mode" in the next step S230, thereby ensuring that the entire wafer inspection process is carried out efficiently, accurately, and safely.

[0117] Furthermore, in some embodiments, step S403, determining whether the displacement required from the target feature point to the optical center of the second detection module exceeds the switching travel threshold, specifically includes:

[0118] Step S4031: Compare the displacement required for the target feature point to reach the optical center of the second detection module with the size of the switching travel threshold.

[0119] Step S4032: When the required displacement is less than or equal to the switching travel threshold, it is determined that the displacement required to switch the area to be tested from the current position to the second detection position has not exceeded the switching travel threshold.

[0120] Step S4033: When the required displacement is greater than the switching travel threshold, it is determined that the displacement required to switch the area to be tested from the current position to the second detection position exceeds the switching travel threshold.

[0121] After calculating the displacement required from the target feature point to the optical center of the second detection module 30, the value is compared with the preset "switching travel threshold" in the system. When the comparison result shows that the calculated required displacement value is less than or equal to the switching travel threshold, it means that the movement path from the current target feature point to the target position is within the safe and efficient direct movement capability range of the displacement stage. The processor will then trigger the first motion mode, that is, translate on the X-axis and / or Y-axis to move the area to be measured to the second detection position. And when the target feature point is the geometric center, this can ensure that the target feature point is aligned with the optical center of the second detection module 30.

[0122] When the comparison results show that the required displacement value is greater than the switching travel threshold, it means that the movement requirement from the current target feature point to the target position has exceeded the range that direct and simple translational movement can handle. At this time, the processor will trigger the second motion mode, which will replan the path by introducing rotational movement of the R-axis to avoid mechanical limitations and ensure that the movement can be completed safely and accurately.

[0123] Figure 5 This is a flowchart illustrating a wafer inspection control method provided in another embodiment of this application. Figure 5 As shown, based on any of the above embodiments, step S220, determining whether the displacement required to switch each test area from its current position to the second detection position exceeds a preset switching travel threshold, based on the relative positional relationship between each test area and the second detection position, specifically includes the following steps: marking at least one target feature point in each test area and determining the first coordinate information of the target feature point.

[0124] Step S501: In the same coordinate system, determine the relative position of the target feature point and the preset reference line based on the first coordinate information; wherein, the preset reference line is perpendicular to the line connecting the optical center of the first detection module and the optical center of the second detection module 30, and the preset reference line divides the wafer under test into a first region close to the second detection module 30 and a second region far from the second detection module 30. For example, the preset reference line passes through the optical center of the first detection module and is perpendicular to the line connecting the optical center of the first detection module and the optical center of the second detection module 30.

[0125] In this embodiment, the processor uses a preset reference line to determine the positional relationship between the current position and the reference line, serving as the basis for deciding whether each test area should switch to the second detection position selection motion module mode from its current position. The preset reference line is spatially perpendicular to the line connecting the optical centers of the first and second detection modules 30, dividing the entire wafer carrier area into two parts: a first region closer to the second detection module 30 and a second region farther from it. For each target feature point in the test area, the processor first obtains its coordinate information in the same defined coordinate system, then compares its position with the defined reference line to determine whether the feature point at the current position is located in the closer and more convenient first region, or in the farther and more complex second region.

[0126] Step S502: When the target feature point is located in the first region, it is determined that the displacement required to switch the region to be tested from the current position to the second detection position does not exceed the switching travel threshold.

[0127] Step S503: When the target feature point is located in the second region, it is determined that the displacement required to switch the test area from the current position to the second detection position exceeds the switching travel threshold.

[0128] When the target feature point is determined to be located in the first region, the processor will determine that the displacement required to switch the region to be tested to the second detection position does not exceed the switching stroke threshold. In other words, the current feature point is already close to the target position, and the actual path length from its position to the second detection position is within the preset switching stroke. Therefore, the efficient and direct first motion mode can be used to complete the switching without complex path calculation.

[0129] In this embodiment, the four-axis displacement stage is controlled using a first motion mode, specifically:

[0130] The four-axis stage 10 is controlled to move in the horizontal plane. By driving the motors on the X and / or Y axes, the wafer is precisely translated linearly. This allows the area under test to be accurately delivered to the target position in the shortest time and with minimal mechanical complexity, maximizing detection efficiency while ensuring positioning accuracy. However, when the target feature point is determined to be located in the second region, the processor will determine that the displacement required to switch this area under test to the second detection position exceeds the switching travel threshold. In other words, the current feature point is far from the target, and the actual distance between it and the second detection position is long, making direct movement risky. Therefore, for such areas under test, a safer second motion mode is required, which involves rotating the wafer to optimize the path, thereby ensuring the safety and feasibility of the movement process and improving movement efficiency.

[0131] In this embodiment, the second motion mode is used to control the movement of the four-axis displacement stage, specifically:

[0132] First, the four-axis stage 10 is rotated by a first angle along the R-axis so that the relative displacement between the rotated target feature point and the optical center of the second detection module 30 is less than or equal to the switching travel threshold, or the first coordinate information of the target feature point is located within the first region. Then, the four-axis stage 10 is translated along the X-axis and / or Y-axis. By changing the orientation of the wafer on the horizontal plane, the area to be tested is adjusted to a new position that is more conducive to approaching the target detection position, even if its rotated coordinates fall into the first region that can be moved directly, or if the displacement between it and the target point is shortened to within the threshold. Then, the first motion mode is used to control the movement of the four-axis stage 10 to complete the switching from the area to be tested to the second detection position.

[0133] Figure 6 This is a flowchart illustrating a wafer inspection control method provided in another embodiment of this application. Figure 6 As shown, the wafer inspection control method provided in this embodiment specifically includes the following steps:

[0134] Step S610: Using the four-axis displacement stage as a reference, perform optical center calibration on the first detection module and the second detection module in sequence.

[0135] Before the system officially begins executing the wafer inspection process, such as before controlling the first inspection module 20 to perform two-dimensional surface inspection of the wafer under test, the system needs to undergo at least one high-precision optical center calibration. This fundamentally eliminates the systematic positional errors caused by physical installation deviations between the two inspection modules, ensuring that subsequent processes, whether two-dimensional or three-dimensional inspection, and the switching movement of the wafer between different inspection positions, can be based on the same precise spatial reference system. The calibration process aims to precisely calibrate the absolute position coordinates of the optical centers of the first inspection module 20 and the second inspection module 30 within this unified spatial reference system, using the mechanical coordinate system of the four-axis displacement stage 10 that supports the wafer as the unified spatial reference.

[0136] Step S620: Control the first detection module to perform two-dimensional surface detection on the wafer to be tested placed on the four-axis displacement stage, and determine one or more areas on the wafer to be tested that need to be three-dimensionally detected based on the two-dimensional detection results.

[0137] Step S630: Based on the relative positional relationship between each test area and the second detection position, determine whether the displacement required to switch each test area from its current position to the second detection position exceeds the preset switching travel threshold.

[0138] Step S640: Select different motion modes to control the movement of the four-axis displacement stage according to the judgment result, so as to switch each area to be tested to the second detection position.

[0139] Step S650: Control the second detection module to perform three-dimensional morphological detection on the area to be tested at the second detection position, and obtain the three-dimensional detection result.

[0140] It should be noted that the implementation principles and processes of steps S620-S650 in this embodiment are the same or similar to those of steps S210-S240 in the aforementioned multiple embodiments, and they have the same technical effects. To avoid repetition, they will not be described again here.

[0141] The following describes the specific process of step S610, which involves using a four-axis displacement stage as a reference to perform optical center calibration on the first and second detection modules in sequence.

[0142] Figure 7 This is a flowchart illustrating a wafer inspection control method provided in another embodiment of this application. Figure 7 As shown, based on any of the above embodiments, step S610, which involves optical center correction of the first detection module, specifically includes the following steps:

[0143] Step S701: Control the four-axis displacement stage on which the standard wafer is placed to move to the first detection position.

[0144] Step S702: Adjust the position of the first detection module so that the optical center of the first detection module is initially aligned with the mechanical center of the four-axis displacement stage.

[0145] Step S703: Control the four-axis displacement stage to move along the X-axis, Y-axis and / or R-axis, and perform correction based on the angle correction algorithm to make the optical center of the first detection module coincide with the mechanical center of the four-axis displacement stage.

[0146] Before starting the calibration, a "standard wafer" specifically for calibration is selected, placed on the four-axis displacement stage 10, and fixed. Then, through the control system command, the four-axis displacement stage 10 is driven to move precisely, moving the standard wafer it carries to the first detection position corresponding to the first detection module 20. Then, the first coarse calibration process is performed. The position or angle of the first detection module 20 itself can be physically adjusted by manual operation or through an automated mechanism, so that its optical center is initially aligned with the mechanical center of the four-axis displacement stage 10. During the alignment process, the center of the field of view and optical axis of the first detection module 20 can be aligned with the origin of the displacement stage coordinate system or a known reference point to eliminate large installation deviations and make the optical center fall within the precision adjustment range of the displacement stage as much as possible.

[0147] After coarse adjustment, the four-axis displacement stage 10 is controlled to carry the standard wafer through small, programmed movements, such as micro-movements on the X, Y, and R axes. During the movement, the first detection module 20 captures images of specific marked points on the standard wafer in real time through its own detector. Then, based on the angle correction algorithm, the edge fitting or center positioning based on image recognition is performed to calculate the remaining small angle deviation and center offset, and feeds them back to the displacement stage for closed-loop correction. Finally, the optical center and mechanical center are highly coincident, and the coordinate system of the wafer is parallel to the coordinate system of the detection module.

[0148] Furthermore, optical center calibration is performed on the second detection module 30, specifically including the following steps:

[0149] Step S704: Select a marker point on the standard wafer.

[0150] Step S705: Control the movement of the four-axis displacement stage using the first motion mode or the second motion mode, and control the four-axis displacement stage to move to the second detection position.

[0151] Step S706: Adjust the position of the second detection module so that the optical center of the second detection module coincides with the center of the marker point.

[0152] After the calibration of the first detection module 20 is completed, the second detection module 30 is calibrated using the same method as the aforementioned measurement process. Specifically, firstly, a pre-fabricated, clearly defined, and precisely positioned marker point, such as a specific crosshair or square pattern, is selected on the standard wafer as the physical reference for aligning the optical center of the second detection module 30. Then, based on the relative position of the current coordinates of the marker point and the second detection position, the first or second motion mode is selected to control the movement of the four-axis displacement stage 10. Finally, the marker point is precisely moved to the corresponding detection position of the second detection module 30 so that the marker point and the second detection module 30 are initially aligned. Finally, the installation position of the second detection module 30 is physically adjusted manually or through an automated mechanism, and its output image is observed until the center of the marker point on the standard wafer completely coincides with its optical center in the image of the second detection module 30. This achieves the precise association of the optical center coordinates of the second detection module 30 with the displacement stage coordinate system that has been unified with the first detection module 20, thereby completing the spatial reference unification of the entire system.

[0153] In some embodiments, step S705, driving the four-axis displacement stage to move using a first motion mode or a second motion mode, and controlling the four-axis displacement stage to move to the second detection position, specifically includes the following steps:

[0154] Step S7051: Based on the relative position of the marker point and the second detection position, determine whether switching it to the second detection position exceeds the preset switching travel threshold.

[0155] Step S7052: When the displacement required for switching does not exceed the switching stroke threshold, select the first motion mode to control the movement of the four-axis displacement table.

[0156] Step S7053: When the displacement required for switching exceeds the switching stroke threshold, select the second motion mode to control the movement of the four-axis displacement table.

[0157] The detection position switching control during the calibration process is consistent with the path judgment in the detection process. The processor system calculates the displacement required to move the center of the marker point to the optical center of the second detection position in a unified coordinate system based on the first coordinate of the marker point currently selected on the standard wafer and the theoretical second detection position coordinate of the second detection module 30. The calculated displacement value is compared with the preset switching stroke threshold in the system. If the judgment result is "not exceeded" of the switching stroke threshold, the most efficient first motion mode is selected, that is, the four-axis displacement stage 10 is controlled to perform linear translation in the X-axis and / or Y-axis directions, so as to quickly and accurately deliver the marker point to the second detection position with the shortest time and the fewest mechanical movements. If the judgment result is "exceeded" of the switching stroke threshold, the more complex but safer second motion mode is selected, that is, the four-axis displacement stage 10 is first controlled to rotate along the R-axis by a specific angle, and the movement path is optimized by changing the orientation of the wafer to shorten the horizontal movement distance. Then, the displacement stage is controlled to perform translation in the X / Y directions, and finally the marker point is accurately positioned to the second detection position.

[0158] This application also provides a computer-readable storage medium storing a computer-executable program or instructions. When the computer-executable program or instructions are executed by a processor, they are used to implement various processes of any embodiment of the above-described wafer inspection control method and can achieve the same technical effect. To avoid repetition, they will not be described again here.

[0159] The processor can be a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of this application. The readable storage medium includes computer-readable storage media, such as computer read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk.

[0160] Those skilled in the art will understand that all or part of the functions of the various methods in the above embodiments can be implemented by hardware or by computer programs. When all or part of the functions in the above embodiments are implemented by computer programs, the program can be stored in a computer-readable storage medium, which may include: read-only memory, random access memory, disk, optical disk, hard disk, etc., and the program is executed by a computer to achieve the above functions. For example, the program can be stored in the memory of a device, and when the program in the memory is executed by the processor, all or part of the above functions can be achieved. In addition, when all or part of the functions in the above embodiments are implemented by computer programs, the program can also be stored in a server, another computer, disk, optical disk, flash drive, or external hard drive, etc., and can be downloaded or copied to the memory of a local device, or the system of the local device can be updated. When the program in the memory is executed by the processor, all or part of the functions in the above embodiments can be achieved.

[0161] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art, under the guidance of this application, can make several simple deductions, modifications or substitutions based on the spirit of this application and the scope of protection of the claims without departing from the spirit of this application and the claims. All of these are within the protection scope of this application.

Claims

1. A wafer inspection control method, applied to a wafer inspection system, the wafer inspection system comprising a four-axis displacement stage for carrying a wafer to be inspected, a first inspection module for performing two-dimensional surface inspection on the wafer to be inspected, and a second inspection module for performing three-dimensional topography inspection on the wafer to be inspected, wherein the first inspection module and the second inspection module have corresponding first inspection positions and second inspection positions; Its features are, The wafer inspection and control method includes: The first detection module is controlled to perform two-dimensional surface detection on the wafer to be tested placed on the four-axis displacement stage, and one or more test areas on the wafer to be tested that need to be three-dimensionally detected are determined based on the two-dimensional detection results. Based on the relative positional relationship between each of the test areas and the second detection position, it is determined whether the displacement required to switch each of the test areas from its current position to the second detection position exceeds a preset switching travel threshold. Based on the judgment result, different motion modes are selected to control the movement of the four-axis displacement stage, so as to switch each of the areas to be tested to the second detection position; The second detection module is controlled to perform three-dimensional shape detection on the area to be tested located at the second detection position, and a three-dimensional detection result is obtained.

2. The wafer inspection and control method according to claim 1, characterized in that, The switching travel threshold is configured to control the straight-line distance between the optical center of the first detection module and the optical center of the second detection module.

3. The wafer inspection and control method according to claim 2, characterized in that, The step of selecting different motion modes to control the movement of the four-axis displacement table based on the judgment result includes: When the displacement required for switching in the area to be tested does not exceed the switching stroke threshold, the first motion mode is selected to control the four-axis displacement stage. When the displacement required for switching in the area to be tested exceeds the switching stroke threshold, the second motion mode is selected to control the four-axis displacement stage. The first motion mode includes controlling the four-axis displacement stage to translate along the X-axis and / or Y-axis; the second motion mode includes controlling the four-axis displacement stage to rotate along the R-axis, and then to translate along the X-axis and / or Y-axis after rotation.

4. The wafer inspection and control method according to claim 1, characterized in that, The step of determining whether the displacement required to switch each of the tested regions from its current position to the second detection position exceeds a preset switching travel threshold, based on the relative positional relationship between each tested region and the second detection position, includes: Mark at least one target feature point in each of the regions to be tested, and determine the first coordinate information of the target feature points; In the same coordinate system, for each area to be tested, the displacement required from the target feature point to the optical center of the second detection module is calculated based on the first coordinate information of the target feature point. Determine whether the displacement required from the target feature point to the optical center of the second detection module exceeds the switching travel threshold.

5. The wafer inspection and control method according to claim 4, characterized in that, The step of determining whether the displacement required from the target feature point to the optical center of the second detection module exceeds the switching travel threshold includes: Compare the displacement required from the target feature point to the optical center of the second detection module with the magnitude of the switching travel threshold; When the required displacement is less than or equal to the switching travel threshold, it is determined that the displacement required to switch the area to be tested from the current position to the second detection position does not exceed the switching travel threshold. If the required displacement is greater than the switching travel threshold, it is determined that the displacement required to switch the area to be tested from the current position to the second detection position exceeds the switching travel threshold.

6. The wafer inspection and control method according to claim 1, characterized in that, The step of determining whether the displacement required to switch each of the tested regions from its current position to the second detection position exceeds a preset switching travel threshold based on the relative positional relationship between each tested region and the second detection position includes: Mark at least one target feature point in each of the regions to be tested, and determine the first coordinate information of the target feature points; In the same coordinate system, the relative position of the target feature point and the preset reference line is determined based on the first coordinate information; When the target feature point is located in the first region, it is determined that the displacement required to switch the region to be tested from the current position to the second detection position does not exceed the switching travel threshold. When the target feature point is located in the second region, it is determined that the displacement required to switch the region to be tested from the current position to the second detection position exceeds the switching travel threshold. The preset reference line is perpendicular to the line connecting the optical center of the first detection module and the optical center of the second detection module, and the preset reference line divides the wafer under test into a first region close to the second detection module and a second region far away from the second detection module.

7. The wafer inspection and control method according to any one of claims 4-5, characterized in that, The target feature point is the geometric center point of the area to be tested, the centroid of the defect, or one of several key points determined according to the shape of the defect.

8. The wafer inspection and control method according to claim 7, characterized in that, Selecting the second motion mode to control the movement of the four-axis displacement stage includes: The four-axis displacement stage is controlled to rotate along the R-axis by a first angle so that the relative displacement between the target feature point and the optical center of the second detection module after rotation is less than or equal to the switching travel threshold, or the first coordinate information of the target feature point is located in the first region. Control the four-axis displacement stage to translate along the X-axis and / or Y-axis.

9. The wafer inspection and control method according to claim 1, characterized in that, The step of determining one or more regions on the wafer to be tested that require three-dimensional testing based on the two-dimensional detection results includes: Extract the grayscale feature information and / or two-dimensional size information of all measured areas from the two-dimensional detection results; The grayscale feature information is compared with a preset grayscale threshold, and / or the two-dimensional size information is compared with a preset size threshold; Based on the comparison results, one or more areas to be tested that require 3D detection are identified.

10. The wafer inspection and control method according to claim 1, characterized in that, Before performing two-dimensional inspection on the wafer to be tested, the following steps are also included: Using the four-axis displacement stage as a reference, the optical center of the first detection module and the second detection module are calibrated sequentially.

11. The wafer inspection and control method according to claim 10, characterized in that, Optical center calibration of the first detection module includes: The four-axis displacement stage, on which the standard wafer is placed, is controlled to move to the first detection position; Adjust the position of the first detection module so that the optical center of the first detection module is initially aligned with the mechanical center of the four-axis displacement stage; The four-axis displacement stage is controlled to move along the X-axis, Y-axis and / or R-axis, and correction is performed based on an angle correction algorithm to make the optical center of the first detection module coincide with the mechanical center of the four-axis displacement stage.

12. The wafer inspection and control method according to claim 11, characterized in that, The second detection module undergoes optical center calibration, including: Select a marker point on the standard wafer; The four-axis displacement stage is driven to move using either the first motion mode or the second motion mode, and the four-axis displacement stage is controlled to move to the second detection position; Adjust the position of the second detection module so that the optical center of the second detection module coincides with the center of the marker point.

13. The wafer inspection and control method according to claim 12, characterized in that, The step of driving the four-axis displacement stage to move using a first motion mode or a second motion mode, and controlling the four-axis displacement stage to move to the second detection position, includes: Based on the relative position of the marker point and the second detection position, determine whether switching it to the second detection position exceeds a preset switching travel threshold. When the displacement required for switching does not exceed the switching stroke threshold, the first motion mode is selected to control the movement of the four-axis displacement table; When the displacement required for switching exceeds the switching stroke threshold, the second motion mode is selected to control the movement of the four-axis displacement table.

14. A wafer inspection system, characterized in that, include: A four-axis displacement stage is used to support the wafer under test and can move along the X-axis, Y-axis and R-axis to move the wafer under test. The first detection module is used to perform two-dimensional surface inspection on the wafer under test. The second detection module is used to perform three-dimensional morphology detection on the wafer under test. The processor is communicatively connected to the four-axis displacement stage, the first detection module, and the second detection module, respectively; the processor is configured to execute the wafer inspection control method as described in any one of claims 1 to 13.

15. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer-executable program or instructions, which, when executed by a processor, are used to implement the wafer inspection control method as described in any one of claims 1 to 13.

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