Wafer inspection device and wafer inspection system

Abstract

The utility model discloses a wafer detection device and wafer detection system, this wafer detection device, include: TDI camera is configured as to the scanning imaging of wafer, back light source is configured as to provide back light illumination to wafer, diffraction light line sheltering portion is set up on the propagation path before the diffraction light line of wafer edge generation reaches TDI camera photosensitive element, is configured as intercepts diffraction light line. Can cut off the diffraction light line of resulting overexposure from the physical root, thereby prevent the cumulative amplification effect of TDI camera resulting in wafer edge overexposure problem.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor testing technology, and in particular to a wafer testing device and a wafer testing system. Background Technology

[0002] In the semiconductor manufacturing industry, wafers are the fundamental material for manufacturing integrated circuit chips. The wafer manufacturing process is extremely complex and precise. During manufacturing, various reasons (such as particulate contamination, machine malfunctions, or process deviations) can introduce various types of defects onto or near the wafer surface, such as micro-scratches, particle adhesion, missing patterns, or surface stains. These defects have a significant negative impact on the electrical performance, reliability, and final yield of subsequent chips. Therefore, to prevent defective wafers from flowing into later processes, high-precision defect detection at multiple critical nodes in the manufacturing process is an indispensable quality control step.

[0003] Currently, automated optical inspection is the mainstream technology for wafer defect detection. In automated optical inspection systems, certain specific inspection needs (e.g., inspection of wafer edge contours or specific transparent / semi-transparent films) employ high-sensitivity time-delay integration (TDI) cameras, coupled with high-intensity backlight sources, for imaging inspection. TDI cameras, through their unique multi-level signal accumulation mechanism, can obtain high signal-to-noise ratio images even under high-speed scanning conditions.

[0004] However, when using a TDI camera with a backlight source to inspect wafers, the edge areas of the wafer in the inspection image are overexposed, causing a sharp decrease in the contrast of defects in the edge areas (such as chipping and micro-cracks), which are thus missed by the system. Utility Model Content

[0005] To address the aforementioned technical problems, this utility model aims to provide a wafer inspection device and a wafer inspection system that can solve the problem of overexposure at the edges of wafer images acquired in TDI camera backlight inspection applications.

[0006] The technical solution of this utility model is implemented as follows: In a first aspect, the present invention provides a wafer inspection device, which includes: a TDI camera configured to scan and image a wafer; a backlight source configured to provide backlight illumination to the wafer; and a diffraction light blocking part disposed on the propagation path of diffraction light generated at the edge of the wafer before it reaches the photosensitive element of the TDI camera, and configured to block the diffraction light.

[0007] Secondly, this utility model provides a wafer inspection system, comprising: a wafer inspection device of the first aspect, a carrier for carrying the wafer, a controller for controlling the movement of the carrier, and a controller for controlling the wafer inspection device to acquire images.

[0008] The wafer inspection device provided by this utility model, by introducing a diffraction light blocking part with a specific spatial relationship in the optical path, cuts off the diffraction light that causes overexposure from the physical source, thereby preventing the cumulative magnification effect of the TDI camera, and ultimately achieving the effects of suppressing wafer edge overexposure, optimizing grayscale uniformity, and reducing missed detections. Attached Figure Description

[0009] Figure 1 This is a schematic diagram illustrating the working principle of a TDI camera according to this utility model.

[0010] Figure 2 This is a schematic diagram illustrating the principle of overexposure at the edge of a wafer image according to this utility model.

[0011] Figure 3 This is a schematic diagram of a wafer image with overexposed edges according to the present invention.

[0012] Figure 4 This is a schematic diagram of the composition of a wafer inspection device provided by this utility model.

[0013] Figure 5 This is a schematic diagram of the composition of the wafer inspection device capable of automatic alignment provided by this utility model.

[0014] Figure 6 A schematic diagram of the preset spacing provided by this utility model.

[0015] Figure 7 A comparative schematic diagram of wafer images acquired under different preset spacings provided by this utility model.

[0016] Figure 8 This is a schematic diagram of the overall architecture of a wafer inspection system provided by this utility model. Detailed Implementation

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the technical solutions in the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0018] refer to Figure 1The diagram illustrates the working principle of the TDI camera 110. During inspection, the wafer 120 moves along the Y direction at a constant speed V. The line scan speed of the TDI camera 110 (i.e., the charge transfer speed in the photosensitive element) is set to be precisely synchronized with the movement speed V of the wafer 120.

[0019] When a point (e.g., point P) on wafer 120 passes through the field of view of the sensor of TDI camera 110, it is first exposed by the first row of photosensitive elements S1, and S1 collects the signal (photogenerated charge) of point P. In the next clock cycle, when point P moves directly below the second row of photosensitive elements S2, the charge collected in S1 is vertically transferred to the corresponding pixel in S2. In S2, the charge transferred from S1 is added to the signal of point P newly collected by the second row of photosensitive elements at this moment. In the next clock cycle, when point P moves directly below the third row of photosensitive elements S3, the charge accumulated in S2 (S1+S2) is vertically transferred to S3 and added to the signal of point P newly collected by S3.

[0020] This synchronous scanning and accumulation process is repeated along all N rows of photosensitive elements (e.g., S1 to Sn, n=96, 128, or 256). Finally, in the last row of photosensitive elements (e.g., Sn), the output signal is the total signal accumulated at point P over n exposures (S1+S2+...+Sn).

[0021] This multi-stage exposure accumulation method significantly improves signal strength and signal-to-noise ratio. Its equivalent exposure time is N times that of a single-line linear array camera (where N is the number of TDI stages). Therefore, the TDI camera 110 can obtain very bright, low-noise images even in low-light conditions or at extremely high scanning speeds. This makes it ideal for scanning and detecting minute defects in wafer 120, as defects such as edge chipping, microcracks, and tiny particles have extremely weak signals. The integration and accumulation characteristics of the TDI camera 110 can amplify these weak signals, improving the defect detection rate. Area array cameras, on the other hand, lack the ability to capture such weak signals, easily leading to missed defects.

[0022] However, TDI cameras typically have a backlight source, such as... Figure 2As shown, the backlight source 210 is located below the wafer 120 to provide high-intensity, highly uniform background illumination. In wafer 120 inspection, the backlight source 210 can be a large-area LED (light-emitting diode) array flat panel light source. The light emitted passes through a diffuser and collimating optical elements (such as a Fresnel lens group, not shown) to form a nearly parallel detection beam that illuminates the wafer 120 vertically upwards. This configuration of the backlight source 210 makes the wafer 120 itself (typically opaque or semi-transparent) appear dark or gray, while the background (i.e., the area where the light is not blocked) appears bright white, thus forming a high-contrast contour image, facilitating the detection of the edges of the wafer 120 and particles or contaminants on the wafer 120 surface. The wavelength of the light source can also be selected according to the detection requirements, for example, using visible light (such as white light, green light) or invisible light (such as infrared light).

[0023] Wafer 120 (opaque) blocks light, and its imaging area has a specific grayscale value, such as grayscale 125. The area outside wafer 120 (unobstructed) is completely transparent, and its imaging area is saturated (pure white, such as grayscale 255). Ideally, the edge of wafer 120 should be a clear transition line from grayscale 125 to 255.

[0024] However, the actual images acquired showed severe overexposure at the 120 edge of the wafer, such as... Figure 2 As shown, when the parallel light emitted by the backlight source 210 illuminates the edge 121 of the wafer 120, due to the wave nature of light, its propagation path will undergo light diffraction when it encounters the opaque obstacle of the edge 121.

[0025] According to wave optics theory, diffraction causes light to deviate from straight-line propagation and bypass the edge of an obstacle. At edge 121, a weak beam of diffracted light 211 is generated, which enters the geometric shadow region of edge 121 on the photosensitive unit.

[0026] Therefore, the cumulative effect of the TDI camera 110 acts as an amplifier for the diffracted light 211. The originally weak and invisible diffracted light 211 is amplified tens or even hundreds of times after signal accumulation by the TDI camera 110, forming a high-intensity signal that cannot be ignored. This amplified diffraction signal is superimposed on the grayscale value that the edge 121 should have displayed, ultimately leading to overexposure of the edge 121. Figure 3 As shown, an image of wafer 120 acquired by TDI camera 110 is shown as an example. Dense filling in the central region indicates a smaller gray value, while sparse filling in the edge region indicates a larger gray value, i.e., overexposure.

[0027] Therefore, this disclosure aims to provide a wafer inspection device that can avoid overexposure of the wafer edge caused by diffraction light 211, such as Figure 4 As shown, the wafer inspection device includes: a TDI camera 110, a backlight source 210, and a diffraction light blocking part 410.

[0028] The TDI camera 110 is configured to scan and image the wafer 120. The backlight source 210 is configured to provide backlight illumination to the wafer 120.

[0029] The diffraction light blocking part 410 is disposed on the propagation path of the diffraction light generated at the edge of the wafer before it reaches the photosensitive element of the TDI camera 110, and is configured to block the diffraction light.

[0030] In some feasible implementations, the diffraction light blocking part 410 is an annular structure, made of at least one of stainless steel, aluminum alloy, or polyetheretherketone (PEEK) engineering plastic. The annular structure is configured concentrically with the carrier of the wafer 120, and its inner diameter is adapted to the size of the wafer 120. During assembly, the diffraction light blocking part 410 is positioned and installed using a central locating pin on the carrier, ensuring concentricity with the carrier. The upper surface of the annular structure's diffraction light blocking part 410 is flush with or slightly lower than the upper surface of the wafer 120, avoiding interference with the imaging of the TDI camera 110. The annular structure provides omnidirectional blocking of the edge 121 of the wafer 120, adapts to the standard size of the circular wafer 120, and eliminates the need for complex alignment adjustments during installation; assembly can be completed simply through concentric positioning, improving the ease of use and testing efficiency of the device.

[0031] In some feasible implementations, the inner diameter of the annular structure is adjustable to accommodate wafers 120 of different sizes. The annular structure includes a telescopic adjustment mechanism; by adjusting the telescopic adjustment mechanism, the inner diameter of the annular structure can be changed to accommodate wafers 120 of different sizes. For example, the inner diameter can be adjusted within the range of 200mm to 310mm, covering common wafer sizes such as 8-inch and 12-inch wafers. This achieves the adaptation of the same diffraction light blocking part 410 to multiple sizes of wafers 120, eliminating the need to design separate diffraction light blocking parts 410 for different sizes of wafers 120, reducing equipment and replacement costs, and improving the versatility and practicality of the device.

[0032] More specifically, the diffraction ray blocking part 410 is an independently movable sheet-like structure arranged along the edge contour of the wafer 120. Each sheet-like structure is equipped with an independent drive and can move independently along the edge contour of the wafer 120 to adjust its position and angle. This independently movable sheet-like structure is suitable for wafers 120 with irregular edges and special shapes, such as irregularly shaped wafers or wafers with notches on the edges, and the blocking position can be flexibly adjusted by the independently movable sheet-like structure.

[0033] In some embodiments, the diffraction light blocking part 410 is integrated into the edge of the carrier. There are two integration methods: one is integral molding, that is, the diffraction light blocking part 410 and the carrier are integrally made by injection molding or machining, both of which are made of aluminum alloy and have a stable structure; the other is detachable connection, that is, the diffraction light blocking part 410 is fixed to the edge of the carrier by buckles or bolts, which facilitates disassembly, replacement and maintenance.

[0034] During assembly, the carrier only needs to be installed on the testing table, without the need to adjust the position of the diffraction light blocking part 410, which simplifies the assembly process. During testing, the diffraction light blocking part 410 moves synchronously with the carrier, avoiding blocking deviation caused by relative displacement.

[0035] To achieve light shielding, in this embodiment, the surface of the diffraction light blocking part 410 facing the backlight source 210 is made of a light-absorbing material or coated with a light-absorbing coating. The light-absorbing material can be matte black plastic, carbon fiber, etc., and the light-absorbing coating can be a matte black paint coating, anodized black coating, etc., to avoid reflected light. This eliminates the interference of reflected light from the diffraction light blocking part 410 itself on imaging, further optimizing image quality, improving the overall grayscale uniformity of the image, and avoiding additional stray light noise.

[0036] like Figure 2 As shown, the diffracted ray 211 does not propagate along a parallel optical path (i.e., vertically upward), but rather bends at a certain diffraction angle toward the shadow region of the wafer 120. The diffracted ray blocking part 410 is precisely placed on the propagation path of the diffracted ray 211. This suppresses overexposure at the image edges caused by the amplification of the diffracted ray due to the integration accumulation characteristics of the TDI camera 110.

[0037] The assembly process of the wafer inspection device is as follows: First, fix the backlight source 210 below the inspection stage with its emitting surface facing upward to ensure uniform backlight illumination for the wafer 120 above; Second, install the carrier (not shown in the figure) directly above the backlight source 210 and adjust its position to align it with the center of the backlight source 210; Third, install the diffraction light blocking part 410 above the edge of the carrier, ensuring that it is located outside the wafer edge and on the propagation path of the diffraction light from the wafer edge to the photosensitive element of the TDI camera 110; Fourth, install the TDI camera 110 directly above the diffraction light blocking part 410 and adjust the camera height and angle so that its photosensitive element can fully receive the backlight signal transmitted through the wafer 120 without being interfered with by the diffraction light blocking part 410.

[0038] During testing, the backlight source 210 is activated and emits uniform light. The light passes through the wafer 120 and propagates towards the TDI camera 110. When the light reaches the edge 121 of the wafer 120, some of the light diffracts and attempts to propagate towards the photosensitive element of the TDI camera 110. At this time, the diffracted light blocking part 410 physically intercepts this part of the diffracted light 211, preventing it from reaching the TDI camera 110. The TDI camera 110 scans and images the wafer 120 according to preset parameters (such as scanning speed and integration level). Because the diffracted light 211 is intercepted, the signal accumulated by the camera is only the normal light signal transmitted from the wafer 120, and there is no overexposure at the image edges.

[0039] By introducing a diffraction light blocking part 410 with a specific spatial relationship in the optical path, the diffraction light 211 that causes overexposure is cut off from the physical source, thereby preventing the cumulative magnification effect of the TDI camera 110, and finally achieving the effects of suppressing wafer edge overexposure, optimizing grayscale uniformity, and reducing missed detections.

[0040] In some embodiments, the wafer inspection apparatus further includes an alignment adjustment module; the alignment adjustment module is configured to acquire edge position information of the wafer 120 and adjust the position of the diffraction light blocking portion 410 relative to the edge 121 according to the edge position information.

[0041] The alignment adjustment module is a functional module that can automatically identify the edge position of the wafer 120 and adjust the position of the diffraction light blocking part 410 to achieve precise alignment. It is used to compensate for the eccentricity and rotation error when the wafer 120 is placed, and to avoid the effective area being blocked due to excessive blocking, or the diffraction light 211 being not completely blocked due to insufficient blocking.

[0042] The alignment adjustment module is electrically connected to the diffraction light blocking part 410 and communicates with the TDI camera 110. During assembly, the control unit of the alignment adjustment module is connected to the main controller of the detection system to ensure that it can receive wafer position signals and output adjustment commands.

[0043] The testing process is in Figure 4 Based on the corresponding embodiment, an alignment adjustment step is added. First, after the wafer 120 is placed on the carrier, the main controller controls the alignment adjustment module to start. Second, the alignment adjustment module acquires the edge position information of the wafer 120 (which can be obtained by analyzing the initial image captured by the TDI camera 110 or by acquiring it through its own integrated position sensor). Third, the alignment adjustment module calculates the direction and distance that the diffraction light blocking part 410 needs to be adjusted based on the edge position information. Fourth, the alignment adjustment module outputs a control signal to drive the diffraction light blocking part 410 to move relative to the edge of the wafer until it reaches the preset alignment position.

[0044] The automatic alignment function ensures that the diffraction light blocking part 410 always accurately covers the diffraction light propagation path of the edge 121 of the wafer 120, avoiding the error of manual alignment, improving the adaptability and detection stability of the device, and can still achieve effective diffraction light interception even if the wafer 120 has slight eccentricity or rotation.

[0045] In some feasible ways, such as Figure 5 As shown, the alignment adjustment module includes an image acquisition unit 510 and a driving unit 520. The image acquisition unit 510 is configured to acquire an initial edge image of the wafer 120 and identify the edge position; the driving unit 520 is configured to drive the diffraction light blocking part 410 to move to a preset position according to the edge position.

[0046] Image acquisition unit 510 refers to a component with image capture and edge recognition functions, which is usually composed of a miniature camera and an image processor; drive unit 520 refers to an execution component that can drive the diffraction light blocking part 410 to move, which is usually composed of a motor, a transmission mechanism (such as a lead screw and a guide rail) and a position sensor.

[0047] During assembly, the image acquisition unit 410 is mounted next to the TDI camera 110. Figure 5(The installation location shown is only an example) to ensure that its shooting range can cover the entire edge 121 of the wafer 120; the driving unit 520 is mechanically connected to the diffraction light blocking part 410, and the control terminal of the driving unit 520 is electrically connected to the signal output terminal of the image acquisition unit 510. The image processor of the image acquisition unit 510 has a pre-stored edge recognition algorithm, which can extract the coordinate information of the edge 121 of the wafer 120 from the captured image; the driving unit 520 has a pre-stored position closed-loop control logic, which can accurately adjust the position of the diffraction light blocking part 410 according to the edge coordinate information.

[0048] The alignment process during inspection is as follows: First, the image acquisition unit 510 starts and captures the initial edge image of the wafer 120. The image processor performs grayscale conversion and edge extraction processing on the image, identifies the actual position coordinates of the edge 121, and sends the coordinate information to the drive unit 520. Second, after receiving the position coordinate information, the drive unit 520 calculates the deviation between the current position of the diffraction ray blocking part 410 and the preset position. Third, the drive unit 520 controls the motor to start, and drives the diffraction ray blocking part 410 to move in all directions through the transmission mechanism. At the same time, the position sensor provides real-time feedback on the actual position of the diffraction ray blocking part 410. Fourth, when the diffraction ray blocking part 410 moves to the preset position (the relative position with the edge 121 meets the preset requirements), the position sensor sends a position signal, the drive unit 520 stops working, and the alignment is completed.

[0049] This embodiment of the present disclosure achieves high-precision alignment of the diffraction light blocking part 410 through precise edge recognition of the image acquisition unit 510 and closed-loop control of the driving unit 520. The alignment error can be controlled at the micrometer level, which further improves the reliability of diffraction light interception and ensures stable edge imaging quality.

[0050] In some embodiments, the horizontal distance between the diffraction light blocking portion 410 and the edge 121 is configured to be less than or equal to 0.5 mm.

[0051] The diffraction ray blocking portion 410 and the edge 121 of the wafer 120 are configured to maintain a preset distance D. This preset distance is a physical, non-contact gap to prevent the diffraction ray blocking portion 410 from making physical contact with the high-value wafer 120, which could result in scratches or damage. Simultaneously, the value of this preset distance D needs to be precisely controlled to block the diffraction ray 211, preventing it from entering the TDI camera 110. Figure 6 The figure shown is a schematic diagram of the preset spacing D.

[0052] The preset spacing D is set to be greater than 0 and less than or equal to 0.5 mm. This preset spacing D refers to the shortest horizontal distance between the outer edge of edge 121 and the inner edge of the diffraction ray blocking part 410. Its value is a critical threshold obtained based on extensive experimental verification: when the preset spacing is greater than 0.5 mm, some high-angle diffraction rays 211 will escape from the spacing and cannot be completely intercepted; when the preset spacing is ≤ 0.5 mm, the diffraction ray blocking part 410 can cover the propagation angle of most diffracted light, resulting in a significant interception effect. Figure 7 As shown, the left image is an image of wafer 120 acquired with a preset spacing of 0.3mm, and the right image is an image of wafer 120 acquired with a preset spacing of 1mm. The comparison shows that when the preset spacing is less than 0.5mm, the grayscale of the image at the edge 121 is almost indistinguishable from that of the central region. When the preset spacing is less than 1mm, the image at the edge 121 is significantly different from the image at the center. Figure 3 The exposure is reduced, but there is still some overexposure.

[0053] During assembly, the horizontal distance between the diffraction light blocking part 410 and the edge 121 is adjusted to 0.3mm by the drive unit 520. During the inspection process, the position sensor monitors the distance change in real time. If the distance deviates from the preset value due to the movement of the wafer 120 or the vibration of the equipment, the drive unit 520 will adjust it in time to ensure that the distance is always maintained within the range of ≤0.5mm.

[0054] This embodiment maximizes the interception of diffracted light from different angles by quantitatively limiting the horizontal spacing, thereby further improving the uniformity of grayscale at the image edges and significantly increasing the recognition rate of defects in the edge regions.

[0055] The aforementioned wafer inspection device can be applied to an automated wafer inspection system. (See also...) Figure 8 , Figure 8 This is a schematic diagram of the overall architecture of a wafer inspection system, which is the application environment of the technical solution of this embodiment.

[0056] This wafer inspection system is designed for optical inspection of wafers 120. A typical wafer inspection system includes a highly stable platform (e.g., made of marble or a high-damping composite material, not shown) and multiple subsystems mounted on that platform.

[0057] The multiple subsystems include an illumination subsystem, which in this embodiment is specifically a backlight source 210. The backlight source 210 is located below the wafer 120 and is used to provide high-intensity, high-uniformity background illumination.

[0058] Multiple subsystems include a carrier 810 for wafer 120. Wafer 120 is placed and secured on the carrier 810, for example, by vacuum adsorption. The carrier 810 is typically a high-precision multi-axis motion platform (e.g., an XYZ-θ four-axis motion stage) driven by a linear motor or precision ball screw. During inspection, the carrier 810 carries wafer 120 and performs high-speed, uniform linear motion (e.g., along a path) below the imaging subsystem. Figure 1 (Moves along the Y-axis) to achieve scanning inspection of wafer 120.

[0059] Multiple subsystems include an imaging subsystem, which is fixed to a gantry (not shown) on the machine base, located above the support 810. In this embodiment, the imaging subsystem is specifically a TDI camera 110.

[0060] The system includes a controller 820, such as an industrial computer or embedded system. This controller 820 coordinates the switching and brightness of the backlight source 210, the movement of the carrier 810, and the scanning synchronization and image acquisition of the TDI camera 110. The image data (typically a large amount of data) acquired by the TDI camera 110 is transmitted in real-time via a high-speed interface to an image processing card or controller 820, where it is analyzed by a defect detection algorithm (e.g., compared with a standard template).

[0061] It should be noted that the technical solutions described in the embodiments of this utility model can be combined arbitrarily without conflict.

[0062] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. A wafer inspection device, characterized in that, The wafer inspection device includes: A time-delay integral (TDI) camera is configured to scan and image the wafer; A backlight source is configured to provide backlight illumination to the wafer; A diffraction ray blocking part is disposed on the propagation path of diffraction rays generated at the edge of the wafer before they reach the photosensitive element of the TDI camera, and is configured to block the diffraction rays.

2. The wafer inspection apparatus according to claim 1, characterized in that, The wafer inspection device also includes an alignment adjustment module; The alignment adjustment module is configured to acquire edge position information of the wafer and adjust the position of the diffraction light blocking part relative to the edge based on the edge position information.

3. The wafer inspection apparatus according to claim 2, characterized in that, The alignment adjustment module includes: an image acquisition unit and a driving unit; The image acquisition unit is configured to acquire an initial edge image of the wafer and identify the edge position; The driving unit is configured to drive the diffraction light blocking part to move to a preset position according to the edge position.

4. The wafer inspection apparatus according to claim 3, characterized in that, The horizontal distance between the diffraction light blocking portion and the wafer edge is configured to be less than or equal to 0.5 mm.

5. The wafer inspection apparatus according to any one of claims 1 to 4, characterized in that, The diffraction light blocking part is a ring structure, which is configured to be concentric with the carrier of the wafer, and the inner diameter of the ring structure is adapted to the size of the wafer.

6. The wafer inspection apparatus according to claim 5, characterized in that, The inner diameter of the annular structure is adjustable to accommodate wafers of different sizes.

7. The wafer inspection apparatus according to any one of claims 1 to 4, characterized in that, The diffraction light blocking part is an independently movable sheet-like structure, which is arranged along the edge contour of the wafer.

8. The wafer inspection apparatus according to any one of claims 1 to 4, characterized in that, The diffraction light blocking part is integrated on the carrier of the wafer, and the diffraction light blocking part is integrally formed with the carrier or detachably connected.

9. The wafer inspection apparatus according to claim 1, characterized in that, The surface of the diffraction light blocking part facing the backlight source is made of light-absorbing material or coated with a light-absorbing coating.

10. A wafer inspection system, characterized in that, include: The wafer inspection apparatus according to any one of claims 1 to 9 includes a carrier for carrying a wafer, a controller for controlling the movement of the carrier, and a controller for controlling the wafer inspection apparatus to acquire images.

Images