Wafer clamping device and wafer post-processing equipment

Abstract

The invention discloses a wafer clamping device and a wafer post-processing device, wherein the wafer clamping device comprises a clamping claw for clamping a wafer, a lifting assembly connected to the clamping claw, and a driving mechanism; the lifting assembly comprises a lifting mechanism and an opening and closing mechanism, the lifting mechanism is used to support the wafer, and the opening and closing mechanism is used to control the clamping claw to clamp or release the wafer; when the driving mechanism causes the lifting assembly to descend, the lifting mechanism supports the wafer to descend while the opening and closing mechanism causes the clamping claw to clamp the peripheral portion of the wafer; when the driving mechanism causes the lifting assembly to ascend, the lifting mechanism supports the wafer to ascend while the opening and closing mechanism causes the clamping claw to release the peripheral portion of the wafer. The wafer post-processing device comprises a wafer clamping device, a turntable, a supply unit for conveying a fluid, and a retaining ring arranged around the turntable.

Description

Technical Field

[0001] The invention relates to the technical field of chemical mechanical polishing post-processing, and in particular to a wafer clamping device and wafer post-processing equipment. Background Art

[0002] The integrated circuit industry is the core of the information technology industry and plays a key role in promoting the transformation and upgrading of the manufacturing industry towards digitalization and intelligence. Chips are the carriers of integrated circuits, and chip manufacturing involves chip design, wafer manufacturing, wafer processing, electrical measurement, cutting packaging and testing.

[0003] During the manufacturing process of integrated circuits, wafers are exposed to a large number of particles during multiple processes such as thin film deposition, etching, and polishing. In order to keep the surface of the wafer clean and eliminate particles left on the surface of the wafer during the process, the wafer must be cleaned after each process. Among them, the horizontal cleaning technology is to place the wafer on a clamping device and rotate it at a certain speed; at the same time, a certain flow of cleaning liquid is sprayed on the wafer to clean and / or dry the surface of the wafer.

[0004] In horizontal cleaning technology, it is necessary for the wafer to achieve high-speed rotation and interact with the robot. To achieve these actions, very complex mechanisms are often required, which can easily lead to stability problems of the mechanical hardware. In addition, due to the complex mechanical structure and numerous parts, it is easy to cause contamination. Summary of the invention

[0005] The embodiments of the present invention provide a wafer clamping device and a wafer post-processing device, aiming to solve at least one of the technical problems existing in the prior art.

[0006] A first aspect of an embodiment of the present invention provides a wafer clamping device, comprising a clamping claw for clamping a wafer, a lifting assembly connected to the clamping claw, and a driving mechanism;

[0007] The lifting assembly includes a lifting mechanism and an opening and closing mechanism, wherein the lifting mechanism is used to support the wafer, and the opening and closing mechanism is used to control the clamping claws to clamp or release the wafer;

[0008] When the driving mechanism causes the lifting assembly to descend, the lifting mechanism holds the wafer down while the opening and closing mechanism causes the claws to clamp the periphery of the wafer; when the driving mechanism causes the lifting assembly to ascend, the lifting mechanism holds the wafer up while the opening and closing mechanism causes the claws to release the periphery of the wafer.

[0009] In one embodiment, the lifting mechanism includes a fixing sleeve, a lifting cylinder and an elastic structure;

[0010] The fixing sleeve is fixedly mounted on the edge of the turntable, a shielding portion is provided on the top of the fixing sleeve, the lifting cylinder passes through the hollow portion of the fixing sleeve and can move up and down relative to the fixing sleeve, an extended arm is provided on the outer periphery of the lifting cylinder, the arm is located above the shielding portion so as to rest on the shielding portion after the lifting cylinder is lowered, thereby limiting the lifting cylinder to a lowered position; the elastic structure is connected to the lifting cylinder, and is used to limit the moving range of the lifting cylinder and keep the lifting cylinder in a lowered position under normal conditions.

[0011] In one embodiment, the lifting mechanism further includes a wear-resistant spacer sleeve, and the spacer sleeve is arranged between the fixing sleeve and the lifting cylinder.

[0012] In one embodiment, the elastic structure includes a top sheet, a vertical spring and an outer retaining spring;

[0013] The outer retaining spring is fixedly connected to the outer peripheral wall of the lifting cylinder, the vertical spring is sleeved on the outer periphery of the lifting cylinder, the vertical spring is located between the spacer sleeve and the outer retaining spring, and top plates are respectively provided between the vertical spring and the spacer sleeve and between the vertical spring and the outer retaining spring.

[0014] In one embodiment, the middle portion of the clamping jaw is connected to a rotation axis, and the clamping jaw can rotate around the rotation axis.

[0015] In one embodiment, the opening and closing mechanism includes a lifting rod structure and a horizontal pushing structure;

[0016] The lifting rod structure is used to generate a lateral force on the bottom of the claw when rising so that the claw rotates around the rotation axis to release the wafer, and to reduce the lateral force when descending so as to facilitate the claw to clamp the wafer;

[0017] The horizontal pushing structure is used to apply a pushing force opposite to the lateral force to the lower part of the clamping claw so that the clamping claw clamps the wafer.

[0018] In one embodiment, the lifting cylinder has through holes penetrating the upper and lower surfaces thereof;

[0019] The clamping claw and the lifting rod structure are both arranged in the through hole, and the clamping claw is located above the lifting rod structure.

[0020] In one embodiment, the lifting rod structure includes a lifting rod and a roller;

[0021] The roller is fixed to the top of the lifting rod, an inner retaining spring for limiting is arranged below the lifting rod, the inner retaining spring is fixed to the inner wall of the lifting cylinder, and the bottom end of the lifting rod extends out of the bottom surface of the lifting cylinder.

[0022] In one embodiment, the horizontal pushing structure includes a horizontal push rod and a horizontal spring.

[0023] A groove connected to the through hole is provided in the arm, and the horizontal push rod and the horizontal spring are arranged in the groove. The horizontal spring pushes the horizontal push rod against the inner lower part of the claw to apply an outward pushing force to the lower part of the claw so that the upper end of the claw has a tendency to move inward.

[0024] A second aspect of an embodiment of the present invention provides a wafer post-processing device, comprising the wafer clamping device as described above, a turntable, a supply unit for conveying a fluid, and a retaining ring arranged around the turntable.

[0025] The beneficial effects of the embodiments of the present invention include: utilizing a simple and reliable structure to achieve clamping the wafer after descent to perform high-speed rotation and releasing the wafer after ascending to interact with the robot. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The advantages of the present invention will become clearer and easier to understand through the detailed description made in conjunction with the following drawings, but these drawings are only schematic and do not limit the scope of protection of the present invention, wherein:

[0027] Figure 1 A schematic diagram of the structure of a wafer post-processing device provided by an embodiment of the present invention;

[0028] Figure 2 A schematic diagram of a wafer clamping device in a descending state provided by an embodiment of the present invention;

[0029] Figure 3 A schematic diagram of a wafer clamping device in a rising state provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0030] The technical scheme of the present invention is described in detail below in conjunction with specific embodiments and their accompanying drawings. The embodiments recorded herein are specific embodiments of the present invention, which are used to illustrate the concept of the present invention; these descriptions are explanatory and exemplary, and should not be understood as limitations on the embodiments of the present invention and the scope of protection of the present invention. It should be noted that, in the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. In addition to the embodiments recorded herein, those skilled in the art can also adopt other obvious technical solutions based on the contents disclosed in the claims of this application and its specification, which include technical solutions that adopt any obvious replacements and modifications to the embodiments recorded herein. It should be understood that, unless otherwise specified, for ease of understanding, the following description of the specific embodiments of the present invention is based on the description of the relevant equipment, devices, components, etc. in the original static natural state without external control signals and driving forces.

[0031] In addition, it should be noted that the terms used in this application to indicate orientation, such as front, back, up, down, left, right, top, bottom, front, back, horizontal, vertical, etc., are merely for convenience of description to help understand relative positions or directions, and are not intended to limit the orientation of any device or structure.

[0032] In order to illustrate the technical solution of the present invention, the following description will be given with reference to the accompanying drawings and in combination with embodiments.

[0033] In this application, chemical mechanical polishing is also referred to as chemical mechanical planarization, and a wafer is also referred to as a chip, a silicon wafer, a base wafer or a substrate, which have the same meaning and practical function.

[0034] Figure 1 A schematic structural diagram of a wafer post-processing device 1 provided in an embodiment of the present invention is shown, which includes a wafer clamping device 30 , a turntable 10 , a supply unit for conveying fluid, and a retaining ring 20 arranged around the turntable 10 .

[0035] A plurality of wafer clamping devices 30 may be disposed on the turntable 10 to hold the wafer w and drive the wafer w to rotate vertically around the central axis of the wafer w in the box. The central axis of the wafer w passes through the center of the wafer w and is perpendicular to the surface of the wafer w.

[0036] It should be noted that the “inside”, “outside”, “inner side” and “outer side” mentioned in the present application are all described with reference to the central axis, wherein “inside” refers to toward the central axis and “outside” refers to away from the central axis.

[0037] When the turntable 10 clamps the wafer w through the wafer clamping device 30 to drive the wafer w to rotate horizontally, the supply unit delivers fluid to the surface of the wafer w, and the retaining ring 20 surrounds the outside of the wafer w to block the fluid flying outward and collect the fluid.

[0038] In one embodiment, the supply unit can spray different types of fluids to the wafer w according to different cleaning and drying requirements, including a cleaning solution for cleaning the wafer w and a drying gas for drying the wafer w to respectively realize the cleaning operation and the drying operation. In the cleaning operation, the cleaning solution provided by the supply unit is generally divided into water, an acidic solution and an alkaline solution. The solution components mainly include a pH regulator, a chelating agent, and a corrosion inhibitor. The pH regulator is used to adjust the pH value of the solution. The chelating agent is mainly used to remove metal ions. The corrosion inhibitor is used to prevent corrosion of the wafer w during cleaning. During the drying operation, the drying gas can be clean air, nitrogen, isopropyl alcohol vapor, etc.

[0039] In one embodiment, the retaining ring 20 surrounds the outer side of the turntable 10 and is provided with a lifting unit for controlling the lifting of the retaining ring 20. The retaining ring 20 can be made of acid- and alkali-resistant plastics, such as polypropylene (PP), polyphenylene sulfide (PPS) or polyvinyl chloride (PVC).

[0040] In one embodiment, the wafer post-processing device 1 is disposed in a closed box, and the box may be provided with an air filtering circulation system and a gas-liquid exhaust system.

[0041] Figure 2 and Figure 3 A schematic structural diagram of a wafer clamping device 30 provided in an embodiment of the present invention is shown, which includes a clamping claw 40 for clamping a wafer w, a lifting assembly connected to the clamping claw 40, and a driving mechanism 80.

[0042] like Figure 2 As shown, the lifting assembly includes a lifting mechanism 60 and an opening and closing mechanism 70, the lifting mechanism 60 is used to support the wafer w, and the opening and closing mechanism 70 is used to control the claws 40 to clamp or release the wafer w;

[0043] When the driving mechanism 80 causes the lifting assembly to descend, the lifting mechanism 60 holds the wafer w down and the opening and closing mechanism 70 causes the claws 40 to clamp the peripheral portion of the wafer w; when the driving mechanism 80 causes the lifting assembly to ascend, the lifting mechanism 60 holds the wafer w up and the opening and closing mechanism 70 causes the claws 40 to release the peripheral portion of the wafer w.

[0044] In the embodiment of the present invention, when the lifting assembly descends, the wafer w descends to below the retaining ring 20, and the claws 40 clamp the wafer w, so that high-speed rotation of the wafer w can be achieved; when the lifting assembly rises, the wafer w rises to above the retaining ring 20, and the claws 40 release the wafer w, so that the robot can operate to take away or place the wafer w.

[0045] like Figure 2 and Figure 3 As shown, in one embodiment, the driving mechanism 80 is located below the lifting assembly and is used to move the lifting assembly upward.

[0046] like Figure 2 As shown, in one embodiment, the lifting mechanism 60 includes a fixing sleeve 61, a lifting cylinder 62 and an elastic structure 63;

[0047] The fixing sleeve 61 is fixedly connected to the turntable 10 and is fixedly installed on the edge of the turntable 10 . The fixing sleeve 61 has a hollow portion 611 that runs through its upper and lower surfaces. A shielding portion 612 is provided on the top of the fixing sleeve 61 , and the opening of the shielding portion 612 is smaller than the opening at the bottom of the fixing sleeve 61 .

[0048] The lifting cylinder 62 passes through the hollow portion 611 of the fixing sleeve 61 and can move up and down relative to the fixing sleeve 61. The upper edge of the lifting cylinder 62 is used to support the wafer w to move up and down. The outer periphery of the lifting cylinder 62 is provided with an extended arm 621, such as Figure 3 As shown, the arm 621 is located above the shielding portion 612 so as to rest on the shielding portion 612 after the lifting cylinder 62 is lowered, thereby limiting the lifting cylinder 62 in the lowered position.

[0049] The elastic structure 63 is connected to the lifting cylinder 62 and is used to limit the movement range of the lifting cylinder 62 and make the lifting cylinder 62 be in a lowered position in a normal state.

[0050] like Figure 2 As shown, in one embodiment, the lifting mechanism 60 further includes a wear-resistant spacer 64, which is sleeved between the fixed sleeve 61 and the lifting cylinder 62. The lifting cylinder 62 slides relative to the spacer 64, and the spacer 64 limits the lifting cylinder 62 when the lifting cylinder 62 moves. The spacer 64 can ensure the coaxiality of the lifting cylinder 62 during the movement, keep the lifting cylinder 62 moving vertically, and the spacer 64 is made of wear-resistant material, such as POM (polyoxymethylene) or PTFE (polytetrafluoroethylene), which can reduce the friction between the spacer 64 and the lifting cylinder 62, prevent the generation of grinding debris during the friction process from causing pollution, and increase the service life.

[0051] The spacer sleeve 64 is placed in the fixing sleeve 61 , the upper end of the spacer sleeve 64 is limited by the shielding portion 612 , and the lower end of the spacer sleeve 64 is limited by the elastic structure 63 .

[0052] like Figure 3 As shown, in one embodiment, the elastic structure 63 includes a top sheet 631, a vertical spring 632 and an outer retaining spring 633;

[0053] The outer retaining spring 633 is fixedly connected to the outer peripheral wall of the lifting cylinder 62, the vertical spring 632 is sleeved on the outer periphery of the lifting cylinder 62, the vertical spring 632 is located between the spacer sleeve 64 and the outer retaining spring 633, and a top plate 631 is respectively provided between the vertical spring 632 and the spacer sleeve 64 and between the vertical spring 632 and the outer retaining spring 633.

[0054] After the driving mechanism 80 drives the lifting cylinder 62 to rise, the vertical spring 632 is compressed; when the driving mechanism 80 descends, the lifting cylinder 62 moves downward under the action of its own gravity and the pressure of the vertical spring 632 until the arm 621 falls on the shielding portion 612 and stops moving downward.

[0055] like Figure 3As shown, in one embodiment, the middle of the clamping claw 40 is connected to the rotating shaft 44, and the clamping claw 40 can rotate around the rotating shaft 44. The rotating shaft 44 passes through the clamping claw 40 and the fixing hole opened on the side wall of the lifting cylinder 62 for fixing. Among them, the clamping claw 40 can be made of non-metallic material, such as PEEK or PPS. The rotating shaft 44 can be made of non-metallic material, such as POM (polyoxymethylene) or PTFE (polytetrafluoroethylene). Further, the outer sleeve of the lifting cylinder 62 is provided with a clamping sleeve for clamping the rotating shaft 44.

[0056] Furthermore, a gasket is provided between the side of the claw 40 passing through the rotating shaft 44 and the inner wall of the lifting cylinder 62. The gasket is made of wear-resistant material, such as metal material, including stainless steel, etc., which can prevent friction between the claw 40 and the inner wall of the lifting cylinder 62, thereby preventing the generation of wear debris and causing pollution.

[0057] like Figure 2 As shown, in one embodiment, the opening and closing mechanism 70 includes a lifting rod structure 71 and a horizontal pushing structure 72;

[0058] The lifting rod structure 71 is used to generate a lateral force on the bottom of the claw 40 when rising so that the claw 40 rotates around the rotation axis 44 to release the wafer w, and to reduce the lateral force when descending so that the claw 40 can clamp the wafer w;

[0059] The horizontal pushing structure 72 is used to apply a pushing force opposite to the lateral force to the lower part of the clamping claw 40 so that the clamping claw 40 clamps the wafer w.

[0060] like Figure 3 As shown, in one embodiment, the lifting cylinder 62 has a through hole 623 penetrating the upper and lower surfaces thereof; the claw 40 and the lifting rod structure 71 are both disposed in the through hole 623 , and the claw 40 is located above the lifting rod structure 71 .

[0061] like Figure 3 As shown, in one embodiment, the lifting rod structure 71 includes a lifting rod 711 and a roller 712;

[0062] A roller 712 is fixed to the top of the lifting rod 711 , an inner retaining spring 713 for limiting is provided below the lifting rod 711 , the inner retaining spring 713 is fixed to the inner wall of the lifting cylinder 62 , and the bottom end of the lifting rod 711 extends out of the bottom surface of the lifting cylinder 62 .

[0063] like Figure 3As shown, the bottom surface of the claw 40 in contact with the roller 712 is an inclined surface. When the roller 712 rises, it will generate a lateral component of force when passing through the inclined surface. The lateral component of force causes the lower part of the claw 40 to move inward, and at the same time, the upper part of the claw 40 moves outward to release the wafer w. The claw 40 includes a main body 41, an end 42 formed by the upper end of the main body 41 extending inward, and an inclined portion 43 formed by the lower end of the main body 41 extending obliquely inward. Among them, the bottom surface of the inclined portion 43 is an inclined surface, which is used to interact with the roller 712. The lifting cylinder 62 is provided with a notch 624 at a position corresponding to the bottom end of the inclined portion 43, which is used to avoid the bottom end of the inclined portion 43 when the claw 40 rises and the inclined portion 43 rotates a certain angle, so as to provide space for the inclined portion 43 to rotate. The main body 41 is provided with a hole for the rotation shaft 44 to pass through, so that the claw 40 can rotate around the rotation shaft 44.

[0064] like Figure 3 As shown, in one embodiment, the horizontal pushing structure 72 includes a horizontal push rod 721 and a horizontal spring.

[0065] A slot 622 connected to the through hole 623 is provided in the arm 621, and a horizontal push rod 721 and a horizontal spring are arranged in the slot 622. The horizontal spring pushes the horizontal push rod 721 against the inner lower part of the claw 40 to apply an outward pushing force to the lower part of the claw 40 so that the upper end of the claw 40 has a tendency to move inward.

[0066] In one embodiment, the horizontal push rod 721 is made of metal. When the wafer w rotates at high speed, due to the large mass of the horizontal push rod 721 and the large outward centrifugal force, the horizontal push rod 721 will exert a greater force on the lower part of the claw 40 under the dual action of the centrifugal force and the elastic force of the horizontal spring, thereby increasing the clamping force of the claw 40 on the wafer w, so that the wafer w can remain stable when rotating at high speed.

[0067] Specifically, the working process of the wafer clamping device 30 provided in the embodiment of the present invention includes the following two states:

[0068] 1) If Figure 2 The descending state shown:

[0069] During the process of clamping wafer w, the driving mechanism 80 moves downward, and under the influence of gravity, the lifting rod 711 falls onto the inner retaining spring 713, and the lifting cylinder 62 falls onto the fixed sleeve 61. The horizontal push rod 721 pushes the clamping claw 40 under the drive of the horizontal spring, so that the clamping claw 40 clamps wafer w. At this time, multiple groups of clamping claws 40 work together to allow wafer w to rotate at high speed.

[0070] 2) If Figure 3 The rising state shown:

[0071] During the interaction with the robot, the driving mechanism 80 moves upward, the bottom end of the lifting rod 711 is subjected to an upward force, the vertical spring 632 is compressed, the roller 712 contacts the claw 40, the roller 712 slides to open the claw 40, and the wafer w is in a loosened state. At the same time, the upward force causes the bottom surfaces of the lifting rod 711 and the lifting cylinder 62 to be in the same plane, and they rise together, so that the lifting cylinder 62 is higher than the retaining ring 20, which is convenient for the robot to operate the wafer w.

[0072] The drawings in the specification are schematic diagrams, which assist in explaining the concept of the present invention and schematically show the shapes of various parts and their mutual relationships. It should be understood that in order to clearly show the structures of various components of the embodiments of the present invention, the drawings are not drawn according to the same scale, and the same reference numerals are used to represent the same parts in the drawings.

[0073] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0074] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A wafer clamping device, characterized in that: It includes a clamping claw for clamping a wafer, a lifting assembly connected to the clamping claw, and a driving mechanism; The middle part of the clamping claw is connected to the rotating shaft, and the clamping claw can rotate around the rotating shaft; The lifting assembly includes a lifting mechanism and an opening and closing mechanism, wherein the lifting mechanism is used to support the wafer, and the opening and closing mechanism is used to control the clamping claws to clamp or release the wafer; The lifting mechanism includes a fixed sleeve and a lifting cylinder, the lifting cylinder moves up and down relative to the fixed sleeve, and the upper edge of the lifting cylinder is used to support the wafer to move up and down; The opening and closing mechanism includes a lifting rod structure and a horizontal pushing structure. The lifting rod structure is used to generate a lateral force on the bottom of the claw when rising so that the claw rotates around the rotation axis to release the wafer, and to reduce the lateral force when descending to facilitate the claw to clamp the wafer. The horizontal pushing structure is used to apply a pushing force opposite to the lateral force to the lower part of the claw so that the claw clamps the wafer; When the driving mechanism causes the lifting assembly to descend, the lifting cylinder holds the wafer down and the opening and closing mechanism causes the claws to clamp the periphery of the wafer; when the driving mechanism causes the lifting assembly to ascend, the lifting cylinder holds the wafer up and the opening and closing mechanism causes the claws to release the periphery of the wafer.

2. The wafer clamping device according to claim 1, characterized in that: The lifting mechanism also includes an elastic structure; The fixing sleeve is fixedly mounted on the edge of the turntable, a shielding portion is provided on the top of the fixing sleeve, the lifting cylinder passes through the hollow portion of the fixing sleeve and can move up and down relative to the fixing sleeve, an extended arm is provided on the outer periphery of the lifting cylinder, the arm is located above the shielding portion so as to rest on the shielding portion after the lifting cylinder is lowered, thereby limiting the lifting cylinder to a lowered position; the elastic structure is connected to the lifting cylinder, and is used to limit the moving range of the lifting cylinder and keep the lifting cylinder in a lowered position under normal conditions.

3. The wafer clamping device according to claim 2, characterized in that: The lifting mechanism also includes a wear-resistant spacer sleeve, which is arranged between the fixed sleeve and the lifting cylinder.

4. The wafer clamping device according to claim 3, characterized in that: The elastic structure includes a top sheet, a vertical spring and an outer retaining spring; The outer retaining spring is fixedly connected to the outer peripheral wall of the lifting cylinder, the vertical spring is sleeved on the outer periphery of the lifting cylinder, the vertical spring is located between the spacer sleeve and the outer retaining spring, and top plates are respectively provided between the vertical spring and the spacer sleeve and between the vertical spring and the outer retaining spring.

5. The wafer holding device according to claim 2, characterized in that: The lifting cylinder has through holes penetrating the upper and lower surfaces thereof; The clamping claw and the lifting rod structure are both arranged in the through hole, and the clamping claw is located above the lifting rod structure.

6. The wafer clamping device according to claim 1, characterized in that: The lifting rod structure comprises a lifting rod and a roller; The roller is fixed to the top of the lifting rod, an inner retaining spring for limiting is arranged below the lifting rod, the inner retaining spring is fixed to the inner wall of the lifting cylinder, and the bottom end of the lifting rod extends out of the bottom surface of the lifting cylinder.

7. The wafer holding device according to claim 5, characterized in that: The horizontal pushing structure includes a horizontal push rod and a horizontal spring. A groove connected to the through hole is provided in the arm, and the horizontal push rod and the horizontal spring are arranged in the groove. The horizontal spring pushes the horizontal push rod against the inner lower part of the claw to apply an outward pushing force to the lower part of the claw so that the upper end of the claw has a tendency to move inward.

8. A wafer post-processing device, characterized in that: The invention comprises a wafer clamping device as claimed in any one of claims 1 to 7, a turntable, a supply unit for conveying a fluid and a retaining ring arranged around the turntable.

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