Polishing head, polishing apparatus, polishing method, processor, and storage medium

Abstract

Embodiments of the present application provide a polishing head, a polishing device, a polishing method, a processor and a storage medium. The polishing head comprises a base, a retaining ring arranged below the base, a polishing head air film arranged on the base and inside the retaining ring for holding a wafer, and a retaining ring air film arranged inside the retaining ring and between the retaining ring and the polishing head air film. When the retaining ring air film is pressurized and expanded, it is in contact with the edge of the wafer to exert a force on the edge of the wafer, and the force forms a radial clamping force and an axial downward pressure on the edge of the wafer. The radial clamping force can hold the wafer to prevent the wafer from moving during polishing, thereby reducing the risk of a slip sheet. The axial downward pressure can exert a pressing force on the edge of the wafer during polishing, which can more accurately control the polishing effect of the edge of the wafer and ensure the polishing consistency of the entire wafer surface.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the technical field of semiconductor processing, and in particular, to a polishing head, a polishing device, a polishing method, a processor and a storage medium. BACKGROUND

[0002] In the technical field of semiconductor processing, chemical mechanical polishing (CMP) is a kind of global planarization ultra-precision surface processing technology. In chemical mechanical polishing, a wafer is attracted or clamped to the bottom surface of a carrier head, the side of the wafer with a deposited layer is pressed against the upper surface of a polishing pad, the carrier head is rotated under the actuation of a driving assembly and gives the wafer a downward load; at the same time, a polishing liquid is supplied to the upper surface of the polishing pad and distributed between the wafer and the polishing pad, so that the wafer is subjected to the combined action of chemical and mechanical forces to complete the chemical mechanical polishing of the wafer.

[0003] In the chemical mechanical polishing process, the pressure applied to the wafer by the polishing head is a direct factor affecting the polishing effect of the wafer. In order to more accurately control the polishing effect of the wafer, the internal zones of the polishing head are continuously optimized. However, the polishing head in the related art still cannot control the polishing of the edge of the wafer, resulting in an unsatisfactory polishing effect of the edge of the wafer. In addition, in the polishing process, the back surface of the wafer or the surface of the gas film of the polishing head may be damaged, causing the processed wafer to not meet the requirements and the service life of the gas film of the polishing head to be short, and the risk of causing debris in the polishing process of the wafer. SUMMARY

[0004] Therefore, embodiments of the present application provide a polishing head, a polishing device, a polishing method, a processor and a storage medium to at least partially solve the above problems.

[0005] According to a first aspect of embodiments of the present application, a polishing head is provided for pressing a wafer against a polishing pad for polishing processing, the polishing head comprising: a base; a retaining ring arranged below the base; a polishing head gas film arranged in the base and inside the retaining ring for holding the wafer; and a retaining ring gas film arranged inside the retaining ring and between the retaining ring and the polishing head gas film, the retaining ring gas film being in contact with the edge of the wafer when pressurized and expanded to exert a force on the edge of the wafer, the force forming a radial clamping force and an axial downward pressure on the edge of the wafer.

[0006] Further, in the above-mentioned polishing head, the lower surface of the retaining ring gas film is in contact with the polishing pad when pressurized and expanded to control the bulging of the polishing pad in contact with the edge of the wafer during polishing.

[0007] Further, the polishing head has a gap between the retaining ring air film and the polishing head air film; the gap is exposed when the retaining ring air film shrinks under reduced pressure, so as to clean the gap.

[0008] Further, the polishing head has a gap between the retaining ring air film and the polishing head air film; the gap is exposed when the retaining ring air film shrinks under reduced pressure, so as to clean the gap.

[0009] Further, the polishing head has a gap between the retaining ring air film and the polishing head air film; the gap is exposed when the retaining ring air film shrinks under reduced pressure, so as to clean the gap.

[0010] Further, the polishing head has a gap between the retaining ring air film and the polishing head air film; the gap is exposed when the retaining ring air film shrinks under reduced pressure, so as to clean the gap.

[0011] Further, the polishing head has a gap between the retaining ring air film and the polishing head air film; the gap is exposed when the retaining ring air film shrinks under reduced pressure, so as to clean the gap.

[0012] Further, the polishing head has a gap between the retaining ring air film and the polishing head air film; the gap is exposed when the retaining ring air film shrinks under reduced pressure, so as to clean the gap.

[0013] Further, the polishing head has a gap between the retaining ring air film and the polishing head air film; the gap is exposed when the retaining ring air film shrinks under reduced pressure, so as to clean the gap.

[0014] Further, the polishing head has a gap between the retaining ring air film and the polishing head air film; the gap is exposed when the retaining ring air film shrinks under reduced pressure, so as to clean the gap.

[0015] Further, the polishing head has a gap between the retaining ring air film and the polishing head air film; the gap is exposed when the retaining ring air film shrinks under reduced pressure, so as to clean the gap.

[0016] Further, the polishing head has a gap between the retaining ring air film and the polishing head air film; the gap is exposed when the retaining ring air film shrinks under reduced pressure, so as to clean the gap.

[0017] Further, in the polishing head, a cross-sectional area of the retaining ring air film at a bending position where the retaining ring air film is bent by being pressed against the boss is smaller than a cross-sectional area of a portion of the retaining ring air film that is bent in a direction toward the polishing head air film.

[0018] According to a second aspect of the embodiments of the present application, a polishing device is provided, which comprises a base, a polishing plate arranged on the base, a polishing pad arranged on the polishing plate, and any one of the polishing heads.

[0019] According to a third aspect of the embodiments of the present application, a polishing method is provided, which comprises the following steps: controlling any one of the polishing heads to load a wafer; controlling the polishing head loaded with the wafer to move toward and press against the polishing pad; controlling the polishing liquid to be delivered to the polishing pad; controlling the polishing head air film and the retaining ring air film to be inflated and pressurized, so that the retaining ring air film is inflated and contacts the edge of the wafer, and an acting force is applied to the edge of the wafer; the acting force forms a radial clamping force and an axial downward pressure on the edge of the wafer; controlling the polishing head and the polishing plate to rotate, and starting to polish the wafer; and controlling the polishing head to deliver the wafer to a loading and unloading station after the polishing of the wafer is completed.

[0020] Further, in the polishing method, after the polishing head delivers the wafer to the loading and unloading station after the polishing of the wafer is completed, the method further comprises the following steps: controlling the retaining ring air film to be depressurized, so that the retaining ring air film is deflated, and a gap between the retaining ring air film and the polishing head air film is exposed; and cleaning the gap.

[0021] According to a fourth aspect of the embodiments of the present application, a processor is provided, which is used to execute the related steps of any one of the polishing methods.

[0022] According to a fifth aspect of the embodiments of the present application, a computer storage medium is provided, which stores a computer program, and the program is executed by a processor to implement any one of the polishing methods.

[0023] In the embodiments of the present application, the retaining ring air film applies a radial clamping force and an axial downward pressure to the edge of the wafer, the radial clamping force can clamp the wafer and fix the wafer in the radial direction, so that the wafer is prevented from moving relative to the polishing head air film during the polishing process, the risk of a slip is reduced, and the damage to the back surface of the wafer or the lower surface of the polishing head air film is avoided. The axial downward pressure can apply a pressing force to the edge of the wafer during the polishing process of the wafer, the polishing effect of the edge of the wafer can be more accurately controlled, and the polishing consistency of the entire wafer surface is ensured. In addition, since the retaining ring air film is in flexible contact with the wafer, the stress concentration of the edge of the wafer during the polishing process can be avoided, and the risk of a wafer fragment is reduced.

[0024] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application, as claimed. BRIEF DESCRIPTION OF DRAWINGS

[0025] The above and other objects, features and advantages of the present application will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which like reference characters refer to like parts throughout and in which:

[0026] Figure 1 An axial sectional view of a polishing head according to an embodiment of the present application;

[0027] Figure 2 An enlarged structural schematic view of A shown in FIG. 1; Figure 1

[0028] Figure 3 An enlarged structural schematic view of B shown in FIG. 1; Figure 2

[0029] Figure 4 An enlarged structural schematic view of C shown in FIG. 1;

[0030] Figure 5 Another axial sectional view of a polishing head according to an embodiment of the present application;

[0031] Figure 6 An enlarged structural schematic view of D shown in FIG. 2; Figure 5

[0032] Another enlarged structural schematic view of a polishing head according to an embodiment of the present application; Figure 7

[0033] Still another enlarged structural schematic view of a polishing head according to an embodiment of the present application; Figure 8

[0034] A structural schematic view of a polishing head gas film according to an embodiment of the present application; Figure 9

[0035] A structural schematic view of a retaining ring gas film according to an embodiment of the present application; Figure 10

[0036] A structural schematic view of a polishing apparatus according to an embodiment of the present application; Figure 11

[0037] A flow structural schematic view of a polishing method according to an embodiment of the present application; Figure 12

[0038] Figure 13 ​​​Another flow structure schematic diagram of the polishing method provided by the embodiment of the present application is shown in FIG. 6.

[0039] In the drawings:

[0040] Polishing head 100; base 110; disc body 111; connecting body 112; retaining ring 120; boss 121; polishing head air film 130; partition 131; annular support body 132; retaining ring air film 140; lower surface 141; annular air bag 142; inflation interface 1421; first piece ring 1422; second piece ring 1423; first recessed portion 1424; second recessed portion 1425; annular inner support body 143; annular outer support body 144; folding structure 145;

[0041] Wafer 200;

[0042] Polishing apparatus 300; polishing disc 310; polishing pad 320; polishing liquid supply device 330; dresser 340; loading and unloading station 350. DETAILED DESCRIPTION

[0043] The preferred embodiments of the present application will be described in greater detail below with reference to the accompanying drawings. While the preferred embodiments of the present application are shown in the drawings, it is understood that the present application can be embodied in various forms without being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the application to those skilled in the art.

[0044] The terminology used in the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. As used in the description of the application and the appended claims, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0045] It should be understood that, although the terms "first", "second", "third", etc. can be employed in describing various components, these components should not be limited by these terms. These terms are only used to distinguish one component from another. For example, a first component could be termed a second component, and, similarly, a second component could be termed a first component without departing from the scope of the application. As such, the terms "first", "second", etc. should be understood as having relative meanings and should not be taken to otherwise limit the scope of the present application. In the description of the application, the meaning of "a", "an" and "the" is intended to include both singular and plural forms, unless the context clearly indicates otherwise.

[0046] In the description of this application, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0047] Unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0048] In chemical mechanical polishing (CMP), the polishing head presses the wafer firmly onto a rotating polishing pad. The polishing pad is fixed to a polishing disk and rotates under its rotation. Simultaneously, a rotational force is applied to the polishing head, causing the wafer to rotate relative to the polishing pad. During this process, polishing fluid is uniformly delivered to the polishing pad to achieve chemical mechanical polishing of the wafer surface.

[0049] The pressure applied by the polishing head to the wafer is a direct factor affecting the wafer polishing effect. Even with continuous optimization of the internal partitioning of the polishing head to achieve more precise control over the wafer polishing effect, the polishing heads in related technologies still struggle to accurately control the polishing effect at the wafer edges, resulting in unsatisfactory polishing results at the wafer edges. Furthermore, the polishing process may damage the back side of the wafer or the surface of the polishing head's gas film, leading to wafers that fail to meet requirements after processing and a short lifespan for the polishing head's gas film. Additionally, the polishing process carries the risk of chipping during the wafer polishing process.

[0050] To address the aforementioned problems, this application provides a polishing head. The technical solution of this application embodiment is described in detail below with reference to the accompanying drawings.

[0051] See Figures 1 to 6 , Figures 9 to 10 According to one embodiment of this application, a polishing head 100 includes a base 110, a retaining ring 120, a polishing head gas film 130, and a retaining ring gas film 140. The polishing head 100 is used to press a wafer 200 against a polishing pad (not shown) for polishing.

[0052] The retaining ring 120 is located below the base 110 (relative to...). Figure 1In the shown state, the polishing head air film 130 is arranged on the base 110 and inside the retaining ring 120 (relative to the shown state). Figure 1 In the shown state, the retaining ring air film 140 is arranged inside the retaining ring 120 (close to the polishing head air film 130) and between the retaining ring 120 and the polishing head air film 130.

[0053] In one implementation, the retaining ring 120 can be a ring-shaped body, the base 110 can include a disc-shaped body 111 and a connecting body 112, the retaining ring 120 and the polishing head air film 130 are connected to the lower end surface of the disc-shaped body 111 (relative to the shown state), and the connecting body 112 is used to be connected to a driving device (e.g., a motor). Figure 1 In the shown state, the polishing head air film 130 is arranged on the base 110 and inside the retaining ring 120 (relative to the shown state).

[0054] When the polishing head air film 130 is pressurized, it expands to make flexible contact with and pressurize the wafer 200, so as to avoid damaging the wafer 200. It can be understood that in some examples, the polishing head air film 130 can be provided with multiple sub-zones 131, and each sub-zone can exert different pressure on the wafer 200 during polishing, so as to meet the polishing pressure requirements of different regions of the wafer 200.

[0055] The retaining ring air film 140 is arranged inside the retaining ring 120 (close to the polishing head air film 130) and between the retaining ring 120 and the polishing head air film 130. When the retaining ring air film 140 is pressurized and expanded, it contacts the edge of the wafer 200 to exert a force F on the edge of the wafer 200, which forms a radial clamping force F1 and an axial downward pressure F2 (shown) on the edge of the wafer 200. Figure 3

[0056] In one implementation, the retaining ring air film 140 is a ring-shaped body, which expands when pressurized and shrinks when depressurized. The retaining ring air film 140 can be made of elastic materials such as rubber, silicone, etc., or non-elastic materials such as plastic, etc.

[0057] In the present embodiment, referring to Figure 3 When the retaining ring air film 140 is pressurized and expanded, the retaining ring air film 140 contacts the edge of the wafer 200 to exert an obliquely downward (relative to the shown state) force F on the edge of the wafer 200, which can be decomposed into a radial clamping force F1 and an axial downward pressure F2 on the wafer 200. The radial clamping force F1 can clamp the wafer 200, and the axial downward pressure F2 can exert a force on the wafer 200 to press it against the polishing pad during polishing. Figure 3

[0058] During polishing, the edge of the wafer 200 can extend beyond the edge of the polishing head air film 130 in some working conditions, as shown in Figure 4 ​​As shown, the ring air film 140 can also exert an oblique downward pressure F on the edge of the wafer 200 in this working condition, which can also be decomposed into a radial clamping force F1 and an axial downward pressure F2 on the wafer 200.

[0059] In the embodiments of the present application, the ring air film 140 exerts a radial clamping force and an axial downward pressure on the edge of the wafer 200, the radial clamping force can clamp the wafer 200 and fix the wafer 200 radially to prevent the wafer 200 from moving relative to the polishing head air film 130 during polishing, thereby reducing the risk of slippage and avoiding damage to the back surface of the wafer (the surface in contact with the polishing head air film) or the lower surface of the polishing head air film 130 (the surface in contact with the wafer); the axial downward pressure can exert a pressing force on the edge of the wafer 200 during polishing of the wafer 200, which can more accurately control the polishing effect of the edge of the wafer 200 and ensure the polishing consistency of the entire wafer surface; in addition, since the ring air film 140 of the present application has a flexible contact with the wafer 200, stress concentration at the edge of the wafer during polishing can be avoided, thereby reducing the risk of chipping.

[0060] In the related art, since the ring air film 140 in the embodiments of the present application is not provided, the ring and the wafer are in rigid contact, and at the same time, the ring, the wafer and the polishing pad are all in rigid pressing, which causes the polishing pad at the edge of the wafer to easily bulge during polishing, which affects the load exerted by the polishing head air film 130 on the edge region of the wafer, such as causing the material removal rate of the edge region of the wafer to be greater than that of the center region of the wafer, and the global planarization of the wafer cannot be achieved.

[0061] Based on this, in some embodiments, referring to Figure 2 , the lower surface 141 of the ring air film 140 is in abutting pressure with the polishing pad when it is pressurized and expanded, so as to suppress the bulging degree of the polishing pad at the edge of the wafer during polishing, thereby improving the stress at the edge region of the wafer and controlling the material removal rate of the edge of the wafer.

[0062] In a specific implementation, when the ring air film 140 is pressurized and expanded, the lower surface 141 (relative to the state shown in Figure 2 ) is flush with the lower surface of the wafer 200 (relative to the state shown in Figure 3 ).

[0063] In the present embodiment, the ring air film 140 is arranged between the rigidly abutting pressure region of the ring 120, the wafer 200 and the polishing pad, and is in flexible abutting pressure with the polishing pad, which effectively buffers the above-mentioned rigid abutting pressure, reduces the stress concentration at the edge of the wafer, and further controls the bulging of the polishing pad at the edge of the wafer during polishing.

[0064] In some embodiments, the holding ring air film 140 has a gap D (as shown) with the polishing head air film 130 to avoid the holding ring air film 140 from contacting the polishing head air film 130 when the holding ring air film 140 is inflated, and to prevent the holding ring air film 140 from affecting the polishing head air film 130 during use. Figure 6 As shown, the gap D is formed between the holding ring air film 140 and the polishing head air film 130 to avoid the holding ring air film 140 from contacting the polishing head air film 130 when the holding ring air film 140 is inflated, and to prevent the holding ring air film 140 from affecting the polishing head air film 130 during use.

[0065] It should be noted that the specific value of the gap D can be determined according to actual conditions, and the present embodiment does not make any limitation thereto.

[0066] In the present embodiment, the gap D can be exposed when the holding ring air film 140 is deflated under reduced pressure, so that the cleaning liquid can enter the gap D to clean the polishing liquid in the gap D, and avoid the pollutants on the outer circumferential side of the polishing head air film 130 and the holding ring air film 140 from being cleaned in time and forming crystals. The crystals formed by the pollutants can fall on the polishing pad during operation and cause scratches on the wafer.

[0067] In some embodiments, referring to Figure 2 The holding ring air film 140 includes an annular air bag 142 and an annular inner support 143. The annular air bag 142 is provided with an inflation interface 1421 for connecting with an inflation device. The annular inner support 143 is attached to the inner side surface of the portion of the annular air bag 142 close to the polishing head air film 130 to support the inner side of the annular air bag 142, thereby avoiding the annular air bag 142 from contacting the polishing head air film 130 when inflated, and avoiding affecting the polishing head air film 130.

[0068] In a specific implementation, the annular air bag 142 is provided with a first ring 1422 on the inner side surface of the inflation interface 1421 and a second ring 1423 on the outer side surface, and the first ring 1422 and the second ring 1423 are connected to clamp the opening end of the annular air bag 142 between the first ring 1422 and the second ring 1423 to form the inflation interface 1421. In order to better seal, a ring-shaped groove can also be opened on the first ring 1422, and the annular air bag 142 is fixed in the groove by pasting, clamping or the like.

[0069] It can be understood that the inflation interface 1421 is connected with the inflation device through an air channel (not shown in the figure). In a specific implementation, the air channel can be opened in the holding ring 120 and the base 110, of course, it can also be opened only in the holding ring 120 or the base 110. When the air channel is only opened in the base 110, the inflation interface 1421 needs to be arranged on the top of the holding ring air film 140, and the present embodiment does not make any limitation to the specific arrangement form of the air channel.

[0070] Further, in some embodiments, the inner side surface of the annular air bag 142 is formed with a first recessed portion 1424 (as shown in Figure 8), the annular inner support body 143 is arranged in the first recessed portion 1424 to better fix the annular inner support body 143 on the inner side surface of the annular air bag 142.

[0071] In a specific implementation, the annular inner support body 143 can be directly embedded in the first recessed portion 1424, or can be fixed in the first recessed portion 1424 by pasting, clamping or the like. The embodiment does not limit the specific arrangement form.

[0072] Further, in some embodiments, continuing to refer to Figure 2 , the polishing head air film 130 is provided with an annular support body 132 on the outer side surface facing the retaining ring air film 140, which supports the outer side surface of the polishing head air film 130; the annular inner support body 143 is arranged corresponding to the annular support body 132 and has a gap D, thereby ensuring that the gap D is arranged between the polishing head air film 130 and the retaining ring air film 140, avoiding the influence of the retaining ring air film 140 on the polishing head air film 130 when the retaining ring air film 140 is inflated.

[0073] In some embodiments, the annular inner support body 143 can abut the annular support body 132. In order to avoid adhesion caused by abutment of the same material, the annular inner support body 143 and the annular support body 132 need to be made of different non-metallic materials. In addition, metal ion pollution caused by metal materials is also avoided.

[0074] In the embodiment, the materials of the annular inner support body 143 and the annular support body 132 are different non-metals and have a certain hardness to play a supporting role. In a specific implementation, the materials can be plastics such as polyimide, rubbers such as fluororubber, ceramics, hard foams, etc. As long as the materials are non-metals and the annular inner support body 143 and the annular support body 132 have a certain hardness, the embodiment does not limit the specific materials.

[0075] In some embodiments, continuing to refer to Figure 2 , Figure 7 and Figure 9 , the retaining ring air film 140 further includes an annular outer support body 144. The annular outer support body 144 is arranged on the outer side surface of the annular air bag 142 close to the retaining ring 120 to support the outer side of the annular air bag 142.

[0076] Further, in some embodiments, the outer side surface of the annular air bag 142 is formed with a second recessed portion 1425, referring to Figure 8 , the annular outer support body 144 is arranged in the second recessed portion 1425.

[0077] In a specific implementation, the annular outer support body 144 can be directly embedded in the second recessed portion, or can be fixed in the second recessed portion by means of adhesion or the like. The present embodiment does not limit the specific arrangement form.

[0078] In some embodiments, continuing to refer to Figure 2 , the annular air bag 142 is in contact with the retaining ring 120 near the outer side surface of the retaining ring 120; the retaining ring 120 extends to form a boss 121 at an end away from the base 110, and the boss 121 extrudes the retaining ring air film 140 to make the retaining ring air film 140 bend towards the polishing head air film 130.

[0079] In the present embodiment, the boss 121 extrudes the retaining ring air film 140 to make the retaining ring air film 140 deform, so that the wafer can be better subjected to the obliquely downward pressure, and the pressure can be transmitted to the edge of the wafer 200 in a more uniform manner to control the polishing speed of the edge of the wafer, inhibit the edge effect of wafer polishing, and improve the uniformity of polishing.

[0080] In some embodiments, referring to Figure 2 and Figure 6 , the retaining ring air film 140 and the polishing head air film 130 have a gap D, and the part of the retaining ring air film 140 that bends towards the polishing head air film 130 forms a retractable structure 145 for retracting when the annular air bag 142 is depressurized to expose the gap D between the retaining ring air film 140 and the polishing head air film 130.

[0081] In a specific implementation, the retractable structure 145 can adopt a folding structure, which can approach each other to form a fold when the chamber pressure is reduced. Figure 3 is the unfolded state of the retractable structure 145, Figure 7 is the folded and retracted state of the retractable structure 145.

[0082] In the present embodiment, when the polishing head is cleaned, the annular air bag 142 can be vacuumed by an independent air path to make the annular air bag 142 deform, expose the gap D between the retaining ring air film 140 and the polishing head air film 130, and clean the polishing liquid or the crystallization of the polishing liquid in the gap D to avoid pollution caused by the accumulation of the crystallization of the polishing liquid in the gap D.

[0083] In some embodiments, the lower surface (opposite to Figure 3 the state shown) of the annular inner support body 143 and the upper surface (opposite to Figure 3In the illustrated state, the cross section of the retaining ring gas film 140 is flush with the cross section of the protrusion 121, and the interaction between the two effectively promotes the deformation of the retaining ring gas film 140 at the protrusion 121; in addition, because the annular inner support 143 and the protrusion 121 have a certain hardness, they can jointly provide a stable support surface for the retaining ring gas film 140, ensuring that the retaining ring gas film 140 can uniformly bend when subjected to pressure, and thus enabling the retaining ring gas film 140 to more effectively tilt towards the polishing head gas film 130, thereby exerting a tilting downward pressure on the wafer 200.

[0084] In some embodiments, continuing to refer to Figure 2 , the cross section of the retaining ring gas film 140 at the location where the retaining ring gas film 140 is bent due to the extrusion of the protrusion 121 is smaller than the cross section of the portion of the retaining ring gas film 140 that is bent towards the polishing head gas film 130, so that the pressure response of the portion that is bent towards the polishing head gas film 130 is more sensitive when the pressure changes, thereby better controlling the force on the edge of the wafer.

[0085] In some specific implementations, the cross section of the retaining ring gas film 140 at the location where the retaining ring gas film 140 is bent between the annular inner support 143 and the protrusion 121 is smaller than the cross section of the other portions of the retaining ring gas film 140 that are bent towards the polishing head gas film 130.

[0086] As can be seen, the embodiments adjust the sensitivity and control of the pressure by changing the cross section, can quickly respond to small adjustments in pressure, and thus improve the dynamic response of the entire system.

[0087] The embodiments of the present application also provide a polishing device 300, referring to Figure 11 , the device comprises a base, a polishing disc 310 arranged on the base, a polishing pad 320 arranged on the polishing disc 310, and any one of the above polishing heads 100.

[0088] It can be understood that in some embodiments, the polishing device 300 should also comprise a polishing liquid supply device 330, a conditioner 340, and a loading and unloading station 350.

[0089] The specific implementation process of the polishing head 100 can be referred to the above description, and the present application will not be described here.

[0090] The polishing liquid supply device 350 is used to deliver polishing liquid to the polishing pad, the conditioner 340 is used to maintain and correct the polishing pad 320, the loading and unloading station 350 is arranged on one side of the polishing disc 310, and the polishing head 100 is configured to receive a wafer to be polished from the loading and unloading station 350 or transfer the polished wafer to the loading and unloading station 350.

[0091] Because the polishing head 100 has the above effects, the polishing device with the polishing head 100 also has corresponding technical effects.

[0092] The embodiment of the present application also provides a polishing method, referring to Figure 12 The method comprises the following steps:

[0093] Step S1001, control the polishing head to load the wafer.

[0094] Specifically, the polishing head 100 in any of the above embodiments is controlled to load the wafer 200.

[0095] Specifically, for example, the polishing head 100 can hold the wafer 200 by adsorption, clamping or the like.

[0096] Step S1002, control the polishing head 100 loaded with the wafer 200 to move towards the polishing pad 320 and press against the polishing pad 320.

[0097] Specifically, the polishing head 100 can press the wafer 200 against the polishing pad 320 to exert the required pressure for polishing the wafer 200.

[0098] Step S1003, control the polishing liquid to be delivered to the polishing pad 320.

[0099] Specifically, the polishing liquid can be delivered to the polishing pad 320 by the polishing liquid supply device 350.

[0100] Step S1004, control the polishing head air film 130 and the retaining ring air film 140 to be inflated and pressurized, so that the retaining ring air film 140 is inflated and contacts the edge of the wafer 200, to exert a force on the edge of the wafer 200. The force forms a radial clamping force F1 and an axial downward pressure F2 on the edge of the wafer 200.

[0101] Specifically, the retaining ring air film 140 can be controlled to be inflated and pressurized by the inflation device.

[0102] Step S1005, control the polishing head 100 and the polishing disc 310 to rotate, and start polishing the wafer 200.

[0103] Step S1006, after the polishing of the wafer 200 is completed, control the polishing head 100 to send the wafer 200 to the loading and unloading station 350, and the robot sends the wafer 200 on the loading and unloading station 350 to the next process.

[0104] In the embodiment of the present application, the retaining ring air film 140 exerts a radial clamping force and an axial downward pressure on the edge of the wafer 200. The radial clamping force can clamp the wafer 200 and fix the wafer 200 in the radial direction, preventing the wafer 200 from moving relative to the polishing head air film 130 during polishing, reducing the risk of sliding and avoiding damage to the back surface of the wafer or the lower surface of the polishing head air film 130. The axial downward pressure can exert a pressing force on the edge of the wafer 200 during polishing of the wafer 200, allowing more accurate control of the polishing effect of the edge of the wafer 200 and ensuring the polishing consistency of the entire wafer surface. In addition, since the retaining ring air film 140 is in flexible contact with the wafer 200 in the embodiment of the present application, stress concentration at the edge of the wafer during polishing can be avoided, reducing the risk of chipping.

[0105] In some embodiments, Figure 12 The polishing method shown can polish one or more wafers, and then clean the polishing head 100. Referring to Figure 13 , specifically comprising the following steps:

[0106] Step S1101, control the retaining ring air film 140 to be decompressed so that the retaining ring air film 140 shrinks, and the gap D between the retaining ring air film 140 and the polishing head air film 140 is exposed.

[0107] Specifically, the retaining ring air film 140 can be vacuumed by a vacuum device to make the retaining ring air film 140 shrink.

[0108] Step S1102, clean the gap.

[0109] Specifically, the polishing liquid in the gap is cleaned by the cleaning liquid.

[0110] In the embodiment, the annular air bag 142 can be vacuumed by an independent air path during cleaning, so that the annular air bag 142 deforms, the gap D between the retaining ring air film 140 and the polishing head air film 130 is exposed, and the gap D is cleaned to avoid pollution caused by accumulation of polishing liquid crystals in the gap D.

[0111] The embodiment of the present application also provides a processor for executing the related steps of any of the above polishing methods.

[0112] Specifically, the program can include program code including computer operation instructions.

[0113] The processor can be a central processing unit CPU, or an application specific integrated circuit ASIC, or one or more integrated circuits configured to implement the embodiments of the present application.

[0114] The embodiment of the present application further provides a computer storage medium, which stores a computer program, and the program is executed by a processor to implement any of the above polishing methods.

[0115] The above method according to the embodiment of the present application can be implemented in hardware, firmware, or as software or computer code that can be stored in a recording medium such as a CD ROM, a RAM, a floppy disk, a hard disk or a magneto-optical disk, or be downloaded through a network from a remote recording medium or a non-transitory machine-readable medium originally stored in a local recording medium and then stored in a local recording medium, so that the method described herein can be processed by such software using a general purpose computer, a special purpose processor, or programmable or special hardware such as an ASIC or an FPGA. It can be understood that the computer, the processor, the microprocessor controller or the programmable hardware includes a storage component (for example, a RAM, a ROM, a flash memory, etc.) that can store or receive software or computer code, and when the software or computer code is accessed and executed by the computer, the processor or the hardware, the polishing method described herein is implemented. In addition, when a general purpose computer accesses the code for implementing the polishing method shown herein, the execution of the code will convert the general purpose computer into a special purpose computer for executing the polishing method shown herein.

[0116] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application belong to the scope of the claims of the present application and their equivalents, the present application also intends to include these modifications and variations.

Claims

1. A polishing head for pressing a wafer against a polishing pad for polishing, characterized by, The polishing head comprises: a base; a retaining ring arranged below the base; a polishing head air film arranged on the base and inside the retaining ring for holding a wafer; a retaining ring air film arranged inside the retaining ring and between the retaining ring and the polishing head air film, the retaining ring air film being in contact with the edge of the wafer when inflated to exert a force on the edge of the wafer, the force forming a radial clamping force and an axial downward pressure on the edge of the wafer; the retaining ring air film comprises: a ring-shaped air bag provided with an inflation interface for connecting with an inflation device; a ring-shaped inner support arranged on the inner side surface of the ring-shaped air bag near the polishing head air film to support the inner side of the ring-shaped air bag and avoid contact with the polishing head air film; a first recessed part is formed on the inner side surface of the ring-shaped air bag, and the ring-shaped inner support is arranged in the first recessed part; a ring-shaped support is arranged on the outer side surface of the polishing head air film towards the retaining ring air film; the ring-shaped inner support is arranged corresponding to the ring-shaped support with a gap.

2. The polishing head according to claim 1, wherein the lower surface of the retaining ring air film is in contact with the polishing pad when inflated to control the wafer edge to be in contact with the polishing pad to rise during polishing.

3. The polishing head according to claim 1, wherein the retaining ring air film and the polishing head air film have a gap therebetween; the gap can be exposed when the retaining ring air film is deflated to clean the gap.

4. The polishing head according to claim 1, wherein the ring-shaped inner support and the ring-shaped support are made of different non-metals.

5. The polishing head of claim 1, wherein the retaining ring air film further comprises: a ring-shaped outer support arranged on the outer side surface of the ring-shaped air bag near the retaining ring to support the outer side of the ring-shaped air bag.

6. The polishing head according to claim 5, wherein a second recessed part is formed on the outer side surface of the ring-shaped air bag, and the ring-shaped outer support is arranged in the second recessed part.

7. The polishing head according to claim 1, wherein the outer side surface of the ring-shaped air bag near the retaining ring is in contact with the retaining ring; a boss is formed on the end of the retaining ring away from the base and extending towards the polishing head air film, the boss extruding the retaining ring air film to make the retaining ring air film bend towards the polishing head air film.

8. The polishing head according to claim 7, wherein the retaining ring air film and the polishing head air film have a gap therebetween; the part of the retaining ring air film that is bent forms an extendable structure for shrinking when the ring-shaped air bag is deflated to expose the gap between the retaining ring air film and the polishing head air film.

9. The polishing head according to claim 7, wherein the lower end surface of the ring-shaped inner support is flush with the upper surface of the boss.

10. The polishing head according to claim 7, wherein the cross-sectional area of the part of the retaining ring air film that is bent by extrusion with the boss is smaller than the cross-sectional area of the part of the retaining ring air film that is bent towards the polishing head air film.

11. A polishing apparatus characterized by comprising: ​ A base, a polishing pad disposed on the base, a polishing pad disposed on the polishing pad, and a polishing head as claimed in any one of claims 1 to 10.

12. A method of polishing, characterized by, comprising the steps of: controlling the polishing head loaded with the wafer to move towards the polishing pad and to press against the polishing pad; controlling the polishing head loaded with the wafer to move towards the polishing pad and to press against the polishing pad; controlling the polishing head loaded with the wafer to move towards the polishing pad and to press against the polishing pad; controlling the polishing head loaded with the wafer to move towards the polishing pad and to press against the polishing pad; controlling the polishing head loaded with the wafer to move towards the polishing pad and to press against the polishing pad; controlling the polishing head loaded with the wafer to move towards the polishing pad and to press against the polishing pad; 13. The polishing method according to claim 12, wherein controlling the polishing head loaded with the wafer to move towards the polishing pad and to press against the polishing pad; controlling the polishing head loaded with the wafer to move towards the polishing pad and to press against the polishing pad; controlling the polishing head loaded with the wafer to move towards the polishing pad and to press against the polishing pad; 14. A processor, comprising: controlling the polishing head loaded with the wafer to move towards the polishing pad and to press against the polishing pad; controlling the polishing head loaded with the wafer to move towards the polishing pad and to press against the polishing pad; controlling the polishing head loaded with the wafer to move towards the polishing pad and to press against the polishing pad; controlling the polishing head loaded with the wafer to move towards the polishing pad and to press against the polishing pad; controlling the polishing head loaded with the wafer to move towards the polishing pad and to press against the polishing pad; controlling the polishing head loaded with the wafer to move towards the polishing pad and to press against the polishing pad; controlling the polishing head loaded with the wafer to move towards the polishing pad and to press against the polishing pad; controlling the polishing head loaded with the wafer to move towards the polishing pad and to press against the polishing pad; controlling the polishing head loaded with the wafer to move towards the polishing pad and to press against the polishing pad; controlling the polishing head loaded with the wafer to move towards the polishing pad and to press against the polishing pad; controlling the polishing head loaded with the wafer to move towards the polishing pad and to press against the polishing pad; controlling the polishing head loaded with the wafer to move towards the polishing pad and to press against the polishing pad; controlling the polishing head loaded with the wafer to move towards the polishing pad and to press against the polishing pad; controlling the polishing head loaded with the wafer to move towards the polishing pad and to press against the polishing pad; controlling the polishing head loaded with the wafer to move towards the polishing pad and to press against the polishing pad; controlling the polishing head loaded with the wafer to move towards the polishing pad and to press against the polishing pad; controlling the polishing head loaded with the wafer to move towards the polishing pad and to press against the polishing pad; controlling the polishing head loaded with the wafer to move towards the polishing pad and to press against the polishing pad; controlling the polishing head loaded with the wafer to move towards the polishing pad and to press against the polishing pad; controlling the polishing head loaded with the wafer to move towards the polishing pad and to press against the polishing pad; controlling the polishing head loaded with the wafer to move towards the polishing pad and to press against the polishing pad; controlling the polishing head loaded with the wafer to move towards the polishing pad and to press against the polishing pad; controlling the polishing head loaded with the wafer to move towards the polishing pad and to press against the polishing pad; controlling the polishing head loaded with

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