Polishing head and polishing equipment

Abstract

The embodiment of the utility model provides a polishing head and polishing equipment. The polishing head comprises a base, a polishing head and a driving device, the retaining ring is arranged below the base; the polishing head gas film is arranged on the base, is arranged on the inner side of the retaining ring and is used for fixedly holding the wafer; the retaining ring gas film is arranged on the inner side of the retaining ring and is arranged between the retaining ring and the polishing head gas film, the retaining ring gas film is in contact with the edge of the wafer when the retaining ring gas film is pressurized and expanded so as to apply acting force to the edge of the wafer, and the acting force forms radial clamping force and axial downward pressure on the edge of the wafer. Radial clamping force and axial downward pressure are applied to the edge of the wafer through the retaining ring gas film, the wafer can be clamped through the radial clamping force, the wafer is prevented from moving in the polishing process, and the risk of wafer sliding is reduced; the axial downward pressure can apply pressing force to the edge of the wafer in the wafer polishing process, the polishing effect of the edge of the wafer can be controlled more accurately, and the polishing consistency of the surface of the whole wafer is guaranteed.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of semiconductor processing technology, and in particular to a polishing head and polishing equipment. Background Art

[0002] In semiconductor processing, chemical mechanical polishing (CMP) is a globally planarized, ultra-precision surface finishing technique. CMP typically involves attaching or clamping a wafer to the bottom of a carrier head. The side of the wafer with the deposited layer presses against the top surface of a polishing pad. Driven by a drive assembly, the carrier head rotates, applying a downward load to the wafer. Simultaneously, polishing fluid is applied to the top surface of the polishing pad and distributed between the wafer and the pad, completing the CMP process through a combination of chemical and mechanical forces.

[0003] During the chemical mechanical polishing process, the pressure exerted by the polishing head on the wafer is a direct factor affecting the wafer polishing effect. In order to more accurately control the wafer polishing effect, the internal partitioning of the polishing head has been continuously optimized. However, the polishing heads in related technologies still have difficulty controlling the polishing of the wafer edge, resulting in unsatisfactory polishing effects on the wafer edge. In addition, the polishing process may damage the back of the wafer or the surface of the polishing head air film, resulting in the processed wafer not meeting the requirements and a low service life of the polishing head air film. At the same time, there is a risk of fragmentation during the wafer polishing process. Utility Model Content

[0004] In view of this, embodiments of the present application provide a polishing head and a polishing device to at least partially solve the above-mentioned problems.

[0005] According to a first aspect of an embodiment of the present application, a polishing head is provided for pressing a wafer against a polishing pad for polishing, the polishing head comprising: a base; a retaining ring, arranged below the base; a polishing head air film, arranged on the base and placed on the inner side of the retaining ring, for holding the wafer; a retaining ring air film, arranged on the inner side of the retaining ring and placed between the retaining ring and the polishing head air film, wherein the retaining ring air film contacts the edge of the wafer when pressurized and expanded to apply a force to the edge of the wafer, wherein the force forms a radial clamping force and an axial downward pressure on the edge of the wafer.

[0006] Furthermore, in the above-mentioned polishing head, the lower surface of the retaining ring air film is pressed against the polishing pad when it is pressurized and expanded, so as to control the polishing pad pressed against the edge of the wafer to bulge during the polishing process.

[0007] Furthermore, in the polishing head, there is a gap between the retaining ring air film and the polishing head air film; the retaining ring air film can reveal the gap when it shrinks under reduced pressure, so as to clean the gap.

[0008] Furthermore, in the above-mentioned polishing head, the retaining ring air film includes: an annular airbag, provided with an inflation interface for connecting to an inflation device; an annular inner support body, attached to the inner surface of the annular airbag close to the polishing head air film, so as to support the inner side of the annular airbag and avoid contact with the polishing head air film.

[0009] Furthermore, in the above-mentioned polishing head, a first recessed portion is formed on the inner surface of the annular airbag, and the annular inner support body is disposed in the first recessed portion.

[0010] Furthermore, in the above-mentioned polishing head, an annular support body is provided on the outer surface of the polishing head air film facing the retaining ring air film; and the annular inner support body is provided corresponding to the annular support body and has a gap therebetween.

[0011] Furthermore, in the above-mentioned polishing head, the annular inner support body and the annular support body are made of different non-metallic materials.

[0012] Furthermore, in the above-mentioned polishing head, the retaining ring air film further comprises: an annular outer support body, which is attached to the outer surface of the annular airbag close to the retaining ring to support the outer side of the annular airbag.

[0013] Furthermore, in the above-mentioned polishing head, a second concave portion is formed on the outer surface of the annular airbag, and the annular outer support body is arranged in the second concave portion.

[0014] Furthermore, in the above-mentioned polishing head, the annular airbag is in contact and connected with the retaining ring near the outer surface of the retaining ring; the retaining ring extends toward the direction of the polishing head air film at the end away from the base to form a boss, and the boss squeezes the retaining ring air film so that the retaining ring air film is bent toward the direction of the polishing head air film.

[0015] Furthermore, in the above-mentioned polishing head, there is a gap between the retaining ring air film and the polishing head air film; the bent part of the retaining ring air film forms a folding structure, which is used to shrink when the annular airbag is decompressed to reveal the gap between the retaining ring air film and the polishing head air film.

[0016] Furthermore, in the above-mentioned polishing head, the lower end surface of the annular inner support body away from the base is flush with the upper surface of the boss.

[0017] Furthermore, in the polishing head, the cross-sectional area of ​​the retaining ring air film at the point where it is bent due to being squeezed by the boss is smaller than the cross-sectional area of ​​the portion of the retaining ring air film that is bent toward the polishing head air film.

[0018] According to a second aspect of an embodiment of the present application, a polishing device is provided, which includes: a base, a polishing plate disposed on the base, a polishing pad disposed on the polishing plate, and any of the above-mentioned polishing heads.

[0019] In an embodiment of the present application, a radial clamping force and an axial downward pressure are applied to the edge of the wafer by maintaining the annular air film. The radial clamping force can clamp the wafer and radially fix the wafer to prevent the wafer from moving relative to the polishing head air film during the polishing process, thereby reducing the risk of the slide and avoiding damage to the back of the wafer or the lower surface of the polishing head air film. The axial downward pressure can apply a pressing force to the edge of the wafer during the wafer polishing process, which can more accurately control the polishing effect of the wafer edge and ensure the polishing consistency of the entire wafer surface. In addition, since the embodiment of the present application maintains a flexible contact between the annular air film and the wafer, stress concentration at the edge of the wafer during the polishing process can be avoided, reducing the risk of fragments.

[0020] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above and other objects, features and advantages of the present application will become more apparent by describing in more detail exemplary embodiments of the present application in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments of the present application.

[0022] Figure 1 This is an axial cross-sectional view of a polishing head shown in an embodiment of the present application;

[0023] Figure 2 for Figure 1 A schematic diagram of the local enlarged structure at point A shown in FIG;

[0024] Figure 3 for Figure 2 A schematic diagram of the local enlarged structure at point B shown in FIG;

[0025] Figure 4 A schematic diagram of a partial structure of a polishing head shown in an embodiment of the present application;

[0026] Figure 5 Another axial cross-sectional view of a polishing head shown in an embodiment of the present application;

[0027] Figure 6 for Figure 5A schematic diagram of the local enlarged structure at C shown in FIG;

[0028] Figure 7 This is another partial structural diagram of a polishing head shown in an embodiment of the present application;

[0029] Figure 8 This is another partial structural diagram of a polishing head shown in an embodiment of the present application;

[0030] Figure 9 This is a schematic structural diagram of an air film in a polishing head shown in an embodiment of the present application;

[0031] Figure 10 This is a schematic diagram of the structure of a polishing head for maintaining an annular air film in an embodiment of the present application;

[0032] Figure 11 A schematic structural diagram of a polishing device shown in an embodiment of the present application;

[0033] In the picture:

[0034] Polishing head 100; base 110; disc-shaped body 111; connector 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 airbag 142; inflation interface 1421; first ring 1422; second ring 1423; first recessed portion 1424; second recessed portion 1425; annular inner support body 143; annular outer support body 144; folding structure 145;

[0035] Wafer 200;

[0036] Polishing equipment 300; polishing plate 310; polishing pad 320; polishing liquid supply device 330; dresser 340; loading and unloading platform 350. DETAILED DESCRIPTION

[0037] The preferred embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the preferred embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. Instead, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0038] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. As used in this application and the appended claims, the singular forms "a," "an," "the," and "the" are intended to include the plural forms, unless the context clearly indicates otherwise. It should 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.

[0039] It should be understood that although the terms "first", "second", "third", etc. may be used in this application to describe various components, these components should not be limited to these terms. These terms are only used to distinguish components of the same type from each other. For example, without departing from the scope of this application, the first component may also be referred to as the second component, and similarly, the second component may also be referred to as the first component. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "plurality" means two or more, unless otherwise clearly and specifically defined.

[0040] In the description of this application, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position 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, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0041] Unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be interpreted broadly. For example, they may refer to fixed or detachable connections, or integration; mechanical or electrical connections; direct or indirect connections through an intermediary; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0042] During chemical mechanical polishing (CMP), the polishing head presses the wafer against a rotating polishing pad. The polishing pad is fixed to the polishing plate and rotates with it. Simultaneously, the polishing head applies a rotational force, rotating the wafer relative to the polishing pad. During this process, the polishing liquid is evenly distributed across the polishing pad, achieving CMP across the wafer surface.

[0043] The pressure exerted by the polishing head on the wafer is a direct factor affecting the wafer polishing effect. Even though the internal partitioning of the polishing head has been continuously optimized to achieve more precise control of the wafer polishing effect, the polishing head in related technologies still has difficulty in accurately controlling the polishing effect of the wafer edge, resulting in unsatisfactory polishing effect at the wafer edge. In addition, the polishing process may damage the back of the wafer or the surface of the polishing head air film, resulting in the wafer not meeting the requirements after processing and a short service life of the polishing head air film. At the same time, there is a risk of chipping during the polishing process.

[0044] In response to the above problems, an embodiment of the present application provides a polishing head. The technical solution of the embodiment of the present application is described in detail below with reference to the accompanying drawings.

[0045] See also Figures 1 to 6 、 Figures 9 and 10 According to one embodiment of the present application, a polishing head 100 includes a base 110, a retaining ring 120, a polishing head air film 130, and a retaining ring air film 140. The polishing head 100 is used to press a wafer 200 against a polishing pad (not shown) for polishing.

[0046] The retaining ring 120 is disposed below the base 110 (relative to the Figure 1 As shown in the state), the polishing head air film 130 is provided on the base 110 and is placed on the inner side of the retaining ring 120 (relative to Figure 1 status shown).

[0047] In a specific implementation, the retaining ring 120 may be an annular body, the base 110 may include a disc-shaped body 111 and a connecting body 112, and the retaining ring 120 and the polishing head air film 130 are both connected to the lower end surface of the disc-shaped body 111 (relative to the lower end surface of the disc-shaped body 111). Figure 1 The polishing head air film 130 is used to hold the wafer 200. The driving device drives the base 110 to rotate, thereby driving the retaining ring 120, the polishing head air film 130 and the wafer 200 to rotate.

[0048] When pressurized, the polishing head air membrane 130 expands to flexibly contact and pressurize the wafer 200 to avoid damaging the wafer 200. It will be appreciated that in some examples, the polishing head air membrane 130 may be provided with multiple partitions 131, each of which may apply a different pressure to the wafer 200 during polishing to meet the polishing pressure requirements of different areas of the wafer 200.

[0049] The retaining ring air film 140 is arranged on the inner side of the retaining ring 120 (close to the side of the polishing head air film 130) and is placed 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 apply a force F to the edge of the wafer 200. This force forms a radial clamping force F1 and an axial downward pressure F2 on the edge of the wafer 200 ( Figure 3 shown).

[0050] In a specific implementation, the air-maintaining ring membrane 140 is annular, which expands when pressurized and contracts when depressurized. The air-maintaining ring membrane 140 can be made of elastic materials such as rubber, silicone, etc., or can be made of non-elastic materials such as plastic, etc.

[0051] In this embodiment, see Figure 3 When the air-maintaining membrane 140 is pressurized and expanded, the air-maintaining membrane 140 contacts the edge of the wafer 200, applying a downward tilt (relative to the edge of the wafer 200) Figure 3 The force F applied to the wafer 200 (in the state shown) can be decomposed into a radial clamping force F1 and an axial downward pressure F2. The radial clamping force F1 can clamp the wafer 200, and the axial downward pressure F2 can press the wafer 200 against the polishing pad, applying a compressive force to the wafer 200 during polishing.

[0052] During the polishing process of the wafer 200, the edge of the wafer 200 may extend beyond the edge of the polishing head air film 130 under certain working conditions, such as Figure 4 As shown, under this working condition, the air ring film 140 can also apply an oblique downward force F to the edge of the wafer 200 . The oblique downward force can also be decomposed into a radial clamping force F1 and an axial downward force F2 on the wafer 200 .

[0053] In the embodiment of the present application, the radial clamping force and axial downward pressure are applied to the edge of the wafer 200 by maintaining the annular air membrane 140. The radial clamping force can clamp the wafer 200 and radially fix the wafer 200 to prevent the wafer 200 from moving relative to the polishing head air membrane 130 during the polishing process, thereby reducing the risk of sliding and avoiding damage to the back side of the wafer (the surface in contact with the polishing head air membrane) or the lower surface of the polishing head air membrane 130 (the surface in contact with the wafer); the axial downward pressure can apply a clamping force to the edge of the wafer 200 during the polishing process 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 embodiment of the present application maintains the annular air membrane 140 and the wafer 200 in flexible contact, stress concentration at the edge of the wafer during the polishing process can be avoided, reducing the risk of fragments.

[0054] In the related art, since the retaining ring air film 140 in the embodiment of the present application is not provided, the retaining ring is in rigid contact with the wafer. At the same time, the retaining ring, the wafer and the polishing pad are all rigidly pressed, which causes the polishing pad at the edge of the wafer to easily bulge during the polishing process. This will affect the load applied by the polishing head air film 130 to the edge area of ​​the wafer, such as causing the material removal rate in the edge area of ​​the wafer to be greater than the material removal rate in the center area of ​​the wafer, and the global flatness of the wafer cannot be obtained.

[0055] Based on this, in some embodiments, see Figure 2 , keeping the lower surface 141 of the air ring film 140 pressed against the polishing pad when it is pressurized and expanded, so as to suppress the degree of bulging of the polishing pad pressed against the edge of the wafer during the polishing process, thereby improving the force on the edge area of ​​the wafer and controlling the material removal rate at the edge of the wafer.

[0056] In a specific implementation, when the annular membrane 140 is pressurized and expanded, the lower surface 141 (relative to Figure 2 The lower surface of the wafer 200 (relative to the state shown) Figure 3 (as shown) flush.

[0057] In this embodiment, a retaining ring air membrane 140 is arranged between the retaining ring 120, the wafer 200 and the area where the polishing pad is rigidly pressed. The retaining ring air membrane 140 is flexibly pressed against the polishing pad. The flexible pressure effectively buffers the above-mentioned rigid 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 the polishing process.

[0058] In some embodiments, a gap D ( Figure 6 As shown), the ring air film 140 is prevented from contacting the polishing head air film 130 when the ring air film 140 is expanded, thereby preventing the ring air film 140 from affecting the polishing head air film 130 during use.

[0059] It should be noted that, during specific implementation, the specific value of the gap D can be determined according to actual conditions, and this embodiment does not impose any limitation on it.

[0060] In this embodiment, when the retaining ring air film 140 contracts under reduced pressure, the gap D is exposed, allowing cleaning fluid to enter the gap D and clean the polishing fluid within the gap D. This prevents contaminants from forming crystals on the outer periphery of the polishing head air film 130 and the retaining ring air film 140 due to untimely cleaning. Crystals formed from these contaminants could fall onto the polishing pad during operation and cause scratches on the wafer.

[0061] In some embodiments, see Figure 2The retaining ring air film 140 includes an annular airbag 142 and an annular inner support 143. The annular airbag 142 is provided with an inflation port 1421 for connecting to an inflation device. The annular inner support 143 is attached to the inner surface of the annular airbag 142 near the polishing head air film 130 to prop up the inner side of the annular airbag 142, thereby preventing the annular airbag 142 from contacting the polishing head air film 130 during inflation, thereby preventing any impact on the polishing head air film 130.

[0062] In one specific implementation, the annular airbag 142 is provided with a first ring 1422 on the inner surface of the inflation interface 1421 and a second ring 1423 on the outer surface. The first ring 1422 and the second ring 1423 are connected to clamp the open end of the annular airbag 142 between the first ring 1422 and the second ring 1423 to form the inflation interface 1421. For better sealing, an annular groove can be further provided in the first ring 1422, and the annular airbag 142 is fixed in the groove by gluing, clamping, or other means.

[0063] It can be understood that the inflation interface 1421 is connected to the inflation device through an air duct (not shown in the figure). In specific implementation, the air duct can be opened on the retaining ring 120 and the base 110. Of course, it can also be opened only on the retaining ring 120 or the base 110; when the air duct is opened only on the base 110, the inflation interface 1421 needs to be configured on the top of the retaining ring air membrane 140. This embodiment does not impose any restrictions on the specific arrangement of the air duct.

[0064] Furthermore, in some embodiments, the inner surface of the annular airbag 142 is formed with a first concave portion 1424 (see 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 surface of the annular airbag 142.

[0065] In specific implementation, the annular inner support body 143 can be directly embedded in the first recessed portion 1424, or fixed in the first recessed portion 1424 by gluing, snapping, etc. This embodiment does not impose any limitation on the specific setting form.

[0066] Further, in some embodiments, see Figure 2 The polishing head air membrane 130 is provided with an annular support body 132 on the outer surface facing the retaining ring air membrane 140, and the annular support body 132 supports the outer side surface of the polishing head air membrane 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 set between the polishing head air membrane 130 and the retaining ring air membrane 140, avoiding the influence of the retaining ring air membrane 140 on the polishing head air membrane 130 when it is inflated.

[0067] In some embodiments, the annular inner support body 143 may abut the annular support body 132. To avoid adhesion caused by the abutment of the same materials, the annular inner support body 143 and the annular support body 132 need to be made of different non-metallic materials. In addition, this also avoids metal ion contamination caused by metal materials.

[0068] In this embodiment, the annular inner support body 143 and the annular support body 132 are made of different non-metallic materials with a certain hardness to provide support. In specific implementations, these materials can be plastic, such as polyimide, or rubber, such as fluororubber. Alternatively, ceramics or rigid foam can be used. As long as the non-metallic materials provide a certain hardness, the specific materials used in this embodiment are not limited.

[0069] In some embodiments, see Figure 2 、 Figure 7 and Figure 9 The retaining ring air film 140 further includes an annular outer support 144. The annular outer support 144 is attached to the outer surface of the annular airbag 142 close to the retaining ring 120 to prop up the outer side of the annular airbag 142.

[0070] Furthermore, in some embodiments, a second concave portion 1425 is formed on the outer surface of the annular airbag 142, see Figure 8 The annular outer support body 144 is disposed in the second recessed portion 1425 .

[0071] In specific implementation, the annular outer support body 144 can be directly embedded in the second recessed portion, or fixed in the second recessed portion by gluing or other methods. This embodiment does not impose any limitation on the specific setting form.

[0072] In some embodiments, see Figure 2 The annular airbag 142 is in contact with and connected to the retaining ring 120 close to the outer surface of the retaining ring 120; the retaining ring 120 extends toward the polishing head air film 130 at the end away from the base 110 to form a boss 121, and the boss 121 squeezes the retaining ring air film 140 so that the retaining ring air film 140 bends toward the polishing head air film 130.

[0073] In this embodiment, the protective air-locking film 140 is squeezed by the boss 121, so that the air-locking film 140 is deformed and can better apply an oblique downward pressure to the wafer, and can transfer the pressure to the edge of the wafer 200 in a more uniform manner to control the polishing speed of the wafer edge, suppress the edge effect of wafer polishing, and improve the uniformity of polishing.

[0074] In some embodiments, see Figure 2 and Figure 6 There is a gap D between the maintaining ring air membrane 140 and the polishing head air membrane 130, and the part of the maintaining ring air membrane 140 bent toward the polishing head air membrane 130 is formed with a retractable structure 145, which is used to shrink when the annular airbag 142 is depressurized to reveal the gap D between the maintaining ring air membrane 140 and the polishing head air membrane 130.

[0075] In a specific implementation, the retractable structure 145 may be a folding structure. When the chamber pressure decreases, the folding structures can move closer together to form a fold. Figure 3 is the state in which the telescopic structure 145 is unfolded, Figure 7 This is the state where the telescopic structure 145 is folded and contracted.

[0076] In this embodiment, when the polishing head is cleaned, the annular airbag 142 can be vacuumed through an independent air circuit to deform the annular airbag 142, thereby exposing the gap D between the ring air film 140 and the polishing head air film 130, so as to clean the polishing liquid or the crystals of the polishing liquid in the gap D and avoid contamination caused by the accumulation of polishing liquid crystals in the gap D.

[0077] In some embodiments, the lower surface (relative to the lower surface of the annular inner support body 143) Figure 3 As shown in the state) and the upper surface of the boss 121 (relative Figure 3 The ring-shaped inner support body 143 and the boss 121 are flush with each other, and the deformation of the air-maintaining membrane 140 at the boss 121 is effectively promoted through the interaction between the two. In addition, since the annular inner support body 143 and the boss 121 have a certain hardness, they can work together to provide a stable support surface for the air-maintaining membrane 140, ensuring that the air-maintaining membrane 140 can bend evenly when subjected to pressure, thereby enabling the air-maintaining membrane 140 to be more effectively tilted toward the polishing head membrane 130, thereby applying an oblique downward pressure on the wafer 200.

[0078] In some embodiments, see Figure 2 The cross-sectional area of ​​the air ring membrane 140 where it is bent by being squeezed with the boss 121 is kept smaller than the cross-sectional area of ​​the portion of the air ring membrane 140 that is bent toward the polishing head air membrane 130, so that when the pressure changes, the pressure response of the portion that is bent toward the polishing head air membrane 130 is more sensitive, thereby better controlling the force on the edge of the wafer.

[0079] In some specific implementations, the cross-sectional area of ​​the portion where the annular air membrane 140 is bent between the annular inner support body 143 and the boss 121 is smaller than the cross-sectional area of ​​the other portion after being bent toward the polishing head air membrane 130 .

[0080] It can be seen that this embodiment adjusts the sensitivity and control force of pressure by changing the cross-sectional area, and can quickly respond to small adjustments in pressure, thereby improving the dynamic responsiveness of the entire system.

[0081] The present application also provides a polishing device 300, see Figure 11 The device includes: 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-mentioned polishing heads 100.

[0082] It is understood that in some embodiments, the polishing equipment 300 should further include a polishing liquid supply device 330 , a dresser 340 and a loading and unloading platform 350 .

[0083] The specific implementation process of the polishing head 100 can be found in the above description, and will not be elaborated herein.

[0084] The polishing liquid supply device 350 is used to deliver polishing liquid to the polishing pad, the dresser 340 is used to maintain and correct the polishing pad 320, the loading and unloading platform 350 is arranged on one side of the polishing disk 310, and the polishing head 100 is configured to receive the wafer to be polished from the loading and unloading platform 350 or transfer the polished wafer to the loading and unloading platform 350.

[0085] Since the polishing head 100 has the above-mentioned effects, the polishing equipment having the polishing head 100 also has corresponding technical effects.

[0086] The following briefly describes the general steps of using the polishing device 300 provided by this application:

[0087] First, the polishing head is controlled to load the wafer.

[0088] Specifically, any one of the polishing heads 100 in the above embodiments is controlled to load the wafer 200 .

[0089] Specifically, for example, the polishing head 100 may hold the wafer 200 by adsorption, clamping, or the like.

[0090] Next, the polishing head 100 loaded with the wafer 200 is controlled to move toward the polishing pad 320 and press against the polishing pad 320 .

[0091] Specifically, the polishing head 100 may press the wafer 200 against the polishing pad 320 to apply pressure required for polishing to the wafer 200 .

[0092] Next, the polishing liquid is controlled to be supplied to the polishing pad 320 .

[0093] Specifically, the polishing liquid may be delivered to the polishing pad 320 through the polishing liquid supply device 350 .

[0094] Next, the polishing head air membrane 130 and the retaining ring air membrane 140 are controlled to be inflated and pressurized, so that the retaining ring air membrane 140 expands and contacts the edge of the wafer 200, thereby applying a force to the edge of the wafer 200. This force forms a radial clamping force F1 and an axial downward pressure F2 on the edge of the wafer 200.

[0095] Specifically, the inflation device may be controlled to inflate and pressurize the air-maintaining ring membrane 140 .

[0096] Next, the polishing head 100 and the polishing plate 310 are controlled to rotate and the wafer 200 begins to be polished.

[0097] Finally, after the wafer 200 is polished, the polishing head 100 is controlled to send the wafer 200 to the loading and unloading platform 350 , and the robot sends the wafer 200 on the loading and unloading platform 350 to the next process.

[0098] In the embodiment of the present application, the radial clamping force and axial downward pressure are applied to the edge of the wafer 200 by maintaining the annular air membrane 140. The radial clamping force can clamp the wafer 200 and radially fix the wafer 200 to prevent the wafer 200 from moving relative to the polishing head air membrane 130 during the polishing process, thereby reducing the risk of sliding and avoiding damage to the back of the wafer or the lower surface of the polishing head air membrane 130; the axial downward pressure can apply a pressing force to the edge of the wafer 200 during the polishing process 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 annular air membrane 140 and the wafer 200 are maintained in flexible contact in the embodiment of the present application, stress concentration at the edge of the wafer during the polishing process can be avoided, reducing the risk of fragments.

[0099] In some embodiments, after polishing one or more wafers, the polishing head 100 may be cleaned, which specifically includes the following steps:

[0100] The retaining ring film 140 is controlled to be decompressed to shrink the retaining ring film 140, thereby exposing the gap D between the retaining ring film 140 and the polishing head air film 140. Specifically, the retaining ring film 140 can be vacuumed by a vacuuming device to shrink the retaining ring film 140.

[0101] The gap is cleaned. Specifically, the polishing liquid in the gap is cleaned by a cleaning liquid.

[0102] In this embodiment, during cleaning, the annular airbag 142 can be vacuumed through an independent air path, causing the annular airbag 142 to deform, revealing the gap D between the retaining ring air film 140 and the polishing head air film 130, so as to clean the gap D and avoid contamination caused by the accumulation of polishing liquid crystals in the gap D.

[0103] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

Claims

1. A polishing head for pressing a wafer against a polishing pad for polishing, characterized in that: include: base; a retaining ring, disposed below the base; A polishing head air film is provided on the base and placed inside the retaining ring for holding the wafer; A retaining ring air film is arranged on the inner side of the retaining ring and placed between the retaining ring and the polishing head air film. When the retaining ring air film is pressurized and expanded, it contacts the edge of the wafer to apply a force to the edge of the wafer, and the force forms a radial clamping force and an axial downward pressure on the edge of the wafer.

2. The polishing head according to claim 1, characterized in that When the retaining ring air film is pressurized and expanded, the lower surface thereof presses against the polishing pad, so as to control the polishing pad pressed against the edge of the wafer to bulge during the polishing process.

3. The polishing head according to claim 1, characterized in that There is a gap between the retaining ring air film and the polishing head air film; The retaining ring air film can reveal the gap when it shrinks under reduced pressure, so as to clean the gap.

4. The polishing head according to claim 1, characterized in that The retaining ring air film comprises: The annular airbag is provided with an inflation interface for connecting to an inflation device; The annular inner support body is attached to the inner surface of the annular airbag close to the polishing head air film to prop up the inner side of the annular airbag and avoid contact with the polishing head air film.

5. The polishing head according to claim 4, characterized in that A first concave portion is formed on the inner surface of the annular airbag, and the annular inner support body is arranged in the first concave portion.

6. The polishing head according to claim 4, characterized in that The polishing head air film is provided with an annular support body on the outer surface facing the retaining ring air film; The annular inner support body is arranged corresponding to the annular support body and has a gap therebetween.

7. The polishing head according to claim 6, characterized in that The annular inner support body and the annular support body are made of different non-metallic materials.

8. The polishing head according to claim 4, characterized in that The air-retaining ring film further comprises: The annular outer support body is attached to the outer surface of the annular airbag close to the retaining ring to support the outer side of the annular airbag.

9. The polishing head according to claim 8, characterized in that A second concave portion is formed on the outer surface of the annular airbag, and the annular outer support body is arranged in the second concave portion.

10. The polishing head according to claim 4, characterized in that The annular airbag is close to the outer surface of the retaining ring and is in contact with the retaining ring; The retaining ring has a boss extending toward the polishing head air film at one end away from the base, and the boss presses the retaining ring air film to bend the retaining ring air film toward the polishing head air film.

11. The polishing head according to claim 10, characterized in that There is a gap between the retaining ring air film and the polishing head air film; The bent portion of the retaining ring air film is formed with a retractable structure for contracting when the annular airbag is decompressed to reveal a gap between the retaining ring air film and the polishing head air film.

12. The polishing head according to claim 10, characterized in that The lower end surface of the annular inner support body away from the base is flush with the upper surface of the boss.

13. The polishing head according to claim 10, characterized in that The cross-sectional area of ​​the retaining ring air film at the point where it is bent due to being squeezed by the boss is smaller than the cross-sectional area of ​​the portion of the retaining ring air film that is bent toward the polishing head air film.

14. A polishing device, characterized in that: include: A base, a polishing disc arranged on the base, a polishing pad arranged on the polishing disc, and a polishing head according to any one of claims 1 to 13.

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