Wafer chucking device for reducing clamping stress

Abstract

The application discloses a wafer clamping device capable of reducing clamping stress, and belongs to the technical field of wafer manufacturing. The device comprises a driving mechanism, a wafer chuck, a plurality of clamping pieces and a plurality of supporting parts. The wafer chuck is provided with a plurality of fixing holes which are uniformly distributed in the circumferential direction near the edge. The clamping piece comprises a first limiting part, a second limiting part, a third limiting part and a connecting column. The connecting column is arranged in the fixing hole and can rotate in the fixing hole. One end of the first limiting part is fixedly connected with the top of the connecting column. The second limiting part is arranged below the first limiting part and is fixedly connected with the side wall of the connecting column. The upper end and the lower end of the third limiting part are respectively connected with the first limiting part and the second limiting part and are arranged on one side of the second limiting part. The supporting part is arranged on the side of the clamping piece close to the central shaft of the wafer chuck. The driving mechanism drives the clamping piece to rotate relative to the wafer chuck. The device can be applied to clamping wafers with different sizes and thicknesses, and the flexibility of the wafer clamping piece is improved.

Description

Technical Field

[0001] This application relates to a wafer clamping device for reducing clamping stress, belonging to the field of wafer manufacturing technology. Background Technology

[0002] In the semiconductor manufacturing field, wafers are the core basic material, and their processing precision and quality directly determine the performance and reliability of chips. During the chip manufacturing process, key processes such as photolithography, etching, ion implantation, and thin film deposition require wafers to be precisely and stably fixed and clamped to ensure that the wafer position does not shift under micron or even nanometer-level processing precision, and to avoid damage to the wafer surface, so as to ensure the yield and performance indicators of chip manufacturing.

[0003] Currently, traditional wafer clamping devices have some problems when processing wafers. Existing clamping methods often result in uneven distribution of clamping force applied to the wafer, leading to excessively high stress in some areas. Especially when clamping ultra-thin wafers or wafers with special structures or materials, excessive stress can easily cause wafer deformation and cracking, seriously affecting wafer processing quality and yield.

[0004] Furthermore, with the continuous development of semiconductor technology, the market demand for processing wafers of different thicknesses is becoming increasingly diversified. Most existing wafer clamping devices are designed for wafers of the same thickness or with relatively regular edges, but in production, they cannot meet the clamping requirements of wafers of different thicknesses and with irregular edges. This problem necessitates a significant amount of manpower and time to replace wafer clamping devices during production for wafers of different thicknesses, increasing production costs and reducing production efficiency.

[0005] Therefore, we continue to develop a wafer clamping device that can effectively reduce clamping stress, has good compatibility, and is easy to operate. Utility Model Content

[0006] To address the aforementioned issues, this application proposes a wafer clamping device that reduces clamping stress. By combining a support portion and a clamping component, the device effectively clamps and fixes the wafer. Especially under high-speed operation, the support portion and clamping component can effectively prevent wafer displacement. Furthermore, the upper surface of the second limiting portion in the clamping component is inclined downwards from the outside to the inside, making it suitable for clamping wafers of various thicknesses and improving the flexibility of the wafer clamping device.

[0007] This application provides a wafer clamping device for reducing clamping stress, comprising: A wafer chuck, wherein a plurality of fixing holes are evenly provided around the edge of the wafer chuck; A plurality of clamping components, the clamping components including a first limiting part, a second limiting part, a third limiting part and a connecting post, the connecting post being disposed in a fixing hole and being rotatable within the fixing hole, one end of the first limiting part being fixedly connected to the top of the connecting post, the second limiting part being disposed below the first limiting part and being fixedly connected to the side wall of the connecting post, the upper surface of the second limiting part being inclined downward from the outside to the inside, and the upper end and lower end of the third limiting part being connected to the first limiting part and the second limiting part respectively; Several support portions are provided on the side of the clamping member near the central axis of the wafer chuck, and the upper surface of the support portions is used to support the wafer; A drive mechanism is disposed below the wafer chuck, and the drive mechanism drives the clamping member to rotate relative to the wafer chuck.

[0008] Optionally, the top area of ​​the support portion is smaller than the bottom area of ​​the support portion.

[0009] Optionally, the top of the support portion is square, circular, or elliptical.

[0010] Optionally, the distance between the support portion and the clamping member is greater than the length of the second limiting portion.

[0011] Optionally, the height of the connecting column is A, and the height of the support portion is 1 / 3A to 1 / 2A.

[0012] Optionally, the support portion is made of an elastic material.

[0013] Optionally, the drive mechanism includes a plurality of pulleys, a belt, and a motor. The pulleys are fixedly connected to the lower part of the connecting column, the belt is sleeved on the outer side wall of the plurality of pulleys, and the motor is connected to one of the pulleys.

[0014] Optionally, the length of the first limiting portion is shorter than the length of the second limiting portion.

[0015] Optionally, the length of the second limiting part is B, and the length of the first limiting part is 1 / 3B to 1 / 4B of the length of the second limiting part.

[0016] Optionally, an elastic layer is provided on the side of the second limiting portion near the first limiting portion and on the side of the first limiting portion near the second limiting portion.

[0017] Optionally, the surface of the elastic layer is provided with a plurality of elastic protrusions.

[0018] The beneficial effects that this application may produce include, but are not limited to: 1. The wafer clamping device for reducing clamping stress provided in this application can support the wafer by providing a support part. When the clamping part rotates to clamp the wafer, the damage to the lower surface of the wafer caused by the clamping part is greatly reduced, thereby reducing the damage to the wafer surface, facilitating subsequent wafer processing, and improving the product yield.

[0019] 2. The wafer clamping device for reducing clamping stress provided in this application, by tilting the upper surface of the second limiting part, can be applied to wafers of various sizes and thicknesses, thereby improving the application flexibility of the clamping device, reducing manual input, and improving the efficiency and quality of wafer processing.

[0020] 3. The wafer clamping device for reducing clamping stress provided in this application has a first end of the support portion that is higher than the second end. This has several advantages: first, it reduces the contact area between the support portion and the wafer, thus reducing damage to the wafer surface; second, it reduces the introduction of impurities, thus improving the quality of wafer processing; and third, the fact that the bottom area of ​​the support portion is larger than the top area provides better support for the wafer.

[0021] 4. The wafer clamping device for reducing clamping stress provided in this application can better clamp and fix the wafer by providing an elastic layer on the first limiting part and the second limiting part. At the same time, the elastic material can reduce damage to the wafer surface, disperse the clamping stress generated by the first limiting part and the second limiting part clamping the wafer, and prevent the wafer from deforming or breaking. Attached Figure Description

[0022] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a top view schematic diagram of the wafer clamping state of the clamping device involved in the embodiments of this application; Figure 2 This is a top view schematic diagram of the clamping device in the embodiment of this application without clamping the wafer; Figure 3 This is a perspective view of the clamping component involved in the embodiments of this application; Figure 4 A perspective view of the support portion involved in the embodiments of this application.

[0023] List of components and reference numerals: 10. Wafer chuck; 11. Fixing hole; 20. Clamping member; 21. First limiting part; 22. Second limiting part; 23. Third limiting part; 24. Connecting post; 30. Support part; 40. Elastic layer; 50. Wafer. Detailed Implementation

[0024] To more clearly illustrate the overall concept of this application, a detailed explanation is provided below with reference to the accompanying drawings.

[0025] To better understand the above-mentioned objectives, features, and advantages of this application, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0026] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of this application is not limited to the specific embodiments disclosed below.

[0027] Furthermore, it should be understood in the description of this application that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application 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 application.

[0028] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0029] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0030] In this application, unless otherwise expressly specified and limited, the "above" or "below" of the second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. In the description of this specification, references to terms such as "an embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples.

[0031] refer to Figure 1-4 This application discloses a wafer clamping device for reducing clamping stress, comprising: a wafer chuck 10, wherein a plurality of fixing holes 11 are uniformly arranged circumferentially near the edge of the wafer chuck 10; and a plurality of clamping members 20, each clamping member 20 including a first limiting part 21, a second limiting part 22, a third limiting part 23, and a connecting post 24. The connecting post 24 is disposed within the fixing holes 11 and is rotatable within the fixing holes 11. One end of the first limiting part 21 is fixedly connected to the top of the connecting post 24, and the second limiting part 22 is disposed within the first limiting part 21. Below the first limiting part 21, and fixedly connected to the side wall of the connecting post 24, the upper surface of the second limiting part 22 is inclined downward from the outside to the inside, and the upper and lower ends of the third limiting part 23 are respectively connected to the first limiting part 21 and the second limiting part 22; a plurality of supporting parts 30 are provided on the side of the clamping member 20 near the central axis of the wafer chuck 10, and the upper surface of the supporting parts 30 is used to support the wafer 50; a driving mechanism is provided below the wafer chuck 10, and the driving mechanism drives the clamping member 20 to rotate relative to the wafer chuck 10.

[0032] When processing the wafer 50, the wafer 50 is first placed on the support part 30. After the wafer 50 is properly placed, the drive mechanism is activated. The drive mechanism drives the connecting post 24 to rotate. The connecting post 24 drives the first limiting part 21, the second limiting part 22 and the third limiting part 23 to rotate. The first limiting part 21 rotates to the upper surface of the wafer 50 to limit the upper surface. The second limiting part 22 rotates to the lower surface of the wafer 50 to limit the lower surface of the wafer 50. The third limiting part 23 limits the side wall of the wafer 50, thereby realizing multi-directional clamping and fixing of the wafer 50. When the wafer 50 is fixed, the second limiting part 22 rotates to generate an upward lifting force on the wafer 50, and the first limiting part 21 can provide a certain limiting effect on the wafer 50. The third limiting part 23 limits the sidewalls of the wafer 50. The limiting of the wafer 50 is achieved through the cooperation of the first limiting part 21, the second limiting part 22, and the third limiting part 23. When the edge of the wafer 50 is uneven, the upper surface of the second limiting part 22 is inclined downward from the outside to the inside, which can provide a certain degree of containment for the edge of the wafer 50.

[0033] When clamping and limiting a thicker wafer 50, the upper surface of the wafer 50 is closer to the first limiting part 21, and the second limiting part 22 and the third limiting part 23 fix the lower surface and sidewall of the wafer 50. When clamping and limiting a thinner wafer 50, the upper surface of the wafer 50 will be at a certain distance from the first limiting part 21, but the first limiting part 21 can still limit the wafer 50, and the second limiting part 22 and the third limiting part 23 fix the lower surface and sidewall of the wafer 50. At the same time, with the support of the support part 30, the wafer 50 can be fixed and limited.

[0034] This configuration enables the positioning and fixing of wafers 50 of varying thicknesses, improving the flexibility of the wafer 50 clamping device. Simultaneously, the support portion 30 works in conjunction with the clamping member 20, providing support for the wafer 50. The upper surface of the second limiting portion 22 in the clamping member 20 is inclined downwards from the outside in. When the second limiting portion 22 rotates to clamp and fix the wafer 50, it significantly reduces the contact area with the lower surface of the wafer 50, thereby reducing damage to the wafer 50 surface caused by the rotation of the clamping member 20. The third limiting portion 23 limits and fixes the sidewalls of the wafer 50, preventing displacement during high-speed rotation. Furthermore, the first limiting portion 21, the second limiting portion 22, and the third limiting portion 23 limit and fix the wafer 50, reducing clamping stress on the wafer 50 surface and preventing damage and breakage due to excessive stress concentration.

[0035] Specifically, the distance between the top of the support portion 30 and the center of the wafer chuck 10 is less than the radius of the wafer 50. This configuration allows the top of the support portion 30 to support the wafer 50. Simultaneously, because the support portion 30 is closer to the central axis of the wafer 50, a certain distance is maintained to facilitate the rotation of the clamping member 20 and its positioning and clamping of the wafer 50. This ensures that the support portion 30 and the clamping member 20 do not conflict during the clamping of the wafer 50.

[0036] Specifically, the rotational connection method between the connecting post 24 and the fixing hole 11 is not specifically limited, as long as the connecting post 24 can rotate within the fixing hole 11.

[0037] Specifically, the upper end of the third limiting part 23 is connected to the first limiting part 21, the lower end of the third limiting part 23 is connected to the upper end of the second limiting part 22, the side wall of the third limiting part 23 is fixedly connected to the side wall of the connecting post 24, the bottom end of the second limiting part 22 is at a certain distance from the wafer chuck 10 and is not connected to the wafer chuck 10, and only the connecting post 24 in the clamping member 20 is rotatably connected to the fixing hole 11 on the wafer chuck 10.

[0038] Specifically, the third limiting part 23 is an inwardly concave arc shape. This design allows it to better fit against the sidewall of the wafer 50, further improving the strength of fixing and clamping the wafer 50.

[0039] Specifically, the method of fixing the support part 30 to the wafer chuck 10 is not specifically limited. It can be integrally formed. When it is separately formed, it can be bonded, welded, or threaded. As long as the support part 30 can be fixed on the wafer chuck 10, it is acceptable.

[0040] Specifically, the drive mechanism includes several pulleys, a belt, and a motor. The pulleys are fixedly connected to the lower part of the connecting post, and the belt is sleeved on the outer wall of the pulleys. The motor is connected to one of the pulleys. In this configuration, the motor drives one of the pulleys to rotate, and the belt drives the pulleys to rotate in the same direction. This causes the connecting post to rotate, which in turn causes the first limiting part 21, the second limiting part 22, and the third limiting part 23 to rotate towards the wafer 50, thus limiting and fixing the wafer 50. Simultaneously, after the wafer 50 has been processed, the drive motor moves in the opposite direction, causing the connecting post 24 to rotate, which in turn causes the first limiting part 21, the second limiting part 22, and the third limiting part 23 to rotate away from the wafer 50, finally removing the wafer 50.

[0041] Specifically, the motor can be a servo motor or a stepper motor, as long as it can achieve bidirectional drive of the pulley.

[0042] In one implementation, the top area of ​​the support portion 30 is smaller than the bottom area of ​​the support portion 30. This arrangement reduces the contact area between the support portion 30 and the wafer 50, minimizing damage to the wafer 50 surface, reducing the introduction of impurities, and improving the quality of wafer 50 processing. Simultaneously, the larger bottom area of ​​the support portion 30 compared to its top area provides better support for the wafer 50. Compared to a support portion 30 with the same top and bottom dimensions, this not only reduces the contact area with the wafer 50 and minimizes damage, but also provides stronger support.

[0043] In one implementation, the top of the support portion 30 is square, circular, or elliptical. With this configuration, the support portion 30 can better support the wafer 50. At the same time, setting the top of the support portion 30 to be square, circular, or elliptical can enhance the horizontal displacement resistance, reduce centrifugal force deviation during rotation, and also reduce the small displacement of the wafer 50 caused by external vibration, ensuring the support strength of the part of the wafer 50 to be processed.

[0044] In one implementation, the horizontal distance between the support portion 30 and the connecting post 24 is greater than the length of the second limiting portion 22. With this arrangement, a certain distance can be maintained between the support portion 30 and the connecting post 24 in the horizontal direction. When the connecting post 24 drives the first limiting portion 21, the second limiting portion 22, and the third limiting portion 23 to rotate and clamp and fix the wafer 50, conflict between the support portion 30 and the connecting post 24 is avoided, thereby achieving clamping of the wafer 50 by the first limiting portion 21, the second limiting portion 22, and the third limiting portion 23. When the distance between the support part 30 and the connecting post 24 is less than the length of the second limiting part 22, the connecting post 24 drives the first limiting part 21, the second limiting part 22 and the third limiting part 23 to rotate. Since the second limiting part 22 rotates relative to the wafer 50 from below, there is not enough distance between the second limiting part 22 and the support part 30 to allow the second limiting part 22 to rotate to the corresponding position to clamp the wafer 50, thus failing to clamp the wafer 50 well. When the distance between the support part 30 and the connecting post 24 is too large, the support part 30 will be closer to the middle of the wafer 50, and the support effect on the edge of the wafer 50 will be poor. When the first limiting part 21, the second limiting part 22 and the third limiting part 23 clamp the wafer 50, the wafer 50 will shift due to the instability of the supporting force, and the wafer 50 cannot be clamped and fixed well.

[0045] In one embodiment, the height of the connecting post 24 is A, and the height of the support part 30 is 1 / 3A to 1 / 2A. This configuration allows for clamping of wafers 50 of varying thicknesses, increasing the flexibility of the clamping device in clamping the thickness of the wafer 50. It also effectively limits and clamps wafers 50 with uneven thickness and size, ensuring clamping stability and preventing the wafer 50 from breaking or deforming during high-speed rotation.

[0046] When the support part 30 and the connecting post 24 are at the same height, the first limiting part 21 is at the same height as the support part 30. The second limiting part 22 and the third limiting part 23 are both below the first limiting part 21. However, fixing the wafer 50 requires the cooperation of the first limiting part 21, the second limiting part 22 and the third limiting part 23. In this case, it is impossible to clamp the wafer 50. Therefore, it is only possible to clamp the wafer 50 when the height of the support part 30 is lower than the first limiting part 21.

[0047] In one implementation, the support portion 30 is made of an elastic material. With this configuration, when the support portion 30 contacts the bottom surface of the wafer 50, the elastic material undergoes slight deformation according to the surface shape of the wafer 50, thus supporting the wafer 50 and avoiding stress concentration during support. Simultaneously, the elastic material can absorb vibration energy through its own elastic deformation, acting as a shock absorber and buffer, ensuring the wafer 50 remains stable during clamping and effectively guaranteeing processing accuracy.

[0048] In one implementation, the length of the first limiting portion 21 is shorter than the length of the second limiting portion 22. With this configuration, the shorter length of the first limiting portion 21 reduces the area occupied on the upper surface of the wafer 50, allowing the surface of the wafer 50 to be effectively processed to the maximum extent during the processing, thereby improving the utilization rate of the wafer 50 and reducing production costs and efficiency.

[0049] In one embodiment, the length of the second limiting portion 22 is B, and the length of the first limiting portion 21 is 1 / 3B to 1 / 4B of the length of the second limiting portion 22. This configuration better facilitates the clamping of the wafer 50, further reduces the area occupied on the upper surface of the wafer 50, and maximizes the surface treatment area of ​​the wafer 50. It not only achieves clamping and limiting of the wafer 50, but also reduces the frictional area between the first limiting portion 21 and the wafer 50, reducing damage to the wafer 50 and minimizing damage from contaminating ions.

[0050] In one implementation, an elastic layer 40 is provided on both the side of the second limiting part 22 near the first limiting part 21 and the side of the first limiting part 21 near the second limiting part 22. This arrangement fills the minute gaps between the clamping member 20 and the surface of the wafer 50, improving clamping sealing and stability, while reducing the impact of vibration and temperature fluctuations on the clamping effect. Especially for wafers 50 with protrusions or irregular shapes, the elastic layer 40 can adapt to the irregular shape of the wafer 50 surface through deformation, avoiding wear between the traditional rigid clamping member 20 and the protruding structure, thus preventing greater damage to the wafer 50. Simultaneously, the presence of the elastic layer 40 alleviates the contact stress between the wafer 50 and the first and second limiting parts 21 and 22, reducing the probability of damage when the first and second limiting parts 21 and 22 limit and fix the wafer 50.

[0051] In one embodiment, the surface of the elastic layer 40 is provided with a plurality of elastic protrusions. With this configuration, the elastic layer 40 containing the elastic protrusions can be stably fixed by the friction between the protrusions and the wafer 50 without increasing the clamping force. This can also reduce the clamping stress of the first limiting part 21 and the second limiting part 22 on the wafer 50. While ensuring the wafer 50 is firmly clamped, it can also reduce the clamping force applied to the wafer 50, reduce stress concentration, and improve the yield of wafer 50 processing.

[0052] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0053] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A wafer clamping device for reducing clamping stress, characterized in that, include: A wafer chuck, wherein a plurality of fixing holes are evenly provided around the edge of the wafer chuck; A plurality of clamping components, the clamping components including a first limiting part, a second limiting part, a third limiting part and a connecting post, the connecting post being disposed in a fixing hole and being rotatable within the fixing hole, one end of the first limiting part being fixedly connected to the top of the connecting post, the second limiting part being disposed below the first limiting part and being fixedly connected to the side wall of the connecting post, the upper surface of the second limiting part being inclined downward from the outside to the inside, the upper end and the lower end of the third limiting part being connected to the first limiting part and the second limiting part respectively, and being disposed on one side of the second limiting part; Several support portions are provided on the side of the clamping member near the central axis of the wafer chuck, and the upper surface of the support portions is used to support the wafer; A drive mechanism is provided below the wafer chuck, which drives the clamping member to rotate relative to the wafer chuck.

2. The wafer clamping device for reducing clamping stress according to claim 1, characterized in that, The top area of ​​the support is smaller than the bottom area of ​​the support.

3. The wafer clamping device for reducing clamping stress according to claim 1, characterized in that, The top of the support is square, round, or elliptical.

4. The wafer clamping device for reducing clamping stress according to claim 1, characterized in that, The distance between the support portion and the clamping member is greater than the length of the second limiting portion.

5. The wafer clamping device for reducing clamping stress according to claim 1, characterized in that, The height of the connecting column is A, and the height of the support part is 1 / 3A to 1 / 2A.

6. The wafer clamping device for reducing clamping stress according to claim 5, characterized in that, The support is made of an elastic material.

7. The wafer clamping device for reducing clamping stress according to claim 1, characterized in that, The length of the first limiting part is shorter than the length of the second limiting part.

8. The wafer clamping device for reducing clamping stress according to claim 7, characterized in that, The length of the second limiting part is B, and the length of the first limiting part is 1 / 3B to 1 / 4B of the length of the second limiting part.

9. The wafer clamping device for reducing clamping stress according to claim 8, characterized in that, Both the side of the second limiting part near the first limiting part and the side of the first limiting part near the second limiting part are provided with an elastic layer.

10. The wafer clamping device for reducing clamping stress according to claim 9, characterized in that, The surface of the elastic layer is provided with several elastic protrusions.

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