Wafer defect detection apparatus and method

Abstract

The application relates to the technical field of semiconductor detection, and provides a wafer defect detection device, which comprises a bottom plate, a clamping mechanism, a primary detection mechanism, a re-detection mechanism and an internal detection mechanism. The bottom plate is provided with a first support frame and a second support frame. The primary detection mechanism and the internal detection mechanism are arranged on the first support frame. The re-detection mechanism is arranged on the second support frame. The re-detection mechanism, the primary detection mechanism and the internal detection mechanism are sequentially arranged along a first direction. The clamping mechanism is used for clamping a wafer and can move along the first direction and a second direction relative to the re-detection mechanism, the primary detection mechanism and the internal detection mechanism. The first direction and the second direction are perpendicular. The internal detection mechanism comprises a depth sensor. The application further discloses a wafer defect detection method. The wafer defect detection device can not only detect the coordinates of internal defects of a wafer, but also detect the depth values of the defects, so that the specific positions of the defects are obtained. The detection process is simple, and the detection efficiency is high.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor testing technology, and particularly relates to a wafer defect detection device and method. Background Technology

[0002] Currently, in the semiconductor manufacturing process, surface defects on wafers directly affect chip performance and yield. Internal defects on wafers (such as lattice defects, cracks, microvoids, and uneven doping) also have a significant impact on chip quality. However, in wafer defect detection, most people usually pay more attention to the detection of surface defects while neglecting the detection of internal defects. Some existing technologies use X-ray detection to detect internal defects on wafers, which can quickly observe defects inside the sample and is easy to operate. However, it cannot test the size and location of defects, but can only determine whether the defects exist. Other technologies use ultrasonic detection to detect internal defects on wafers, which can detect the location of internal defects on wafers. However, it requires complex and tedious calculations to obtain the information, resulting in low detection efficiency and a high risk of errors.

[0003] To solve the above-mentioned technical problems, this invention designs a wafer defect detection device and detection method. Summary of the Invention

[0004] This invention provides a wafer defect detection device and method, aiming to solve the problems of existing technologies that cannot detect the location of defects inside wafers or have complex and cumbersome detection processes and low detection efficiency.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a wafer defect detection device, comprising a base plate, a clamping mechanism, a preliminary inspection mechanism, a re-inspection mechanism, and an internal inspection mechanism. The base plate is provided with a first support frame and a second support frame. The preliminary inspection mechanism and the internal inspection mechanism are located on the first support frame, and the re-inspection mechanism is located on the second support frame. The re-inspection mechanism, the preliminary inspection mechanism, and the internal inspection mechanism are arranged sequentially along a first direction. The clamping mechanism is used to clamp the wafer and can move relative to the re-inspection mechanism, the preliminary inspection mechanism, and the internal inspection mechanism along a first direction and a second direction, wherein the first direction and the second direction are perpendicular to each other. The internal inspection mechanism includes a depth sensor.

[0006] Based on the above technical solution, the first support frame includes a first crossbeam extending along a second direction. The initial inspection mechanism includes an initial inspection light source and multiple initial inspection cameras. The multiple initial inspection cameras are evenly distributed on the first crossbeam along the second direction. The initial inspection light source is located on the base plate and extends along the second direction. When the clamping mechanism moves along the first direction to a position where the wafer and the initial inspection mechanism are correspondingly positioned, the multiple initial inspection cameras and the initial inspection light source are respectively positioned above and below the wafer.

[0007] Furthermore, the second support frame is disposed on one side of the first support frame along the first direction. The re-inspection mechanism includes a re-inspection camera, a first re-inspection light source, and a second re-inspection light source. The re-inspection camera and the second re-inspection light source are disposed on the second support frame. The first re-inspection light source is disposed on the base plate and is disposed opposite to the re-inspection camera. When the clamping mechanism moves along the first direction to the point where the wafer is disposed corresponding to the re-inspection mechanism, the re-inspection camera and the second re-inspection light source are disposed above the wafer, and the first re-inspection light source is disposed below the wafer.

[0008] Based on the above technical solution, a light source adjustment component is provided between the second re-inspection light source and the second support frame. The light source adjustment component is used to adjust the angle of the second re-inspection light source relative to the wafer.

[0009] Furthermore, a re-inspection adjustment component is provided between the second support frame and the re-inspection camera. The re-inspection adjustment component includes a lateral adjustment component, a longitudinal adjustment component, and an angle adjustment component, which are used to adjust the position of the re-inspection camera along the first direction and the second direction, as well as the angle along the wafer circumference direction.

[0010] Based on the above technical solution, the first support frame includes a second crossbeam, the second crossbeam extends in the same direction as the first crossbeam and is located below the first crossbeam, the second crossbeam is provided with a sensor lateral drive component, the sensor lateral drive component is provided with a sensor longitudinal drive component, the depth sensor is located on the sensor longitudinal drive component, and when the clamping mechanism moves along the first direction to the point where the wafer and the internal inspection mechanism are correspondingly set, the depth sensor is located above the wafer.

[0011] Furthermore, the wafer defect detection equipment also includes a first sliding mechanism and a second sliding mechanism. The first sliding mechanism includes a first slide rail and a first sliding plate. The first slide rail extends along a first direction and is disposed on a base plate. One end of the first sliding plate is slidably connected to the first slide rail, and the other end of the first sliding plate extends along a second direction. The second sliding mechanism includes a second slide rail and a second sliding plate. The second slide rail is disposed on the first sliding plate and extends along a second direction. The second sliding plate is slidably connected to the second slide rail. The clamping mechanism is connected to the second sliding plate.

[0012] Based on the above technical solution, the clamping mechanism includes a support frame, a first jaw assembly, a second jaw assembly, and a drive assembly. The support frame is connected to a second sliding plate. The first jaw assembly and the second jaw assembly are disposed opposite each other on the top wall of the support frame. The drive assembly is disposed on one side of the first jaw assembly. The drive assembly is used to drive the first jaw assembly to move so as to cooperate with the second jaw assembly to clamp or release the wafer.

[0013] Furthermore, the first jaw assembly includes a driving engagement component and a movable jaw. The driving engagement component is rotatably connected to the support frame. The driving engagement component includes a first end and a second end. The first end is correspondingly disposed with the driving component, and the second end abuts against the movable jaw. When the driving component moves in the direction close to the wafer, it can drive the driving engagement component to rotate, thereby driving the movable jaw to move in the direction away from the wafer, so that the movable jaw moves from the clamping position of clamping the wafer to the releasing position of releasing the wafer.

[0014] Secondly, the present invention provides a wafer defect detection method, applied to a wafer defect detection device as described in any of the above embodiments, comprising the following steps: S1, move the wafer to the corresponding position of the initial inspection unit, the initial inspection unit collects the initial inspection image of the wafer defects, and analyzes the initial inspection image to obtain the defect type and defect coordinates; among them, the defect types include distinguishable and difficult-to-distinguish types. Distinguishable types include through holes, surface pits and scratches, while difficult-to-distinguish types include dust particles and internal bubbles. S2. Based on the defect type and defect coordinates obtained in step S1, the defects are re-inspected in sequence. In the case of a distinguishable defect type, the re-inspection organization performs precise inspection of the defect and obtains detailed defect information. In the case of a difficult-to-distinguish defect type, the wafer is moved to the corresponding position of the re-inspection organization. S3, during the wafer movement process in step S2, the distance between the hard-to-distinguish defects and the visual center coordinates of the re-inspection camera is determined and recorded as compensation data. The wafer is moved according to the compensation data until the hard-to-distinguish defects are moved to the center of the field of view of the re-inspection camera. The re-inspection camera acquires the re-inspection image of the hard-to-distinguish defects and determines the specific type of hard-to-distinguish defects. S4. When the specific type of difficult-to-distinguish defect is internal air bubble, based on the absolute deviation between the center of the re-inspection camera's field of view and the focal position of the depth sensor, the internal air bubble defect, which has been compensated to the center of the re-inspection camera's field of view, is directly and relatively displaced to the corresponding position below the depth sensor. The depth sensor emits a laser point to measure the depth value of the internal air bubble.

[0015] Compared with related technologies, the beneficial effects of the present invention are as follows: This invention clamps the wafer using a clamping mechanism and moves it along a first direction to the corresponding position of the preliminary inspection mechanism. The preliminary inspection mechanism performs preliminary identification and location of surface and internal defects on the wafer to obtain preliminary defect information. During the inspection process, the clamping mechanism can adjust the position of the wafer along the first or second direction to meet the inspection requirements. The preliminary inspection mechanism can distinguish between three types of defects: through holes, surface pits, and scratches. However, it cannot directly distinguish between dust particles and internal air bubbles.

[0016] After the initial inspection, the clamping mechanism moves the wafer along the first direction to the corresponding position of the re-inspection mechanism. The re-inspection mechanism re-inspects the wafer defects based on the initial inspection defect information, distinguishes between dust particles and internal bubbles, further determines the specific type and morphology of the defects, and obtains re-inspection defect information such as the defect coordinates of internal bubbles. For internal bubble defects, after the re-inspection, the clamping mechanism moves the wafer along the first direction to the corresponding position of the internal inspection mechanism. The internal inspection mechanism detects the depth value of the internal bubbles using a depth sensor. In this way, not only can the coordinates of the internal defects of the wafer be detected, but also the depth value of the defects can be detected, and the specific location of the defects can be obtained. The detection process is simple and the detection efficiency is high. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only one embodiment of the present invention. For those skilled in the art, other embodiments can be derived from the provided drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of the wafer defect detection equipment provided by the present invention; Figure 2 This is a schematic diagram of the re-inspection mechanism provided by the present invention; Figure 3 This invention provides Figure 1 An enlarged structural diagram of part A shown in the figure; Figure 4 This is a schematic diagram of another wafer internal defect detection device provided by the present invention; Figure 5 This invention provides Figure 4 An enlarged structural diagram of section C shown in the figure; Figure 6 This is a side view of the wafer defect detection device provided by the present invention; Figure 7 This is a schematic diagram of the structure of the first sliding mechanism and the second sliding mechanism provided by the present invention; Figure 8 This is a schematic diagram of the structure of the clamping mechanism provided by the present invention moving to the corresponding positions of the driving component and the driving mating part; Figure 9 This invention provides Figure 8 An enlarged structural diagram of part E shown in the figure; Figure 10 This invention provides Figure 8 An enlarged structural diagram of part F shown in the figure; Figure 11This is a schematic diagram of the structure of the clamping mechanism, the first sliding mechanism, and the second sliding mechanism provided by the present invention. Figure 12 This invention provides Figure 11 An enlarged structural diagram of section H shown in the figure; Figure 13 This invention provides Figure 1 An enlarged structural diagram of part G shown in the figure; Figure 14 This is a flowchart of the wafer defect detection method provided by the present invention.

[0019] In the diagram: 2. Clamping mechanism; 21. Support frame; 211. First fixing block; 22. First claw assembly; 221. Drive mating part; 2211. First end; 2212. Second end; 222. Movable claw; 2221. Extension rod; 223. Elastic element; 224. Limiting part; 225. Third slide rail; 23. Second claw assembly; 231. Second fixing block; 232. Second claw; 24. Drive assembly; 241. Fixing part; 2411. Support rod; 2412. First sensor; 242. Drive element; 243. Moving part; 25. Light shield; 251. Second through hole; 252. Drive part; 253. Drive mating part; 26. Second sensor; 27. Light shield limiting part; 3. Initial inspection mechanism; 31. Base plate; 32. First support frame; 321. First crossbeam; 322. Second crossbeam; 33. Initial inspection light source; 34. Initial inspection camera; 4. Re-inspection mechanism; 41. Second support frame; 42. Re-inspection camera; 43. First re-inspection light source; 44. Second re-inspection light source; 45. Light source adjustment component; 46. Re-inspection adjustment component; 461. Lateral adjustment component; 462. Longitudinal adjustment component; 463. Angle adjustment component; 5. Internal inspection mechanism; 51. Depth sensor; 52. Sensor lateral drive component; 53. Sensor longitudinal drive component; 6. First sliding mechanism; 61. First slide rail; 62. First slide plate; 7. Second sliding mechanism; 71. Second slide rail; 72. Second slide plate; 8. Wafer. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and examples: Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0021] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0022] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0023] Combination Figure 1-6 As shown, this embodiment of the present disclosure provides a wafer defect detection device, including a base plate 31, a clamping mechanism 2, a preliminary inspection mechanism 3, a re-inspection mechanism 4, and an internal inspection mechanism 5. The base plate 31 is provided with a first support frame 32 and a second support frame 41. The preliminary inspection mechanism 3 and the internal inspection mechanism 5 are disposed on the first support frame 32, and the re-inspection mechanism 4 is disposed on the second support frame 41. The re-inspection mechanism 4, the preliminary inspection mechanism 3, and the internal inspection mechanism 5 are arranged sequentially along a first direction. The clamping mechanism 2 is used to clamp the wafer 8 and can move relative to the re-inspection mechanism 4, the preliminary inspection mechanism 3, and the internal inspection mechanism 5 along a first direction and a second direction. The first direction and the second direction are perpendicular to each other. The internal inspection mechanism 5 includes a depth sensor 51.

[0024] Using the wafer defect detection equipment provided in this embodiment, the wafer 8 is clamped by the clamping mechanism 2 and moved along the first direction to the corresponding position of the preliminary inspection mechanism 3. The preliminary inspection mechanism 3 performs preliminary identification and positioning of surface and internal defects of the wafer 8 to obtain preliminary defect information. During the detection process, the clamping mechanism 2 can move the wafer 8 along the first or second direction to adjust the position of the wafer 8 to meet the detection requirements. The preliminary inspection mechanism 3 can distinguish between three types of defects: through holes, surface pits and scratches. Dust particles and internal air bubbles cannot be directly distinguished.

[0025] After the initial inspection, the clamping mechanism 2 moves the wafer 8 along the first direction to the corresponding position of the re-inspection mechanism 4. The re-inspection mechanism 4 re-inspects the defects of the wafer 8 based on the initial inspection defect information, distinguishes between dust particles and internal air bubbles, and further determines the specific type and morphology of the defects, thus obtaining the re-inspection defect information of the wafer 8. For internal air bubble defects, after the re-inspection, the clamping mechanism 2 moves the wafer 8 along the first direction to the corresponding position of the internal inspection mechanism 5. The internal inspection mechanism 5 detects the depth value of the internal air bubbles through the depth sensor 51. In this way, not only can the coordinates of the internal defects of the wafer 8 be detected, but also the depth value of the defects can be detected, thus obtaining the specific location of the defects. The detection process is simple and the detection efficiency is high.

[0026] like Figure 1 As shown, the first direction is the x-axis direction, and the second direction is the y-axis direction.

[0027] Based on the above technical solutions, such as Figure 1 As shown, the first support frame 32 includes a first crossbeam 321, which extends along a second direction. The initial inspection mechanism 3 includes an initial inspection light source 33 and multiple initial inspection cameras 34. The multiple initial inspection cameras 34 are evenly distributed on the first crossbeam 321 along the second direction. The initial inspection light source 33 is disposed on the base plate 31 and extends along the second direction. When the clamping mechanism 2 moves along the first direction to the point where the wafer 8 is correspondingly positioned with the initial inspection mechanism 3, the multiple initial inspection cameras 34 and the initial inspection light source 33 are respectively positioned above and below the wafer 8.

[0028] Specifically, the multiple preliminary inspection cameras 34 are line scan cameras. When the preliminary inspection mechanism 3 performs inspection, the preliminary inspection cameras 34 and the preliminary inspection light source 33 are turned on. The clamping mechanism 2 drives the wafer 8 to move along the first direction so that the wafer 8 passes under the multiple preliminary inspection cameras 34. The multiple preliminary inspection cameras 34 collect images of the surface of the wafer 8, perform preliminary identification and positioning of wafer defects, and obtain preliminary inspection defect information. The preliminary inspection defect information includes defect type and defect coordinates.

[0029] In this embodiment, as Figure 1 As shown, there are three primary inspection cameras 34. Depending on the selection of the primary inspection cameras 34, after the wafer 8 passes under the primary inspection cameras 34 for the first time, the sum of the shooting areas of the three primary inspection cameras 34 is half the area of ​​the wafer 8. Therefore, the detection of the primary inspection mechanism 3 is divided into two steps. After the wafer 8 moves under the primary inspection cameras 34 for the first time, an image of a part of the surface of the wafer 8 is taken. The clamping mechanism 2 drives the wafer 8 to move a certain distance along the second direction, and then moves it again along the first direction so that the wafer 8 passes under the primary inspection cameras 34 and takes an image of the remaining part of the surface of the wafer 8 to complete the detection of the surface of the wafer 8 and obtain the primary inspection defect information of the surface of the wafer 8.

[0030] Furthermore, such as Figure 1and Figure 2 As shown, the second support frame 41 is disposed on one side of the first support frame 32 along the first direction. The re-inspection mechanism 4 includes a re-inspection camera 42, a first re-inspection light source 43 and a second re-inspection light source 44. The re-inspection camera 42 and the second re-inspection light source 44 are disposed on the second support frame. The first re-inspection light source 43 is disposed on the base plate 31 and is disposed opposite to the re-inspection camera 42. When the clamping mechanism moves along the first direction to the point where the wafer 8 is disposed corresponding to the re-inspection mechanism 4, the re-inspection camera 42 and the second re-inspection light source 44 are disposed above the wafer 8 and the first re-inspection light source 43 is disposed below the wafer 8.

[0031] Specifically, the initial inspection mechanism 3 obtains the defect type and coordinates. For difficult-to-distinguish dust particles and internal air bubbles, the re-inspection camera 42, in conjunction with the first re-inspection light source 43 and the second re-inspection light source 44, acquires re-inspection images to further determine the defect type. The first re-inspection light source 43 is transmitted light, and the second re-inspection light source 44 is visible light. Dust particles are located on the surface of the wafer 8, and visible light cannot penetrate the wafer. Under visible light illumination only, the re-inspection image only shows dust particles. With the cooperation of the first and second re-inspection light sources 43 and 44, defects appearing white in the re-inspection image are dust particles, and defects appearing black are internal air bubbles. After identifying the internal air bubbles, the coordinates of this type of defect are marked. The clamping mechanism 2 moves the wafer 8 along a first or second direction as needed to facilitate the re-inspection camera 42 in observing and capturing images of the wafer 8 to obtain re-inspection defect information.

[0032] Based on the above technical solutions, such as Figure 2 As shown, a light source adjustment component 45 is provided between the second re-inspection light source 44 and the second support frame 41. The light source adjustment component 45 is used to adjust the angle of the second re-inspection light source 44 relative to the wafer 8.

[0033] To more precisely adjust the relative position between the inspection camera 42 and the wafer 8, such as Figure 3 As shown, a re-inspection adjustment component 44 is provided between the second support frame 41 and the re-inspection camera 42. The re-inspection adjustment component 44 includes a horizontal adjustment component 441, a vertical adjustment component 442 and an angle adjustment component 443, which are used to adjust the position of the re-inspection camera 42 along the first direction and the second direction, as well as the angle along the circumferential direction of the wafer 8.

[0034] The position of the re-inspection camera 42 relative to the wafer 8 along the first direction can be adjusted by the horizontal adjustment member 441, the position of the re-inspection camera 42 relative to the wafer 8 along the second direction can be adjusted by the vertical adjustment member 442, and the relative angle of the re-inspection camera 42 to the wafer 8 along the circumferential direction can be adjusted by the angle adjustment part 443. This allows for precise adjustment of the position of the re-inspection camera 42 relative to the wafer 8, resulting in better imaging effect of the re-inspection camera 42 and improved inspection accuracy of the wafer 8.

[0035] Specifically, the lateral adjustment component 441, the longitudinal adjustment component 442, and the angle adjustment component 443 are arranged sequentially from bottom to top.

[0036] Based on the above technical solutions, such as Figure 4-6 As shown, the first support frame 32 includes a second crossbeam 322, which extends in the same direction as the first crossbeam 321 and is located below the first crossbeam 321. The second crossbeam 322 is provided with a sensor lateral drive member 52, and a sensor longitudinal drive member 53 is provided on the sensor lateral drive member 52. The depth sensor 51 is located on the sensor longitudinal drive member 53. When the clamping mechanism 2 moves along the first direction to the point where the wafer 8 is correspondingly positioned with the internal inspection mechanism 5, the depth sensor 51 is located above the wafer 8.

[0037] The depth sensor 51 can be a laser interferometer, a structured light sensor, a spectral confocal sensor, or a photoacoustic wave detection sensor.

[0038] Specifically, the clamping mechanism 2 moves the wafer 8 along the first direction to the corresponding position of the internal inspection mechanism 5. The clamping mechanism 2 moves the wafer 8 along the first and second directions. According to the internal defect coordinates of the wafer detected by the re-inspection mechanism 4, the internal defect is moved to the bottom of the depth sensor 51 and placed opposite to the position of the depth sensor 51. The depth sensor 51 emits a laser point to irradiate the wafer 8. The laser point corresponds to the position of the internal bubble hole to measure the depth value of the internal bubble hole.

[0039] Furthermore, such as Figure 4 and Figure 7 As shown, the wafer defect detection equipment also includes a first sliding mechanism 6 and a second sliding mechanism 7. The first sliding mechanism 6 includes a first slide rail 61 and a first slide plate 62. The first slide rail 61 extends along a first direction and is disposed on the base plate 31. One end of the first slide plate 62 is slidably connected to the first slide rail 61, and the other end of the first slide plate 62 extends along a second direction. The second sliding mechanism 7 includes a second slide rail 71 and a second slide plate 72. The second slide rail 71 is disposed on the first slide plate 62 and extends along a second direction. The second slide plate 72 is slidably connected to the second slide rail 71. The clamping mechanism 2 is connected to the second slide plate 72.

[0040] Specifically, the first sliding mechanism 6 also includes a first drive motor, which drives the first slide plate 62 to slide along the first slide rail 61, thereby driving the second sliding mechanism 7 to move relative to the first slide rail 61 in a first direction, and thus driving the clamping mechanism 2 to move in the first direction. The second sliding mechanism 7 also includes a second drive motor, which drives the second slide plate 72 to slide along the second slide rail 71, thereby driving the clamping mechanism 2 to move in a second direction. The arrangement of the first sliding mechanism 6 and the second sliding mechanism 7 can drive the clamping mechanism 2 to move in the first and second directions, so as to facilitate the adjustment of the wafer 8 position during the inspection process and improve the inspection efficiency and effect.

[0041] Based on the above technical solutions, such as Figure 8 As shown, the clamping mechanism 2 includes a support frame 21, a first claw assembly 22, a second claw assembly 23, and a drive assembly 24. The support frame 21 is connected to the second slide plate 72. The first claw assembly 22 and the second claw assembly 23 are disposed opposite each other on the top wall of the support frame 21. The drive assembly 24 is disposed on one side of the first claw assembly 22. The drive assembly 24 is used to drive the first claw assembly 22 to move so as to cooperate with the second claw assembly 23 to clamp or release the wafer 8.

[0042] By setting a support frame 21 and setting a first jaw assembly 22 and a second jaw assembly 23 on the support frame 21, when the wafer 8 is clamped between the first jaw assembly 22 and the second jaw assembly 23, the drive assembly 24 moves from one side of the first jaw assembly 22 in a direction close to the first jaw assembly 22. When it moves to contact the first jaw assembly 22, it continues to move to drive the first jaw assembly 22 to move away from the wafer 8 to release the wafer 8. The drive assembly 24 moves in a direction away from the wafer 8, which enables the first jaw assembly 22 to move in a direction close to the wafer 8, thereby cooperating with the second jaw assembly 23 to clamp the wafer 8.

[0043] Furthermore, such as Figure 9 As shown, the first jaw assembly 22 includes a driving engagement component 221 and a movable jaw 222. The driving engagement component 221 is rotatably connected to the support frame 21. The driving engagement component 221 includes a first end 2211 and a second end 2212. The first end 2211 is correspondingly disposed with the driving assembly 24, and the second end 2212 abuts against the movable jaw 222. When the driving assembly 24 moves in the direction close to the wafer 8, it can drive the driving engagement component 221 to rotate, thereby driving the movable jaw 222 to move in the direction away from the wafer 8, so that the movable jaw 222 moves from the clamping position of clamping the wafer 8 to the releasing position of releasing the wafer 8.

[0044] Specifically, this application takes two first claw assemblies 22 and two second claw assemblies 23 as an example. The two first claw assemblies 22 are disposed on one side of the top wall of the support frame 21, and the two second claw assemblies 23 are disposed on the other side of the top wall of the support frame 21. The drive assembly 24 can drive the two first claw assemblies 22 to move simultaneously. When the drive assembly 24 moves along the direction closer to the wafer 8, that is, when the drive assembly 24 gradually approaches the first end 2211 of the two drive mating parts 221, and moves until the drive assembly 24 contacts the first end 2211 of the two drive mating parts 221, the drive assembly 24 continues to move, causing the drive mating parts 221 to rotate relative to the support frame 21. During the rotation, the second end 2212 of the drive mating part 221 that abuts against the movable claw 222 moves along the direction away from the wafer 8, so as to drive the movable claw 222 away from the wafer 8 to release the wafer 8. The drive mating part 221 is configured to cooperate with the drive assembly 24 to drive the movable jaw 222 to move relative to the wafer 8, so as to achieve stable clamping of the wafer 8.

[0045] like Figure 9 As shown, the first jaw assembly 22 further includes an elastic element 223. The support frame 21 is provided with a first fixing block 211. The first fixing block 211 is disposed on the side of the movable jaw 222 away from the wafer 8. The elastic element 223 is disposed between the first fixing block 211 and the movable jaw 222. When the drive assembly 24 moves in the direction away from the wafer 8, the elastic element 223 drives the movable jaw 222 to move from the loose position to the clamping position.

[0046] like Figure 9 As shown, the movable jaw 222 has an extension rod 2221 on the side near the drive mating member 221, and the extension rod 2221 abuts against the second end 2212 of the drive mating member 221. When the drive assembly 24 moves along the direction close to the wafer 8, and moves to abut against the first end 2211 of the drive mating member 221, it continues to move to drive the drive mating member 221 to rotate. The second end 2212 of the drive mating member 221 abuts against the extension rod 2221 of the movable jaw 222. When the drive mating member 221 rotates, the movable jaw 222 moves through the extension rod 2221.

[0047] To limit the rotation angle of the drive mating part 221, such as Figure 9As shown, the first claw assembly 22 further includes a limiting part 224, which abuts against the side of the second end 2212 of the drive engagement member 221 that is close to the wafer 8, and the extension rod 2221 abuts against the side of the second end 2212 of the drive engagement member 221 that is away from the wafer 8. When the drive assembly 24 drives the drive mating part 221 to rotate so that the movable jaw 222 is in the released position, the drive assembly 24 moves away from the wafer 8, causing the drive mating part 221 to rotate until the second end 2212 of the drive mating part 221 abuts against the limiting part 224. The extension rod 2221 of the movable jaw 222 abuts against the second end 2212 of the drive mating part 221, thereby limiting the movable jaw 222 to the clamping position. The setting of the limiting part 224 can prevent the movable jaw 222 from excessively displacing in the direction close to the wafer 8, ensuring that the clamping force of the movable jaw 222 on the wafer 8 is moderate and avoiding damage to the wafer 8 due to excessive clamping.

[0048] To make the movement of the 222 claw more stable and smooth, such as Figure 9 As shown, the first claw assembly 22 also includes a third slide rail 225, which is disposed on the support frame 21. The third slide rail 225 extends along the radial direction of the wafer 8. The movable claw 222 can move along the third slide rail 225 toward the wafer 8 or away from the wafer 8 to clamp or release the wafer 8.

[0049] like Figure 10 As shown, the second claw assembly 23 includes a second fixing block 231 and a second claw 232. The second fixing block 231 is fixedly mounted on the support frame 21. The second fixing block 231 has a groove that extends radially along the wafer 8. The second claw 232 is located in the groove and has an elongated hole that extends radially along the wafer 8. The second fixing block 231 has a first through hole. A fastener passes through the elongated hole and the first through hole to fix the second claw 232 to the second fixing block 231. By adjusting the position of the fastener relative to the elongated hole along the extension direction, the position of the second claw 232 relative to the wafer 8 can be adjusted.

[0050] Furthermore, such as Figure 8 and Figure 11 As shown, the clamping mechanism 2 also includes a light-shielding plate 25, which is disposed on the bottom wall of the support frame 21. The support frame 21 and the light-shielding plate 25 are both provided with a second through hole 251 at their center. The size of the second through hole 251 is adapted to the size of the wafer 8.

[0051] To prevent other ambient light from affecting the inspection of wafer 8, a light shield 25 is provided to block other light around wafer 8. The end of the movable claw 222 on the support frame 21 near wafer 8 protrudes from the support frame 21 to hold wafer 8. The diameter of the second through hole 251 of the support frame 21 is slightly larger than the diameter of wafer 8, and the diameter of the second through hole 251 of the light shield 25 is slightly smaller than the diameter of wafer 8. In this way, when inspecting the lower surface of wafer 8, the light shield 25 can also block the interference position of the movable claw 222 on wafer 8, thus avoiding affecting the inspection.

[0052] Specifically, such as Figure 11 and Figure 12 As shown, the second support frame 41 is provided with a driving part 252, and the light-shielding plate 25 is provided with a driving engagement part 253. The driving part 252 can drive the driving engagement part 253 to move downward, thereby moving the light-shielding plate 25 downward. An opening is provided on one side of the support frame 21. When the moving unit moves the wafer 8 to the clamping mechanism 2, the driving part 252 of the second support frame 41 drives the driving engagement part 253 of the light-shielding plate 25 to move downward, thereby moving the light-shielding plate 25 downward, creating a gap between the light-shielding plate 25 and the support frame 21. The moving unit, carrying the wafer 8, extends into the support frame 21 through the opening and places the wafer 8 on the first claw assembly 22 and the second claw assembly 23. After the moving unit is withdrawn, the driving part 252 drives the light-shielding plate 25 to return to its original position. The driving part 252 and the driving engagement part 253 prevent the light-shielding plate 25 from interfering with the movement and placement of the wafer 8. The drive unit 252 can be a pneumatic cylinder, a hydraulic cylinder, or an electric cylinder.

[0053] Based on the above technical solutions, such as Figure 13 As shown, the driving assembly 24 includes a fixing member 241, a driving member 242, and a moving member 243. The fixing member 241 is disposed on one side of the first claw assembly 22. The driving member 242 is disposed on the top of the fixing member 241. The moving member 243 is disposed on the top of the driving member 242. The driving member 242 can drive the moving member 243 to move in a direction close to or away from the wafer 8. The moving member 243 is provided with an extension. When the movable claw 222 moves from the clamping position to the releasing position, the end of the extension near the wafer 8 contacts the first end 2211 of the driving mating member 221.

[0054] Specifically, the movable member 243 can move relative to the fixed member 241 in a direction close to or away from the wafer 8 under the drive of the driving member 242. The extension of the movable member 243 extends in the direction close to the wafer 8 and is correspondingly disposed with the first end 2211 of the driving engagement member 221. When the wafer 8 needs to be removed, the driving member 242 drives the movable member 243 to move in the direction close to the wafer 8, so that the extension of the movable member 243 abuts against the first end 2211 of the driving engagement member 221, causing the driving engagement member 221 to rotate, so that the movable chuck 222 releases the wafer 8. The driving member 242 can be a piston cylinder or an electric cylinder.

[0055] Furthermore, such as Figure 13 As shown, the fixing member 241 is provided with a support rod 2411. One end of the support rod 2411 extends along the direction close to the wafer 8 to the bottom of the support frame 21 and is provided with a first sensor 2412. The support frame 21 is provided with a through hole, which is correspondingly arranged with the second end 2212 of the drive mating member 221. The first sensor 2412 is correspondingly arranged with the through hole. The first sensor 2412 is used to detect whether the movable claw 222 is in the clamping position or the loosening position.

[0056] Specifically, there can be one or more support rods 2411. When there are two or more first claw assemblies 22, the number of support rods 2411 is the same as the number of first claw assemblies 22, and they are set one-to-one with the first claw assemblies 22. Each first sensor 2412 detects whether the second end 2212 of the drive mating part 221 is located at the relative position of the through hole, thereby determining whether the movable claw 222 is in the clamping position or the loosening position.

[0057] Furthermore, such as Figure 13 As shown, the clamping mechanism 2 also includes a second sensor 26 and a light-shielding plate limiting member 27. The second sensor 26 is located below the wafer 8 and is used to detect whether the clamping mechanism 2 is clamping the wafer 8. The light-shielding plate limiting member 27 is located below the light-shielding plate 25 corresponding to the opening of the support frame 21. When the driving part 252 of the second support frame 41 drives the driving engagement part 253 on the light-shielding plate 25 to move, so that the light-shielding plate 25 moves downward, the light-shielding plate 25 moves to the light-shielding plate limiting member 27. The light-shielding plate limiting member 27 can limit the light-shielding plate 25, prevent the light-shielding plate 25 from moving too low, and also play a role in shock absorption and protection of the light-shielding plate 25 to a certain extent.

[0058] Combination Figure 14 As shown, this disclosure provides a wafer defect detection method, applied to a wafer defect detection device as described in any of the above embodiments, comprising the following steps: S1, move wafer 8 to the corresponding position of the initial inspection mechanism 3, the initial inspection mechanism 3 collects the initial inspection image of the defects of wafer 8, and analyzes the initial inspection image to obtain the defect type and defect coordinates; among them, the defect types include distinguishable and difficult-to-distinguish types, distinguishable types include through holes, surface pits and scratches, and difficult-to-distinguish types include dust particles and internal air bubbles.

[0059] Specifically, different types of defects include dust particles, through holes, internal air bubbles, surface pits, and scratches. The initial inspection unit 3 can directly identify through holes, surface pits, and scratches, while internal air bubbles and dust particles are difficult to distinguish. Defect differentiation is mainly achieved through the different presentation methods of different defects: dust particles and internal air bubbles appear black, through holes are white, surface pits are annular holes with a black exterior and white interior, and scratches are thin, elongated gray stripes. The characteristics of each defect are determined by the initial inspection images acquired by the initial inspection unit 3, thus classifying each defect. After classification, the process proceeds to S2. The initial inspection unit 3 can perform preliminary detection of the basic information of various defects, including the size, length, and coordinate position of the defect.

[0060] S2. Based on the defect type and defect coordinates obtained in step S1, the defects are inspected again in sequence. When the defect type is distinguishable, the re-inspection mechanism 4 performs precise inspection of the defect and obtains detailed defect information. When the defect type is difficult to distinguish, the wafer 8 is moved to the corresponding position of the re-inspection mechanism 4.

[0061] Specifically, if the defects are through holes, surface scratches, and pits that can be identified by the initial inspection agency, then a more detailed and precise inspection is performed on the defects to obtain detailed defect information, including the coordinate position, size, length, and other information of the defects. If the defects are dust particles and internal air bubbles that are difficult for the initial inspection agency 3 to distinguish, then the re-inspection agency 4 will further distinguish them.

[0062] S3, during the wafer movement process in step S2, the distance between the hard-to-distinguish defects and the visual center coordinates of the re-inspection camera 42 is determined and recorded as compensation data. The wafer 8 is moved according to the compensation data until the hard-to-distinguish defects are moved to the center of the field of view of the re-inspection camera 42. The re-inspection camera 42 acquires the re-inspection image of the hard-to-distinguish defects and determines the specific type of hard-to-distinguish defects.

[0063] Specifically, wafer 8 is moved into inspection mechanism 4 along the first and second directions. The first inspection light source 43 and the second inspection light source 44 are activated. The first inspection light source 43 is transmitted light, preferably near-infrared, and the second inspection light source 44 is visible light. The coordinates of the located defect are sequentially moved to the visual center of inspection camera 42. The distance between the coordinates of the visual center of inspection camera 42 and the coordinates of the located defect is determined based on the visual center coordinates and recorded as compensation data. Wafer 8 is moved based on the compensation data, and the defect position is compared with the visual center of inspection camera 42. Compensation data is recorded again. Wafer 8 is moved again based on the compensation data, and the above operation is repeated until the defect is moved to the exact center of the field of view of inspection camera 42.

[0064] Once the internal bubble defect moves to the center of the field of view of the re-inspection camera 42, the re-inspection camera 42 acquires and saves the re-inspection image. Analyzing the re-inspection image determines whether each defect is a dust particle or an internal bubble. Because the first re-inspection light source 43 is a near-infrared light source and the second re-inspection light source 44 is visible light, and dust particles are located on the wafer surface, visible light cannot penetrate the wafer 8. Therefore, the re-inspection image acquired under visible light only can only show defects on the surface of the wafer 8, i.e., dust particles, while internal bubbles located inside the wafer 8 cannot be captured. Therefore, with the cooperation of the first and second re-inspection light sources 43 and 44, defects appearing white in the re-inspection image are dust particles, and defects appearing black are internal bubbles. After identifying internal bubbles, the coordinates of this type of defect are marked.

[0065] The re-inspection camera 42 uses a telecentric lens. Due to the large depth of field of the telecentric lens, the re-inspection camera 42 can acquire internal defects at any position in the longitudinal depth of the wafer 8.

[0066] S4. In the case where the specific type of difficult-to-distinguish defect is internal air bubble, based on the absolute deviation between the center of the field of view of the re-inspection camera 42 and the focal position of the depth sensor 51, the internal air bubble defect, which has been compensated to the center of the field of view of the re-inspection camera 42, is directly and relatively displaced to the corresponding position below the depth sensor 51. The depth sensor 51 emits a laser point to measure the depth value of the internal air bubble.

[0067] Specifically, the depth sensor 51 emits a laser point that illuminates the surface of the wafer 8. The position on the surface of the wafer 8 corresponds to the position of the internal bubble hole, and is used to measure the depth value of the internal bubble hole. Taking an infrared interferometric thickness sensor as an example, the infrared interferometric thickness sensor is based on Fourier transform infrared spectroscopy and uses a light source in the near-infrared or mid-infrared band. For example, pure silicon has high transmittance in the infrared band and can be considered a transparent medium. The infrared interferometric thickness sensor can penetrate the wafer through the infrared beam, and the light is reflected at the surface of the wafer and the surface of the internal bubble hole. The reflected light returns to the sensor and interferes. By analyzing the interference pattern or interference fringes in the spectrum, the optical thickness between the two reflecting interfaces can be calculated, and the depth value of the internal bubble hole can be obtained.

[0068] Due to the inherent parameter limitations of the depth sensor 51, for it to calculate the depth of the internal bubble, the laser point emitted by the depth sensor 51 needs to perfectly correspond to the position of the internal bubble. As an optimization, when the wafer is positioned under the depth sensor 51 based on the coordinates of the internal bubble, the depth sensor 51 scans and detects a certain area around the defect to avoid discrepancies between the defect's position and the depth sensor 51's position. This scanning and detection of the area surrounding the defect is achieved by moving the depth sensor 51 in the first and second directions, respectively, using the sensor's lateral drive 52 and longitudinal drive 53.

[0069] The present invention has been described above by way of example, but the present invention is not limited to the specific embodiments described above. Any modifications or variations made based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A wafer defect detection device, characterized in that, The device includes a base plate, a clamping mechanism, a preliminary inspection mechanism, a re-inspection mechanism, and an internal inspection mechanism. The base plate is provided with a first support frame and a second support frame. The preliminary inspection mechanism and the internal inspection mechanism are located on the first support frame, and the re-inspection mechanism is located on the second support frame. The re-inspection mechanism, the preliminary inspection mechanism, and the internal inspection mechanism are arranged sequentially along a first direction. The clamping mechanism is used to clamp the wafer and can move relative to the re-inspection mechanism, the preliminary inspection mechanism, and the internal inspection mechanism along a first direction and a second direction. The first direction and the second direction are perpendicular to each other. The internal inspection mechanism includes a depth sensor.

2. The wafer defect detection equipment according to claim 1, characterized in that, The first support frame includes a first crossbeam extending along a second direction. The initial inspection mechanism includes an initial inspection light source and multiple initial inspection cameras. The multiple initial inspection cameras are evenly distributed on the first crossbeam along the second direction. The initial inspection light source is located on the base plate and extends along the second direction. When the clamping mechanism moves along the first direction to a position where the wafer and the initial inspection mechanism are aligned, the multiple initial inspection cameras and the initial inspection light source are respectively positioned above and below the wafer.

3. The wafer defect detection equipment according to claim 2, characterized in that, The second support frame is disposed on one side of the first support frame along the first direction. The re-inspection mechanism includes a re-inspection camera, a first re-inspection light source, and a second re-inspection light source. The re-inspection camera and the second re-inspection light source are disposed on the second support frame. The first re-inspection light source is disposed on the base plate and is disposed opposite to the re-inspection camera. When the clamping mechanism moves along the first direction to the point where the wafer is disposed corresponding to the re-inspection mechanism, the re-inspection camera and the second re-inspection light source are disposed above the wafer, and the first re-inspection light source is disposed below the wafer.

4. The wafer defect detection equipment according to claim 3, characterized in that, A light source adjustment component is provided between the second re-inspection light source and the second support frame. The light source adjustment component is used to adjust the angle of the second re-inspection light source relative to the wafer.

5. The wafer defect detection equipment according to claim 3, characterized in that, A re-inspection adjustment component is provided between the second support frame and the re-inspection camera. The re-inspection adjustment component includes a horizontal adjustment component, a vertical adjustment component, and an angle adjustment component, which are used to adjust the position of the re-inspection camera along the first direction and the second direction, as well as the angle along the wafer circumference direction.

6. The wafer defect detection equipment according to claim 2, characterized in that, The first support frame includes a second crossbeam, which extends in the same direction as the first crossbeam and is located below the first crossbeam. The second crossbeam is provided with a sensor lateral drive component, and a sensor longitudinal drive component is provided on the sensor lateral drive component. The depth sensor is located on the sensor longitudinal drive component. When the clamping mechanism moves along the first direction to the point where the wafer and the internal inspection mechanism are correspondingly arranged, the depth sensor is located above the wafer.

7. The wafer defect detection equipment according to any one of claims 1 to 6, characterized in that, It also includes a first sliding mechanism and a second sliding mechanism. The first sliding mechanism includes a first slide rail and a first slide plate. The first slide rail extends along a first direction and is disposed on the base plate. One end of the first slide plate is slidably connected to the first slide rail, and the other end of the first slide plate extends along a second direction. The second sliding mechanism includes a second slide rail and a second slide plate. The second slide rail is disposed on the first slide plate and extends along a second direction. The second slide plate is slidably connected to the second slide rail. The clamping mechanism is connected to the second slide plate.

8. The wafer defect detection equipment according to any one of claims 1 to 6, characterized in that, The clamping mechanism includes a support frame, a first jaw assembly, a second jaw assembly, and a drive assembly. The support frame is connected to a second slide plate. The first jaw assembly and the second jaw assembly are disposed opposite each other on the top wall of the support frame. The drive assembly is disposed on one side of the first jaw assembly. The drive assembly is used to drive the first jaw assembly to move so as to cooperate with the second jaw assembly to clamp or release the wafer.

9. The wafer defect detection equipment according to claim 8, characterized in that, The first jaw assembly includes a driving engagement component and a movable jaw. The driving engagement component is rotatably connected to the support frame. The driving engagement component includes a first end and a second end. The first end is correspondingly disposed with the driving component, and the second end abuts against the movable jaw. When the driving component moves in the direction close to the wafer, it can drive the driving engagement component to rotate, thereby driving the movable jaw to move in the direction away from the wafer, so that the movable jaw moves from the clamping position of clamping the wafer to the releasing position of releasing the wafer.

10. A wafer defect detection method, applied to the wafer defect detection equipment according to any one of claims 1 to 9, characterized in that, Includes the following steps: S1, move the wafer to the corresponding position of the initial inspection unit, the initial inspection unit collects the initial inspection image of the wafer defects, and analyzes the initial inspection image to obtain the defect type and defect coordinates; among them, the defect types include distinguishable and difficult-to-distinguish types. Distinguishable types include through holes, surface pits and scratches, while difficult-to-distinguish types include dust particles and internal bubbles. S2. Based on the defect type and defect coordinates obtained in step S1, the defects are re-inspected in sequence. In the case of a distinguishable defect type, the re-inspection organization performs precise inspection of the defect and obtains detailed defect information. In the case of a difficult-to-distinguish defect type, the wafer is moved to the corresponding position of the re-inspection organization. S3, during the wafer movement process in step S2, the distance between the hard-to-distinguish defects and the visual center coordinates of the re-inspection camera is determined and recorded as compensation data. The wafer is moved according to the compensation data until the hard-to-distinguish defects are moved to the center of the field of view of the re-inspection camera. The re-inspection camera acquires the re-inspection image of the hard-to-distinguish defects and determines the specific type of hard-to-distinguish defects. S4. When the specific type of difficult-to-distinguish defect is internal air bubble, based on the absolute deviation between the center of the re-inspection camera's field of view and the focal position of the depth sensor, the internal air bubble defect, which has been compensated to the center of the re-inspection camera's field of view, is directly and relatively displaced to the corresponding position below the depth sensor. The depth sensor emits a laser point to measure the depth value of the internal air bubble.

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