Wafer surface defect detection device

Abstract

The wafer surface defect detection device comprises a camera and a clamp, the clamp comprises an upper clamp and a lower clamp which are installed together, the upper clamp comprises two upper clamping jaws, the two upper clamping jaws are provided with cover plates, and the two upper clamping jaws are hinged together and can be opened in a rotating mode so that the cover plates of the upper clamp can be separated from the edge of the front face of a wafer; the lower clamp comprises two lower clamping jaws, the two lower clamping jaws are both provided with supporting plates, and the two lower clamping jaws are hinged together and can be opened in a rotating mode so that the supporting plates of the lower clamp can be separated from the edge of the back face of the wafer. When the front surface of the wafer is subjected to defect detection, the upper clamp is rotated and opened to enable the cover plate of the upper clamp to leave the edge of the front surface of the wafer, so that the cover plate cannot shield the edge of the front surface of the wafer. And after the front surface detection is completed, the clamp drives the clamped wafer to rotate together until the wafer is upside down. When defect detection needs to be carried out on the reverse side of the wafer, the lower clamp is rotated and opened, and then the camera is used for shooting the reverse side of the wafer so as to carry out defect detection on the wafer.

Description

Technical Field

[0001] This utility model relates to the field of wafer inspection technology, and specifically to a wafer surface defect detection device. Background Technology

[0002] A wafer is a silicon chip used in the fabrication of silicon semiconductor integrated circuits. It is called a wafer because of its circular shape. After wafer fabrication, defects need to be detected on both sides. Chinese invention patent document CN220508772U discloses a wafer surface defect detection device, which includes a top-mounted camera and a bottom-mounted detection seat. The detection seat has a detection groove. The wafer is placed in the detection groove with its front side facing up. The bottom wall of the detection groove supports the edge of the wafer's back side. An observation hole is opened at the center of the bottom wall. The detection seat can be rotated to be upside down. The detection device includes a pressure ring that can be mounted on the detection seat to press down the edge of the wafer's front side. In use, the camera first takes a picture of the wafer's front side to detect defects. Then, the pressure ring presses down on the edge of the wafer's front side, and the detection seat rotates the wafer to be upside down. After rotation, the wafer's front side faces down and the back side faces up. The pressure ring acts as a support, supporting the edge of the wafer's front side, and the bottom wall of the detection groove covers the edge of the wafer's back side. The camera takes a picture of the wafer's back side through the observation hole to detect defects. The inspection seat and the pressure ring together form a wafer fixture. This device can perform defect inspection on both sides of the wafer with only one clamping, which improves the inspection efficiency. However, since the bottom wall of the inspection slot covers the edge of the wafer's reverse side after rotation, it will block the edge of the wafer's reverse side and affect the camera's ability to capture the edge of the wafer's reverse side. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide a wafer surface defect detection device that can detect defects on both sides of the wafer with only one clamping, and the clamp will not obstruct the edge of the wafer surface.

[0004] To solve the above-mentioned technical problems, this utility model provides a wafer surface defect detection device, including a camera for detecting wafer surface defects and a clamp for clamping a wafer with the front side facing up. The clamp includes an upper clamp and a lower clamp mounted together. The upper clamp includes two upper jaws for clamping the upper part of the wafer. Each upper jaw is provided with a cover plate for covering the edge of the front side of the wafer. The two upper jaws are hinged together and can be rotated open to allow the cover plate to leave the edge of the front side of the wafer. The lower clamp includes two lower jaws for clamping the lower part of the wafer. Each lower jaw is provided with a support plate for supporting the edge of the back side of the wafer. The two lower jaws are hinged together and can be rotated open to allow the support plate to leave the edge of the back side of the wafer. The upper and lower clamps can drive the clamped wafer to rotate together around a horizontal axis until it is upside down.

[0005] Furthermore, the fixture is rotatably mounted on the base, which can cause the clamped wafer to rotate together around the vertical axis.

[0006] Furthermore, the support plate of the lower jaw extends upward to support the first silicone block for supporting the reverse edge of the wafer. When the first silicone block rotates around the vertical axis, it applies frictional force to the reverse edge of the wafer, thereby causing the wafer to rotate together around the vertical axis. The pressure plate of the upper jaw extends downward to support the second silicone block. When the upper and lower jaws rotate the clamped wafer around the horizontal axis until it is upside down, the second silicone block supports the front edge of the wafer. When the upper jaw rotates around the vertical axis, the second silicone block applies frictional force to the front edge of the supported wafer, thereby causing the wafer to rotate together around the vertical axis.

[0007] Furthermore, the support plate of the lower gripper has a first mounting groove with the opening facing upwards, and the first silicone block is movably mounted on the support plate and can be moved into the first mounting groove; the cover plate of the upper gripper has a second mounting groove with the opening facing downwards, and the second silicone block is movably mounted on the cover plate and can be moved into the second mounting groove.

[0008] Furthermore, the two upper jaws are hinged together at their head ends and magnetically attracted at their tail ends. When the tail ends of the two upper jaws are released from magnetic attraction and move away from each other, the two upper jaws will rotate and open. Similarly, the two lower jaws are hinged together at their head ends and magnetically attracted at their tail ends. When the tail ends of the two lower jaws are released from magnetic attraction and move away from each other, the two upper jaws will rotate and open.

[0009] Furthermore, the inner sidewall of the lower jaw is provided with multiple spherical rotating beads, and the sidewalls of the two lower jaws clamp the lower sidewall of the wafer through the rotating beads.

[0010] Furthermore, it also includes a support frame and a transverse rotating shaft mounted on the support frame. The upper and lower clamps are mounted on the transverse rotating shaft, which has a protrusion. The support frame has two opposing limiting blocks, a first and a second. The protrusion is supported on the first limiting block. The transverse rotating shaft drives the upper and lower clamps to rotate upside down, thereby driving the wafer clamped by the upper and lower clamps to rotate upside down. When the wafer is upside down, the protrusion rotates toward the second limiting block and is supported on the second limiting block.

[0011] Before performing defect inspection on the wafer surface, the wafer is placed face up in the fixture. Upper and lower fixtures clamp the upper and lower parts of the wafer, respectively, while the lower fixture's support plate supports the wafer's reverse edge. In this state, the upper fixture's cover plate covers the wafer's face edge. When inspecting the wafer's face for defects: first, the upper fixture is rotated open, removing the cover plate from the wafer's face edge. Then, a camera is used to photograph the wafer's face for defect inspection. Because the upper fixture's cover plate is away from the wafer's face edge, it does not obstruct the camera's view of the front edge. After the front inspection is complete, the upper fixture is rotated to close and clamp the upper part of the wafer. Then, the fixture rotates the clamped wafer until it is upside down. After rotation, the wafer's face is down, the upper fixture's cover plate supports the wafer's face edge, and the lower fixture's support plate covers the wafer's reverse edge. When it is necessary to perform defect detection on the reverse side of the wafer, the lower clamp is rotated to open, so that the support plate of the lower clamp is away from the edge of the reverse side of the wafer. Then, the camera is used to photograph the reverse side of the wafer to perform defect detection. It can be seen that this device can perform defect detection on both sides of the wafer with only one clamping. Since the support plate of the lower clamp is away from the edge of the reverse side of the wafer, it will not block the edge of the reverse side of the wafer and will not affect the camera's ability to photograph the edge of the reverse side of the wafer. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of a fixture for a wafer surface defect detection device, with the fixture in a flat position.

[0013] Figure 2 This is a top view of the fixture.

[0014] Figure 3 yes Figure 2 AA sectional view

[0015] Figure 4 yes Figure 2 BB cross-sectional view.

[0016] Figure 5 yes Figure 4 A magnified view of a portion of the image, showing a larger area. Figure 4 Part D.

[0017] Figure 6 This is a schematic diagram from another perspective of the wafer surface defect detection device, in which the fixture is in a flat position.

[0018] Figure 7 yes Figure 6 A magnified view of a portion of the image, showing a larger area. Figure 6 Part E.

[0019] Figure 8 This is an exploded view of the lower gripper.

[0020] Figure 9 This is a schematic diagram of a wafer surface defect detection device, in which the upper fixture has been rotated and opened.

[0021] Figure 10 This is a schematic diagram of a wafer surface defect detection device, in which the fixture is in a rotating state. Detailed Implementation

[0022] Wafer surface defect detection device (see) Figure 1 The system includes a base 2, on which a motor 6 is mounted. A drive shaft 61 of the motor 6 extends upwards and is fixedly mounted on a base plate 7. A support frame 4 extends upwards from the left end of the base plate 7. A horizontal rotating shaft 5 in the left-right direction is rotatably mounted on the support frame 4, and a clamp 3 is mounted on the horizontal rotating shaft 5. (See...) Figure 6 , Figure 7 The support frame 4 is equipped with two limiting blocks 41 and 42, one in front and one in back. The transverse rotating shaft 5 extends forward with a protruding block 51 that supports the front limiting block 41. The device includes a mounting frame 8, which is installed at the rear of the base 2. The top of the mounting frame 8 extends forward and is equipped with a camera 1, which faces downward and is aligned with the fixture 3. Before performing defect inspection on both sides of the wafer 9, the wafer 9 is placed face up in the fixture 3 and clamped by the fixture 3. In this state, the camera 1 faces downward and is aligned with the wafer 9, and the vertical axis (not shown in the figure) of the drive shaft 61 of the motor 6 passes exactly through the center of the wafer 9.

[0023] The procedure for defect detection on both the front and back surfaces of wafer 9 is as follows:

[0024] See Figure 9 Camera 1 is used to photograph the front of wafer 9 to perform defect detection. During this process, motor 6 is started, causing its drive shaft 61 to rotate around its vertical axis, driving substrate 7, support frame 4, and horizontal rotating shaft 5 to rotate around this vertical axis. This, in turn, drives clamp 3 to rotate the wafer 9 it holds around this vertical axis, aligning different areas of wafer 9 with camera 1. Camera 1 then photographs different areas of the front of wafer 9. See Figure 10 After the front-side inspection is completed, stop motor 6. Then, hold clamp 3 with your right hand and rotate the transverse shaft 5 with your left hand. Rotate the transverse shaft 5 to the right around its transverse axis, causing the clamp and the wafer 9 it holds to rotate to the right around the transverse axis until the clamp and the wafer 9 it holds are upside down. During this process, see [link to relevant documentation]. Figure 7 The protruding block 51 of the horizontal pivot 5 rotates to the right until it is supported on the rear limiting block 42. If wafer 9 is inverted, then wafer 9 will be facing upwards (see [reference]). Figure 9Camera 1 is used to photograph the reverse side of wafer 9 to detect defects on the reverse side of wafer 9. During this process, motor 6 is started to make the drive shaft 61 of motor 6 rotate around its vertical axis, driving substrate 7, support frame 4, and horizontal rotating shaft 5 to rotate around the vertical axis, thereby driving clamp 3 to rotate the wafer 9 it clamps around the vertical axis, so that different areas of wafer 9 are aligned with camera 1, and camera 1 photographs different areas of the reverse side of wafer 9.

[0025] See Figure 1 , Figure 2 and Figure 6 The fixture 3 includes a circular upper fixture 31 and a circular lower fixture 32. The lower fixture 32 includes two semi-circular lower jaws 320, whose ends are hinged together and whose ends are magnetically attracted by magnets 35. The two lower jaws 320 form a circular wafer placement position 329. Figure 8 As shown, the inner walls of both lower jaws 320 are provided with multiple spherical rolling balls 34; the bottom of both lower jaws 320 is provided with a semi-circular annular support plate 321, as shown. Figure 3 , Figure 5 As shown, the support plate 321 has an upward-facing mounting groove 330. A mounting block 331 is installed in the mounting groove 330 and can slide up and down along the mounting groove 330. The top of the mounting block 331 has a silicone block 332 that extends upward out of the mounting groove 330. The bottom of the mounting block 331 has a downward-facing protrusion 3310 with a receiving cavity 3311. The bottom of the receiving cavity 3311 has a mounting hole 3312. The bottom of the mounting groove 330 has a threaded hole 339. A bolt 334 is screwed into the threaded hole 339. The head of the bolt 334 is exposed downward, and the tail is extended upward through the mounting hole 3312 into the receiving cavity 3311 to support the mounting block 331. A nut 333 is fitted onto the tail of the bolt 334. The nut 333 is larger than the mounting hole 3312 and therefore cannot pass through the mounting hole 3312. The upper clamp 31 and the lower clamp 32 are symmetrical in structure, which will not be described in detail here. The two upper jaws 310 of the upper clamp 31 and the two lower jaws 320 of the lower clamp 32 are hinged together by the same hinge shaft, and the upper and lower clamps 31 and 32 are installed together in this way.

[0026] Before performing defect inspection on the front and back surfaces of wafer 9, the following procedures are followed:

[0027] like Figure 9 As shown, first manually pry open the two upper jaws 310 of the upper clamp 31 to release the magnetic attraction at the ends of the two upper jaws 310 and move them away from each other, thereby allowing the two upper jaws 310 of the upper clamp 31 to rotate and open. Then, place the wafer 9 with its face up from top to bottom into the wafer placement position 329 of the lower clamp 32 (see...). Figure 6 In this process, see Figure 4 , Figure 5The sidewall of wafer 9 contacts the spherical rotating bead 34 on the inner sidewall of the lower clamp 32, causing the rotating bead 34 to rotate. The friction between the lower clamp 32 and the sidewall of wafer 9 is small, making it less likely to scratch the sidewall of wafer 9. When the lower part of wafer 9 is placed in the wafer placement position 329 of the lower clamp 32, the silicone blocks 322 on the support plates 321 of the two lower jaws 320 jointly support the reverse edge of wafer 9, and the sidewalls of the two lower jaws 320 clamp the lower sidewall of wafer 9 via the rotating bead 34. Tighten the bolt 334 of the upper clamp 310, causing the tail of the bolt 334 to move the nut 333 upwards. Since the nut 333 is larger than the mounting hole 3312 and cannot pass through it, the nut 333 pushes upwards against the cavity wall of the mounting block 3311, thereby moving the mounting block 331 and the silicone block 332 at its bottom upwards until the silicone block 332 retracts into the mounting groove 330. See... Figure 1 The upper clamp 31 is rotated and closed, causing the ends of the two upper jaws 310 of the upper clamp 31 to come closer together and magnetically attract each other. This is used to determine whether the wafer 9 has been placed in place. If the upper clamp 31 can rotate and close, it means that the wafer 9 has been placed in place and can be tested. When the upper clamp 31 rotates and closes, the support plate 321 of the two upper jaws 310 acts as a cover plate, covering the front edge of the wafer 9. The sidewalls of the two upper jaws 310 are connected by rotating beads 34 (see...). Figure 5 It clamps the upper sidewall of wafer 9.

[0028] When inspecting defects on both sides of wafer 9:

[0029] See Figure 9 First, rotate and open the two upper jaws 310 of the upper clamp 31 so that the support plate 321 of the upper clamp moves away from the front edge of the wafer 9. During this process, due to the silicone block 332 of the upper jaw 310 (see... Figure 5 It has been retracted into mounting slot 330 (see) Figure 5 Inside, it will not scratch the front side of wafer 9. Camera 1 is used to photograph the front side of wafer 9 for defect detection. During this process, the lower clamp 32 rotates around the vertical axis of the drive shaft 61 of the motor 6 under the drive of the motor 6. Naturally, see Figure 3 and Figure 5The silicone block 332 of the support plate 321 of the lower clamp 32 also rotates around the vertical axis. This silicone block 332 applies friction to the reverse edge of the wafer 9, causing the wafer 9 to rotate along the vertical axis. Since the support plate 321 of the upper clamp 31 is away from the front edge of the wafer 9, it does not obstruct the front edge of the wafer 9, thus not affecting the camera 1's capture of the front edge of the wafer 9. After the front detection is completed, the upper clamp 31 is rotated and closed. Then, the bolt 334 of the upper jaw 310 is turned in the opposite direction, causing the tail of the bolt 334 to drive the nut 333 downwards, pushing the mounting block 331 downwards. This causes the mounting block 331 and the silicone block 332 at its bottom to move downwards until the silicone block 332 presses against the front edge of the wafer 9. See... Figure 10 The upper and lower clamps 31 and 32 rotate together with the wafer 9 they hold around the transverse axis of the transverse rotation shaft 5 until they are upside down. In this state, see [reference needed]. Figure 3 , Figure 5 With the reverse side of wafer 9 facing upwards, the silicone block 332 on the support plate 321 of the upper jaw 310 supports the front edge of wafer 9. The support plate 321 of the lower jaw 320 acts as a cover plate, covering the reverse edge of wafer 9. Tightening the bolt 334 of the lower jaw 320 causes the tail of the bolt 334 to move the nut 333 upwards, thereby moving the mounting block 331 and the silicone block 332 at the bottom of the mounting block 331 upwards until the silicone block 332 retracts into the mounting groove. See also... Figure 5 and Figure 9 The two lower jaws 320 of the lower clamp 32 are rotated open, causing the support plate 321 of the lower clamp 32 to move away from the edge of the reverse side of the wafer 9. During this process, since the silicone block 332 of the lower jaws 320 has retracted into the mounting groove 330, it will not scratch the reverse side of the wafer 9. The reverse side of the wafer 9 is then photographed by the camera 1 for defect detection. During this process, the upper clamp 31 rotates around the vertical axis of the drive shaft 61 of the motor 6 under the drive of the motor 6. Naturally, the silicone block 332 of the support plate 321 of the upper clamp 31 also rotates around this vertical axis. The silicone block 332 applies frictional force to the edge of the front side of the wafer 9, thereby causing the wafer 9 to rotate together around this vertical axis. Since the support plate 321 of the lower clamp 32 moves away from the edge of the reverse side of the wafer 9, it will not obstruct the edge of the reverse side of the wafer 9, thus not affecting the camera 1's photographing of the edge of the reverse side of the wafer 9.

Claims

1. A wafer surface defect detection device, comprising a camera for detecting wafer surface defects and a clamp for holding the wafer with its front side facing up, characterized in that: The fixture includes an upper fixture and a lower fixture mounted together. The upper fixture includes two upper jaws for clamping the upper part of the wafer. Each upper jaw is provided with a cover plate for covering the edge of the front side of the wafer. The two upper jaws are hinged together and can be rotated open to allow the cover plate to move away from the edge of the front side of the wafer. The lower fixture includes two lower jaws for clamping the lower part of the wafer. Each lower jaw is provided with a support plate for supporting the edge of the back side of the wafer. The two lower jaws are hinged together and can be rotated open to allow the support plate to move away from the edge of the back side of the wafer. The upper and lower clamps can rotate the clamped wafers together around the horizontal axis until they are upside down.

2. The wafer surface defect detection device according to claim 1, characterized in that: Includes a base, and the clamp is rotatably mounted on the base, which can drive the clamped wafer to rotate together around the vertical axis.

3. The wafer surface defect detection device according to claim 2, characterized in that: The lower jaw has an upward-extending support plate with a first silicone block for supporting the reverse edge of the wafer. When the first silicone block rotates around the vertical axis, it applies frictional force to the reverse edge of the wafer, thereby causing the wafer to rotate around the vertical axis as well. The upper jaw has a downward-extending pressure plate with a second silicone block. When the upper and lower jaws rotate the clamped wafer around the horizontal axis until it is upside down, the second silicone block supports the front edge of the wafer. When the upper jaw rotates around the vertical axis, the second silicone block applies frictional force to the front edge of the supported wafer, thereby causing the wafer to rotate around the vertical axis as well.

4. The wafer surface defect detection device according to claim 3, characterized in that: The support plate of the lower gripper has a first mounting groove with the opening facing upwards. The first silicone block is movably mounted on the support plate and can be moved into the first mounting groove. The cover plate of the upper gripper has a second mounting groove with the opening facing downwards. The second silicone block is movably mounted on the cover plate and can be moved into the second mounting groove.

5. The wafer surface defect detection device according to claim 1, characterized in that: The two upper jaws are hinged together at their head ends and magnetically attracted at their tail ends. When the tail ends of the two upper jaws are released from magnetic attraction and move away from each other, the two upper jaws will rotate and open. The two lower jaws are hinged together at their head ends and magnetically attracted at their tail ends. When the tail ends of the two lower jaws are released from magnetic attraction and move away from each other, the two upper jaws will rotate and open.

6. The wafer surface defect detection device according to claim 1, characterized in that: The inner sidewall of the lower jaw is provided with multiple spherical rotating beads, and the sidewalls of the two lower jaws clamp the lower sidewall of the wafer through the rotating beads.

7. The wafer surface defect detection device according to claim 1, characterized in that: It also includes a support frame and a transverse rotating shaft mounted on the support frame. The upper and lower clamps are mounted on the transverse rotating shaft, and the transverse rotating shaft is provided with a protrusion. The support frame is provided with two opposing limiting blocks, a first and a second. The protrusion is supported on the first limiting block. The transverse rotating shaft drives the upper and lower clamps to rotate upside down, thereby driving the wafer clamped by the upper and lower clamps to rotate upside down. When the wafer is upside down, the protrusion rotates toward the second limiting block and is supported on the second limiting block.

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