Visual inspection equipment for surface defects of silicon wafer

Abstract

The invention discloses visual detection equipment for surface defects of a silicon wafer, and relates to the technical field of semiconductor detection, and the technical key points are that the visual detection equipment comprises a base and a bracket fixedly mounted on the back surface of the base, a detector positioned right above the base is fixedly mounted on the bracket, and a position adjusting mechanism is arranged at the top of the base; a quantum dot fluorescence mechanism is arranged on the front face of the base, the position adjusting mechanism comprises a three-dimensional position adjusting assembly and a containing table, and the three-dimensional position adjusting assembly comprises an X rod fixedly installed on the top of the base. Free movement, accurate positioning and quantum dot fluorescence enhancement-based defect detection of the silicon wafer in a three-dimensional space are realized, the limitation of traditional equipment is broken through, wafers with different sizes and shapes are flexibly coped, comprehensive coverage and dead-corner-free detection are ensured, meanwhile, the accuracy and sensitivity of detection are remarkably improved, and the detection efficiency is improved. The detection error and the omission ratio are reduced, and reliable quality guarantee is provided for the semiconductor manufacturing industry.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor detection technology, and in particular to a visual detection device for surface defects of silicon wafers. Background Art

[0002] In the sophisticated and highly technical industry of semiconductor manufacturing, silicon wafers are the indispensable cornerstone of integrated circuits, and their surface quality has a decisive impact on the performance and reliability of the final product. Therefore, detecting surface defects on silicon wafers is not only a critical step in the production process but also a cornerstone for ensuring the overall quality of semiconductor devices and improving production efficiency. This step requires extremely high precision and comprehensiveness to ensure that every wafer meets stringent quality standards.

[0003] However, with the rapid development of semiconductor technology, the shapes and sizes of silicon wafers are becoming increasingly diverse, and the limitations of traditional visual inspection equipment are becoming increasingly prominent. These devices mostly use a fixed placement table design to accommodate standard-sized wafers, but they have difficulty handling wafers with complex shapes or special sizes. The fixed table design restricts the placement of the wafer, resulting in the camera being unable to fully capture the surface details of the wafer. This is especially true for wafers with curved surfaces, irregular edges, or special cut shapes, where critical defects are often missed. This not only reduces inspection accuracy, but can also lead to a significant drop in subsequent production yields due to potential problems not being discovered in a timely manner, resulting in significant economic losses for the company. Therefore, we propose a new type of visual inspection equipment for silicon wafer surface defects. Summary of the Invention

[0004] In response to the deficiencies in the prior art, the present invention provides a visual inspection device for silicon wafer surface defects, which solves the problems of low efficiency, poor sensitivity and insufficient flexibility of traditional visual inspection equipment in detecting silicon wafer surface defects.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: a visual inspection device for surface defects of silicon wafers, comprising a base and a bracket fixedly mounted on the back of the base, a detector located directly above the base fixedly mounted on the bracket, a positioning mechanism provided on the top of the base, and a quantum dot fluorescence mechanism provided on the front of the base.

[0006] The positioning mechanism includes a three-dimensional positioning component and a placement platform.

[0007] The three-dimensional positioning assembly includes an X-rod fixedly mounted on the top of the base, an X-motor fixedly mounted on the outer side of the X-rod, an X-screw that penetrates the X-rod and is rotatably connected to the X-rod fixedly mounted on the output end of the X-motor, and an X-ball screw block threadedly connected to the outer side of the X-screw.

[0008] A Y rod is fixedly installed on the top of the X ball screw block, a Y motor is fixedly installed on the outside of the Y rod, a Y screw that penetrates the Y rod and is rotatably connected to the Y rod is fixedly installed on the output end of the Y motor, and a Y ball screw block is threadedly connected to the outside of the Y screw block.

[0009] A Z rod is fixedly installed on the outside of the Y ball screw block, a Z motor is fixedly installed on the outside of the Z rod, a Z screw that passes through the Z rod and is rotatably connected to the Z rod is fixedly installed on the output end of the Z motor, and a Z ball screw block is threadedly connected to the outside of the Z screw.

[0010] Preferably, the detector is composed of an imaging component, a light source component and a microprocessing unit.

[0011] Preferably, the X-rod, Y-rod and Z-rod are independent of each other and perpendicular to each other.

[0012] Preferably, the placement platform is fixedly connected to the Z ball screw block, wherein the placement platform is located below the detector.

[0013] Preferably, the quantum dot fluorescence mechanism includes a robotic arm fixedly mounted on the front side of the base, a special fluorescent reagent bottle containing quantum dots is fixedly mounted on the execution end of the robotic arm, an electric valve is fixedly mounted at the center of the bottom of the special fluorescent reagent bottle containing quantum dots, the output end of the electric valve is fixedly mounted on a main liquid pipe, the liquid outlet end of the main liquid pipe is fixedly mounted on several branch pipes connected to the inner cavity of the main liquid pipe, the liquid outlet end of the branch pipe is fixedly mounted on a liquid outlet ring, and several nozzles are fixedly mounted on the bottom of the liquid outlet ring.

[0014] Preferably, the movable range of the nozzle is larger than the movable range of the placement table.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1. The present invention realizes the free movement and precise positioning of silicon wafers in three-dimensional space by setting a three-dimensional positioning component. This design breaks through the limitations of the fixed placement table of traditional visual inspection equipment, allowing the equipment to flexibly handle silicon wafers of different sizes and shapes, especially wafers with curved surfaces, irregular edges or special cutting shapes. Through the mutual cooperation of the X-rod, Y-rod and Z-rod, as well as their independent motors, screws and ball screw block structures, the precise movement of the silicon wafer in the three axes of X, Y and Z is ensured, thereby achieving full coverage of the wafer surface and detection without blind spots. This innovative design greatly improves the flexibility and accuracy of detection, and reduces the detection errors caused by differences in wafer shape or size.

[0017] 2. The present invention further improves the accuracy and sensitivity of silicon wafer surface defect detection by setting up a quantum dot fluorescence mechanism. As a new type of fluorescent material, quantum dots can specifically bind to defective areas on the surface of silicon wafers and emit strong fluorescence signals under the irradiation of excitation light of a specific wavelength. The spraying of fluorescent reagents is precisely controlled by a robotic arm so that the quantum dots are evenly covered on the surface of the silicon wafer. The imaging component in the detector uses a highly sensitive quantum dot fluorescence detector to capture these fluorescence signals and convert them into high-contrast images. This imaging technology based on quantum dot fluorescence enhancement significantly enhances the contrast between defects and normal areas, making tiny defects more clearly identifiable in the image. The introduction of this technology not only improves the accuracy of detection, but also greatly reduces the missed detection rate, providing more reliable quality assurance for the semiconductor manufacturing industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the present invention;

[0019] Figure 2 Schematic diagram of the structure of the three-dimensional positioning assembly of the present invention;

[0020] Figure 3 For the present invention Figure 2 Another perspective structural diagram;

[0021] Figure 4 Schematic diagram of the structure of the nozzle of the present invention.

[0022] In the picture:

[0023] 1. Base;

[0024] 2. Bracket;

[0025] 3. Detector;

[0026] 4. Positioning mechanism;

[0027] 41. Three-dimensional positioning assembly; 411. X-rod; 412. X-motor; 413. X-screw; 414. X-ball screw; 415. Y-rod; 416. Y-motor; 417. Y-screw; 418. Y-ball screw; 419. Z-rod; 4101. Z-motor; 4102. Z-screw; 4103. Z-ball screw;

[0028] 42. Placement table;

[0029] 5. Quantum dot fluorescence mechanism;

[0030] 51. Robotic arm; 52. Special fluorescent reagent bottle containing quantum dots; 53. Electric valve; 54. Main liquid pipe; 55. Branch pipe; 56. Liquid outlet ring; 57. Nozzle. DETAILED DESCRIPTION

[0031] In the present invention, unless otherwise specified, directions such as "up" and "down" are generally used with respect to the directions shown in the drawings, or with respect to the vertical, perpendicular or gravity directions; similarly, for ease of understanding and description, "left" and "right" are generally used with respect to the left and right shown in the drawings; "inside" and "outside" refer to the inside and outside relative to the outline of each component itself, but the above-mentioned directions are not used to limit the present invention.

[0032] See also Figures 1 to 4 A visual inspection device for surface defects of silicon wafers includes a base 1 and a bracket 2 fixedly mounted on the back of the base 1, a detector 3 located directly above the base 1 is fixedly mounted on the bracket 2, a positioning mechanism 4 is provided on the top of the base 1, and a quantum dot fluorescence mechanism 5 is provided on the front of the base 1.

[0033] Positioning mechanism 4 includes a three-dimensional positioning assembly 41 and a placement platform 42. These components work together to precisely position the silicon wafer in three dimensions. The three-dimensional positioning assembly 41 uses a motor, screw, and ball screw structure in the X, Y, and Z axes to smoothly drive the placement platform 42, allowing for flexible adjustment of the silicon wafer's position. This design ensures the detector can fully cover the wafer surface, particularly for wafers with curved surfaces, irregular edges, or special cut shapes, achieving precise detection without blind spots, greatly improving detection flexibility and accuracy.

[0034] The three-dimensional positioning assembly 41 includes an X-rod 411 fixedly mounted on the top of the base 1. An X-motor 412 is fixedly mounted on the outer side of the X-rod 411. An X-screw 413, which extends through and is rotatably connected to the X-rod 411, is fixedly mounted on the output end of the X-motor 412. A X-ball screw 414 is threadedly connected to the outer side of the X-screw 413. The X-rod 411, X-motor 412, and X-screw 413 in the three-dimensional positioning assembly 41 work together to precisely position the silicon wafer in the X-axis direction. The X-motor 412 drives the X-screw 413 to rotate. Because the X-screw 413 is threadedly connected to the X-ball screw 414, the X-ball screw 414 moves smoothly on the X-rod 411. This process, through precise mechanical transmission, ensures precise adjustment of the silicon wafer's position in the X-axis direction, providing the foundation for comprehensive coverage of the wafer surface and seamless inspection.

[0035] A Y-rod 415 is fixedly mounted on the top of the X-ball screw block 414, a Y-motor 416 is fixedly mounted on the outside of the Y-rod 415, a Y-screw 417 is fixedly mounted on the output end of the Y-motor 416, which passes through the Y-rod 415 and is rotatably connected to the Y-rod 415, and a Y-ball screw block 418 is threadedly connected to the outside of the Y-screw 417. The Y-rod 415 fixed on the top of the X-ball screw block 414 and the Y-motor 416, Y-screw 417 and Y-ball screw block 418 thereon constitute a Y-axis positioning mechanism to achieve precise horizontal movement of the silicon wafer (Y-axis). The Y motor 416 drives the Y screw 417 to rotate. The threaded connection between the Y screw 417 and the Y ball screw block 418 enables the Y ball screw block 418 to move smoothly along the Y rod 415, thereby driving the entire Z-axis positioning mechanism and the silicon wafer on the placement table 42 to move, ensuring that the detector 3 can fully scan the wafer surface, especially for the edges and curved parts of complex-shaped wafers to perform blind-angle detection.

[0036] A Z-rod 419 is fixedly mounted on the outside of the Y-ball screw 418. A Z-motor 4101 is fixedly mounted on the outside of the Z-rod 419. A Z-screw 4102, which passes through and is rotatably connected to the Z-rod 419, is fixedly mounted on the output end of the Z-motor 4101. A Z-ball screw 4103 is threadedly connected to the outside of the Z-screw 4102. The Z-rod 419, along with the Z-motor 4101, Z-screw 4102, and Z-ball screw 4103, fixed on the outside of the Y-ball screw 418, form a Z-axis positioning mechanism, enabling precise vertical movement of the silicon wafer (Z-axis). The Z-motor 4101 drives the Z-screw 4102 to rotate. The threaded connection between the Z-screw 4102 and the Z-ball screw 4103 causes the Z-ball screw 4103 to move up and down along the Z-rod 419, driving the placement table 42 up and down. This adjusts the relative height between the silicon wafer and the detector 3, ensuring comprehensive and accurate detection of surface defects on wafers at different heights.

[0037] Furthermore, detector 3 is composed of an imaging component, a light source component, and a microprocessor unit. This design addresses the high-precision requirements for silicon wafer surface defect detection. The imaging component is responsible for capturing images of the wafer surface, the light source component provides stable lighting to ensure image quality, and the microprocessor processes image data and identifies defects. Working together, these three components enable comprehensive and precise inspection of the wafer surface, effectively overcoming the limitations of traditional equipment when inspecting complex wafer shapes and improving inspection accuracy and efficiency.

[0038] Furthermore, the X-rod 411, Y-rod 415, and Z-rod 419 are independent and perpendicular to each other, ensuring precise and flexible positioning of silicon wafers in three-dimensional space. This structure prevents movement in the X, Y, and Z axes from interfering with each other, enabling precise positioning of the wafer in any direction. This overcomes the limitations of traditional equipment when inspecting complex wafer shapes, ensures full coverage of the wafer surface, and enables accurate, comprehensive inspection of curved wafers with irregular edges.

[0039] Furthermore, the placement table 42 is fixedly connected to the Z ball screw 4103, with the placement table 42 located below the detector 3. This design allows the silicon wafer to be precisely positioned along the Z axis along with the Z ball screw 4103. The Z motor 4101 drives the Z screw 4102 to rotate, and the Z ball screw 4103 drives the placement table 42 up and down, thereby adjusting the distance between the silicon wafer and the detector 3, ensuring that the detector can clearly capture image information of the wafer surface. This design provides the necessary flexibility and accuracy, especially for wafers of varying thicknesses or surface features.

[0040] Furthermore, the quantum dot fluorescence mechanism 5 includes a robotic arm 51 fixedly mounted on the front side of the base 1, a special fluorescent reagent bottle 52 containing quantum dots fixedly mounted on the execution end of the robotic arm 51, an electric valve 53 fixedly mounted at the center of the bottom of the special fluorescent reagent bottle 52 containing quantum dots, an output end of the electric valve 53 fixedly mounted with a main liquid pipe 54, a liquid outlet end of the main liquid pipe 54 fixedly mounted with a plurality of branch pipes 55 connected to the inner cavity of the main liquid pipe 54, a liquid outlet ring 56 fixedly mounted on the liquid outlet end of the branch pipe 55, a plurality of nozzles 57 fixedly mounted on the bottom of the liquid outlet ring 56, the quantum dot fluorescence mechanism 5 accurately positions the special fluorescent reagent bottle 52 containing quantum dots above the silicon wafer through the robotic arm 51, the electric valve 53 controls the fluorescent reagent to be diverted to multiple branch pipes 55 through the main liquid pipe 54, and then converges at the liquid outlet ring 56 and is evenly sprayed on the wafer surface through the nozzle 57. This design ensures that the fluorescent reagent can fully cover the wafer, especially the curved surface and edge parts. By specifically binding to defects and emitting fluorescence under excitation light, the visualization of defects is enhanced, and the sensitivity and accuracy of detection are improved.

[0041] Furthermore, the movable range of the nozzle 57 is larger than the movable range of the placement table 42. The movable range of the nozzle 57 is larger than the movable range of the placement table 42, ensuring that the quantum dot fluorescent reagent can be evenly sprayed onto the surface of silicon wafers of various shapes and sizes, even the edges or irregular parts of the wafers can be fully covered, thereby improving the comprehensiveness and accuracy of the detection and avoiding detection blind spots caused by inadequate spraying of the reagent.

[0042] When used specifically, the working principle of the present invention is as follows:

[0043] During operation, the silicon wafer is placed on the placement table 42 of the positioning mechanism 4. The core of the positioning mechanism 4 lies in its three-dimensional positioning assembly 41. This assembly, through sophisticated mechanical design, enables the free movement of the silicon wafer in three dimensions. Specifically, the X-rod 411, Y-rod 415, and Z-rod 419 are responsible for positioning in the X, Y, and Z axes, respectively. These rods are independent and perpendicular to each other, ensuring accurate and flexible spatial positioning.

[0044] The X-rod 411 drives the X-screw 413 to rotate via the X-motor 412, thereby driving the X-ball screw 414 to move smoothly on the X-rod 411, thereby achieving precise positioning of the silicon wafer in the X-axis direction. Similarly, the Y-rod 415 and the Z-rod 419 are also driven by the Y-motor 416 and the Z-motor 4101, respectively, to achieve precise positioning in the Y-axis and Z-axis directions. This three-dimensional positioning design enables the detector 3 to flexibly adjust its detection position according to silicon wafers of different sizes and shapes, ensuring full coverage of the wafer surface, especially for wafers with curved surfaces, irregular edges or special cutting shapes, and can also achieve accurate detection without blind spots.

[0045] Detector 3, a key component of the equipment, consists of an imaging assembly, a light source assembly, and a microprocessor unit. The optimized configuration of the imaging and light source assemblies ensures high-quality image acquisition. During the inspection process, the light source assembly provides stable and uniform illumination, while the imaging assembly captures image information from the silicon wafer surface and converts it into digital signals. The microprocessor unit is responsible for processing this image data. Using advanced image processing algorithms, it initially screens for possible defect areas, providing a reliable data foundation for subsequent defect identification.

[0046] In order to further improve the accuracy and sensitivity of detection, the present invention introduces a quantum dot fluorescence mechanism 5. During the detection process, the robotic arm 51 moves the special fluorescent reagent bottle 52 containing quantum dots to the top of the silicon wafer through its execution end, and accurately controls the opening of the electric valve 53, so that the fluorescent reagent flows through the main liquid pipe 54 and several branch pipes 55, flows into the liquid outlet ring 56, and is sprayed out through the nozzle 57 and evenly sprayed on the surface of the silicon wafer. Quantum dots, as a new type of fluorescent material, can specifically bind to defective areas on the surface of silicon wafers. Under the irradiation of excitation light of a specific wavelength, these quantum dots bound to the defective areas will emit a strong fluorescence signal.

[0047] The imaging component in Detector 3 utilizes a highly sensitive quantum dot fluorescence detector to precisely capture these fluorescence signals and convert them into high-contrast images. This imaging technology, based on quantum dot fluorescence enhancement, significantly enhances the contrast between defects and normal areas, making tiny defects more clearly visible in the image. This technology not only improves detection accuracy but also significantly reduces missed detection rates.

[0048] In summary, the present invention achieves precise positioning through a reconfigurable three-dimensional positioning component, combined with imaging technology based on quantum dot fluorescence enhancement and intelligent processing of image data, to construct a highly efficient and accurate silicon wafer surface defect detection system. This system not only improves detection efficiency and accuracy, but also greatly enhances detection flexibility, making it applicable to silicon wafers of various sizes and shapes.

[0049] The above are only specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent substitutions, or modifications based on the present invention to solve substantially the same technical problems and achieve substantially the same technical effects are all included in the scope of protection of the present invention.

Claims

1. A visual inspection device for silicon wafer surface defects, comprising a base (1) and a bracket (2) fixedly mounted on the back of the base (1), characterized in that: A detector (3) located directly above the base (1) is fixedly mounted on the bracket (2); a positioning mechanism (4) is provided on the top of the base (1); and a quantum dot fluorescent mechanism (5) is provided on the front of the base (1); The positioning mechanism (4) includes a three-dimensional positioning component (41) and a placement platform (42); The three-dimensional positioning assembly (41) comprises an X-rod (411) fixedly mounted on the top of the base (1); an X-motor (412) is fixedly mounted on the outer side of the X-rod (411); an X-screw (413) penetrating the X-rod (411) and rotatably connected to the X-rod (411) is fixedly mounted on the output end of the X-motor (412); and an X-ball screw block (414) is threadedly connected to the outer side of the X-screw (413); A Y rod (415) is fixedly mounted on the top of the X ball screw (414), a Y motor (416) is fixedly mounted on the outside of the Y rod (415), a Y screw (417) is fixedly mounted on the output end of the Y motor (416), and the Y screw (417) passes through the Y rod (415) and is rotatably connected to the Y rod (415), and a Y ball screw (418) is threadedly connected to the outside of the Y screw (417); A Z rod (419) is fixedly mounted on the outer side of the Y ball screw (418), a Z motor (4101) is fixedly mounted on the outer side of the Z rod (419), a Z screw rod (4102) that passes through the Z rod (419) and is rotatably connected to the Z rod (419) is fixedly mounted on the output end of the Z motor (4101), and a Z ball screw (4103) is threadedly connected to the outer side of the Z screw rod (4102).

2. The visual inspection device for silicon wafer surface defects according to claim 1, characterized in that: The detector (3) is composed of an imaging component, a light source component and a microprocessing unit.

3. The visual inspection device for silicon wafer surface defects according to claim 1, characterized in that: The X-rod (411), the Y-rod (415) and the Z-rod (419) are independent of each other and perpendicular to each other.

4. The visual inspection device for silicon wafer surface defects according to claim 1, characterized in that: The placement platform (42) is fixedly connected to the Z ball screw block (4103), wherein the placement platform (42) is located below the detector (3).

5. The visual inspection device for silicon wafer surface defects according to claim 1, characterized in that: The quantum dot fluorescence mechanism (5) comprises a mechanical arm (51) fixedly mounted on the front of the base (1); a special fluorescent reagent bottle (52) containing quantum dots is fixedly mounted on the execution end of the mechanical arm (51); an electric valve (53) is fixedly mounted at the center of the bottom of the special fluorescent reagent bottle (52) containing quantum dots; a main liquid pipe (54) is fixedly mounted on the output end of the electric valve (53); a plurality of branch pipes (55) communicating with the inner cavity of the main liquid pipe (54) are fixedly mounted on the liquid outlet end of the main liquid pipe (54); a liquid outlet ring (56) is fixedly mounted on the liquid outlet end of the branch pipe (55); and a plurality of nozzles (57) are fixedly mounted on the bottom of the liquid outlet ring (56).

6. The visual inspection device for silicon wafer surface defects according to claim 5, characterized in that: The movable range of the nozzle (57) is greater than the movable range of the placement table (42).

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