Retaining ring, polishing head and equipment for CMP (chemical mechanical polishing) grinding
By designing a retaining ring for CMP grinding, the problem of poor grinding uniformity in wafer manufacturing with Notch is solved, and the effect of improving wafer surface quality and reducing defect rate is achieved.
Patent Information
- Application Number
- CN202422111650.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-29
- Publication Date
- 2025-06-17
- Estimated Expiration
- 2034-08-29
AI Technical Summary
During the wafer manufacturing process with Notch, poor grinding uniformity leads to a decrease in wafer surface quality and high defect rate.
A retaining ring for CMP grinding is designed, and the ring body and the limiting portion are surrounded to form a limiting groove. The limiting portion is embedded in the notch groove of the wafer. The first side wall and the second side wall of the limiting portion are tapered along the axis line direction of the ring body to ensure that the wafer is closely fit during the grinding process.
Through this design, the wafer is avoided to shift and shake during the grinding process, the grinding uniformity is improved, defects and scratches on the wafer surface are reduced, the wafer surface quality is improved, and the defect rate in the production process is reduced.
Smart Images
Figure CN222986641U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of wafer manufacturing, and particularly relates to a retaining ring, a polishing head and a device for CMP grinding. Background Art
[0002] A wafer refers to a silicon wafer in a silicon semiconductor integrated circuit. With the rapid development of semiconductor technology, the requirement for the planarization of the silicon wafer surface is becoming increasingly strict. The Chemical Mechanical Polishing (CMP) process is a surface planarization treatment method that combines chemical etching and mechanical grinding, and is a key technology for achieving nanoscale planarization of the wafer surface, occupying an important position in the wafer manufacturing process.
[0003] Currently, in wafer manufacturing technology, CMP equipment mainly adsorbs and transports wafers to a polishing pad through a polishing head for polishing, and then transports the wafers back to a wafer loading bracket for unloading and placing after polishing. However, the retaining ring of the grinding and polishing head in CMP equipment usually adopts a circular design. When a wafer with a Notch is processed using a circular retaining ring, it is difficult for the wafer with a Notch to fit tightly with the circular retaining ring, resulting in uneven distribution of the grinding liquid, which is not conducive to reducing defects and scratches on the wafer surface, will reduce the wafer surface quality, and is also difficult to reduce the defect rate during the production process.
[0004] Therefore, it is necessary to provide a new technical solution to solve the above technical problems. Summary of the Utility Model
[0005] The technical problem to be solved by the utility model is the technical problem of poor grinding uniformity, poor wafer surface quality and high defect rate during the manufacturing process of wafers with Notches.
[0006] To solve the above technical problems, the utility model provides a retaining ring for CMP grinding, where the retaining ring includes: a ring body and a limiting portion provided on the ring body. The ring body and the limiting portion enclose a limiting groove for placing a wafer. The limiting portion is used to be embedded in the notch groove of the wafer. The ring body is in a ring shape, and the limiting portion is tapered in a direction close to the axis line of the ring body. The limiting portion includes a first side wall and a second side wall respectively connected to the ring body, and the intersection point of the first side wall and the second side wall is directly opposite to the axis line of the ring body.
[0007] Optionally, the numerical range of the included angle formed by the first side wall and the second side wall at the intersection point is 30° to 60°.
[0008] Optionally, when the diameter of the wafer is 6 inches, the distance between the intersection point and the axis line ranges from 72 to 74.5 mm; when the diameter of the wafer is 8 inches, the distance between the intersection point and the axis line ranges from 97 to 99.5 mm.
[0009] Optionally, the first side wall and the second side wall are respectively planes.
[0010] Optionally, the surface roughness of the first side wall and the second side wall is respectively less than or equal to 0.5 nm.
[0011] Optionally, the numerical range of the ring width of the ring body is from 1 cm to 3 cm; the ring body and the limiting part are integrally formed.
[0012] According to another aspect of the present invention, the present invention also provides a polishing head for CMP polishing, the polishing head for CMP polishing includes a holding ring for CMP polishing, and further includes: a cover connected to the ring body, a main body respectively connected to the cover and the ring body, and an airbag having an adsorption surface, the airbag is connected to the ring body, and the adsorption surface is located in the limiting groove.
[0013] Optionally, the polishing head for CMP polishing further includes: a driving assembly and a connecting member, the driving assembly is connected to the main body; the connecting member is respectively connected to the main body and the ring body, and the connecting member is made of Teflon material or PVDF material.
[0014] Optionally, the polishing head for CMP polishing further includes: a polishing pad, and the orthographic projection of the ring body along the direction perpendicular to the polishing pad is located on the polishing pad.
[0015] According to another aspect of the present invention, the present invention also provides a device for CMP polishing, the device for CMP polishing includes a polishing head for CMP polishing.
[0016] Beneficial effects:
[0017] The present utility model provides a retaining ring for CMP polishing. By providing a limiting portion on the ring body, a limiting groove for placing a wafer is formed by enclosing the ring body and the limiting portion. The limiting portion is used to be embedded in the notch groove of the wafer. The ring body is in a ring shape, and the limiting portion is tapered along the direction close to the axis line of the ring body. The limiting portion includes a first side wall and a second side wall respectively connected to the ring body, and the intersection point of the first side wall and the second side wall is directly opposite to the axis line of the ring body. In this way, during the manufacturing process of a wafer with a Notch, the wafer to be polished is placed in the limiting groove formed by enclosing the ring body and the limiting portion, and the limiting portion will be embedded in the notch groove of the wafer. The first side wall and the second side wall of the limiting portion are respectively in close contact with the wafer, avoiding uneven distribution of the polishing liquid caused by the offset or shaking of the wafer during the polishing process, improving the polishing uniformity, reducing the defects and scratches on the wafer surface, achieving the improvement of the wafer surface quality, and at the same time improving the stability and controllability of the CMP process, and reducing the defective rate during the production process. Thus, during the manufacturing process of a wafer with a Notch, the technical effects of improving the polishing uniformity, enhancing the wafer surface quality, and reducing the defective rate are achieved. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.
[0019] Figure 1 FIG. is a schematic structural diagram of a retaining ring for CMP polishing provided by an embodiment of the present utility model.
[0020] Figure 2 FIG. is a schematic structural diagram of the axis line and the intersection point in a retaining ring for CMP polishing provided by an embodiment of the present utility model.
[0021] Figure 3 FIG. is a schematic structural diagram of a polishing head for CMP polishing provided by an embodiment of the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0022] The following details the embodiments of the present application. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described below with reference to the drawings are exemplary only for explaining the present application and should not be construed as a limitation of the present application.
[0023] To enable those skilled in the art to better understand the solution of this application, the following will clearly and completely describe the technical solutions in the embodiments of this application with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope protected by this application.
[0024] In the embodiments of this application, "at least one" means one or more; "a plurality" means two or more. In the description of this application, terms such as "first", "second", "third", etc. are only used for the purpose of distinguishing descriptions, and cannot be understood as indicating or implying relative importance, nor can they be understood as indicating or implying an order.
[0025] The reference to "an embodiment" or "some embodiments" etc. described in this specification means that a specific feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of this application. Thus, the terms "including", "comprising", "having" and their variants in this specification all mean "including but not limited to", unless otherwise specifically emphasized in other ways. It should be noted that in the embodiments of this application, "and / or" describes the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone these three situations.
[0026] It should be pointed out that in the embodiments of the present utility model, when a component is referred to as "fixed to" another component, it can be directly on the other component or there can also be an intermediate component. When a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be an intermediate component at the same time. When a component is considered to be "disposed on" another component, it can be directly disposed on the other component or there may be an intermediate component at the same time. At the same time, "connection" in the embodiments of this application can also be understood as electrical connection, and the connection of two electrical components can be a direct or indirect connection between the two electrical components. For example, when A is connected to B, it can be either a direct connection between A and B or an indirect connection between A and B through one or more other electrical components. The terms "vertical", "horizontal", "left", "right" and similar expressions used in the embodiments of the present utility model are only for illustrative purposes and are not intended to limit the present utility model.
[0027] An adapter ring for CMP polishing provided in Embodiment 1 of the present utility model, please refer to Figures 1 to 2 as shown in Figure 1 is a schematic structural diagram of an adapter ring for CMP polishing provided in the embodiments of the present utility model. Figure 2It is a structural schematic diagram of an axis centerline 12 and an intersection 23 of a retaining ring for CMP grinding provided by an embodiment of the utility model. A retaining ring for CMP grinding provided by the utility model in embodiment 1 includes a ring body 1 and a limiting portion 2, the ring body 1 and the limiting portion 2 enclose a limiting groove 11, the limiting groove 11 is used to place a wafer, the limiting portion 2 is used to embed the inside of the notch groove of the wafer, the ring body 1 is annular, the limiting portion 2 is tapered along the direction close to the axis centerline 12 of the ring body 1, the limiting portion 2 includes a first side wall 21 and a second side wall 22 respectively connected to the ring body 1, and the intersection 23 of the first side wall 21 and the second side wall 22 is directly opposite to the axis centerline 12 of the ring body 1.
[0028] Among them, the first side wall 21 and the second side wall 22 are two side surfaces connected to each other in the limiting portion 2, and the distance between the first side wall 21 and the second side wall 22 gradually decreases along the direction close to the center of the ring body 1, so that the first side wall 21 and the second side wall 22 intersect at the intersection 23, and the intersection 23 where the first side wall 21 and the second side wall 22 intersect is opposite to the axial line 12 located at the center of the ring body 1, that is, the intersection 23 where the first side wall 21 and the second side wall 22 intersect is located on the same straight line as the center of the ring body 1.
[0029] In this embodiment, a limiting portion 2 is provided on the ring body 1, and the ring body 1 and the limiting portion 2 enclose a limiting groove 11 for placing a wafer. The limiting portion 2 is used to be embedded in the notch groove of the wafer. The ring body 1 is annular, and the limiting portion 2 is tapered along the direction close to the axis 12 of the ring body 1. The limiting portion 2 includes a first side wall 21 and a second side wall 22 respectively connected to the ring body 1, and the intersection 23 of the first side wall 21 and the second side wall 22 is opposite to the axis 12 of the ring body 1. In this way, during the manufacturing process of wafers with Notch, the wafer to be ground is placed in the limiting groove 11 formed by the ring body 1 and the limiting part 2, and the limiting part 2 is embedded in the notch groove of the wafer. The first side wall 21 and the second side wall 22 of the limiting part 2 are respectively fitted with the wafer to avoid uneven distribution of the grinding liquid caused by the deviation or shaking of the wafer during the grinding process, which can improve the grinding uniformity, reduce the defects and scratches on the wafer surface, and improve the surface quality of the wafer. At the same time, the stability and controllability of the CMP process are improved, and the defect rate in the production process can be reduced. Thus, the technical effect of improving the grinding uniformity, improving the surface quality of the wafer, and reducing the defect rate in the manufacturing process of the wafer with Notch is achieved.
[0030] As an implementation, the numerical range of the included angle formed by the first side wall 21 and the second side wall 22 at the intersection point 23 is 30° to 60°. That is, assuming the included angle formed by the first side wall 21 and the second side wall 22 at the intersection point 23 is A, then 30° ≤ A ≤ 60°. This ensures that the limiting part 2 can be tightly and stably embedded in the notch groove of the wafer, effectively suppressing the offset and shaking of the wafer during the grinding process, which is beneficial to improving the grinding uniformity, reducing the defects and scratches on the wafer surface, and improving the surface quality of the wafer.
[0031] In some implementations, when the diameter of the wafer is 6 inches, the distance range between the intersection point 23 and the axis line 12 is 72 to 74.5 mm. That is, assuming the distance between the intersection point 23 and the axis line 12 is Y1, then 72 mm ≤ Y1 ≤ 74.5 mm. When the diameter of the wafer is 8 inches, the distance range between the intersection point 23 and the axis line 12 is 97 to 99.5 mm. That is, assuming the distance between the intersection point 23 and the axis line 12 is Y2, then 97 mm ≤ Y2 ≤ 99.5 mm. It can adapt to the clamping of wafers of different sizes and ensure good grinding effects on wafers of different sizes.
[0032] In some implementations, the first side wall 21 of the limiting part 2 can be a plane, and the second side wall 22 of the limiting part 2 can also be a plane. The first side wall 21 and the second side wall 22 presented as planes can respectively reduce the contact resistance between the first side wall 21 and the second side wall 22 and the wafer, and reduce the uneven wear and scratches during the grinding process.
[0033] In some implementations, the surface roughness of the first side wall 21 is less than or equal to 0.5 nm. That is, assuming the surface roughness of the first side wall 21 is Ra1, then Ra1 ≤ 0.5 nm. The surface roughness of the second side wall 22 is respectively less than or equal to 0.5 nm. That is, assuming the surface roughness of the second side wall 22 is Ra2, then Ra2 ≤ 0.5 nm. The first side wall 21 and the second side wall 22 with a surface roughness less than or equal to 0.5 nm enable smooth contact between the first side wall 21 and the second side wall 22 and the wafer, reducing the debris and impurities generated during the grinding process, as well as the scratches and defects caused by friction.
[0034] In some implementations, the numerical range of the ring width of the ring body 1 is 1 cm to 3 cm. Assuming the ring width of the ring body 1 is H, then 1 cm ≤ H ≤ 3 cm. The ring body 1 can be integrally formed with the limiting part 2, making the ring body 1 more compact and stable in structure. At the same time, it reduces the failures and potential safety hazards caused by loose connections between components, improves the service life of the retaining ring, helps maintain the stability and controllability of the grinding process, and reduces the defect rate during the production process.
[0035] For a detailed description of a polishing head for CMP grinding provided by the present utility model, the above-mentioned Embodiment 1 has made a detailed description of a retaining ring for CMP grinding. Based on the same inventive concept, the present application also provides a polishing head for CMP grinding, as shown in Embodiment 2 for details.
[0036] Please refer to Figure 3 , Figure 3 which is a schematic structural diagram of a polishing head for CMP grinding provided by an embodiment of the present utility model. Embodiment 2 of the present utility model provides a polishing head for CMP grinding, including the above-mentioned retaining ring for CMP grinding. Embodiment 2 of the present utility model also provides a polishing head for CMP grinding, which further includes a protective cover 3, a main body 4, and an airbag 5. The protective cover 3 is connected to the ring body 1, the main body 4 is respectively connected to the protective cover 3 and the ring body 1, the airbag 5 has an adsorption surface 51 for adsorbing the wafer, the airbag 5 is connected to the ring body 1, and the adsorption surface 51 is located inside the limit groove 11.
[0037] Among them, the protective cover 3 is tightly connected to the ring body 1, effectively resisting vibration and impact during the grinding process, and providing protection for the internal components of the entire polishing head. The main body 4 is respectively connected to the protective cover 3 and the ring body 1 to form the main structural framework of the polishing head. Those skilled in the art can understand that in the polishing head for CMP grinding provided by the embodiment of the present utility model, the specific structure of the airbag 5 is not limited, as long as the adsorption surface 51 of the airbag 5 can ensure that the wafer is tightly adsorbed during the grinding process, preventing the wafer from shifting or shaking.
[0038] In some embodiments, Embodiment 2 of the present utility model also provides a polishing head for CMP grinding, which further includes a driving component and a connecting piece. The driving component is connected to the main body 4, and the connecting piece is respectively connected to the main body 4 and the ring body 1. The connecting piece is made of Teflon material or PVDF material. The main body 4 can be directly connected to the ring body 1 through the connecting piece, so that the ring body 1 is fixed on the main body 4. Then, the protective cover 3 is sleeved outside the main body 4, and a space for installing the internal components of the polishing head is formed by enclosing the protective cover 3, the ring body 1, and the main body 4. Those skilled in the art can understand that in the polishing head for CMP grinding provided by the embodiment of the present utility model, the specific structure of the connecting piece is not limited, as long as the ring body 1 and the main body 4 can be connected through the connecting piece. The driving component includes a cylinder, a motor, etc. During the grinding process, the driving component can drive the polishing head to move along a predetermined trajectory and speed, ensuring that the wafer can be evenly ground. The connecting piece made of Teflon material or PVDF material has good wear resistance, corrosion resistance, and chemical stability, which can ensure that the connecting piece maintains stable performance and reliable connection during long-term use, effectively resisting wear and corrosion generated during the grinding process, and extending the service life of the polishing head.
[0039] In some embodiments, the second embodiment of the present invention provides a polishing head for CMP grinding, which also includes a polishing pad, and the ring body 1 is located on the polishing pad along the orthographic projection of the direction perpendicular to the polishing pad. The polishing pad is used to directly contact the wafer and perform a grinding process, and the ring body 1 facing the polishing pad is conducive to ensuring that the wafer can be evenly ground.
[0040] The utility model provides a polishing head for CMP grinding. A limiting portion 2 is arranged on a ring body 1. The ring body 1 and the limiting portion 2 are combined to form a limiting groove 11 for placing a wafer. The limiting portion 2 is used to be embedded in the notch groove of the wafer. The ring body 1 is annular. The limiting portion 2 is gradually contracted along the direction close to the axis 12 of the ring body 1. The limiting portion 2 includes a first side wall 21 and a second side wall 22 respectively connected to the ring body 1. The intersection 23 of the first side wall 21 and the second side wall 22 is directly opposite to the axis 12 of the ring body 1. In this way, during the manufacturing process of wafers with Notch, the wafer to be ground is placed in the limiting groove 11 formed by the ring body 1 and the limiting part 2, and the limiting part 2 is embedded in the notch groove of the wafer. The first side wall 21 and the second side wall 22 of the limiting part 2 are respectively fitted with the wafer to avoid uneven distribution of the grinding liquid caused by the deviation or shaking of the wafer during the grinding process, which can improve the grinding uniformity, reduce the defects and scratches on the wafer surface, and improve the surface quality of the wafer. At the same time, the stability and controllability of the CMP process are improved, and the defect rate in the production process can be reduced. Thus, the technical effect of improving the grinding uniformity, improving the surface quality of the wafer, and reducing the defect rate in the manufacturing process of the wafer with Notch is achieved.
[0041] In order to explain in detail a device for CMP grinding provided by the utility model, the above-mentioned embodiment 1 explains in detail a retaining ring for CMP grinding. Based on the same utility model concept, the present application also provides a device for CMP grinding, see embodiment 2 for details.
[0042] The third embodiment of the present invention provides a device for CMP grinding, including the above-mentioned polishing head for CMP grinding.
[0043] Among them, the third embodiment of the present invention provides a device for CMP grinding, which can also include a grinding liquid supply component, and the grinding liquid supply component is used to supply the grinding liquid to the above-mentioned polishing pad.
[0044] The present utility model provides an apparatus for CMP polishing. By providing a limiting portion 2 on the ring body 1, a limiting groove 11 for placing a wafer is formed by enclosing the ring body 1 and the limiting portion 2. The limiting portion 2 is used to be embedded in the notch groove of the wafer. The ring body 1 is in a ring shape, and the limiting portion 2 is tapered along the direction close to the axis line 12 of the ring body 1. The limiting portion 2 includes a first side wall 21 and a second side wall 22 respectively connected to the ring body 1, and the intersection point 23 of the first side wall 21 and the second side wall 22 is directly opposite to the axis line 12 of the ring body 1. In this way, during the manufacturing process of a wafer with a Notch, the wafer to be polished is placed in the limiting groove 11 formed by enclosing the ring body 1 and the limiting portion 2, and the limiting portion 2 will be embedded in the notch groove of the wafer. The first side wall 21 and the second side wall 22 of the limiting portion 2 are respectively in contact with the wafer, avoiding uneven distribution of the polishing liquid caused by the offset or shaking of the wafer during the polishing process, improving the polishing uniformity, reducing the defects and scratches on the wafer surface, achieving the improvement of the wafer surface quality, and at the same time improving the stability and controllability of the CMP process, and reducing the defective rate during the production process. Thus, during the manufacturing process of a wafer with a Notch, the technical effects of improving the polishing uniformity, enhancing the wafer surface quality, and reducing the defective rate are achieved.
[0045] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present utility model and not to limit them. Although the present utility model has been described in detail with reference to the examples, those of ordinary skill in the art should understand that the technical solutions of the present utility model can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present utility model, and they should all be covered within the scope of the claims of the present utility model.
Claims
1. A retaining ring for CMP grinding, characterized in that: The retaining ring includes: a ring body and a limiting portion arranged on the ring body, the ring body and the limiting portion enclose a limiting groove for placing a wafer, the limiting portion is used to be embedded in the notch groove of the wafer, the ring body is annular, and the limiting portion is tapered along the direction close to the axis of the ring body, the limiting portion includes a first side wall and a second side wall respectively connected to the ring body, and the intersection of the first side wall and the second side wall is opposite to the axis of the ring body.
2. The retaining ring for CMP grinding according to claim 1, characterized in that: The value range of the angle formed by the first side wall and the second side wall at the intersection is 30° to 60°.
3. The retaining ring for CMP grinding according to claim 1, characterized in that: When the diameter of the wafer is 6 inches, the distance between the intersection and the axis line ranges from 72 to 74.5 mm; when the diameter of the wafer is 8 inches, the distance between the intersection and the axis line ranges from 97 to 99.5 mm.
4. The retaining ring for CMP grinding according to claim 1, characterized in that: The first side wall and the second side wall are respectively planes.
5. The retaining ring for CMP grinding according to claim 1, characterized in that: The surface roughness of the first side wall and the second side wall is respectively less than or equal to 0.5 nm.
6. The retaining ring for CMP grinding according to claim 1, characterized in that: The ring width of the ring body ranges from 1 cm to 3 cm; the ring body and the limiting portion are integrally formed.
7. A polishing head for CMP grinding, characterized in that: The polishing head for CMP grinding includes a retaining ring for CMP grinding as described in any one of claims 1 to 5, and also includes: a protective cover connected to the ring body, a main body connected to the protective cover and the ring body respectively, and an air bag with an adsorption surface, the air bag is connected to the ring body, and the adsorption surface is located in the limiting groove.
8. The polishing head for CMP grinding according to claim 7, characterized in that: The polishing head for CMP grinding also includes: a driving component and a connecting piece, wherein the driving component is connected to the main body; the connecting piece is respectively connected to the main body and the ring body, and the connecting piece is made of Teflon material or PVDF material.
9. The polishing head for CMP grinding according to claim 7, characterized in that: The polishing head for CMP grinding further includes a polishing pad, and the orthographic projection of the ring body along a direction perpendicular to the polishing pad is located on the polishing pad.
10. An apparatus for CMP polishing, characterized in that: The device for CMP grinding comprises the polishing head for CMP grinding according to any one of claims 7 to 9.