A carrier head for chemical mechanical polishing and a chemical mechanical polishing apparatus

Abstract

The present invention discloses a carrier head and a chemical mechanical polishing device for chemical mechanical polishing. The carrier head includes a coupling disk, a balance frame, a carrier disk, a flexible film, and a retaining ring; the balance frame is slidably disposed in a central through hole of the coupling disk and drives the carrier disk to move up and down relative to the coupling disk through the bottom of the balance frame, and a part of the flexible film is clamped to the lower part of the carrier disk to form a sealed chamber; a magnetic attraction part is provided at a corresponding position where the carrier disk is adjacent to the retaining ring near the edge for attracting and engaging the retaining ring.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical mechanical polishing, and particularly to a carrier head for chemical mechanical polishing and a chemical mechanical polishing apparatus. Background Art

[0002] Chemical Mechanical Polishing (CMP) is a super-precision surface machining technology for global planarization. In this polishing method, a wafer is usually placed below a carrier head, and the bottom surface of the wafer with a deposited layer abuts against a rotating polishing pad. The carrier head rotates in the same direction as the polishing pad under the drive of a driving component and applies a downward load to the wafer. At the same time, a polishing liquid is supplied between the polishing pad and the wafer, and material removal of the wafer is achieved under the combined action of chemistry and mechanics.

[0003] A retaining ring is provided at the lower part of the carrier head, and its functions in wafer polishing are as follows: on the one hand, the retaining ring can prevent the wafer from flying out from the bottom of the carrier head during the polishing process; on the other hand, a groove is provided at the bottom of the retaining ring, which can update the polishing liquid between the wafer and the polishing pad; more importantly, the retaining ring presses against the polishing pad and participates in the adjustment of the edge pressure of the wafer.

[0004] Currently, the retaining ring is fixed to the lower part of the carrier head by screws or bolts. During the installation process, after the screws or bolts are tightened, the tightened part applies a local tensile force to the retaining ring, causing deformation of the retaining ring in the corresponding area. And because the screws or bolts are point-like distributed and their contact area with the retaining ring is very small, this deformation only occurs locally. In other words, some parts of the retaining ring are deformed and some parts are not deformed, breaking the original morphology of the retaining ring when it leaves the factory, making the pressure applied by the retaining ring to the polishing pad uneven, thereby affecting the consistency of wafer polishing, and also requiring a large amount of running-in time. Summary of the Invention

[0005] Embodiments of the present invention provide a carrier head for chemical mechanical polishing and a chemical mechanical polishing apparatus, 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 carrier head for chemical mechanical polishing, including a coupling disk, a balance bracket, a carrier disk, a flexible film, and a retaining ring;

[0007] The balance bracket is slidably disposed in a central through hole of the coupling disk and drives the carrier disk to move up and down relative to the coupling disk through the bottom of the balance bracket. A part of the flexible film is clamped to the lower part of the carrier disk to form a sealed chamber; a magnetic attraction portion is provided at a corresponding position on the carrier disk adjacent to the retaining ring near the edge for attracting the retaining ring.

[0008] In one embodiment, the magnetic attraction part is a magnet embedded in the carrier plate, and the magnet is formed by a neodymium magnet, a samarium cobalt magnet, an alnico magnet or a ferrite magnet.

[0009] In one embodiment, a groove is formed in the carrier plate, the magnet is placed in the groove, and a filling member is used to seal above the magnet in the groove.

[0010] In one embodiment, a recess is formed in the carrier plate, the magnet is just received in the recess, and a gland is fixed to the outer edge of the carrier plate and the gland covers above the recess so that the gland fixes the magnet in the recess.

[0011] In one embodiment, an auxiliary disassembly structure is provided between the retaining ring and the carrier plate.

[0012] In one embodiment, the auxiliary disassembly structure is a V-shaped groove provided at the bottom edge of the carrier plate and / or the top edge of the retaining ring, and is used to form a gap between the carrier plate and the retaining ring, so that when disassembling, a tool can be inserted into the V-shaped groove to pry open the retaining ring.

[0013] In one embodiment, the auxiliary disassembly structure is a disassembly air passage provided in the carrier plate. One end of the disassembly air passage is used to connect to an air source, and the other end of the disassembly air passage communicates with the bottom surface of the carrier plate above the retaining ring, and is used to realize that when the air source passes gas into the disassembly air passage, pressure can be applied to separate the carrier plate and the retaining ring.

[0014] In one embodiment, the retaining ring includes a metal part and a non-metal part, and the metal part is used for magnetic connection with the magnetic attraction part.

[0015] In one embodiment, the metal part and the non-metal part are stacked, and the metal part is located above the non-metal part.

[0016] In one embodiment, the non-metal part wraps around the outside of the metal part.

[0017] In one embodiment, the metal part is iron, nickel or an alloy of at least one of them.

[0018] In one embodiment, the magnet is cylindrical or rectangular, and a plurality of magnets are provided and are evenly arranged along the circumference of the carrier plate.

[0019] In one embodiment, the magnet is annular and is arranged along the circumference of the carrier plate.

[0020] In one embodiment, a positioning structure is provided between the carrier plate and the retaining ring, and is used to make the positions corresponding to each other during assembly.

[0021] A second aspect of the embodiments of the present invention provides a chemical mechanical polishing apparatus, which includes the carrier head as described above, and further includes a polishing platen, a dresser, and a polishing liquid supply device.

[0022] The beneficial effects of the embodiments of the present invention include: The retaining ring is magnetically connected to the lower part of the carrier head through the magnetic attraction part, which can achieve uniform force on the retaining ring, without deformation after installation, shorten the running-in time of the retaining ring, and is easy to maintain and replace. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Through the following detailed description in conjunction with the accompanying drawings, the advantages of the present invention will become clearer and easier to understand. However, these drawings are only schematic and do not limit the protection scope of the present invention, where:

[0024] Figure 1 is a schematic structural diagram of a chemical mechanical polishing apparatus provided by an embodiment of the present invention;

[0025] Figure 2 is a three-dimensional schematic diagram of a carrier head provided by an embodiment of the present invention;

[0026] Figure 3 is a cross-sectional view of a carrier head provided by an embodiment of the present invention;

[0027] Figure 4 is a cross-sectional view of a carrier head provided by another embodiment of the present invention;

[0028] Figure 5 compares the influence of two installation methods on the appearance of the retaining ring. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] The following combines specific embodiments and their accompanying drawings to elaborate on the technical solutions of the present invention. The embodiments recorded herein are specific specific implementation manners of the present invention and are used to illustrate the concept of the present invention; these descriptions are all explanatory and exemplary and should not be construed as limiting the implementation manner of the present invention and the protection scope of the present invention. It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. Except for the embodiments recorded herein, those skilled in the art can also adopt other obvious technical solutions based on the content disclosed in the claims and the specification of the present application. These technical solutions include technical solutions that make any obvious substitutions and modifications to the embodiments recorded herein. It should be understood that, unless otherwise specifically stated, for the convenience of understanding, the following descriptions of the specific implementation manners of the present invention are all described under the natural state where the relevant equipment, devices, components, etc. are in the original static state without external control signals and driving forces.

[0030] In addition, it should be noted that the terms indicating directions used in this application, such as front, back, top, bottom, left, right, top, bottom, front, back, horizontal, vertical, etc., are only for convenience of description to assist in understanding the relative position or direction, and are not intended to limit the orientation of any device or structure.

[0031] To illustrate the technical solutions described in the present invention, the following will be described with reference to the accompanying drawings and in conjunction with embodiments.

[0032] In this application, chemical mechanical polishing (Chemical Mechanical Polishing) is also known as chemical mechanical planarization (Chemical Mechanical Planarization), and a wafer is also known as a chip, silicon wafer, substrate or base plate (substrate), etc., and their meanings and actual functions are equivalent.

[0033] As Figure 1 shown, a chemical mechanical polishing apparatus 1 provided by an embodiment of the present invention includes a polishing platen 10, a polishing pad 20 adhered to the polishing platen 10, a carrier head 30 that adsorbs a wafer and drives the wafer to rotate, a dresser 40 for dressing the polishing pad 20, and a polishing liquid supply device 50 that supplies a polishing liquid to the surface of the polishing pad 20.

[0034] Before the polishing starts, the robot arm transports the wafer to the wafer storage section. After the carrier head 30 loads the wafer from the wafer storage section, it moves radially above the polishing platen 10 along the radial direction of the polishing platen 10. During the chemical mechanical polishing process, the carrier head 30 presses the wafer against the polishing pad 20 covering the surface of the polishing platen 10. The size of the polishing pad 20 is larger than the size of the wafer to be polished, for example, 1.2 times or more of the wafer size, thereby ensuring uniform polishing of the wafer. The carrier head 30 rotates and reciprocates radially along the polishing platen 10, so that the surface of the wafer in contact with the polishing pad 20 is gradually removed. At the same time, the polishing platen 10 rotates, and the polishing liquid supply device 50 sprays the polishing liquid onto the surface of the polishing pad 20. Under the chemical action of the polishing liquid, the wafer and the polishing pad 20 are rubbed through the relative movement of the carrier head 30 and the polishing platen 10 for polishing. The polishing liquid composed of submicron or nanometer abrasive grains and chemical solution flows between the wafer and the polishing pad 20. The polishing liquid is evenly distributed under the action of the transmission and rotational centrifugal force of the polishing pad 20 to form a liquid film layer between the wafer and the polishing pad 20. The chemical components in the liquid react with the wafer to convert insoluble substances into soluble substances, and then these chemical reaction products are removed from the wafer surface through the micro-mechanical friction of the abrasive grains and dissolved into the flowing liquid and carried away, that is, the surface material is removed during the alternating process of chemical film formation and mechanical film removal to achieve surface planarization treatment, thereby achieving the purpose of global planarization. During the polishing, the dresser 40 is used to dress and activate the surface topography of the polishing pad 20. Using the dresser 40 can remove the impurity particles remaining on the surface of the polishing pad 20, such as the abrasive particles in the polishing liquid and the waste materials falling off from the wafer surface, etc., and can also flatten the surface deformation of the polishing pad 20 caused by grinding, ensuring the consistency of the surface topography of the polishing pad 20 during the polishing, and further keeping the polishing removal rate stable. After the polishing is completed, the carrier head 30 adsorbs the wafer to place it on the wafer storage section, and the robot arm transports the wafer to the post-processing unit after obtaining the wafer from the wafer storage section.

[0035] Figures 2 to 4 The carrier head for chemical mechanical polishing provided by the present application is shown, including a coupling disk 31, a balance bracket 32, a carrier disk 33, a flexible film 34 and a retaining ring 35.

[0036] Among them, the balance bracket 32 is slidably arranged in the central through hole of the coupling disk 31 and drives the carrier disk 33 to move up and down relative to the coupling disk 31 through the bottom of the balance bracket 32. A part of the flexible film 34 is clamped to the lower part of the carrier disk 33 to form a sealed chamber; the retaining ring 35 is installed at the bottom edge of the carrier disk 33.

[0037] As Figure 3 and Figure 4As shown, the first clamping ring clamps and binds the outer edge of the annular elastic member 36 to the carrier disk 33, and the second clamping ring clamps and binds the inner edge of the annular elastic member 36 to the coupling disk 31, such that when the coupling disk 31 rotates together with an external drive shaft (not shown), the coupling disk 31 can drive the carrier disk 33 to rotate coaxially via the annular elastic member 36; the third clamping ring and the annular washer clamp and fix the balance bracket 32 to the carrier disk 33, and the annular pressure plate 37 airtightly clamps the flexible film 34 to the lower part of the carrier disk 33 such that the flexible film 34 can rotate coaxially with the carrier disk 33 and the balance bracket 32 and move up and down in the vertical direction relative to the coupling disk 31; the retaining ring 35 is connected to the lower surface of the carrier disk 33. When the bearing head operates, the coupling disk 31 is coupled to the external drive shaft, and the wafer to be processed is received and held below the flexible film 34 inside the retaining ring 35.

[0038] As Figures 2 to 4 shown, the retaining ring 35 is installed at the lower part of the bearing head 30.

[0039] During chemical mechanical polishing, a receiving space is formed between the inner diameter surface of the retaining ring 35 and the lower surface of the flexible film 34 for defining the wafer. The bottom surface of the retaining ring 35 faces downward and is opposite to the upper surface of the polishing pad. The wafer located inside the retaining ring 35 presses against the upper surface of the polishing pad. The retaining ring 35 can prevent the wafer from slipping out of the receiving space and participate in applying the load of the wafer. In addition, the carrier disk 33 can move up and down to control the pressure exerted by the bottom surface of the retaining ring 35 on the polishing pad. As Figure 2 shown, the bottom surface of the retaining ring 35 is provided with channels for the polishing liquid to flow in and out.

[0040] As Figure 3 and Figure 4 shown, the retaining ring 35 is coupled to the carrier disk 33, and the retaining ring 35 is installed at the lower part of the bearing head 30 through the carrier disk 33.

[0041] Currently, the method of connecting the retaining ring 35 and the carrier disk 33 with screws or bolts has many disadvantages. On the one hand, when disassembling or replacing the screws or bolts, other parts of the bearing head 30 need to be removed first, and the maintenance efficiency is low; on the other hand, the screws or bolts are disassembled frequently, which is likely to cause the dropping of metal debris. The attachment of metal debris to the bearing head 30 will affect the polishing operation. And the wafer polishing is most afraid of metal particles, which not only has the risk of contamination, but may even cause scribing and fragmentation, resulting in the entire shutdown of the machine tool; on the third hand, the pre-tightening force of the screws or bolts on the retaining ring 35 is basically close to point contact, and the contact area is very small, which is likely to cause large local deformation, thus losing the precision of precision parts and affecting the polishing effect.

[0042] To avoid the above problems, as Figure 3 and Figure 4As shown, in an embodiment of the present invention, a magnetic attraction part is provided at a corresponding position near the edge of the carrier plate 33 adjacent to the retaining ring 35 for attracting and engaging the retaining ring 35.

[0043] Specifically, the magnetic attraction part is located above the retaining ring 35, and the magnetic attraction part is a magnet 331 embedded in the carrier plate 33. The magnet 331 can be formed of metal or ceramic materials. Such materials may include iron or rare earth metals, such as neodymium, neodymium iron boron, samarium cobalt, alnico, and magnets 331 in the ceramic family, where ceramics such as hard magnet ferrites, strontium, and barium ferrites. The magnet 331 can be a permanent magnet, for example, formed of a neodymium magnet, a samarium cobalt magnet, an alnico magnet, or a ferrite magnet. Alternatively, the magnet 331 can also be electromagnetic.

[0044] Specifically, there are various ways to install the magnet 331.

[0045] As Figure 3 shown, in one embodiment, a groove is formed in the carrier plate 33, the magnet 331 is placed in the groove, and the groove is sealed with a filling member above the magnet 331. For example, the inner side surface of the groove is provided with fixing threads, a bolt is inserted above the magnet 331, and the bolt is threadedly connected to the groove, thereby pressing the magnet 331 firmly in the groove.

[0046] As Figure 4 shown, in another embodiment, a recess is formed in the carrier plate 33, the magnet 331 is placed in the recess, and the size of the recess matches that of the magnet 331 so that the magnet 331 can just be accommodated. In other words, the depth and inner diameter of the recess are completely matched with the height, length, and width of the magnet 331, and the recess just accommodates the magnet 331. A gland 38 fixedly connected to the carrier plate 33 is provided at the outer edge of the carrier plate 33. The gland 38 covers the area near the outer edge of the upper surface of the carrier plate 33, and the gland 38 is located above the recess, so that after the gland 38 is fixed to the carrier plate 33, the gland 38 fixes the magnet 331 in the recess.

[0047] In yet another embodiment, a recess can also be formed near the edge of the bottom surface of the carrier plate 33, and the magnet 331 is fixed into the recess. For example, by press-fitting the magnet 331 into the recess or gluing the magnet 331 to the recess.

[0048] In another embodiment, the magnet 331 is embedded inside the carrier plate 33.

[0049] In addition, in one embodiment, the magnet 331 is cylindrical or rectangular, and there are multiple magnets 331. The number can be an even number such as 2, 4, 6, 8, 12, 16, etc., and they are evenly arranged along the circumference of the carrier plate 33.

[0050] In another embodiment, the magnet 331 is annular and is arranged along the circumference of the carrier plate 33.

[0051] As Figure 3 and Figure 4 shown, the retaining ring 35 is kept in a ring shape, including a metal part 351 and a non-metal part 352.

[0052] The metal part 351 is formed of a material sufficient to be attracted to the magnet 331 so as to hold the retaining ring 35. In this way, the magnet 331 reliably holds the retaining ring 35 to the carrier disk 33. The metal part 351 may include such materials, for example, materials attracted by the magnet 331 such as iron, nickel or such alloys. Suitable materials for the metal part 351 may contain ferromagnetic substances, such as martensite, ferritic stainless steel, for example, 400 series stainless steel.

[0053] In one embodiment, the retaining ring 35 may be formed by laminating the metal part 351 and the non-metal part 352, and the non-metal part 352 with wear resistance is disposed at the lower part of the metal part 351.

[0054] Wherein, the retaining ring 35 includes: an annular upper part connected to the carrier disk 33, and an annular lower part having a bottom surface that can contact the polishing pad. This annular lower part can be bonded to the annular upper part by an adhesive layer.

[0055] The annular upper part of the retaining ring 35 is the metal part 351, which can be made of stainless steel, for example.

[0056] The annular lower part is the non-metal part 352, which is formed of a material chemically inert to the CMP process. In addition, the annular lower part should be elastic enough so that the contact of the wafer edge against the retaining ring 35 will not cause the wafer to break or fracture. On the other hand, the annular lower part should be strong enough to have sufficient life under the abrasion from the polishing pad (on the bottom surface) and the wafer (on the inner surface). The annular lower part can be made of plastics, such as polyphenylene sulfide (PPS), polyethylene terephthalate (PET), polyether ether ketone (PEEK), polybutylene terephthalate (PBT), polytetrafluoroethylene (PTFE), polybenzimidazole (PBI), polyethyleneimine (PEI), polyamide-imide (PAI) or composite materials.

[0057] In another embodiment, the retaining ring 35 may also be formed by coating the metal part 351 and the non-metal part 352, and the non-metal part 352 with wear resistance is coated on the outer side of the metal part 351.

[0058] Furthermore, a positioning structure is provided between the carrier disk 33 and the retaining ring 35 for making the positions corresponding to each other during assembly.

[0059] The positioning structure includes at least two pairs of positioning pins (not shown) and positioning holes (not shown), which are respectively arranged on the opposite surfaces of the carrier plate 33 and the retaining ring 35. During assembly, the positioning pins are inserted into the positioning holes to achieve positioning. And when a shearing force in the horizontal direction acts on the retaining ring 35 during polishing, the carrier plate 33 and the retaining ring 35 are kept aligned to avoid misalignment.

[0060] Furthermore, as Figure 3 and Figure 4 shown, an auxiliary disassembly structure is provided between the retaining ring 35 and the carrier plate 33 for helping the retaining ring 35 and the carrier plate 33 to separate.

[0061] As Figure 3 shown, in one embodiment, a V-shaped groove 332 is provided at the bottom edge of the carrier plate 33 to form a gap between the carrier plate 33 and the retaining ring 35, so that when disassembling, a tool can be inserted into this V-shaped groove 332 to pry open the retaining ring 35 for convenient disassembly. Similarly, the V-shaped groove 332 can also be provided at the top edge of the retaining ring 35.

[0062] As Figure 4 shown, in another embodiment, a disassembly air passage 333 leading to the retaining ring 35 is provided inside the carrier plate 33. One end of the disassembly air passage 333 is used to connect to a gas source, and the other end of the disassembly air passage 333 communicates with the bottom surface of the carrier plate 33 above the retaining ring 35, so as to realize that when gas is introduced into the disassembly air passage 333 by the gas source, the pressure can be increased to separate the carrier plate 33 and the retaining ring 35, thereby assisting in disassembling the retaining ring 35. Further, a plurality of communicating air outlet holes can be formed on the bottom surface of the carrier plate 33 for applying air pressure to the top surface of the retaining ring 35 at multiple positions. The plurality of air outlet holes can be evenly distributed along the circumferential direction and communicate inside the carrier plate 33 and lead to the air inlet holes located on the side surface or the top surface of the carrier plate 33. Or, the disassembly air passage 333 can also form a communicating annular air outlet on the bottom surface of the carrier plate 33, and the annular air outlet can apply air pressure to the annular area on the top surface of the retaining ring 35. The annular air outlet communicates with the air inlet holes located on the side surface or the top surface of the carrier plate 33. Preferably, the air outlet position of the disassembly air passage 333 is located below the magnet 331 and corresponds to the position of the magnet 331. In other words, the air outlet holes or the annular air outlet are located below the magnet 331 and correspond to the position of the magnet 331.

[0063] In this application, the retaining ring 35 is magnetically connected to the lower part of the bearing head 30 through a magnetic attraction part, which can realize that the retaining ring 35 is uniformly stressed, does not deform after installation, and is easy to maintain and replace.

[0064] It can be understood that Figure 3 and Figure 4 only two examples are shown and should not be used as a limitation of the protection scope of this application. Each feature can be combined and replaced, and it still belongs to the protection scope of the present invention.

[0065] As shown in Chart 5, the deformation caused by the existing retaining ring installation method using screw fastening is compared with the installation method using magnetic force fastening in the present application.

[0066] In Chart 5, the micro-topography of a region on the bottom surface of the retaining ring is photographed using a special microscopic image acquisition camera. Among them, the column of "corresponding area on the bottom surface of the retaining ring" indicates the position of the corresponding area on the bottom surface of the photographed retaining ring. The figures in the column of "topography scanning image" show the undulation of the topography in the region in gray scale, and the darker the color, the greater the undulation.

[0067] By Figure 5 , it can be clearly seen that for the existing installation method using screw fastening, the bottom surface of the retaining ring will cause large topography undulation deformation in a small range (near the screw), the deformation is large (dark color), and the range of deformation is relatively concentrated. This large-size concave-convex deformation in a small area will increase the running-in time of the retaining ring and affect the operation efficiency. Here, it should be explained that each newly replaced retaining ring needs to be polished on a polishing pad first to polish the topography of the retaining ring to the best matching state. This running-in time occupies the machine operation time and will affect the WPH (wafer output per hour) of the machine and the production efficiency of the machine.

[0068] For the magnetic force fastening installation method in the present application, the undulation distribution on the bottom surface of the retaining ring is relatively uniform, the deformation is very small (light color), which significantly improves the problem that the retaining ring will be deformed after installation. The retaining ring is flatter, the running-in time of the retaining ring is shorter, which is beneficial to improving the polishing effect.

[0069] The drawings in this specification are schematic diagrams to assist in explaining the concept of the present invention, schematically showing the shapes of various parts and their mutual relationships. It should be understood that in order to clearly show the structures of the components in the embodiments of the present invention, the drawings are not drawn in the same proportion, and the same reference numerals are used to represent the same parts in the drawings.

[0070] In the description of this specification, the description referring to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0071] Although embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A carrier head for chemical mechanical polishing, characterized in that, It includes a coupling disk, a balance frame, a bearing disk, a flexible film and a retaining ring; The balance frame is slidably arranged in the central through hole of the coupling disk and drives the bearing disk to move up and down relative to the coupling disk through the bottom of the balance frame. A part of the flexible film is clamped to the lower part of the bearing disk to form a sealed chamber; at the corresponding position where the edge of the bearing disk is adjacent to the retaining ring, a magnetic attraction part is provided for attracting the retaining ring, and the magnetic attraction part is a magnet embedded in the bearing disk.

2. The carrier head according to claim 1, characterized in that, The magnet is formed by a neodymium magnet, a samarium cobalt magnet, an alnico magnet or a ferrite magnet.

3. The carrier head according to claim 2, characterized in that, A groove is formed in the bearing disk, the magnet is placed in the groove, and the groove above the magnet in the groove is sealed by a filling piece.

4. The carrier head according to claim 2, characterized in that, A recess is formed in the bearing disk, the magnet just fits into the recess, and a gland is fixed to the outer edge of the bearing disk and the gland covers above the recess so that the gland fixes the magnet in the recess.

5. The carrier head according to claim 1, characterized in that, An auxiliary disassembly structure is provided between the retaining ring and the bearing disk.

6. The carrier head according to claim 5, characterized in that, The auxiliary disassembly structure is a V-shaped groove provided at the bottom edge of the bearing disk and / or the top edge of the retaining ring, which is used to form a gap between the bearing disk and the retaining ring, so that when disassembling, a tool can be inserted into the V-shaped groove to pry open the retaining ring.

7. The carrier head according to claim 5, characterized in that, The auxiliary disassembly structure is a disassembly air passage provided in the bearing disk. One end of the disassembly air passage is used to connect to an air source, and the other end of the disassembly air passage communicates with the bottom surface of the bearing disk above the retaining ring, which is used to realize that when gas is introduced into the disassembly air passage by the air source, pressure can be applied to separate the bearing disk and the retaining ring.

8. The carrier head according to claim 1, characterized in that, The retaining ring includes a metal part and a non-metal part, and the metal part is used for magnetic connection with the magnetic attraction part.

9. The carrier head according to claim 8, characterized in that, The metal part and the non-metal part are stacked, and the metal part is located above the non-metal part.

10. The carrier head according to claim 8, characterized in that, The non-metal part wraps around the outside of the metal part.

11. The carrier head according to any one of claims 8 to 10, characterized in that, The metal part is iron, nickel or an alloy of at least one of them.

12. The carrier head according to claim 2, characterized in that, The magnet is cylindrical or rectangular, and a plurality of magnets are provided and arranged evenly along the circumference of the bearing disk.

13. The carrier head according to claim 2, characterized in that, The magnet is annular and is arranged along the circumference of the bearing disk.

14. The carrier head according to claim 1, characterized in that, A positioning structure is provided between the bearing disk and the retaining ring, which is used to make the positions corresponding to each other during assembly.

15. A chemical mechanical polishing apparatus, characterized in that, It includes a bearing head according to any one of claims 1 to 14, and also includes a polishing disk, a dresser and a polishing liquid supply device.

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