Retaining ring and polishing head

Abstract

The invention discloses a retaining ring and a polishing head. The retaining ring comprises a base body and a split body capable of being separated from the base body. The base body and the split body are both of an annular structure, the first end of the base body is constructed to be connected with a polishing head, and after the first end of the split body is connected with the base body, the second end of the split body and the second end of the base body are located in the same plane; the base body and the split body are used for applying pressure to the polishing pad in the process that the polishing head places the wafer on the polishing pad to polish the wafer. According to the wafer polishing device, the separable split bodies are arranged, the contact area of the retaining ring and the polishing pad can be adaptively changed according to the polishing requirements of wafers of different specifications, and then the polishing effect of the wafers can be guaranteed.

Description

Technical Field

[0001] The present application relates to the technical field of chemical mechanical polishing, and in particular to a retaining ring and a polishing head. Background Art

[0002] Chemical Mechanical Polishing (CMP) equipment mainly uses a polishing head to adsorb and carry the wafer to the polishing pad, and completes the flattening of the wafer surface under the combined action of mechanical friction and chemical reaction. In order to improve the adsorption effect of the polishing head on the wafer, a retaining ring is usually set on the outside of the polishing head to increase the pressure on the polishing pad to hold the wafer. The pressure applied by the polishing head to the polishing pad through the retaining ring is negatively correlated with the risk of slipping during the polishing process.

[0003] At present, in order to ensure the stability of the wafer processing process, the pressure exerted by the retaining ring on the polishing pad is generally adjusted by adjusting the pressure on the retaining ring in the polishing head chamber. However, the requirements for the pressure exerted by the retaining ring on the retaining ring are different for polishing different types of wafers. Summary of the invention

[0004] In view of this, the present application provides a retaining ring and a polishing head to at least partially solve the above technical problems.

[0005] The first aspect of the present application provides a retaining ring, which is applied to a polishing head, comprising: a base and a split body separable from the base; the base and the split body are both annular structures, the first end of the base is constructed to be connected to the polishing head, and after the first end of the split body is connected to the base, the second end of the split body and the second end of the base are located in the same plane; the base and the split body are used to apply pressure to the polishing pad when the polishing head places a wafer on the polishing pad to polish the wafer.

[0006] Optionally, at least two through holes are provided on the base along the center line direction of the base; at least two internal threaded holes are provided on the first end of the split body along the center direction of the split body, and the internal threaded holes correspond one-to-one to the through holes; the base and the split body are connected by bolts passing through the through holes and threadedly connected to the internal threaded holes.

[0007] Optionally, the retaining ring further includes at least two elastic blockers, which are used to seal the through holes when the split body is separated from the base body, wherein the elastic blockers are connected to the through holes via interference fit, and different through holes are sealed by different elastic blockers.

[0008] Optionally, at least one positioning pin is provided on the base, and at least one pin hole is provided on the first end of the split body. After the base and the split body are connected, one positioning pin is embedded in each of the pin holes, and different positioning pins are embedded in different pin holes.

[0009] Optionally, a first groove is provided at the second end of the base, and a second groove is provided at the second end of the split body. After the first end of the split body is connected to the base, the first groove and the second groove are connected; the first groove and the second groove are used to guide the polishing liquid under the polishing head during polishing of the wafer.

[0010] Optionally, the number of the first grooves is the same as the number of the second grooves, and after the first end of the split body is connected to the base, each of the first grooves is connected to one of the second grooves, and the docking interfaces of the connected first grooves and second grooves have the same size and shape.

[0011] Optionally, a plurality of the positioning pins are provided on the base, and a plurality of pin holes are provided on the first end of the split body; the plurality of positioning pins include a target positioning pin, and the target positioning pin is different in size and / or cross-sectional shape from the other positioning pins; the plurality of pin holes include a target pin hole, and the target pin hole is different in size and / or cross-sectional shape from the other pin holes; when the base is connected to the split body, the target positioning pin is embedded in the target pin hole, so that each of the first grooves is connected to one of the second grooves and the axes coincide.

[0012] Optionally, the axes of the first groove and the second groove are straight lines, and the radii of the first groove and the second groove are the same.

[0013] Optionally, the axes of the first groove and the second groove are straight lines, and along the positive direction of the axes of the first groove and the second groove after being connected, the radius of at least one of the first groove and the second groove increases linearly.

[0014] Optionally, the ratio of the number of the second grooves to the number of the first grooves is in a range of 1.5 to 2.5.

[0015] Optionally, a first concave arc-shaped chamfer is provided along the outer edge of the second end of the base, and a second concave arc-shaped chamfer is provided along the inner edge of the second end of the split body; after the base is connected to the split body, the first concave arc-shaped chamfer and the second concave arc-shaped chamfer are spliced ​​into a confluence groove, and the first groove and the second groove are both connected to the confluence groove.

[0016] Optionally, the ratio of the difference between the outer circle radius and the inner circle radius of the second end of the base body to the difference between the outer circle radius and the inner circle radius of the second end of the split body is in the range of 0.5-2.

[0017] Optionally, at least part of the inner side wall of the split body is a conical surface, and the inner side wall of the conical surface is adjacent to the first end of the split body, and the angle between the inner side wall of the conical surface and the center line of the split body ranges from 75° to 85°.

[0018] Optionally, the inner side wall of the split body adjacent to the first end of the split body is a conical surface, the inner side wall of the split body adjacent to the second end of the split body is a cylindrical surface, and the inner side wall of the split body that is a conical surface intersects with the inner side wall that is a cylindrical surface.

[0019] Optionally, the base body is made of polyetheretherketone, and the split body is made of polyphenylene sulfide.

[0020] A second aspect of the present application provides a carrier head for chemical mechanical polishing, which includes the retaining ring described above.

[0021] By setting up a detachable part, the present application can adaptively change the contact area between the retaining ring and the polishing pad according to the needs of polishing wafers of different specifications. Therefore, when polishing wafers of different models, the retaining ring provides corresponding pressure to ensure the polishing effect of the wafer. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of the present application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0023] Figure 1 is a schematic diagram of an exemplary scenario applicable to an embodiment of the present application;

[0024] Figure 2 is a schematic diagram of a retaining ring according to an embodiment of the present application;

[0025] Figure 3 is a schematic diagram of a retaining ring including a through hole according to an embodiment of the present application;

[0026] Figure 4 is a schematic diagram of a retaining ring including an elastic block according to an embodiment of the present application;

[0027] Figure 5 is a schematic diagram of a retaining ring including a positioning pin according to an embodiment of the present application;

[0028] Figure 6 is a schematic diagram of a retaining ring including a first groove according to an embodiment of the present application;

[0029] Figure 7 is a schematic diagram of a retaining ring including a first groove according to another embodiment of the present application;

[0030] Figure 8 Schematic diagram of a retaining ring including a conduit groove according to an embodiment of the present application. DETAILED DESCRIPTION

[0031] In order to enable those skilled in the art to better understand the technical solutions in the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the embodiments of the present application should fall within the scope of protection of the embodiments of the present application.

[0032] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms of "a", "said" and "the" used in this application and the appended claims are also intended to include plural forms unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0033] It should be understood that although the terms first, second, third, etc. may be used in the present application to describe various information, these information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0034] The technical solutions in the embodiments of the present application are clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application. In the absence of conflict, the following embodiments and their technical features can be combined with each other.

[0035] Figure 1 A schematic diagram of an exemplary scenario applicable to an embodiment of the present application, such as Figure 1As shown, the retaining ring 1 provided in the embodiment of the present application is applied to the polishing head 2. During the polishing process, the polishing head 2 loads the wafer to be polished and abuts it against the polishing pad 3 above the polishing plate 6. During the polishing process, the liquid supply device 4 supplies polishing liquid to the polishing pad 3, and the polishing liquid flows between the wafer and the polishing pad 3 to assist in polishing. During the polishing process, there is also a trimmer 5, which can trim the surface of the polishing pad 3.

[0036] During the polishing process, the wafer is located on the inner side of the retaining ring 1, and the retaining ring 1 is used to provide pressure to the polishing pad 3 around the wafer. However, wafers of different specifications have different requirements for the pressure value at the contact position between the retaining ring 1 and the polishing pad. Some require a small pressure range, and some require a large pressure range. If the retaining ring 1 uses the same specification, the polishing effect of wafers of different specifications will not be uniform. If retaining rings 1 of different specifications are manufactured for wafers of different specifications, the production cost will be relatively high. Therefore, based on the above exemplary scenario, the present application provides a retaining ring to at least partially solve the above problem.

[0037] Figure 2 Schematic diagram of a retaining ring according to an embodiment of the present application. Figure 2 As shown, the retaining ring 1 applied to the polishing head 2 includes: a base 10 and a split body 20 that is separable from the base 10. The base 10 and the split body 20 are both annular structures, and the first end of the base 10 is configured to be connected to the polishing head 2. After the first end of the split body 20 is connected to the base 10, the second end of the split body 20 is located in the same plane as the second end of the base 10. The base 10 and the split body 20 are used to apply pressure to the polishing pad 3 when the polishing head 2 places the wafer on the polishing pad 3 to polish the wafer.

[0038] In order to polish wafers of different specifications, the retaining ring 1 may include a split body 20 that is detachable from the base body 10. When the wafer requires the retaining ring 1 to apply pressure to a larger range of the polishing pad 3, the split body 20 is connected to the base body 10 to increase the contact area between the retaining ring 1 and the polishing pad 3 and reduce the pressure at the contact position. When the wafer requires the retaining ring 1 to apply pressure to a smaller range of the polishing pad 3, the split body 20 is separated from the base body 10. At this time, the retaining ring 1 includes the base body 10 but not the split body 20, thereby reducing the contact area between the retaining ring 1 and the polishing pad 3 and increasing the pressure at the contact position. This solution is particularly suitable for polishing third-generation semiconductors such as silicon carbide.

[0039] Specifically, the ratio of the difference between the outer radius and the inner radius of the second end of the base body 10 to the difference between the outer radius and the inner radius of the second end of the split body 20 is in the range of 0.5-2.

[0040] Since the split body 20 is separable, split bodies 20 of different specifications can be manufactured by changing the size of the second end of the split body 20, that is, changing the difference between the outer circle radius and the inner circle radius of the second end of the split body 20, thereby being able to adapt to wafers of more specifications.

[0041] Specifically, at least part of the inner wall of the split body 20 is a conical surface, and the inner wall of the conical surface is adjacent to the first end of the split body 20, and the angle between the inner wall of the conical surface and the center line of the split body 20 ranges from 75° to 85°.

[0042] The inner wall of the split body 20 is a conical surface and is adjacent to the first end of the split body 20. The angle between the inner wall of the conical surface and the center line of the split body 20 is in the range of 75° to 85°, that is, the cone angle of the surface of the split body 20 opposite to the base body 10 except the first end is 95° to 105°. At this time, if polishing liquid flows into between the base body 10 and the split body 20, it will also flow down along the conical surface under the action of gravity, and it is not easy for the polishing liquid to accumulate.

[0043] Specifically, the inner side wall of the split body 20 adjacent to the first end of the split body 20 is a conical surface, the inner side wall of the split body 20 adjacent to the second end of the split body 20 is a cylindrical surface, and the inner side wall of the split body 20 that is a conical surface intersects with the inner side wall that is a cylindrical surface.

[0044] The inner side wall of the split body 20 may also include a cylindrical surface, which can further facilitate the installation of the base body 10 and the split body 20 .

[0045] Specifically, the base body 10 is made of polyetheretherketone, and the split body 20 is made of polyphenylene sulfide.

[0046] Since in the actual polishing process, the wear amount on the inner and outer sides of the retaining ring 1 is different, and the wear amount on the inner side is actually greater than that on the outer side, by making the base 10 adopt polyetheretherketone material with higher wear resistance, and the split body 20 adopt polyphenylene sulfide material with slightly lower wear resistance but lower cost, it is possible to reduce production costs while ensuring the polishing effect.

[0047] In the embodiment of the present application, by providing a detachable part 20, the contact area between the retaining ring 1 and the polishing pad 3 can be adaptively changed according to the requirements for polishing wafers of different specifications, thereby ensuring the polishing effect of the wafers.

[0048] Figure 3 is a schematic diagram of a retaining ring including a through hole according to an embodiment of the present application, Figure 3 As shown, at least two through holes are provided on the base 10 along the center line direction of the base 10. At least two internal threaded holes are provided on the first end of the split body 20 along the center direction of the split body 20, and the internal threaded holes correspond to the through holes one by one. The base 10 and the split body 20 are connected by bolts 30 that pass through the through holes and are threadedly connected to the internal threaded holes.

[0049] The base 10 and the split body 20 can be connected by bolts 30. At least two through holes are provided on the base 10 along the center line direction of the base 10, and at least two internal threaded holes are provided on the first end of the split body 20 along the center direction of the split body 20. During installation, the internal threaded holes are first aligned with the through holes one by one, and then the bolts 30 having the same number as the through holes are passed through the through holes and then tightened with the internal threaded holes, thereby connecting the base 10 and the split body 20.

[0050] In the embodiment of the present application, the base body 10 and the split body 20 are connected by bolts 30 , which can ensure the connection strength between the base body 10 and the split body 20 while facilitating the disassembly of the split body 20 .

[0051] Figure 4 is a schematic diagram of a retaining ring including an elastic block according to an embodiment of the present application, such as Figure 4 As shown, the retaining ring 1 further includes at least two elastic blocks 40. The elastic blocks 40 are used to block the through holes when the split body 20 is separated from the base body 10, wherein the elastic blocks 40 are connected to the through holes by interference fit, and different through holes are blocked by different elastic blocks 40.

[0052] When the split body 20 is separated from the base body 10, the bolt 30 will also be taken out of the through hole of the base body 10. During polishing, the polishing liquid may flow into the through hole and damage the base body 10. Therefore, an elastic block 40 is provided to be connected to the through hole by an interference fit, so that the base body 10 can be protected when polishing is performed when the split body 20 is separated from the base body 10.

[0053] Figure 5 is a schematic diagram of a retaining ring including a positioning pin according to an embodiment of the present application, such as Figure 5 As shown, at least one positioning pin 11 is provided on the base 10, and at least one pin hole 21 is provided on the first end of the split body 20. After the base 10 is connected to the split body 20, a positioning pin 11 is embedded in each pin hole 21, and different positioning pins 11 are embedded in different pin holes 21.

[0054] In addition to connecting the split body 20 and the base body 10 by means of bolts 30, at least one positioning pin 11 may be provided on the base body 10, and at least one pin hole 21 may be provided on the first end of the split body 20. During installation, the positioning pin 11 is aligned with the pin hole 21, and an external force is applied to embed the positioning pin 11 into the pin hole 21, thereby connecting the split body 20 and the base body 10.

[0055] In the embodiment of the present application, the split body 20 and the base body 10 are connected by embedding the positioning pin 11 into the pin hole 21 , which can further reduce the difficulty of installing and disassembling the split body 20 and the base body 10 .

[0056] Figure 6 is a schematic diagram of a retaining ring including a first groove according to an embodiment of the present application, Figure 6 As shown, the second end of the base 10 is provided with a first groove 12, and the second end of the split body 20 is provided with a second groove 22. After the first end of the split body 20 is connected to the base 10, the first groove 12 is connected to the second groove 22. The first groove 12 and the second groove 22 are used to guide the polishing liquid under the polishing head during the polishing of the wafer, and the polishing liquid can flow into and out from under the wafer.

[0057] When the wafer is polishing, the retaining ring 1 presses the polishing pad 3, and the liquid supply device 4 supplies polishing liquid to the polishing pad 3 from the outside. In order to make the polishing liquid flow into the inside of the retaining ring 1 and contact the wafer, a first groove 12 is provided at the second end of the base 10, and a second groove 22 is provided at the second end of the split body 20, and the first groove 12 and the second groove 22 are connected.

[0058] Specifically, the number of the first grooves 12 is the same as the number of the second grooves 22. After the first end of the split body 20 is connected to the base body 10, each first groove 12 is connected to a second groove 22, and the docking interfaces of the connected first grooves 12 and second grooves 22 have the same size and shape.

[0059] By setting the number of the first grooves 12 to be the same as the number of the second grooves 22 , it is possible to facilitate the drainage of the polishing liquid.

[0060] Specifically, a plurality of positioning pins 11 are provided on the base 10, and a plurality of pin holes 21 are provided on the first end of the split body 20. The plurality of positioning pins 11 include a target positioning pin, and the target positioning pin is different in size and / or cross-sectional shape from the other positioning pins 11. The plurality of pin holes 21 include a target pin hole, and the target pin hole is different in size and / or cross-sectional shape from the other pin holes 21. When the base 10 is connected to the split body 20, the target positioning pin is embedded in the target pin hole, so that each first groove 12 is connected to a second groove 22 and the axes coincide.

[0061] Since the first groove 12 needs to be connected to a second groove 22 and drain the polishing liquid, if the docking interface between the first groove 12 and the second groove 22 is not aligned or not fully aligned when the split body 20 and the base body 10 are installed, it will have a negative impact on the effect of draining the polishing liquid. Therefore, the multiple positioning pins 11 set on the base body 10 include a target positioning pin, and correspondingly, the multiple pin holes 21 set on the first end of the split body 20 include a target pin hole. During installation, the target positioning pin is aligned with the target pin hole to ensure that the docking interface between the first groove 12 and the second groove 22 is fully aligned.

[0062] Specifically, the axes of the first groove 12 and the second groove 22 are straight lines, and the radii of the first groove 12 and the second groove 22 are the same.

[0063] By setting the axes of the first groove 12 and the second groove 22 to be a straight line and the radii of the first groove 12 and the second groove 22 to be the same, the polishing liquid can be better drained.

[0064] It should be noted that Figure 6 The radius of the first groove 12 and the second groove 22 shown in the figure is the same, however, the radius of the first groove 12 and the second groove 22 may be different. Specifically, the axis of the first groove 12 and the second groove 22 is a straight line, and along the positive direction of the axis of the first groove 12 and the second groove 22 after being connected, the radius of at least one of the first groove 12 and the second groove 22 increases linearly, specifically, as shown in FIG. Figure 7 As shown, Figure 7 As shown in FIG. 1 , the positive direction of the axis of the first groove 12 and the second groove 22 points to the outside of the retaining ring 1 . The positive direction of the axis of the first groove 12 and the second groove 22 may also point to the inside of the retaining ring 1 .

[0065] By setting and linearly increasing the radius of at least one of the first groove 12 and the second groove 22 along the positive direction of the axis of the connected first groove 12 and the second groove 22, solid particles in the polishing liquid can be retained in the first groove 12 or the second groove 22 to avoid damage to other devices.

[0066] In the embodiment of the present application, by providing the first groove 12 and the second groove 22 , the polishing liquid can be drained during the polishing process.

[0067] It should be noted that Figure 6 The numbers of the first grooves 12 and the second grooves 22 shown in the figure are the same. However, in some embodiments, the numbers of the first grooves 12 and the second grooves 22 may be different, and the ratio of the number of the second grooves 22 to the number of the first grooves 12 may range from 1.5 to 2.5.

[0068] By setting the ratio of the number of second grooves 22 to the number of first grooves 12 in the range of 1.5 to 2.5, the rate at which the polishing liquid enters from the outside of the retaining ring 1 can be increased, while the rate at which the polishing liquid flows out from the inside of the retaining ring 1 can be reduced, thereby ensuring that there is enough polishing liquid inside the retaining ring 1 to supply the wafer.

[0069] Figure 8 is a schematic diagram of a retaining ring including a confluence groove according to an embodiment of the present application, such as Figure 8As shown, a first concave arc chamfer is provided along the outer edge of the second end of the base 10, and a second concave arc chamfer is provided along the inner edge of the second end of the split body 20. After the base 10 and the split body 20 are connected, the first concave arc chamfer and the second concave arc chamfer are spliced ​​into a confluence groove 50, and the first groove 12 and the second groove 22 are both connected to the confluence groove.

[0070] Since the number of the first grooves 12 and the second grooves 22 are different, the first grooves 12 and the second grooves 22 cannot be connected one to one. At this time, a first concave arc chamfer is arranged along the outer edge of the second end of the base 10, and a second concave arc chamfer is arranged along the inner edge of the second end of the split body 20. After the base 10 and the split body 20 are connected, a confluence groove 50 is formed by the first concave arc chamfer and the second concave arc chamfer, which can realize the drainage of the polishing liquid.

[0071] It should be noted that, similar to the above embodiment, when the number of first grooves 12 and second grooves 22 is different, the radius of at least one of the first groove 12 and the second groove 22 increases linearly along the positive direction of the axis of the first groove 12 or the second groove 22 .

[0072] In the embodiment of the present application, the first concave arc chamfer and the second concave arc chamfer are spliced ​​into a confluence groove 50, which can ensure that different numbers of first grooves 12 and second grooves 22 are connected, thereby ensuring the drainage of the polishing liquid.

[0073] The second aspect of the present application provides a polishing head for CMP, which includes the retaining ring 1 described above. The retaining ring is provided with a detachable part, and the contact area between the retaining ring and the polishing pad can be adaptively changed according to the requirements of polishing wafers of different specifications, thereby ensuring the polishing effect of the wafer.

[0074] Although the present application has been shown and described with respect to one or more implementations, equivalent variations and modifications will occur to those skilled in the art based on reading and understanding of this specification and the accompanying drawings. The present application includes all such modifications and variations and is limited only by the scope of the appended claims. In particular, with respect to the various functions performed by the above-mentioned components, the terms used to describe such components are intended to correspond to any component (unless otherwise indicated) that performs the specified function of the component (e.g., it is functionally equivalent), even if the structure is not equivalent to the disclosed structure that performs the function in the exemplary implementation of the present specification shown herein.

[0075] That is, the above description is only an embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the specification and drawings of the present application, such as the mutual combination of technical features between the embodiments, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

[0076] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0077] In order to enable any technician in the field to implement and use the application, the application provides the above description. In the above description, various details are listed for the purpose of explanation. It should be understood that those of ordinary skill in the art can recognize that the application can also be implemented without using these specific details. In other embodiments, the well-known process will not be elaborated in detail to avoid unnecessary details that make the description of the application obscure. Therefore, the application is not intended to be limited to the embodiments shown, but is consistent with the widest range of principles and features disclosed in the application.

[0078] It should be noted that, under the premise of no conflict, the various embodiments and / or the technical features in the various embodiments described in this application can be arbitrarily combined with each other, and the technical solution obtained after the combination should also fall within the protection scope of this application.

[0079] It should be understood that the specific examples in the embodiments of the present application are only to help those skilled in the art to better understand the embodiments of the present application, rather than to limit the scope of the embodiments of the present application. Those skilled in the art can make various improvements and modifications based on the above embodiments, and these improvements or modifications all fall within the scope of protection of the present application.

[0080] 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 who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A retaining ring, applied to a polishing head, characterized in that: include: A base body and a separate body separable from the base body; The base and the split body are both annular structures, the first end of the base is configured to be connected to the polishing head, and after the first end of the split body is connected to the base, the second end of the split body and the second end of the base are located in the same plane; The base body and the split body are used to apply pressure to the polishing pad when the polishing head places the wafer on the polishing pad to polish the wafer.

2. The retaining ring according to claim 1, characterized in that: At least two through holes are provided on the base body along the center line direction of the base body; At least two internal threaded holes are provided on the first end of the split body along the central direction of the split body, and the internal threaded holes correspond to the through holes one by one; The base body and the split body are connected by bolts passing through the through hole and threadedly connected to the internal threaded hole.

3. The retaining ring according to claim 2, characterized in that: The retaining ring also includes at least two elastic blockers; The elastic block is used to seal the through hole when the split body is separated from the base body, wherein the elastic block is connected to the through hole through an interference fit, and different through holes are sealed by different elastic blocks.

4. The retaining ring according to claim 1, characterized in that: At least one positioning pin is arranged on the base, and at least one pin hole is arranged on the first end of the split body. After the base and the split body are connected, one positioning pin is embedded in each of the pin holes, and different positioning pins are embedded in different pin holes.

5. The retaining ring according to claim 4, characterized in that: The second end of the base is provided with a first groove, the second end of the split body is provided with a second groove, and after the first end of the split body is connected to the base, the first groove and the second groove are communicated; The first groove and the second groove are used to guide the polishing liquid under the polishing head during the process of polishing the wafer.

6. The retaining ring according to claim 5, characterized in that The number of the first grooves is the same as the number of the second grooves. After the first end of the split body is connected to the base, each of the first grooves is connected to one of the second grooves, and the docking interfaces of the connected first grooves and second grooves have the same size and shape.

7. The retaining ring according to claim 6, characterized in that: The base is provided with a plurality of positioning pins, and the first end of the split body is provided with a plurality of pin holes; The plurality of positioning pins include a target positioning pin, and the target positioning pin is different in size and / or cross-sectional shape from the other positioning pins; The plurality of pin holes include a target pin hole, and the target pin hole has a different size and / or cross-sectional shape from the other pin holes; When the base body is connected to the split body, the target positioning pin is embedded in the target pin hole, so that each of the first grooves is connected to one of the second grooves and the axes coincide with each other.

8. The retaining ring according to claim 6, characterized in that The axes of the first groove and the second groove are straight lines, and the radii of the first groove and the second groove are the same.

9. The retaining ring according to claim 6, characterized in that: The axes of the first groove and the second groove are straight lines, and along the positive direction of the axes of the first groove and the second groove after being connected, the radius of at least one of the first groove and the second groove increases linearly.

10. The retaining ring according to claim 5, characterized in that The ratio of the number of the second grooves to the number of the first grooves is in a range of 1.5 to 2.

5.

11. The retaining ring according to claim 10, characterized in that A first concave arc-shaped chamfer is provided along the outer edge of the second end of the base body, and a second concave arc-shaped chamfer is provided along the inner edge of the second end of the split body; After the base body is connected to the split body, the first concave arc-shaped chamfer and the second concave arc-shaped chamfer are spliced ​​into a confluence groove, and the first groove and the second groove are both connected to the confluence groove.

12. The retaining ring according to claim 1, characterized in that The ratio of the difference between the outer circle radius and the inner circle radius of the second end of the base body to the difference between the outer circle radius and the inner circle radius of the second end of the split body is in the range of 0.5 to 2.

13. The retaining ring according to claim 1, characterized in that At least part of the inner side wall of the split body is a conical surface, and the inner side wall of the conical surface is adjacent to the first end of the split body, and the angle between the inner side wall of the conical surface and the center line of the split body ranges from 75° to 85°.

14. The retaining ring according to claim 13, characterized in that The inner side wall of the split body adjacent to the first end of the split body is a conical surface, the inner side wall of the split body adjacent to the second end of the split body is a cylindrical surface, and the inner side wall of the split body that is a conical surface intersects with the inner side wall that is a cylindrical surface.

15. The retaining ring according to any one of claims 1 to 14, characterized in that: The base body is made of polyetheretherketone, and the split body is made of polyphenylene sulfide.

16. A polishing head for chemical mechanical polishing, characterized in that: Comprising the retaining ring according to any one of claims 1-15.

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