Annular scanning device and rotating sample stage for wafer defect detection

Abstract

The present application relates to wafer detection technical field, especially to the annular scanning device and rotating sample stage for wafer defect detection.The annular scanning device includes mounting frame, detection structure and lofting structure;The detection structure includes detection cover;The detection cover is provided with annular track and illumination assembly;The optical scanning detection assembly is arranged on the annular track;Two ends of the optical scanning detection assembly are provided with detection piece one, and the middle part is provided with detection piece two;The lofting structure includes lofting cylinder;Lofting station is arranged on the lofting cylinder;The positioning cleaning frame is arranged on the lofting cylinder.The present application realizes the partition synchronous scanning of wafer through the cooperation of annular track in detection structure and multi-degree-of-freedom optical scanning assembly and active topography compensation rotating sample stage in lofting structure.Not only the high efficiency, dead angle free defect capture is achieved by annular motion path, but also the precision of new material detection is improved through real-time topography sensing and focus tracking of sample stage.

Description

Technical Field

[0001] This invention relates to the field of wafer inspection technology, and more particularly to a ring scanning device and a rotating sample stage for wafer defect detection. Background Technology

[0002] With the rapid development of third-generation semiconductors, represented by silicon carbide, gallium nitride, and gallium oxide, and various new substrate materials, wafer manufacturing processes face greater challenges. These new materials often possess higher hardness, more complex crystal structures, and more significant inherent warpage, making them more susceptible to microcracks, crystal defects (such as COP), edge chipping, and subsurface damage during processing. High-sensitivity, high-efficiency, and full-area detection of these defects, especially submicron and even nanometer-scale defects, has become crucial for ensuring the performance of new material devices, improving yield, and accelerating process development iterations. Simultaneously, the industrialization of new materials places stricter demands on the metrological accuracy of testing data, process standardization, and the verifiability of results.

[0003] Chinese Patent CN221078509U discloses a wafer surface inspection device and its related equipment. The wafer surface inspection device includes an inspection stage, a main camera, an auxiliary camera, and a laser focusing mechanism. The inspection stage is used to place the wafer to be inspected, and the main camera, auxiliary camera, and laser focusing mechanism are mounted above the inspection stage. The auxiliary camera has a higher inspection accuracy than the main camera. The main camera is used to detect defects on the wafer surface, and the auxiliary camera is used to review the defects detected by the main camera. The laser focusing mechanism is used to detect the relative height of the main camera and auxiliary camera to the wafer, so that the main camera and auxiliary camera can focus.

[0004] The aforementioned wafer defect detection technologies typically employ a main and auxiliary camera architecture combined with laser focusing, relying on the X / Y axis movement of the stage to achieve region-by-region scanning of the entire wafer. This type of technology has significant shortcomings in practice: First, its step-by-step "main inspection first, then re-inspection" mode and the two-dimensional stepping scanning method of the stage result in low detection efficiency, making it difficult to meet the throughput requirements of mass production. Second, the stage in such devices is usually passively fixed or only provides lifting / adsorption functions, unable to dynamically sense and actively compensate for the inherent warpage and surface undulations of new material wafers. When dealing with large-size, highly warped wafers, defocusing easily leads to a significant decrease in detection sensitivity at the edges and center areas, or even missed detections. Therefore, there is an urgent need for a new wafer defect detection solution that can balance high efficiency, high precision, strong adaptability, and standardized processes. Summary of the Invention

[0005] To address the problems existing in the background technology, a ring scanning device and rotating sample stage for wafer defect detection are proposed. By cooperating with the ring track and multi-degree-of-freedom optical scanning components in the detection structure and the active topography compensation rotating sample stage in the lofting structure, the device achieves synchronous scanning of the wafer in different areas. It not only achieves efficient and blind-spot-free defect capture through a ring motion path, but also improves the accuracy of new material detection through real-time topography perception and focus tracking of the sample stage.

[0006] This invention proposes a ring scanning device for wafer defect detection, comprising a mounting frame, a detection structure located at the top of the mounting frame, and a lofting structure located at the bottom of the mounting frame; the detection structure includes a downward-opening detection cover; a rotatable ring track and an illumination component located on the side of the ring track are provided on the detection cover; a rotatable optical scanning detection component is provided on the ring track; two detection elements are respectively provided at both ends of the optical scanning detection component, which rotate while performing a ring trajectory scan on the outer edge area of ​​the wafer, and a second detection element is provided in the middle, which moves linearly while performing a ring trajectory scan on the center area of ​​the wafer; the lofting structure includes an upward-opening lofting cylinder; a lofting station is provided at the open end of the lofting cylinder; the lofting station is opposite to the optical scanning detection component; a positioning cleaning frame corresponding to the position of the lofting station is also provided on the lofting cylinder; the positioning cleaning frame clamps, positions, and ventilates and cleans the wafer at the lofting station from the outer periphery.

[0007] Preferably, the detection cover is mounted on the mounting frame in a height-adjustable manner; the bottom of the annular track is provided with an annular groove for the optical scanning detection component to rotate, the top is provided with a turntable that can be movably covered by the detection cover, and the side is provided with a drive structure that drives it to rotate coaxially along the inner wall of the detection cover.

[0008] Preferably, the optical scanning detection assembly includes a drive motor located on a turntable; the scanning frame is driven by the drive motor and arranged along the diameter direction of the annular track while rotating coaxially along the annular groove; detection element one is arranged at both ends of the scanning frame; detection element two moves horizontally along the scanning frame.

[0009] Preferably, the scanning frame has mounting slots at both ends; the test pieces are arranged in pairs, and each pair of test pieces includes a rotating frame; one end of each pair of rotating frames is rotatably mounted in the mounting slot, and the other end is equipped with an outer edge scanning detection sensor.

[0010] Preferably, a guide groove is provided at the bottom of the scanning frame; the second detection component includes an electrically controlled slider that moves horizontally along the guide groove; a center scanning detection sensor is provided at the bottom of the electrically controlled slider.

[0011] Preferably, the end of the scanning frame is provided with a connector that rotates along the annular groove; the top of the connector is provided with a rolling element that cooperates with the annular groove, and the bottom is provided with an electrically controlled telescopic platform that is connected to the scanning frame; the drive motor is connected to the middle of the scanning frame through a telescopic rod.

[0012] Preferably, the inner wall of the detection cover is provided with an annular groove located below the annular track; the lighting assembly includes a lead screw arranged vertically and rotatably disposed in the annular groove; the annular seat is connected to the lead screw by a thread to move up and down in the annular groove; multiple sets of lighting lamps are arranged along the inner annular wall of the annular seat.

[0013] Preferably, the positioning and cleaning frame includes an annular frame arranged around the lofting station; a positioning and cleaning groove is provided on the inner wall of the annular frame; the positioning and cleaning groove is annular, and a positioning frame and a cleaning head are arranged inside the ring; the positioning frame rotates in and out of the positioning and cleaning groove to push and position the wafer from the outer periphery; the cleaning head sprays high-pressure gas to clean the surface of the wafer from the outer periphery.

[0014] The present invention further proposes a rotating sample stage for wafer defect detection, which is set at the above-mentioned lofting station and includes a base located inside the lofting cylinder, an electrically controlled telescopic stage on the base, and a rotating stage rotatably set on the telescopic stage.

[0015] Preferably, the rotary table has multiple sets of mounting holes on its surface; each mounting hole is equipped with an adsorption positioning head with a telescopic rod and a micro-force sensor; the multiple sets of adsorption positioning heads mesh the wafer surface and acquire 3D topographic data of the entire wafer.

[0016] Compared with the prior art, the present invention has the following beneficial technical effects:

[0017] The detection structure (detection hood, ring track, optical scanning detection components) and the sample placement structure (sample placement cylinder, positioning cleaning frame, rotating sample stage) of this solution do not operate independently, but rather form a complete automated detection process through precise timing and spatial coordination.

[0018] The optical scanning inspection assembly revolves around the center of the wafer via a circular track, combining this with the rotation and radial movement of its own scanning frame to create a dynamic composite scanning path. For the outer edge region, inspection components at both ends of the scanning frame can be independently adjusted in tilt and extend, performing a constant-distance edge scan of the outermost annular region of the wafer under the influence of the circular track. The inspection angle is specifically optimized for defects such as edge cracks and chipping. For the center and middle regions, inspection component two, located in the middle of the scanning frame, moves radially, acting as a "pointer" for the scanning frame. With the cooperation of the circular track's revolution, its trajectory forms a series of spiral lines radiating outwards from the center, thus covering most of the area except for the specially scanned outer annular zone. This strategy of simultaneously performing "external annular scanning" and "central region spiral scanning" physically avoids scanning blind spots and significantly improves inspection throughput in terms of time.

[0019] The sample placement tube not only serves as a carrier, but its docking with the detection hood also forms a sealable clean detection chamber, effectively isolating external interference. After the process starts, the positioning rack of the cleaning rack first performs mechanical pre-alignment and clamping of the wafer, followed by standardized purging cleaning by the cleaning head. After cleaning, the telescopic platform of the rotating sample stage smoothly lifts the wafer to the detection station, while the detection hood above lowers and seals it. This series of closely coordinated actions ensures that the wafer remains in a controlled environment from sample placement to the start of detection, laying a standardized foundation for obtaining reliable and comparable test data.

[0020] The basic function of the rotating sample stage is to support the wafer and coordinate the scanning motion with the rotation of the stage. More importantly, its integrated multiple sets of adsorption positioning heads form an intelligent adaptive support and measurement network. In the initial stage of inspection, these adsorption heads gently contact the back of the wafer under the feedback of micro-force sensors. Through independent fine-tuning of each telescopic rod, it can not only adapt to wafer warping and achieve stress-free stable clamping, but also sense and record the position data of multiple support points on the back of the wafer in real time. Combining the rotation of the stage and the lifting of the telescopic stage, the system can quickly reconstruct a 3D topographic image of the entire wafer, which is used to drive the electrically controlled telescopic stage in the optical scanning inspection component to perform real-time Z-axis tracking compensation, ensuring that the optimal focal plane is always maintained when scanning undulating surfaces. Attached Figure Description

[0021] Figure 1 A schematic diagram showing the working state of a ring scanning device used for wafer defect detection;

[0022] Figure 2 This is a schematic diagram of the second working state of a ring scanning device used for wafer defect detection;

[0023] Figure 3 This is a schematic diagram showing the three working states of a ring scanning device used for wafer defect detection.

[0024] Figure 4 This is a schematic diagram of the detection structure;

[0025] Figure 5 This is a schematic diagram of the lofted structure;

[0026] Figure 6 This is a bottom view of the circular track.

[0027] Figure 7 This is a structural diagram of the optical scanning detection component;

[0028] Figure 8 for Figure 4 Enlarged view of point A in the middle;

[0029] Figure 9 for Figure 1 Enlarged view at point B in the middle;

[0030] Figure 10 This is a structural diagram of a rotating sample stage used for wafer defect detection.

[0031] Reference numerals: 1. Mounting frame; 2. Detection cover; 201. Annular groove; 3. Cylinder; 4. Annular track; 401. Annular groove; 5. Turntable; 6. Lighting assembly; 601. Ring seat; 602. Lighting lamp; 603. Lead screw; 7. Optical scanning detection assembly; 701. Scanning frame; 702. Drive motor; 703. Electrically controlled slider; 704. Center scanning detection sensor; 705. Connector; 706. Rotating frame; 707. Electrically controlled telescopic table; 708. Outer edge scanning detection sensor; 8. Sample placement cylinder; 9. Positioning cleaning frame; 901. Positioning cleaning groove; 902. Annular frame; 903. Cleaning head; 904. Positioning frame; 10. Base; 11. Telescopic table; 12. Rotary table; 13. Adsorption positioning head. Detailed Implementation

[0032] Example 1: This invention proposes a ring scanning device for wafer defect detection, such as... Figures 1-5 As shown, the device includes a mounting frame 1, a detection structure located at the top of the mounting frame 1, and a lofting structure located at the bottom of the mounting frame 1. The detection structure includes a detection cover 2 with a downward opening. The detection cover 2 is equipped with a rotatable annular track 4 and an illumination component 6 located on the side of the annular track 4. A rotatable optical scanning detection component 7 is installed on the annular track 4. At both ends of the optical scanning detection component 7, there are detection components one that perform annular trajectory scanning on the outer edge area of ​​the wafer while rotating, and detection components two that perform annular trajectory scanning on the center area of ​​the wafer while moving in a straight line. The lofting structure includes a lofting cylinder 8 with an upward opening. The lofting station is located at the open end of the lofting cylinder 8. The lofting station is opposite to the optical scanning detection component 7. The lofting cylinder 8 is also equipped with a positioning and cleaning frame 9 corresponding to the position of the lofting station. The positioning and cleaning frame 9 clamps, positions, and ventilates and cleans the wafer on the lofting station from the outer periphery.

[0033] like Figure 4 and Figure 6 As shown, the detection cover 2 is driven by the cylinder 3 and is mounted on the mounting frame 1 in a height-adjustable manner; the bottom of the annular track 4 is provided with an annular groove 401 for the optical scanning detection component 7 to rotate, the top is provided with a turntable 5 that can be moved to cover the detection cover 2, and the side is provided with a drive structure that drives it to rotate coaxially along the inner wall of the detection cover 2.

[0034] A servo motor is fixedly mounted on the side of the detection housing 2. The output shaft of the servo motor is connected to a precision reducer to increase torque and ensure smooth movement. The output end of the reducer is connected to a drive gear (or drive synchronous belt pulley) via a coupling. A ring gear (or a track surface that meshes with the synchronous belt) is machined or fixed on the outer circumference of the ring track 4. The drive gear meshes with the ring gear to form a gear-ring transmission pair (or a synchronous belt drive is used). In this way, the rotational motion of the servo motor is converted into the rotational motion of the ring track 4 around its central axis (i.e., the central axis of the detection housing).

[0035] The optical scanning detection assembly 7 rotates synchronously along the inner wall of the detection cover 2 via the annular track 4. Detection element one and detection element two perform annular trajectory scanning detection in the outer edge region and center region of the wafer, respectively, as the optical scanning detection assembly 7 rotates.

[0036] like Figure 7 As shown, the optical scanning detection assembly 7 includes a drive motor 702 located on the turntable 5; the scanning frame 701 is driven by the drive motor 702 and is arranged along the diameter direction of the annular track 4 while rotating coaxially along the annular groove 401; the first detection element is arranged at both ends of the scanning frame 701; the second detection element moves horizontally along the scanning frame 701.

[0037] By setting the drive motor 702, the optical scanning and inspection component 7 rotates synchronously with the annular track 4, while the first and second inspection components rotate within a set range as the scanning frame 701 rotates. This can be a large-range rotation or a small-range back-and-forth swing, further meeting the needs of scanning and inspecting the outer edge and central areas of the wafer.

[0038] It should be further explained that the scanning frame 701 has mounting slots at both ends; the detection pieces are arranged in pairs, and each pair of detection pieces includes a rotating frame 706; each pair of rotating frames 706 is driven by a motor at one end and rotated in the mounting slot, and the other end is equipped with an outer edge scanning detection sensor 708.

[0039] It should be further explained that the rotation adjustment structure of each pair of rotating frames 706 is set independently, that is, the outer edge scanning detection sensors 708 on both sides can be set to different rotation angles.

[0040] The outer edge scanning sensor 708 moves in and out of the mounting slot via the rotation of the rotating frame 706, switching between sleep and working states. Furthermore, the rotation angle can be adjusted to change the scanning position. This structure, combined with the rotation of the annular track 4 and the scanning frame 701, enables comprehensive inspection of the outer edge region of the wafer.

[0041] It should be further explained that a guide groove is provided at the bottom of the scanning frame 701; the second detection component includes an electrically controlled slider 703 that moves horizontally along the guide groove; a center scanning detection sensor 704 is provided at the bottom of the electrically controlled slider 703.

[0042] The center scanning detection sensor 704 moves synchronously along the guide groove with the electronically controlled slider 703 to adjust the scanning position. Combined with the rotation of the annular track 4 and the scanning frame 701, it can achieve comprehensive detection of the center area of ​​the wafer.

[0043] The scanning of the outer and central regions is synchronized and independent, making wafer inspection efficient and comprehensive.

[0044] The center scanning sensor 704 and the outer edge scanning sensor 708 are modular optical inspection sensor units integrated on the annular track 4. The primary equipment used is a high-resolution area array camera with an internal bright-field / dark-field illumination structure. Bright-field illumination is used to detect macroscopic defects such as particle contamination, scratches, and pattern missing parts. Dark-field illumination is particularly adept at capturing tiny particles, pits, and crystal defects (COPs) on the wafer surface. Because it is mounted on the annular track 4, dark-field illumination at any angle can be achieved, completely eliminating blind spots caused by fixed angles, especially for detecting complex patterns at the wafer edges. Alternatively, a laser scattering scanner can be used, which scans the wafer surface by emitting a focused laser beam, collecting and analyzing the scattered light signal. It has extremely high sensitivity to submicron and even nanometer-sized particles. Simultaneous collection via multi-angle scattering not only improves the capture rate but also allows for preliminary determination of defect types through scattered light pattern analysis.

[0045] It should be further explained that the end of the scanning frame 701 is provided with a connector 705 that rotates along the annular groove 401; the top of the connector 705 is provided with a rolling element that cooperates with the annular groove 401, and the bottom is provided with an electrically controlled telescopic platform 707 that is connected to the scanning frame 701; the drive motor 702 is connected to the middle of the scanning frame 701 through a telescopic rod.

[0046] The drive motor 702 drives the scanning frame 701 to rotate, while the electrically controlled telescopic stage 707 drives the scanning frame 701 to rise and fall, further enriching the movement path of the outer edge scanning detection sensor 708 and the center scanning detection sensor 704, and improving the flexibility of scanning detection.

[0047] like Figure 8 As shown, the inner wall of the detection cover 2 is provided with an annular groove 201 located below the annular track 4; the lighting assembly 6 includes a lead screw 603 arranged vertically and driven by a motor to rotate within the annular groove 201; the ring seat 601 moves up and down within the annular groove 201 by threaded connection to the lead screw 603; multiple sets of lighting lamps 602 are arranged along the inner annular wall of the ring seat 601.

[0048] The illumination assembly 6 projects light from different directions from the ring seat 601, ensuring that light is always captured by the center scanning detection sensor 704 and the outer edge scanning detection sensor 708, further eliminating shadows during scanning. It can also automatically switch the optimal wavelength and illumination mode (e.g., from bright field to dark field) for different wafer regions (such as metal interconnect areas and dielectric layers) to achieve the highest defect contrast.

[0049] like Figure 5 and Figure 9 As shown, the positioning and cleaning rack 9 includes an annular rack 902 arranged around the lofting station; a positioning and cleaning groove 901 is provided on the inner wall of the annular rack 902; the positioning and cleaning groove 901 is annular, and a positioning rack 904 and a cleaning head 903 are arranged inside the ring; the positioning rack 904 is driven by a motor to rotate and move in and out of the positioning and cleaning groove 901, pushing and positioning the wafer from the outer periphery; the cleaning head 903 is controlled by an air pump to spray high-pressure gas to clean the surface of the wafer from the outer periphery.

[0050] Example 2: Based on the ring scanning device for wafer defect detection in Example 1, this example proposes a rotating sample stage for wafer defect detection, which is set on the sample placement station described in Example 1, as follows: Figure 10 As shown, it includes a base 10 located inside the lofting cylinder 8, a telescopic platform 11 that is electrically controlled to extend and retract on the base 10, and a rotary platform 12 that is rotatably mounted on the telescopic platform 11.

[0051] The wafer is placed on the rotary stage 12 and located inside the sample placement cylinder 8. The positioning frame 904 rotates to approach the wafer and positions it. The cleaning head 903 sprays air to clean the wafer. Then, the wafer is raised by the extension and retraction of the telescopic stage 11, and the detection cover 2 above it lowers to cover the sample placement cylinder 8, forming a closed scanning environment. The rotary stage 12 rotates and the telescopic stage 11 rises and falls, adjusting the position of the wafer during the detection process to further improve the detection effect.

[0052] The rotating stage 12 has multiple sets of mounting holes on its surface; each mounting hole contains an adsorption positioning head 13 with a telescopic rod and a micro-force sensor; the mounting holes are arranged radially. The multiple sets of adsorption positioning heads 13 mesh the wafer surface and acquire 3D topographic data of the entire wafer.

[0053] It should be further explained that after the wafer is positioned by the positioning holder 904 and cleaned by the cleaning head 903, the adsorption positioning head 13 extends out of the mounting hole to adsorb it. This not only maintains the wafer's stable position during subsequent inspection but also provides better support. Furthermore, the adsorption positioning head 13 adjusts the position of the adsorption positioning point by extending and retracting the corresponding telescopic rod, conforming it to the surface undulations of the wafer, thereby obtaining a 3D topographic map of the entire wafer. In subsequent defect scanning, this "topographic map" can be used to pre-plan the height of the Z-axis and the focal plane of each scanning point, achieving active compensation. It can also acquire the overall tilt angle (the macroscopic manifestation of warping) and then automatically adjust the wafer's tilt to optimally match the wafer's "average plane" with the ideal focal planes of the center scanning detection sensor 704 and the outer edge scanning detection sensor 708, thus controlling the entire wafer's undulations within the autofocus's working stroke.

[0054] Example 3: Based on the ring scanning device and rotating sample stage for wafer defect detection described in the above examples, this example proposes a wafer defect detection method, the steps of which are as follows:

[0055] S1. Pre-test calibration and environmental standardization based on the properties of new materials

[0056] Before inspecting any batch of wafers, the inspection system is calibrated using a standard reference material (SRM, such as wafers with standard particles and scribe line dimensions) certified by a national metrology institution. The ring track 4 and scanning frame 701 are driven to enable the center scanning inspection sensor 704 and the outer edge scanning inspection sensor 708 to perform a full-area scan of the SRM. The acquired defect size and location data are compared with the certified values ​​of the SRM to establish a systematic measurement correction coefficient, ensuring that the measurement uncertainty of the center / outer edge scanning inspection sensors (704, 708) is better than 3 nanometers (e.g., for particles with a nominal size of 10 nanometers, the measurement error is ≤ ±1.5 nanometers). For new materials to be tested (such as wide-bandgap semiconductors), a pre-stored material optical property database is invoked. The wavelength of the illumination lamp 602 of the illumination assembly 6 is adjusted (e.g., 365nm ultraviolet light can be selected for SiC to enhance the contrast of surface micro-defects) and the illumination mode (bright field / dark field ratio). Meanwhile, preset parameters such as sensor gain and exposure time ensure a signal-to-noise ratio greater than 10:1, meeting the detection sensitivity requirements of relevant standards of the International Semiconductor Equipment and Materials Association (such as SEMI MF1530);

[0057] Place the wafer to be tested on the rotary stage 12 and start the positioning and cleaning rack 9 program. The positioning rack 904 rotates out and gently contacts the edge of the wafer, precisely positioning it at the center of rotation, with the eccentricity error controlled to be less than 50 micrometers. Subsequently, the cleaning head 903 sprays filtered, dry, clean nitrogen gas (pressure 0.1-0.3 MPa, duration 5 seconds) to remove surface deposits;

[0058] S2, Active Topography Mapping and Adaptive Scan Path Planning

[0059] The telescopic stage 11 rises, bringing the wafer into the measurement position. The rotary stage 12 rotates at a constant speed (e.g., 10 RPM), while the telescopic rods of all adsorption positioning heads 13 are dynamically fine-tuned based on feedback from built-in micro-force sensors, aligning their tips with the back of the wafer and providing uniform, weak support (approximately 0.1 N / point). In this state, the center scanning sensor 704 in the optical scanning inspection assembly 7 can be configured in high-precision confocal displacement sensor mode to perform rapid gridded scanning of the wafer surface (e.g., sampling density of 100 points / mm²). Combining the rotation of the rotary stage 12 with the step-up and down-and-down movement of the telescopic stage 11, 3D topographic data of the entire wafer is acquired, including overall warpage, local undulations, and thickness variations. The measurement expansion uncertainty (k=2) of this topographic data should be declared and recorded, for example, "Overall thickness variation measurement uncertainty: U=±0.15μm". Based on this high-precision topographic map, a wafer coordinate system is generated. The system automatically calculates the optimal focal plane and plans the rotation path of the scanning carriage 701, the movement trajectory of the electronically controlled slider 703, and the Z-axis compensation curve of the electronically controlled telescopic stage 707 to achieve active focus tracking.

[0060] S3, Multimodal Collaborative Scanning and Defect Data Acquisition

[0061] The detection cover 2 descends and seals, creating a stable detection environment. The rotary stage 12 moves synchronously with the annular track 4 (e.g., the ratio of wafer rotation speed to scanning track revolution speed is 1:10), eliminating scanning blind spots. The rotating brackets 706 at both ends of the scanning frame 701 drive the outer edge scanning detection sensor 708 to extend at a preset angle (e.g., tilt angle 70°) and scan along the outermost 2mm ring of the wafer. Simultaneously, the annular track 4 drives the entire assembly to rotate, achieving comprehensive coverage of this area. For defects such as cracks and stacking faults commonly found at the edges of new materials, dark field illumination at a specific angle is used. The center scanning detection sensor 704 is located in the guide groove of the scanning frame 701 and is driven by the electrically controlled slider 703, moving radially from the wafer center towards the edge. During the movement, the electrically controlled telescopic stage 707 adjusts the Z-axis height in real time according to the morphology compensation data from step 3, ensuring that the focal plane always optimally coincides with the wafer surface. The ring mount 601 of the illumination component 6 dynamically adjusts its height and illumination angle according to the scanning position, providing optimal illumination conditions for different areas (such as pattern areas and blank areas). During this process, bright-field and dark-field images and laser scattering signals are acquired synchronously, with timestamps linked to precise mechanical coordinates (X, Y, Z, θ). The data acquisition rate must meet the requirement of completing a full wafer scan within 10 minutes, with a pixel resolution of no less than 0.1 μm / pixel.

[0062] S4. Data Standardization Analysis and Certification Report Generation

[0063] A machine learning algorithm trained on a standardized dataset is used to automatically detect defects in acquired multimodal images and signals. Defects are classified according to the SEMI standard, including particles, scratches, crystal-native pits, and pattern defects. For each identified defect, its quantitative features are extracted, such as size (equivalent diameter), location (coordinates in a standardized wafer coordinate system), contrast, and shape factor. All metrological data include measurement uncertainties calculated based on the calibration results from step 1. For new materials, the system associates defect features with a material processing knowledge base, annotating possible causes (such as epitaxial growth defects, polishing residues, etc.), providing standardized data support for process improvement.

[0064] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited thereto. Various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention.

Claims

1. A ring scanning device for wafer defect detection, characterized in that, It includes a mounting frame (1), a detection structure located at the top of the mounting frame (1), and a layout structure located at the bottom of the mounting frame (1); The detection structure includes a detection cover (2) with a downward opening; a rotatable annular track (4) and an illumination component (6) located on the side of the annular track (4) are provided on the detection cover (2); a rotatable optical scanning detection component (7) is provided on the annular track (4); at both ends of the optical scanning detection component (7) are detection component one that performs annular trajectory scanning on the outer edge area of ​​the wafer while rotating, and detection component two that performs annular trajectory scanning on the center area of ​​the wafer while moving in a straight line is provided in the middle; The optical scanning detection assembly (7) includes a drive motor (702) located on the turntable (5); the scanning frame (701) is driven by the drive motor (702) and is arranged along the diameter direction of the annular track (4) while rotating coaxially along the annular groove (401); the first detection piece is arranged at both ends of the scanning frame (701); the second detection piece moves horizontally along the scanning frame (701); The scanning frame (701) is provided with mounting slots at both ends; the detection pieces are arranged in pairs, and each pair of detection pieces includes a rotating frame (706); one end of each pair of rotating frames (706) is rotatably mounted in the mounting slot, and the other end is provided with an outer edge scanning detection sensor (708). The bottom of the scanning frame (701) is provided with a guide groove; the second detection component includes an electrically controlled slider (703) that moves horizontally along the guide groove; a center scanning detection sensor (704) is provided at the bottom of the electrically controlled slider (703). The lofting structure includes a lofting cylinder (8) with an upward opening; the lofting station is set on the open end of the lofting cylinder (8); the lofting station is opposite to the optical scanning detection component (7); the lofting cylinder (8) is also provided with a positioning cleaning rack (9) corresponding to the position of the lofting station; the positioning cleaning rack (9) clamps, positions and ventilates the wafers on the lofting station from the outer periphery.

2. The ring scanning device for wafer defect detection according to claim 1, characterized in that, The detection cover (2) is mounted on the mounting frame (1) in a height-adjustable manner; the bottom of the annular track (4) is provided with an annular groove (401) for the optical scanning detection component (7) to rotate, the top is provided with a turntable (5) that can be moved to cover the detection cover (2), and the side is provided with a drive structure that drives it to rotate coaxially along the inner wall of the detection cover (2).

3. The ring scanning device for wafer defect detection according to claim 1, characterized in that, The end of the scanning frame (701) is provided with a connector (705) that rotates along the annular groove (401); the top of the connector (705) is provided with a rolling element that cooperates with the annular groove (401), and the bottom is provided with an electrically controlled telescopic platform (707) that is connected to the scanning frame (701). The drive motor (702) is connected to the middle of the scanning frame (701) via a telescopic rod.

4. The ring scanning device for wafer defect detection according to claim 1, characterized in that, The inner wall of the detection cover (2) is provided with an annular groove (201) located below the annular track (4); the lighting assembly (6) includes a lead screw (603) arranged vertically and rotatably disposed in the annular groove (201); the ring seat (601) is connected to the lead screw (603) by a thread to move up and down in the annular groove (201); multiple sets of lighting lamps (602) are provided along the inner annular wall of the ring seat (601).

5. The ring scanning device for wafer defect detection according to claim 1, characterized in that, The positioning cleaning rack (9) includes a ring rack (902) arranged around the layout station; a positioning cleaning groove (901) is provided on the inner wall of the ring rack (902); the positioning cleaning groove (901) is ring-shaped, and a layer of positioning rack (904) and a layer of cleaning head (903) are provided inside the ring. The positioning frame (904) rotates in and out of the positioning cleaning tank (901) to push and position the wafer from the outer periphery; The cleaning head (903) sprays high-pressure gas to clean the surface of the wafer from the outer periphery.

6. The ring scanning device for wafer defect detection according to claim 1, characterized in that, It includes a base (10) located inside the lofting cylinder (8), an electrically telescopic platform (11) that telescopically extends on the base (10), and a rotary table (12) that is rotatably set on the telescopic platform (11).

7. The ring scanning device for wafer defect detection according to claim 6, characterized in that, The rotating table (12) has multiple sets of mounting holes on its surface; each mounting hole is equipped with an adsorption positioning head (13) with a telescopic rod and a micro-force sensor. Multiple adsorption positioning heads (13) mesh the wafer surface and acquire 3D topographic data of the entire wafer.

Images