Wafer alignment device

Abstract

The present application relates to the technical field of semiconductor, in particular to a wafer alignment device. The wafer alignment device has the advantages of simple structure, low cost, convenient use and high alignment precision, and specifically comprises a wafer positioning mechanism, a wafer carrier and at least two wafer limiting mechanisms, each wafer limiting mechanism and the wafer positioning mechanism are arranged at the periphery of the wafer carrier, the wafer limiting mechanism comprises a first positioning block, the first positioning block is adapted to be close to or away from the wafer carrier, the first positioning block is used for abutting against the edge of the wafer to be aligned, the wafer positioning mechanism comprises a third positioning block and a fourth positioning block, the third positioning block and the fourth positioning block are adapted to be close to or away from the wafer carrier, the third positioning block and the fourth positioning block are used for abutting against the edge of the wafer to be aligned, and the first positioning block, the third positioning block and the fourth positioning block are rotatable.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a wafer alignment apparatus. Background Technology

[0002] With the continuous development of the semiconductor industry, the demand for integration and performance of very large-scale integrated circuits (VLSI) is gradually increasing to adapt to the trend of electronic products becoming smaller and more powerful. However, this trend of increasing chip functionality and integration also brings increasingly stringent technical requirements for various stages of the manufacturing process. The integration density of transistors within chips is gradually reaching its limit, leading to the emergence of 3D integrated circuit (IC) technology. 3D integrated circuits are defined as a system-level integrated structure. Through bonding processes, 3D integrated circuits achieve vertical interconnection between multiple chips, increasing chip space, improving transistor integration density, and simultaneously increasing the operating speed and reducing power consumption. Therefore, 3D chip technology requires the vertical alignment of the two bonded wafers, which is crucial for subsequent process manufacturing and the performance of the final product.

[0003] Wafer bonding technology refers to the process of tightly joining two mirror-polished homogeneous or heterogeneous wafers together through chemical and physical interactions. After bonding, the atoms at the interface react under external forces to form covalent bonds, achieving a specific bonding strength. The alignment accuracy of the two wafers determines whether the various process parameters of the bonded wafer pair are up to standard, directly affecting subsequent process flows. Therefore, there is an urgent need for a device that can accurately align the edges of two wafers. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a wafer alignment device that is simple in structure, low in cost, easy to use, and has higher alignment accuracy.

[0005] To address the aforementioned technical problems, this application provides the following technical solution: This invention relates to a wafer alignment apparatus, comprising a wafer positioning mechanism, a wafer stage, and at least two wafer limiting mechanisms. Each wafer limiting mechanism and each wafer positioning mechanism is spaced apart and disposed around the periphery of the wafer stage. The wafer stage carries two wafers to be aligned. Each wafer limiting mechanism includes a first positioning block adapted to move closer to or further away from the wafer stage. Each wafer positioning mechanism includes a third positioning block, a fourth positioning block, and a third push plate. The third and fourth positioning blocks are adapted to move closer to or further away from the wafer stage. All three positioning blocks are rotatable, allowing the two wafers to be aligned to be placed on the wafer stage. At least two of the first positioning blocks move closer to the wafer stage to restrict the wafers from moving away from the wafer positioning mechanisms. At the termination point of the movement, the third positioning block and the fourth positioning block approach the wafer stage. The movement of the wafer positioning mechanism causes the third positioning block and the fourth positioning block to squeeze the wafer. Under the action of the squeezing force, the tangent edges of the two wafers to be aligned are rotated to parallel, and at least two of the first positioning blocks, the third positioning block, and the fourth positioning block are in complete contact with the two wafers to be aligned. By using four-point circle positioning, the center positions of the two wafers to be aligned are aligned. The wafer positioning mechanism also includes a first rotating block, a second rotating block, and a pin. The pin is connected to the third push plate. The first rotating block and the second rotating block are both rotatably connected to the pin. The third positioning block and the fourth positioning block are respectively rotatably connected to the first rotating block and the second rotating block.

[0006] The wafer alignment device of the present invention further includes a third cylinder, wherein the wafer positioning mechanism includes a third cylinder, one end of the third push plate is connected to the third cylinder, and the piston of the third cylinder drives the third push plate to move relative to the third cylinder, thereby causing the third positioning block and the fourth positioning block to move closer to or further away from the wafer stage.

[0007] The wafer alignment device of the present invention further includes a third displacement sensor for real-time monitoring of the displacement of the third pusher plate.

[0008] The wafer alignment device of the present invention further includes an elastic element in the wafer positioning mechanism. The elastic element is disposed between the first rotating block, the second rotating block and the pin. The elastic element is used to cause the first rotating block and the second rotating block to drive the third positioning block and the fourth positioning block to abut against the edge of the wafer to be aligned, and to cause the first rotating block and the second rotating block to automatically return to their original positions after alignment.

[0009] The wafer alignment apparatus of the present invention, wherein the bottom surfaces of the third positioning block and the fourth positioning block are lower than the top surface of the wafer stage.

[0010] The wafer alignment device of the present invention includes a wafer positioning mechanism that further includes a first cylinder and a first push plate. A first positioning block is connected to one end of the first push plate, and the other end of the first push plate is connected to the first cylinder. A first piston in the first cylinder drives the first push plate to move relative to the first cylinder, thereby causing the first positioning block to move closer to or further away from the wafer stage under the action of the first push plate.

[0011] The wafer alignment device of the present invention includes a wafer positioning mechanism that further includes a push rod guide rail. A first slider is provided on the first push plate, and the first push plate is adapted to drive the first slider to move relative to the push rod guide rail.

[0012] The wafer alignment device of the present invention further includes a first displacement sensor in the wafer positioning mechanism, the first displacement sensor being used to monitor the displacement of the first push plate in real time.

[0013] The wafer alignment device of the present invention, wherein the two first positioning blocks, the third positioning block and the fourth positioning block are all cylinders made of ceramic material.

[0014] Compared with the prior art, the wafer alignment device of the present invention has at least the following beneficial effects: The wafer alignment device of this invention includes a wafer limiting mechanism, a wafer positioning mechanism, and a wafer stage. The first positioning block is adapted to be close to or away from the wafer stage, and the third and fourth positioning blocks are adapted to be close to or away from the wafer stage. Both the third and fourth positioning blocks can rotate in place. Therefore, the edges and tangents of the two wafers to be aligned can be aligned by rotating the third and fourth positioning blocks, ensuring the accuracy of the alignment of the edges and tangents of the two wafers, improving the alignment accuracy and efficiency of the wafers. The structure is simple and easy to use, and it can be widely used in wafer manufacturing and processing fields. Since the alignment of the two wafers is mainly achieved by aligning the wafer tangents, the wafer alignment device of this invention is particularly suitable for wafers with tangents. Furthermore, the wafer alignment is independent of the wafer thickness and can adapt to the alignment of wafers of the same diameter but different thicknesses.

[0015] The wafer alignment apparatus of the present invention will be further described below with reference to the accompanying drawings. Attached Figure Description

[0016] Figure 1 This is a three-dimensional structural diagram of the wafer alignment device of the present invention in use. Figure 2 This is a schematic diagram of the wafer positioning mechanism in the wafer alignment device of the present invention; Figure 3 This is a schematic diagram of the structure of the first wafer positioning mechanism in the wafer alignment device of the present invention; Figure 4 This is a side view of the wafer alignment device of the present invention in use. Figure 5 This is a top view of the wafer alignment device of the present invention in use. Detailed Implementation

[0017] like Figure 1 , Figure 2 , Figure 3 As shown, the present invention provides a wafer alignment device, including a wafer positioning mechanism 3, a wafer stage 5, and two wafer limiting mechanisms 1. The two wafer limiting mechanisms 1 and the wafer positioning mechanism 3 are all spaced apart on the periphery of the wafer stage 5. The wafer stage 5 is disk-shaped and is provided with a support component for supporting the wafer to be aligned. The wafer stage 5 is used to carry the wafer 4 to be aligned. The wafer limiting mechanism 1 includes a first positioning block 11, which is adapted to be close to or away from the wafer stage 5 and is used to abut against the edge of the wafer 4 to be aligned. The wafer positioning mechanism 3 includes a third positioning block 31 and a fourth positioning block 32, which are adapted to be close to or away from the wafer stage 5 and are used to abut against the edge of the wafer 4 to be aligned. The first positioning block 11, the third positioning block 31, and the fourth positioning block 32 are all rotatable.

[0018] The wafer transfer device places two wafers 4 to be aligned onto the wafer stage 5 sequentially. The wafers 4 are placed on the support components of the wafer stage 5. The wafer positioning mechanism 3 moves towards the wafer stage 5, causing the two first positioning blocks 11 to approach the wafer stage 5 and reach the termination point that restricts the wafer's movement away from the wafer positioning mechanism 3. The third positioning block 31 and the fourth positioning block 32 approach the wafer stage 5. Because the two first positioning blocks 11 restrict the wafers 4 to move away from the wafer positioning mechanism 3, the movement of the wafer positioning mechanism 3 causes it to compress the wafers 4, resulting in misaligned edges on the wafers 4. In the correct case, since the third positioning block 31 and the fourth positioning block 32 can rotate, the cutting edges of the two wafers to be aligned 4 can be rotated to parallel under the action of the extrusion force. At the same time, the two first positioning blocks 11, the third positioning block 31, and the fourth positioning block 32 are in complete contact with the two wafers to be aligned 4 and are externally tangent. The four points are fixed in a circle, so that the center positions of the two wafers to be aligned 4 are aligned, and the edges and cutting edges of the two wafers to be aligned 4 are aligned. Specifically, the two first positioning blocks 11, the third positioning blocks 31, and the fourth positioning blocks 32 are all cylinders made of ceramic material. The number of wafer limiting mechanisms 1 can also be set to more than two.

[0019] Since the wafer alignment device of the present invention includes a wafer limiting mechanism 1, a wafer positioning mechanism 3, and a wafer stage 5, the first positioning block 11 is adapted to be close to or away from the wafer stage 5, and the third positioning block 31 and the fourth positioning block 32 are adapted to be close to or away from the wafer stage 5. The third positioning block 31 and the fourth positioning block 32 can both rotate. Therefore, the edges and tangents of the two wafers to be aligned can be aligned by rotating the third positioning block 31 and the fourth positioning block 32, which ensures the accuracy of the alignment of the edges and tangents of the two wafers, improves the alignment accuracy and alignment efficiency of the wafers, has a simple structure, is easy to use, and can be widely used in wafer manufacturing and processing fields. Since the edge alignment of the two wafers is mainly achieved by the alignment of the wafer tangents, the wafer alignment device of the present invention is particularly suitable for wafers with tangents. Moreover, the wafer alignment is independent of the wafer thickness and can adapt to the alignment of wafers with the same diameter but different thicknesses.

[0020] Furthermore, the wafer positioning mechanism 1 also includes a first cylinder 16 and a first pusher plate 14. A first positioning block 11 is connected to one end of the first pusher plate 14, and the other end of the first pusher plate 14 is connected to the first cylinder 16. A first piston inside the first cylinder 16 drives the first pusher plate 14 to move relative to the first cylinder 16, thereby causing the first positioning block 11 to move closer to or further away from the wafer stage 5 under the action of the first pusher plate 14, which can precisely set the wafer positioning position. Specifically, the first positioning block 11 is connected to the first pusher plate 14 through a bearing, and the first positioning block 11 can rotate relative to the first pusher plate 14.

[0021] Furthermore, the wafer positioning mechanism 1 also includes a push rod guide rail 15, which is fixed to the mounting plate of the overall wafer alignment device. A first slider 141 is provided on the first push plate 14, and the first push plate 14 is adapted to drive the first slider 141 to move relative to the push rod guide rail 15. Due to the setting of the push rod guide rail 15, the movement direction of the first push plate 14 is ensured not to deviate from the track, thereby improving the alignment accuracy.

[0022] Furthermore, the wafer positioning mechanism 1 also includes a first displacement sensor 18, which monitors the displacement of the first push plate 14 in real time and precisely controls the movement position of the first push plate 14 to achieve the positioning function; specifically, the first displacement sensor 18 is connected to the mounting plate of the wafer alignment device, and the first displacement sensor 18 can be a linear potentiometer.

[0023] Furthermore, the wafer positioning mechanism 3 also includes a third cylinder 33, a third pusher plate 34, a third positioning block 31 and a fourth positioning block 32 rotatably connected to one end of the third pusher plate 34, and the other end of the third pusher plate 34 connected to the third cylinder 33. The piston of the third cylinder 33 drives the third pusher plate 34 to move relative to the third cylinder 33, thereby making the third pusher plate 34 closer to or away from the wafer stage 5.

[0024] Furthermore, the wafer positioning mechanism 3 also includes a first rotating block 35, a second rotating block 36, and a pin 37. The pin 37 is connected to the third push plate 34. The first rotating block 35 and the second rotating block 36 are both rotatably connected to the pin 37. The third positioning block 31 and the fourth positioning block 32 are respectively rotatably connected to the first rotating block 35 and the second rotating block 36. Specifically, the third positioning block 31 and the fourth positioning block 32 are respectively rotatably connected to the first rotating block 35 and the second rotating block 36 through bearings. Since the first rotating block 35 and the second rotating block 36 can rotate around the pin 37, damage to the wafer during the alignment process can be prevented due to incorrect placement of the wafer to be aligned.

[0025] Furthermore, the wafer positioning mechanism 3 also includes an elastic element 38, which is disposed between the first rotating block 35, the second rotating block 36, and the pin 37. The elastic element 38 ensures that the first rotating block 35 and the second rotating block 36 drive the third positioning block 31 and the fourth positioning block 32 to closely adhere to the cleaved edge of the wafer 4 to be aligned, ensuring the alignment of the cleaved edge. Simultaneously, after alignment, the first rotating block 35 and the second rotating block 36 can automatically return to their original positions. The elastic element 38 can specifically be a torsion spring.

[0026] Furthermore, the wafer positioning mechanism 3 also includes a third displacement sensor 39, which is used to monitor the displacement of the third pusher plate 34 in real time. Specifically, the third displacement sensor 39 is connected to the mounting plate of the wafer alignment device, and the third displacement sensor 39 can be a linear potentiometer. During the process of the third pusher plate 34 moving closer to or further away from the third cylinder 33, the displacement of the third pusher plate 34 is monitored in real time by the third displacement sensor 39 to accurately control the movement position of the third positioning block 31 and the fourth positioning block 32, thereby realizing the positioning adjustment function.

[0027] Furthermore, such as Figure 4 As shown, the bottom surfaces of the third positioning block 31 and the fourth positioning block 32 are lower than the top surface of the wafer stage 5 to prevent the wafer 4 to be aligned from being inserted into the gap between the third positioning block 31, the fourth positioning block 32 and the third push plate 34 under the squeezing action of the third positioning block 31 and the fourth positioning block 32, thus ensuring alignment accuracy.

[0028] Furthermore, such as Figure 5 As shown, the two wafer limiting mechanisms 1 and wafer positioning mechanism 3 are evenly arranged around the wafer stage 5 to ensure that the wafer 4 to be aligned is subjected to uniform force and improve the alignment accuracy.

[0029] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A wafer alignment apparatus, characterized in that, The device includes a wafer positioning mechanism (3), a wafer stage (5), and at least two wafer positioning mechanisms (1). Each wafer positioning mechanism (1) and the wafer positioning mechanism (3) are spaced apart around the wafer stage (5). The wafer stage (5) is used to support two wafers (4) to be aligned. The wafer positioning mechanism (1) includes a first positioning block (11), which is adapted to be close to or away from the wafer stage (5). The wafer positioning mechanism (3) includes a third positioning block (31), a fourth positioning block (32), and a third push plate (34). The third positioning block (31) and the fourth positioning block (32) are adapted to be close to or away from the wafer stage (5). The first positioning block (11), the third positioning block (31), and the fourth positioning block (32) are all rotatable. The two wafers (4) to be aligned are placed on the wafer stage (5). At least two of the first positioning blocks (11) approach the wafer stage (5) to reach the termination point that restricts the wafer from moving away from the wafer positioning mechanism (3). The third positioning block (31) and the fourth positioning block (32) approach the wafer stage (5). The movement of the wafer positioning mechanism (3) causes the third positioning block (31) and the fourth positioning block (32) to squeeze the wafer (4). Under the action of the squeezing force, the cut edges of the two wafers (4) to be aligned are rotated to parallel, and at least two of the first positioning blocks (11) and the third positioning block (32) are squeezed. The positioning block (31) and the fourth positioning block (32) are in complete contact with the two wafers (4) to be aligned. By using four points to fix the circle, the center positions of the two wafers (4) to be aligned are aligned. The wafer positioning mechanism (3) also includes a first rotating block (35), a second rotating block (36), and a pin (37). The pin (37) is connected to the third push plate (34). The first rotating block (35) and the second rotating block (36) are rotatably connected to the pin (37). The third positioning block (31) and the fourth positioning block (32) are rotatably connected to the first rotating block (35) and the second rotating block (36), respectively.

2. The wafer alignment apparatus according to claim 1, characterized in that, The wafer positioning mechanism (3) also includes a third cylinder (33), one end of the third push plate (34) is connected to the third cylinder (33), and the piston of the third cylinder (33) drives the third push plate (34) to move relative to the third cylinder (33), thereby causing the third positioning block (31) and the fourth positioning block (32) to move closer to or further away from the wafer stage (5).

3. The wafer alignment apparatus according to claim 2, characterized in that, The wafer positioning mechanism (3) also includes a third displacement sensor (39) for real-time monitoring of the displacement of the third pusher plate (34).

4. The wafer alignment apparatus according to claim 3, characterized in that, The wafer positioning mechanism (3) further includes an elastic element (38), which is disposed between the first rotating block (35), the second rotating block (36) and the pin (37). The elastic element (38) is used to cause the first rotating block (35) and the second rotating block (36) to drive the third positioning block (31) and the fourth positioning block (32) to abut against the edge of the wafer (4) to be aligned, and to cause the first rotating block (35) and the second rotating block (36) to automatically return to their original positions after alignment.

5. The wafer alignment apparatus according to claim 1, characterized in that, The bottom surfaces of the third positioning block (31) and the fourth positioning block (32) are lower than the top surface of the wafer stage (5).

6. The wafer alignment apparatus according to claim 1, characterized in that, The wafer positioning mechanism (1) further includes a first cylinder (16) and a first push plate (14). The first positioning block (11) is connected to one end of the first push plate (14), and the other end of the first push plate (14) is connected to the first cylinder (16). The first piston in the first cylinder (16) drives the first push plate (14) to move relative to the first cylinder (16), so that the first positioning block (11) moves closer to or further away from the wafer stage (5) under the drive of the first push plate (14).

7. The wafer alignment apparatus according to claim 6, characterized in that, The wafer positioning mechanism (1) further includes a push rod guide rail (15), and a first slider (141) is provided on the first push plate (14). The first push plate (14) is adapted to drive the first slider (141) to move relative to the push rod guide rail (15).

8. The wafer alignment apparatus according to claim 7, characterized in that, The wafer limiting mechanism (1) also includes a first displacement sensor (18) for real-time monitoring of the displacement of the first push plate (14).

9. The wafer alignment apparatus according to any one of claims 1-8, characterized in that, The two first positioning blocks (11), the third positioning block (31), and the fourth positioning block (32) are all cylinders made of ceramic material.

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