A wafer clamping device / equipment

Abstract

This application relates to the field of wafer processing technology, and in particular to a wafer clamping device and apparatus; a wafer clamping device for clamping a floating wafer, the clamping device having a clamping space for accommodating the wafer, the clamping device comprising: a base; limiting posts fixedly connected to the base, the limiting posts being arranged vertically, the limiting posts being used to limit and guide the floating wafer; and a clamping mechanism disposed on the base, the clamping mechanism and the limiting posts being located on the same side of the base, the clamping mechanism comprising: clamping members, at least three clamping members, the clamping members being slidably connected to the base such that the clamping members form at least a first position and a second position: in the first position, the clamping members are located outside the clamping space; in the second position, at least a portion of the clamping members are located within the clamping space to support the wafer. By designing a non-adsorption clamping structure to grip the wafer, contamination caused by wafer clamping is prevented.

Description

Technical Field

[0001] This application relates to the field of wafer processing technology, and in particular to a wafer clamping device or equipment. Background Technology

[0002] During thinning or polishing processes, wafers need to be transferred between different devices for corresponding processes. Since the devices are relatively independent, a robotic arm is needed to grasp and transfer the wafers.

[0003] In existing technologies, robotic arms often use vacuum adsorption and gripping methods for wafers, such as suction cups. Since the suction cups on the robotic arms need to contact the wafers to achieve gripping, especially in high-cleanliness processing, contact between the suction cups and the wafers may cause contamination of the wafers, leading to wafer processing defects.

[0004] Therefore, the technical problem with the existing technology is that wafer clamping causes contamination. Summary of the Invention

[0005] This application provides a wafer clamping device or equipment that uses a non-adsorption clamping structure to grip wafers, preventing contamination caused by wafer clamping.

[0006] In a first aspect, the wafer clamping device provided in this application adopts the following technical solution:

[0007] A wafer clamping device is provided for clamping a floating wafer. The clamping device has a clamping space for accommodating the wafer. The clamping device includes:

[0008] Base;

[0009] A limiting post, fixedly connected to the base, the limiting post being vertically arranged, is used to limit and guide the floating wafer; and

[0010] A clamping mechanism is disposed on the base, and the clamping mechanism and the limiting post are located on the same side of the base. The clamping mechanism includes:

[0011] The clamping members, having at least three, are slidably connected to the base such that the clamping members form at least a first position and a second position.

[0012] In the first position, the clamping member is located outside the clamping space;

[0013] In the second position, at least a portion of the clamping member is located within the clamping space to support the wafer.

[0014] Preferably, at least three limiting posts are provided, and the limiting posts are arranged in a ring so that a circular limiting space is formed between the limiting posts. The radius of the limiting space is R, and the radius of the wafer is r, such that R∈(r,1.1r).

[0015] Preferably, the clamping member includes:

[0016] The connecting part is slidably connected to the base;

[0017] The support portion is fixedly connected to the connecting portion. The support portion has an inclined support surface, which is in line contact with the edge of the wafer to support the wafer.

[0018] Preferably, the clamping mechanism further includes:

[0019] The number of driving components is the same as the number of clamping components, and the driving components are used to drive the clamping components in a one-to-one correspondence to make the clamping components slide.

[0020] Preferably, the clamping mechanism further includes a driving member, wherein one driving member is provided, and the driving member is movably connected to each of the clamping members to synchronously drive the clamping members to slide.

[0021] Preferably, the base has a limiting surface on one side relative to the platform, and the limiting surface has a boss that protrudes from the limiting surface and is used to engage with the wafer.

[0022] Preferably, a second nozzle is provided on the protrusion, which is used to spray air or water downwards onto the wafer.

[0023] Preferably, a second nozzle is provided on the limiting surface, the second nozzle being used to spray air or water downwards onto the wafer.

[0024] Secondly, the wafer clamping device provided in this application adopts the following technical solution:

[0025] A wafer processing apparatus includes a platform for supporting wafers. A first nozzle is provided on the platform for spraying air upwards onto the wafer to make it float.

[0026] A clamping device, wherein the clamping device is the aforementioned clamping device, the clamping device being used to clamp the floating wafer.

[0027] Thirdly, the wafer clamping method provided in this application adopts the following technical solution:

[0028] A wafer clamping method, applicable to the aforementioned wafer processing equipment, the clamping method comprising:

[0029] Position the clamping device above the platform and lower it;

[0030] The limiting post is made to abut against the platform, and the limiting post is located on the periphery of the wafer;

[0031] The first nozzle sprays air to lift the wafer.

[0032] The clamping member moves from the first position to the second position to support the wafer.

[0033] In summary, this application includes at least one of the following beneficial technical effects:

[0034] This application uses a platform to pneumatically drive the wafer to float, and uses limiting posts for initial positioning and guidance. The clamping component retracts to receive the wafer, which can accurately and non-contactly clamp the wafer, preventing contamination caused by wafer clamping. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the first position of the clamping member in the clamping device described in this application;

[0036] Figure 2 This is a schematic diagram of the second position of the clamping member in the clamping device described in this application;

[0037] Figure 3 This is a schematic diagram of the clamping element and the wafer in the clamping device described in this application;

[0038] Figure 4 This is a schematic diagram of the limiting post of the clamping device described in this application (the base has been hidden);

[0039] Figure 5 and Figure 6 This is a schematic diagram of the force exerted on the wafer in the clamping device described in this application.

[0040] Explanation of reference numerals in the attached drawings: W, wafer; 100, clamping device; 110, base; 111, limiting surface; 112, boss; 140, second nozzle; 120, limiting post; 121, limiting space; 130, clamping mechanism; 131, clamping space; 132, clamping element; 1321, connecting part; 1322, supporting part; 1323, supporting surface; 200, platform; 210, first nozzle. Detailed Implementation

[0041] The serial numbers assigned to components in this document, such as "first" and "second," are used solely to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages). It should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are used solely for the convenience of describing this application and simplifying the description. They 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, and therefore should not be construed as a limitation of this application.

[0042] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0043] This application provides a wafer clamping device 100, equipment, and method, which uses a non-adsorption clamping structure to grip the wafer W, preventing contamination caused by clamping the wafer W.

[0044] To better understand the above technical solutions, a detailed description of the technical solutions will be provided below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit the scope of this application.

[0045] In the semiconductor wafer manufacturing process, wafer handling and positioning are key steps. Traditional wafer clamping methods mainly include vacuum adsorption and mechanical gripper. Vacuum adsorption easily leaves adsorption marks on the wafer surface and is not effective for wafers with uneven surfaces or microstructures. Although mechanical gripper can provide stable clamping force, it has problems such as large contact area with the wafer and easy generation of particulate contamination.

[0046] To address the aforementioned issues, this application proposes a scheme for non-contact handling of wafer W using the principle of airflow suspension. Wafer W is suspended by upward airflow through a porous ceramic platform 200, and then the suspended wafer W is positioned and transferred using a mechanical structure.

[0047] However, a contradiction remains between suspension stability and contamination control. To ensure stable suspension of wafer W, a sufficiently strong airflow is required, but excessively strong airflow can cause wafer W to collide with or make large-area contact with the upper limiting structure, resulting in surface contamination. Simultaneously, there is the issue of impact during wafer W's descent. Wafer W's descent relies primarily on closing or weakening the airflow; under this condition, wafer W falls rapidly under gravity, making it prone to collisions with the receiving structure, leading to edge damage or positional displacement. Furthermore, there is a contradiction between receiving accuracy and individual wafer differences. Due to variations in thickness and surface condition, different wafers exhibit varying suspension heights under the same airflow conditions. The mechanical receiving structure struggles to adapt to these differences, easily leading to receiving failure.

[0048] Therefore, this application proposes a clamping technology solution that can achieve stable suspension, precise acceptance, and avoid contamination of wafer W; the purpose is to provide a wafer clamping device 100 and its control method, which realizes precise control of the entire process from suspension to acceptance of wafer W through the principle of gas-liquid coupling force balance, while minimizing the risk of surface contamination of wafer W.

[0049] This application discloses a wafer clamping device 100, such as... Figure 1 , 2 As shown, the clamping device 100 is used to clamp the floating wafer W. The clamping device 100 has a clamping space 131 for accommodating the wafer W. The clamping device 100 includes a base 110, a limiting post 120, and a clamping mechanism 130. The base 110 serves as the mounting base and the main frame of the clamping device 100. The limiting post 120 is fixedly connected to the base 110 and is arranged vertically. The limiting post 120 is used to limit and guide the floating wafer W. The mechanism 130 is disposed on the base 110. The clamping mechanism 130 and the limiting post 120 are located on the same side of the base 110. The clamping mechanism 130 includes clamping members 132. There are at least three clamping members 132. The clamping members 132 are slidably connected to the base 110 so that the clamping members 132 form at least a first position and a second position: in the first position, the clamping members 132 are located outside the clamping space 131; in the second position, at least a portion of the clamping members 132 are located inside the clamping space 131 to support the wafer W.

[0050] In other words, such as Figure 1 , 2 As shown, the core structure of the wafer W clamping device 100 includes a base 110, a limiting post 120, and a clamping architecture. The clamping device 100 is positioned directly above the wafer W processing platform 200 and is connected to and driven by an external robotic arm or lifting mechanism via the base 110. When the wafer W floats up under the action of air jets on the platform 200, the clamping device 100 achieves a smooth transition of the wafer W from a suspended state to a receiving state through gas-liquid coupling.

[0051] Specifically, as Figure 1 , 2 shown, the base 110 is the basic support structure of the device, and one side of it relative to the platform 200 has a limiting surface 111. A boss 112 is provided on the limiting surface 111. The boss 112 protrudes compared with the limiting surface 111 and is used to抵触配合 with the wafer W. The design of the boss 112 effectively prevents the wafer W from contacting the base 110 over a large area. Even if there is contact, it only occurs between the boss 112 and the wafer W, significantly reducing the pollution risk.

[0052] Furthermore, as Figure 3 shown, a second nozzle 140 is provided on the boss 112, and the second nozzle 140 is used to blow air or water downward onto the wafer W; or, a second nozzle 140 is provided on the limiting surface 111, and the second nozzle 140 is used to blow air or water downward onto the wafer W. That is to say, a second nozzle 140 for cooperating with the floating wafer W is provided on the base 110. Specifically, a first nozzle 210 is provided on the platform 200 and is used to blow air upward to make the wafer W float. The first nozzle 210 is made of porous ceramic or quartz material and integrates a micron-level air hole array. The flow rate of the compressed gas (such as high-purity nitrogen) is adjusted in real time through a pressure sensor to form a stable suspension air cushion; a second nozzle 140 is provided on the boss 112 or the limiting surface 111 and is used to blow air or water downward onto the wafer W. The second nozzle 140 uses a micro atomizing nozzle to atomize deionized water or an inert solvent into liquid droplets, mix with the air flow to form a gas-liquid two-phase flow, balance the suspension force with the assistance of surface tension, and generate a downward acting force F_water.

[0053] As Figure 4 shown, the limiting posts 120 are used to perform preliminary limiting and guiding on the floating wafer W. At least three limiting posts 120 are provided, and the limiting posts 120 are distributed in a ring shape so that a circular limiting space 121 is formed between the limiting posts 120. The radius of the limiting space 121 is R, and the radius of the wafer is r, such that R ∈ (r, 1.1r].

[0054] As Figure 4 shown, the number of the limiting posts 120 ≥ 3, and they are vertically fixed on the outer peripheral edge of the limiting surface 111 of the base 110 and are symmetrically distributed in a ring shape; the space between the limiting posts 120 forms a circular limiting space 121, and the radius R of the limiting space 121 satisfies: the radius r of the wafer W, where r < R ≤ 1.1r; preferably, the radius R of the limiting space 121 is 2 mm, 5 mm or 8 mm larger than the radius r of the wafer. When the clamping device 100 descends, the limiting posts 120 closely surround the outer circumference of the wafer W, limit the radial offset of the wafer W, and provide a vertical guiding channel for the floating or descending of the wafer W, ensuring that the wafer W maintains a stable position during the suspension process.

[0055] The clamping mechanism 130 is used to clamp the floating wafer W, specifically, as follows: Figure 5 , 6 As shown, the clamping mechanism 130 includes a clamping member 132 and a driving member (not shown). The clamping member 132 is slidably connected to the base 110 and is used to contact the wafer W to clamp the wafer W. The driving member serves as the driving structure for the sliding of the clamping member 132 and is connected to and acts on the clamping member 132. Specifically, the clamping member 132 includes a connecting portion 1321 and a supporting portion 1322. The connecting portion 1321 is slidably connected to the base 110. The supporting portion 1322 is fixedly connected to the connecting portion and has an inclined supporting surface 1323. The supporting surface 1323 is in line contact with the edge of the wafer W to support the wafer W.

[0056] In other words, the clamping mechanism 130 is disposed on the base 110, and is located on the same side of the base 110 as the limiting post 120; the clamping mechanism 130 includes at least three clamping members 132; such as Figure 5 , 6 As shown, the clamping member 132 is slidably connected to the base 110, forming a first position and a second position. In the first position, the clamping member 132 is located outside the clamping space 131; in the second position, at least a portion of the clamping member 132 is located within the clamping space 131 to support the wafer W. The clamping space 131 refers to the position where the wafer W is clamped by the clamping mechanism 130. Further, the number of clamping members 132 is ≥3, and each clamping member 132 includes a connecting portion 1321 and a supporting portion 1322. The connecting portion 1321 is slidably connected to the base 110 via a linear slide rail or guide groove, enabling the clamping member 132 to move. The supporting portion 1322 has a wedge-shaped structure and an inclined supporting surface 1323 with an inclination angle of 15° to 45°, making line contact with the edge of the wafer W for line contact support. This effectively reduces the contact area and lowers the risk of contamination.

[0057] In one embodiment, the number of driving members is the same as the number of clamping members 132, and the driving members are used to drive the clamping members 132 one-to-one to make the clamping members 132 slide. Each clamping member 132 is equipped with an independent cylinder / motor driving member to realize independent displacement control of the clamping member 132. In another embodiment, there is one driving member, which is movably connected to each clamping member 132 to synchronously drive the clamping member 132 to slide. A single driving member can simultaneously drive all clamping members 132 through a linkage mechanism to realize synchronous movement of multiple clamping members 132.

[0058] This application also provides a wafer processing device, such as... Figure 1 , 2As shown, it includes a platform 200 and a clamping device 100. The platform 200 is used to support the wafer W. A first nozzle 210 is provided on the platform 200. The first nozzle 210 is used to spray air upwards onto the wafer W to make the wafer W float. The clamping device 100 is the clamping device 100 mentioned above. The clamping device 100 is used to clamp the floated wafer W.

[0059] The wafer W processing equipment includes a platform 200 and a clamping device 100. The two are linked in space through a three-dimensional motion mechanism (such as an XYZ axis robotic arm). The platform 200 is used to carry the wafer W and provide initial levitation power, while the clamping device 100 limits, supports and transfers the suspended wafer W to achieve precise coordination.

[0060] Specifically, platform 200 is made of ceramic material to avoid warping of wafer W due to deformation of platform 200; a circular bearing area is set in the center of platform 200, with a radius larger than that of wafer W, and the bearing area is evenly distributed with the array of first nozzles 210 to ensure that the airflow evenly covers the bottom surface of wafer W.

[0061] The first nozzle 210 is connected to the air source through the air passage. The first nozzle 210 sprays air upward to form an air cushion on the bottom surface of the wafer W, so that the wafer W is suspended on the platform 200. The airflow speed is calculated to avoid the airflow being too strong and causing the wafer W to collide with the clamping device 100.

[0062] like Figure 3 As shown, the clamping device 100 is positioned directly above the platform 200. A robotic arm enables Z-axis (vertical) lifting and planar movement. The base 110 has a horizontal limiting surface 111 at its bottom, with a boss 112 on the limiting surface 111 to ensure point contact rather than surface contact when in contact with the edge of the wafer W, thus avoiding large-area contamination. The base 110 is equipped with a second nozzle 140, specifically located on the boss 112 or the limiting surface 111, which can spray deionized water mist and / or gas downwards to assist the wafer W in its descent.

[0063] like Figure 4 As shown, at least three limiting posts 120 are provided, which are evenly distributed in a ring on the edge of the base 110. The spacing between adjacent limiting posts 120 is equal, forming a circular limiting space 121 with a diameter slightly larger than that of the wafer W (the radius R of the limiting space 121 satisfies r < R ≤ 1.1r, where r is the radius of the wafer W), to ensure circumferential limiting and guidance of the suspended wafer W.

[0064] like Figure 5 , 6As shown, the clamping mechanism 130 includes at least three clamping members 132, which are radially slidably connected to the periphery of the limiting surface 111 along the base 110. Each clamping member 132 has an inclined support portion 1322, and the support surface 1323 is in line contact with the edge of the wafer W, ensuring that the gravity of the wafer W is decomposed into radial positioning force and axial support force along the support surface 1323. The clamping members 132 are driven by a servo motor or pneumatic cylinder and can be quickly switched between a first position (located outside the clamping station, avoiding the floating space of the wafer W) and a second position (partially extended into the clamping station, supporting the edge of the wafer W).

[0065] This application requires the linkage between the platform 200 jet, the wafer W, the clamping member 132, and the boss 112: the wafer W is lifted by the jet from the platform 200, then the clamping member 132 retracts, the boss sprays water to make the wafer W descend, and finally the jet from the platform 200 is turned off.

[0066] Specifically: such as Figure 5 , 6 As shown, to ensure the wafer W floats steadily, the air blown out by the platform 200 needs to be large enough. However, a large amount of air would cause the wafer W to make large-area contact with the base 110 (limiting surface 111), resulting in contamination. Furthermore, the airflow is often difficult to control precisely. Therefore, a boss 112 is designed on the base 110 (limiting surface 111) to prevent large-area contact between the wafer W and the base 110 (limiting surface 111). Even if there is contact, it is only a small-area contact between the wafer W and the boss 112. Further, after the wafer W floats, the clamping member 132 retracts, requiring the wafer W to fall to support it. Here, a stable fall of the wafer W is necessary. Therefore, water is sprayed onto the boss 112. On the one hand, Spraying water can keep the wafer W moist; on the other hand, the spraying water has a downward force on the wafer W. At this time, the force on the wafer W is F = G + F water - F air, where F water refers to the force of the boss 112 spraying water on the wafer W, and F air refers to the buoyancy of the platform 200 spraying air on the wafer W. After the combined force, the wafer W is subjected to a downward force so that the wafer W falls steadily to the support part 1322 of the clamping member 132 (the support surface 1323 is in linear contact), and then the air jet of the platform 200 is turned off. If there is no water spraying from the boss 112, if the wafer W needs to fall, the air jet of the platform 200 needs to be turned off. After the air jet of the platform 200 is turned off, the wafer W will fall immediately under the force of gravity, causing the wafer W to collide with the clamping member 132.

[0067] Furthermore, such as Figure 5 , 6As shown, due to limitations such as the precision of the gripper retraction, and the inconsistent rising height of each wafer W (with differences in thickness and gravity) under the action of airflow, it is difficult to achieve a perfect fit between the wafer W and the support surface 1323. Therefore, this application designs a method that combines the upward blowing of air from the platform 200 and the downward spraying of water from the boss 112 to ensure that the wafer W falls steadily on the support part 1322.

[0068] This application also proposes a wafer clamping method applicable to the aforementioned wafer W processing equipment. The clamping method includes: Figure 1 , 2 As shown, the clamping device 100 is positioned above the platform 200 and lowered; the limiting post 120 is brought into contact with the platform 200, and the limiting post 120 is positioned on the periphery of the wafer W; as Figure 5 , 6 As shown, the first nozzle 210 sprays air to make the wafer W float; the clamping member 132 moves from the first position to the second position to support the wafer W.

[0069] Specifically, S101: Move the clamping device 100 directly above the platform 200;

[0070] S102: Drive the clamping device 100 to descend vertically until:

[0071] The bottom of the limiting post 120 is in close contact with the surface of the platform 200, forming an annular limiting space 121;

[0072] The limiting posts 120 are arranged in a ring array on the outer periphery of the wafer W, forming a limiting space 121 with a radius R∈(r,1.1r] (r is the radius of the wafer W). At this time, the clamping member 132 is in the first position, and its supporting part 1322 is located outside the limiting space 121 to avoid interference with the suspension of the wafer W.

[0073] S201: Start platform 200, first nozzle 210 sprays air upwards:

[0074] S202: When wafer W rises vertically under the action of air flotation, it may come into contact with boss 112 when the gas is difficult to control precisely. When the airflow intensity is sufficient to maintain stable suspension (F gas ≥ G), the traditional solution will cause wafer W to rub against the base 110 over a large area. This method achieves this through boss 112: changing the contact mode from surface contact to point / micro-area contact; the contact pressure is distributed to boss 112.

[0075] S301: Simultaneously trigger two actions:

[0076] The driving component pushes the clamping component 132 radially inward from the first position to the second position;

[0077] Activate the second nozzle 140 on the boss 112 to spray downwards;

[0078] S401: On the support surface 1323 of the wafer W edge contact clamp; Compared with the traditional free fall, this solution reduces the deceleration by 80% to 90% through: hydraulic buffering; the inclined surface design converts vertical impact into horizontal sliding; and the linear contact mode avoids edge damage.

[0079] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0080] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A wafer chucking device characterized by comprising: The clamping device (100) is used to clamp the floating wafer (W), the clamping device (100) has a clamping space (131) for accommodating the wafer (W), and the clamping device (100) includes: Base (110); A limiting post (120) is fixedly connected to the base (110). The limiting post (120) is arranged vertically and is used to limit and guide the floating wafer (W). A clamping mechanism (130) is disposed on the base (110), and the clamping mechanism (130) and the limiting post (120) are located on the same side of the base (110). The clamping mechanism (130) includes: A clamping member (132), having at least three clamping members (132), is slidably connected to the base (110) such that the clamping member (132) forms at least a first position and a second position: In the first position, the clamping member (132) is located outside the clamping space (131); In the second position, at least a portion of the clamping member (132) is located within the clamping space (131) to support the wafer (W).

2. The wafer chucking device of claim 1, wherein At least three limiting posts (120) are provided, and the limiting posts (120) are arranged in a ring so that a circular limiting space (121) is formed between the limiting posts (120). The radius of the limiting space (121) is R, and the radius of the wafer is r, such that R∈(r,1.1r).

3. The wafer chucking device of claim 1, wherein The clamping member (132) includes: A connecting part (1321) is slidably connected to the base (110); The support portion (1322) is fixedly connected to the connecting portion. The support portion (1322) has an inclined support surface (1323) for making line contact with the edge of the wafer (W) to support the wafer (W).

4. The wafer chucking device according to claim 1 or 3, wherein The clamping mechanism (130) further includes: The number of driving members is the same as that of the clamping members (132), and the driving members are used to drive the clamping members (132) in a one-to-one correspondence to make the clamping members (132) slide.

5. The wafer chucking device according to claim 1 or 3, wherein The clamping mechanism (130) further includes: A drive member is provided, wherein one drive member is movably connected to each of the clamping members (132) to synchronously drive the clamping members (132) to slide.

6. The wafer chucking device of claim 1, wherein The base (110) has a limiting surface (111) on one side of the platform (200), and the limiting surface (111) has a boss (112) that protrudes from the limiting surface (111) and is used to engage with the wafer (W).

7. The wafer chucking device of claim 6, wherein The boss (112) is provided with a second nozzle (140), which is used to spray air or water onto the wafer (W).

8. The wafer chucking device of claim 6, wherein A second nozzle (140) is arranged on the limiting surface (111) and used for spraying air or water to the wafer (W).

9. A wafer processing apparatus, characterized by, a platform (200) for carrying a wafer (W); a clamping device (100) as claimed in any one of claims 1 to 8 for clamping the wafer (W) floating.

10. A wafer processing equipment according to claim 9, characterized in that, A first nozzle (210) is arranged on the platform (200) and used for spraying air upward to the wafer (W) to make the wafer (W) float.

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