Support assembly and polishing apparatus for wafer polishing

Abstract

The application provides a support assembly and a polishing device for wafer polishing, the support assembly comprising a frame, a power mechanism, a first protective member and a second protective member, the power mechanism being connected with the frame in transverse sliding mode and being at least partially located below the frame; the first protective member has a first avoiding hole to be sleeved outside the power mechanism, the first protective member being connected below the frame; the second protective member has a second avoiding hole to be sleeved outside the power mechanism, the second protective member being sealingly connected with the power mechanism, and the second protective member being located below the first protective member; first protective structures and second protective structures which are spaced apart are arranged between the first protective member and the second protective member, and the first protective structures and the second protective structures are used for blocking liquid from entering the inside of the power mechanism.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wafer polishing, and more particularly, to a support assembly and a polishing device for wafer polishing. BACKGROUND

[0002] Chemical mechanical polishing (CMP) is a kind of global planarization ultra-precision surface processing technology. The device for chemical mechanical polishing generally comprises a support assembly, a carrier head and a polishing pad, the carrier head is connected with the support assembly, the lower surface of the carrier head is used for fixing a wafer, the lower surface of the wafer has a deposition layer, the lower surface of the wafer is pressed against the upper surface of the polishing pad, the carrier head is rotated with the polishing pad in the same direction under the actuation of a driving assembly and gives the wafer a downward load; a polishing liquid is supplied to the upper surface of the polishing pad and distributed between the lower surface of the wafer and the upper surface of the polishing pad, so that the wafer completes chemical mechanical polishing of the wafer under the joint action of chemical and mechanical.

[0003] In the related art, the support assembly comprises a frame, at least two power mechanisms and at least two carrier heads, the two carrier heads are respectively installed on the two power mechanisms, the power mechanisms can reciprocate along the transverse direction relative to the frame, so that the two carrier heads can reciprocate along the transverse direction relative to the frame to alternately load wafers, thereby improving the production efficiency of the polishing stage.

[0004] However, there will always be splashing of the polishing liquid in the polishing chamber during the polishing process, and since the carrier head needs to reciprocate along the transverse direction relative to the frame, the situation that the splashed polishing liquid enters from the gap and invades the electrical elements of the power mechanism is prone to occur. SUMMARY

[0005] The present application provides a support assembly and a polishing device for wafer polishing, which can effectively block the invasion of the polishing liquid into the electrical elements of the power mechanism.

[0006] In a first aspect, the present application provides a support assembly for wafer polishing, comprising:

[0007] a frame,

[0008] a power mechanism installed on the frame and capable of sliding along the transverse direction relative to the frame, at least part of the structure of the power mechanism being located below the frame;

[0009] a first protective member having a first avoiding hole to be sleeved outside the power mechanism, the first protective member being connected with the frame and located below the frame;

[0010] A second guard member has a second avoiding hole to be sleeved outside the power mechanism, and the second guard member is in sealed connection with the power mechanism to move synchronously with the power mechanism, and the second guard member is located below the first guard member.

[0011] The first guard member and the second guard member are provided with first guard structures and second guard structures, the first guard structures and the second guard structures are spaced apart, and the first guard structures and the second guard structures allow the second guard member to slide relative to the first guard member in the transverse direction to block the liquid from entering the inside of the power mechanism.

[0012] Optionally, the first guard structure includes two groups of comb teeth and two groups of first grooves, the two groups of comb teeth are respectively located at two ends of the second guard member in the transverse direction, and the two groups of first grooves are respectively located at two sides of the first avoiding hole on the lower surface of the first guard member in the transverse direction; each group of the comb teeth includes a plurality of comb teeth spaced apart, and each group of the first grooves includes a plurality of first grooves spaced apart, the first grooves extend in the transverse direction, and the comb teeth are inserted into the corresponding first grooves in a shape matching manner.

[0013] Optionally, the first guard structure further includes two guard plates and two second grooves, the two guard plates are respectively located at two ends of the second guard member in the longitudinal direction, and the two second grooves are respectively located at two sides of the first avoiding hole on the lower surface of the first guard member in the longitudinal direction; the second grooves extend in the transverse direction, and the guard plates are inserted into the corresponding second grooves in a shape matching manner; wherein the longitudinal direction is perpendicular to the transverse direction and perpendicular to the up-down direction.

[0014] Optionally, in the transverse direction, the end of the first groove is flush with the end of the second groove away from the first avoiding hole.

[0015] Optionally, the second guard structure includes a first guard protrusion arranged on the lower surface of the first guard member, the first guard protrusion is annular and surrounds the first avoiding hole, and the first guard protrusion is located between the first avoiding hole and the first guard structure; when the second guard member slides relative to the first guard member, the first guard protrusion is in sliding contact with the upper surface of the second guard member, and the first guard protrusion is used to block the flow of liquid.

[0016] Optionally, the support assembly further comprises a first vacuum tube located above the first guard, a suction port of the first vacuum tube facing the upper surface of the second guard, the upper surface of the second guard comprising a first flow guide slope for guiding liquid to flow towards the first vacuum tube, the liquid being sucked by the first vacuum tube through the first avoiding hole; and / or the polishing head assembly further comprises a second vacuum tube spaced apart from the first vacuum tube, the second vacuum tube located above the first guard, a suction port of the second vacuum tube facing the upper surface of the second guard, the upper surface of the second guard comprising a first flow guide slope for guiding liquid to flow towards the second vacuum tube, the liquid being sucked by the second vacuum tube through the first avoiding hole.

[0017] Optionally, the second guard comprises a second guard protrusion arranged on the upper surface of the second guard, the second guard protrusion being annular and surrounding the second avoiding hole, the second guard protrusion being inserted into the first avoiding hole.

[0018] Optionally, the power mechanism comprises a frame and a motor, a lower end of the frame being connected with a main body of the motor, an upper end of the frame being connected with the frame, the frame having a fourth avoiding hole for being sleeved outside the motor; the second guard protrusion is sleeved outside the frame in a shape-fitting manner, the second guard being sealingly connected with an upper surface of the frame.

[0019] Optionally, the upper surface of the frame is provided with an annular groove surrounding the fourth avoiding hole, a lower surface of the second guard covering the annular groove, the support assembly further comprising a sealing member arranged in the annular groove.

[0020] In a second aspect, the present application provides a polishing apparatus, comprising a support assembly as described above and a carrier head, the carrier head being connected with the power mechanism of the support assembly, the carrier head being used for fixing a wafer, under the driving of the power mechanism, the wafer rotating synchronously with the carrier head.

[0021] Based on the above technical solution, by arranging the first guard structure and the second guard structure between the first guard and the second guard, liquid can be blocked from entering the inside of the power mechanism. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced below. The advantages and benefits of the solutions will become clear to those skilled in the art by reading the following detailed description of the embodiments. The drawings are only used for the purpose of illustrating the preferred embodiments and are not considered as limiting the present application.

[0023] In the drawings:

[0024] Figure 1 A schematic view of a support assembly for wafer polishing is shown.

[0025] Figure 2 A sectional view of a support assembly is shown.

[0026] Figure 3 An enlarged view of part A is shown. Figure 2

[0027] Figure 4 An enlarged view of part B is shown. Figure 2

[0028] Another sectional view of a support assembly is shown. Figure 5

[0029] An enlarged view of part C is shown. Figure 6 Figure 5 A schematic view of some components combination in a support assembly is shown.

[0030] Figure 7 A schematic view of some components combination in a support assembly is shown.

[0031] Figure 8 A schematic view of some components combination in a support assembly is shown.

[0032] Figure 9 A schematic view of a first guard in a support assembly is shown.

[0033] Figure 10 A schematic view of a first guard in a support assembly is shown.

[0034] Figure 11 A schematic view of a second guard in a support assembly is shown.

[0035] Figure 12 Reference signs:

[0036] 10 - frame;

[0037] 10 - frame;

[0038] 20 - first guard, 2A - first avoiding hole, 21 - first groove, 22 - second groove, 23 - first guard protrusion;

[0039] ​​30 - second protection member, 3A - second avoiding hole, 31 - comb tooth, 32 - protection plate, 33 - second protection protrusion;

[0040] 41 - first vacuum suction pipe, 42 - second vacuum suction pipe;

[0041] 50 - power mechanism, 51 - motor, 52 - frame, 521 - first base plate, 522 - second base plate,

[0042] 53 - linear guide rail, 54 - sliding block;

[0043] 60 - sealing member, 70 - gas supply unit. DETAILED DESCRIPTION

[0044] The technical solutions in the present application will be described below with reference to the drawings.

[0045] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

[0046] Reference Figure 1 The present application provides a polishing device for wafer polishing, comprising a support assembly and a carrier head, the support assembly comprises a frame 10 and a power mechanism 50, the power mechanism 50 is installed on the frame 10 and can slide transversely relative to the frame 10, at least part of the structure of the power mechanism 50 is located below the frame 10, the carrier head is installed below the power mechanism 50, the lower surface of the carrier head is used to fix the wafer, under the drive of the power mechanism 50, the wafer rotates synchronously with the carrier head.

[0047] Further, the polishing device further comprises a polishing pad and a liquid supply assembly, the polishing pad is located below the carrier head, the power mechanism 50 drives the wafer to press downward on the polishing pad, and the liquid supply assembly is used to supply polishing liquid to the polishing pad. In this way, the wafer can be pressed on the polishing pad while rotating, so that chemical mechanical polishing can be realized.

[0048] Reference Figures 1 to 4 , and Figure 7The support assembly provided in this application also includes a first protective member 20 and a second protective member 30. The first protective member 20 has a first clearance hole 2A to be fitted over the power mechanism 50. The first protective member 20 is connected to the frame 10 and is located below the frame 10. The second protective member 30 has a second clearance hole 3A to be fitted over the power mechanism 50. The second protective member 30 is sealed to the power mechanism 50 to move synchronously with the power mechanism 50. The second protective member 30 is located below the first protective member 20. A first protective structure and a second protective structure are provided between the first protective member 20 and the second protective member 30. The first protective structure and the second protective structure are spaced apart. The first protective structure and the second protective structure allow the second protective member 30 to slide laterally X relative to the first protective member 20 and are used to prevent liquid from entering the interior of the power mechanism 50, thereby preventing the motor 51 mentioned below from being disturbed by liquid and failing to work properly.

[0049] Based on the above technical solution, the relative positions of the first protective member 20 and the frame 10 are fixed, and the relative position of the second protective member 30 relative to the power mechanism 50 is fixed. Therefore, the second protective member 30 can slide synchronously with the power mechanism 50 in the lateral direction. That is, the second protective member 30 can slide in the lateral direction relative to the first protective member 20. Therefore, by setting the first protective structure and the second protective structure between the first protective member 20 and the second protective member 30, liquid can be prevented from entering the first protective protrusion 23 of the first protective member 20. Figure 3 (shown) and the second protective protrusion 33 of the second protective member 30 Figure 3 (As shown) This prevents liquid from entering the power mechanism 50, which is covered by the second protective member 30. Furthermore, the sealed connection between the second protective member 30 and the power mechanism 50 also prevents liquid from entering through the connection between the second protective member 30 and the power mechanism 50 and thus preventing liquid from entering and disturbing the power mechanism 50.

[0050] It should be clarified that the power mechanism 50 can move laterally and reciprocally relative to the frame 10 in the first clearance hole 2A. Therefore, the lateral inner diameter of the first clearance hole 2A must be larger than the lateral inner diameter of the second clearance hole 3A.

[0051] In one possible implementation, refer to Figures 2 to 4 ,as well as Figures 8 to 12The first protection structure comprises two groups of comb teeth 31 and two groups of first grooves 21. The two groups of comb teeth 31 are respectively located at two ends of the second protection piece 30 in the transverse direction. The two groups of first grooves 21 are located on the lower surface of the first protection piece 20 and are respectively located on two sides of the first avoiding hole 2A in the transverse direction. Each group of comb teeth 31 comprises a plurality of comb teeth 31 distributed at intervals. Each group of first grooves 21 comprises a plurality of first grooves 21 distributed at intervals. The first grooves 21 extend in the transverse direction. The comb teeth 31 are inserted into the corresponding first grooves 21 in a shape matching manner. In this way, each group of comb teeth 31 comprises a plurality of comb teeth 31 distributed at intervals. Each group of first grooves 21 comprises a plurality of first grooves 21 distributed at intervals. By inserting the comb teeth 31 into the first grooves 21 in a shape matching manner, a labyrinth-like blocking structure can be formed. The comb teeth 31 can be used to block the liquid from entering the gap between the lower surface of the first protection piece 20 and the upper surface of the second protection piece 30. The comb teeth 31 can also cooperate with the first grooves 21 to guide the second protection assembly and the power mechanism 50 to move synchronously and reciprocally in the transverse direction.

[0052] The width of the comb teeth 31 is slightly smaller than the width of the first grooves 21. The difference between the widths of the two can be 0.4mm to 0.8mm. In this way, the smooth sliding of the comb teeth 31 in the first grooves 21 can be ensured. A water film can be formed between the comb teeth 31 and the groove walls of the first grooves 21, thereby achieving a liquid sealing effect and helping to block the liquid from entering the gap between the lower surface of the first protection piece 20 and the upper surface of the second protection piece 30.

[0053] Further, with reference to Figure 1 , Figure 8 , Figure 10 and Figure 12 The first protection structure further comprises two protection plates 32 and two second grooves 22. The two protection plates 32 are respectively located at two ends of the second protection piece 30 in the longitudinal direction Y. The two second grooves 22 are located on the lower surface of the first protection piece 20 and are respectively located on two sides of the first avoiding hole 2A in the longitudinal direction. The second grooves 22 extend in the transverse direction X. The protection plates 32 are inserted into the corresponding second grooves 22 in a shape matching manner. The longitudinal direction Y is perpendicular to the transverse direction X and perpendicular to the up-down direction Z. In this way, the protection plates 32 can block the liquid from entering the gap between the lower surface of the first protection piece 20 and the upper surface of the second protection piece 30. The protection plates 32 can also cooperate with the second grooves 22 to guide the second protection assembly and the power mechanism 50 to move synchronously and reciprocally in the transverse direction. As can be seen from the above, the four sides of the second protection piece 30 are provided with the comb teeth 31 and the protection plates 32, which can play a good blocking role.

[0054] In an example, with reference to Figure 10In the lateral direction X, the end of the first groove 21 away from the first escape hole 2A is flush with the end of the second groove 22 away from the first escape hole 2A. In this way, not only can the appearance be improved, but also the protective plate 32 can be kept in cooperation with the second groove 22 during the lateral sliding stroke of the second protective member 30, so that the liquid can be well blocked.

[0055] Regarding the second protective structure, reference is made to Figure 3 and Figure 4 , and Figure 10 and Figure 11 In a possible implementation, the second protective structure includes a first protective protrusion 23 arranged on the lower surface of the first protective member 20, the first protective protrusion 23 is annular and surrounds the first escape hole 2A, and the first protective protrusion 23 is located between the first escape hole 2A and the first protective structure; when the second protective member 30 slides relative to the first protective member 20, the first protective protrusion 23 is in sliding contact with the upper surface of the second protective member 30, and the first protective protrusion 23 is used to block the flow of liquid. Through this technical solution, as the second protective member 30 slides relative to the first protective member 20, the liquid entering through the first protective structure first falls on the upper surface of the second protective member 30 and is located outside the first protective protrusion 23, and the first protective protrusion 23 can block these liquids from entering the range surrounded by the first protective protrusion 23. Since the first protective protrusion 23 is in sliding contact with the upper surface of the second protective member 30, the second protective member 30 can slide smoothly in the lateral direction.

[0056] It should be noted that the first protective structure and the second protective structure must both be located around the first escape hole 2A, and in actual production, part of the liquid will still fall on the upper surface of the second protective member 30 after passing through the first protective structure and the second protective structure, and then part of the liquid will be located in the region corresponding to the first escape hole 2A. For example, the first protective protrusion 23 is located between the first escape hole 2A and the first protective structure, and when part of the liquid enters between the comb tooth 31 and the first protective protrusion 23 from the cooperation position of the comb tooth 31 and the first groove 21, since the first protective protrusion 23 is in sliding contact with the upper surface of the second protective member 30, there is still a gap between the first protective protrusion 23 and the upper surface of the second protective member 30, and part of the liquid will still enter the range surrounded by the first protective protrusion 23 from the gap, thereby easily invading the power mechanism 50 or forming a humid environment around the power mechanism 50. Therefore, in order to solve this technical problem, reference is made to Figure 1The support assembly provided by the present application further comprises a first vacuum tube 41 located above the first guard 20, and the suction port of the first vacuum tube 41 faces the upper surface of the second guard 30, which comprises a first flow guide slope for guiding the liquid to flow towards the first vacuum tube 41, and the liquid is sucked by the first vacuum tube 41 through the first escape hole 2A. Specifically, the suction port of the first vacuum tube 41 faces the gap between the first guard protrusion 23 of the first guard 20 and the guard plate 32 of the second guard 30, so as to suck the liquid between the lower surface of the first guard 20 and the upper surface of the second guard 30, thereby preventing the liquid from flowing towards the second guard protrusion 33 through the first guard protrusion 23, and ensuring the normal operation of the power mechanism 50.

[0057] Similarly, referring to Figure 7 , the support assembly can further comprise a second vacuum tube 42 located above the first guard 20, and the suction port of the second vacuum tube 42 faces the upper surface of the second guard 30, which comprises a first flow guide slope for guiding the liquid to flow towards the second vacuum tube 42, and the liquid is sucked by the second vacuum tube 42 through the first escape hole 2A. Similarly, the suction port of the second vacuum tube 42 also faces the gap between the first guard protrusion 23 of the first guard 20 and the guard plate 32 of the second guard 30. The second vacuum tube 42 and the first vacuum tube 41 are distributed along the transverse direction and are close to the joint of the comb teeth 31 and the first groove 21, so as to suck the liquid at different positions in the area between the upper surface of the second guard 30 and the lower surface of the first guard 20.

[0058] In a possible implementation, referring to Figure 7 , the second guard 30 comprises a second guard protrusion 33 arranged on the upper surface of the second guard 30, which is annular and surrounds the second escape hole 3A, and the second guard protrusion 33 is inserted into the first escape hole 2A. In this way, the second guard protrusion 33 can block the liquid from flowing towards the power mechanism 50, and prevent the liquid from splashing onto the power mechanism 50. It should be noted that, in the transverse direction, the inner diameter of the first escape hole 2A is larger than the length of the second guard protrusion 33, so as to avoid affecting the sliding of the second guard 30 along the transverse direction.

[0059] In an embodiment, referring to Figures 1 to 3The power mechanism 50 comprises a frame 52 and a motor 51, the lower end of the frame 52 is connected with the main body of the motor 51, the upper end of the frame 52 is connected with the frame 10, and the frame 52 has a fourth avoiding hole for sleeving outside the motor 51; the second protection protrusion 33 is sleeved outside the frame 52 in a shape fitting manner, and the second protection member 30 is sealingly connected with the upper surface of the frame 52. In this way, the position of the second protection member 30 relative to the motor 51 can be defined by the frame 52 and the second protection protrusion 33, and the second protection protrusion 33 can block the liquid from invading the motor 51 through the fourth avoiding hole.

[0060] In an example, referring to Figure 3 and Figure 4 The upper surface of the frame 52 is provided with an annular groove surrounding the fourth avoiding hole, the lower surface of the second protection member 30 covers the annular groove, and the support assembly comprises a sealing member 60 arranged in the annular groove. In this way, the sealing connection between the power mechanism 50 and the second protection member 30 is realized. Specifically, the frame 52 comprises an annular first base plate 521 and a second base plate 522, the lower surface of the first base plate 521 is connected with the main body of the motor 51, the upper surface of the first base plate 521 is connected with the lower end of the second base plate 522 in a vertical manner, the annular groove is located on the upper surface of the first base plate 521 and surrounds the second base plate 522.

[0061] In a possible implementation, referring to Figure 1 and Figure 2 The frame 10 comprises a third avoiding hole, the power mechanism 50 further comprises a linear guide rail 53 and a sliding block 54, both of which are mounted on the upper surface of the frame 10, the linear guide rail 53 extends in the transverse direction, and the sliding block 54 is connected with the linear guide rail 53 in a sliding fitting manner; the frame 52 penetrates through the third avoiding hole, and the upper end of the frame 52 is connected with the sliding block 54. In this way, the sliding block 54 can drive the motor 51 to slide in the transverse direction through the frame 52. Of course, the power mechanism 50 can further comprise a driving mechanism in transmission connection with the sliding block 54 to drive the sliding block 54 to slide in the transverse direction. The driving mechanism is easily thought of by those skilled in the art, and will not be described herein.

[0062] In addition, the frame 10 can comprise two third avoiding holes, and one power mechanism 50 is arranged in each third avoiding hole. Correspondingly, the number of the first protection members 20 is two to correspond to the two third avoiding holes respectively, and the number of the second protection members 30 is two to correspond to the two third avoiding holes respectively.

[0063] In addition, the motor 51 can be a flat direct drive motor, the center of the motor 51 has an avoiding through hole, the upper end of a bearing head of the polishing apparatus is connected with the motor 51, and the lower end of the bearing head is used for fixing a wafer. In an example, the bearing head comprises a gas chamber, and the pressure of the wafer pressed on the polishing pad can be adjusted by adjusting the air pressure in the gas chamber. Referring toFigure 1 and Figure 2 The polishing apparatus can further include a gas supply part 70 communicating with the gas chamber through the escape through-hole to supply gas into the gas chamber.

[0064] It should be noted that the various embodiments described in the present application and / or the technical features in the various embodiments can be combined with each other in any manner without conflict, and the technical solutions obtained after combination shall also fall within the protection scope of the present application.

[0065] It should be understood that the specific examples in the embodiments of the present application are only to help those skilled in the art better understand the embodiments of the present application, and not to limit the scope of the embodiments of the present application, and those skilled in the art can make various improvements and modifications on the basis of the above-mentioned embodiments, and these improvements or modifications shall fall within the protection scope of the present application.

[0066] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited to this, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the present application, which shall be covered within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A support assembly for wafer polishing, comprising: The support assembly comprises: a frame, a power mechanism mounted on the frame and sliding relative to the frame in a transverse direction, at least part of the power mechanism being located below the frame; a first guard member having a first avoiding hole to cover the power mechanism, the first guard member being connected to the frame and located below the frame; a second guard member having a second avoiding hole to cover the power mechanism, the second guard member being sealingly connected to the power mechanism to move synchronously with the power mechanism, the second guard member being located below the first guard member; wherein a first guard structure and a second guard structure are arranged between the first guard member and the second guard member, the first guard structure and the second guard structure being spaced apart and allowing the second guard member to slide relative to the first guard member in the transverse direction to block liquid from entering the interior of the power mechanism; the first guard structure comprises two groups of comb teeth and two groups of first grooves, the two groups of comb teeth being respectively located at two ends of the second guard member in the transverse direction, and the two groups of first grooves being respectively located at two sides of the first avoiding hole in the transverse direction; each group of comb teeth comprises a plurality of comb teeth spaced apart, and each group of first grooves comprises a plurality of first grooves spaced apart and extending in the transverse direction, the comb teeth being inserted into the corresponding first grooves in a shape-fitting manner; the support assembly further comprises a first vacuum suction pipe located above the first guard member, a suction port of the first vacuum suction pipe facing an upper surface of the second guard member, the upper surface of the second guard member comprising a first flow guide slope for guiding liquid to flow towards the first vacuum suction pipe, the liquid being sucked by the first vacuum suction pipe through the first avoiding hole; the second guard member comprises a second guard protrusion arranged on the upper surface of the second guard member and in a ring shape surrounding the second avoiding hole, the second guard protrusion being inserted into the first avoiding hole; the second guard structure comprises a first guard protrusion arranged on the lower surface of the first guard member, the first guard protrusion being in a ring shape and surrounding the first avoiding hole and being located between the first avoiding hole and the first guard structure, the first guard protrusion being in sliding contact with the upper surface of the second guard member when the second guard member slides relative to the first guard member, and the first guard protrusion being used for blocking liquid flow.

2. The support assembly of claim 1, wherein, The first guard structure further comprises two guard plates and two second grooves, the two guard plates being respectively located at two ends of the second guard member in a longitudinal direction, and the two second grooves being respectively located at two sides of the first avoiding hole in the longitudinal direction; the second grooves extend in the transverse direction, and the guard plates are inserted into the corresponding second grooves in a shape-fitting manner; wherein the longitudinal direction is perpendicular to the transverse direction and to an up-down direction.

3. The support assembly of claim 2, wherein, In the transverse direction, end portions of the first grooves are flush with end portions of the second grooves away from the first avoiding hole.

4. The support assembly of any one of claims 1-3, wherein, The support assembly further comprises a second vacuum suction pipe spaced apart from the first vacuum suction pipe, the second vacuum suction pipe being located above the first guard member, a suction port of the second vacuum suction pipe facing the upper surface of the second guard member, the upper surface of the second guard member comprising a first flow guide slope for guiding liquid to flow towards the second vacuum suction pipe, the liquid being sucked by the second vacuum suction pipe through the first avoiding hole.

5. The support assembly of claim 1, wherein, The power mechanism comprises a frame and a motor, a lower end of the frame is connected with a main body of the motor, an upper end of the frame is connected with the frame, the frame has a fourth avoiding hole to be sleeved outside the motor; the second protection protrusion is sleeved outside the frame in a shape fitting manner, and the second protection member is sealingly connected with an upper surface of the frame.

6. The support assembly of claim 5, wherein, An upper surface of the frame is provided with an annular groove which surrounds the fourth avoiding hole, a lower surface of the second protection member covers the annular groove, and the support assembly further comprises a sealing member arranged in the annular groove.

7. A polishing apparatus characterized by comprising: The support assembly comprises a bearing head and the support assembly according to any one of claims 1-6, the bearing head is connected with the power mechanism of the support assembly, and the bearing head is used for fixing a wafer, under the driving of the power mechanism, the wafer synchronously rotates with the bearing head.

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