Carrying head for wafer polishing, polishing method and polishing apparatus

Abstract

The embodiment of the present application provides a carrier head for wafer polishing, a polishing method and a polishing device, wherein the carrier head for wafer polishing comprises: an air film assembly, an end ring, a retaining ring and a base; the end ring is detachably mounted between the base and the retaining ring, the air film assembly is connected with the base, and the air film assembly is located in the end ring and the retaining ring, and a gap exists between the air film assembly and the end ring and the retaining ring; the air film assembly is used for abutting the wafer against a polishing pad when the wafer is polished; the end ring, the base and the air film assembly enclose an annular accommodating cavity, and an outer annular cavity wall of the annular accommodating cavity comprises an inner wall of the end ring. The end ring can bear the sacrifice function, wear caused by corrosion of the polishing liquid and wafer debris and other sundries is borne by the end ring, damage of the base is avoided, and therefore the use cost of the carrier head is reduced.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the technical field of semiconductor manufacturing, and in particular, to a carrier head for wafer polishing, a polishing method and a polishing device. BACKGROUND

[0002] The base is one of the core parts of the overall mechanical structure of the carrier head. In the prior art, the base is usually a single part with a complex configuration, and the carrier head is connected and fixed with other structural parts such as the retaining ring and the air film assembly through the base. In addition, a base groove is usually provided in the base for mounting the air film assembly.

[0003] In the prior art, in order to ensure that the air film assembly does not interfere with the action during polishing, a cavity is usually designed between the air film assembly and the base groove. When the wafer is chemically mechanically polished, the polishing liquid containing wafer residues and polishing pad residues will enter the cavity. With the immersion and erosion of the long-time polishing liquid mixture (polishing liquid + wafer residues + polishing pad residues), the base is very prone to damage at the cavity position. Once the base is damaged at the cavity position, the entire base needs to be replaced, which greatly increases the cost of using the carrier head. SUMMARY

[0004] Therefore, the present application provides a carrier head for wafer polishing, a polishing method and a polishing device to at least partially solve the above problems.

[0005] According to a first aspect of the embodiments of the present application, a carrier head for wafer polishing is provided, comprising: an air film assembly, an end ring, a retaining ring and a base; the end ring is detachably mounted between the base and the retaining ring, the air film assembly is connected with the base, and the air film assembly is located within the end ring and the retaining ring, and there is a gap between the air film assembly and the end ring and the retaining ring; the air film assembly is used to abut the wafer on the polishing pad when polishing the wafer; the end ring, the base and the air film assembly form an annular receiving cavity, and the outer cavity wall of the annular receiving cavity comprises the inner wall of the end ring.

[0006] In a possible implementation, a liquid storage groove is provided on the end ring and communicates with the annular receiving cavity.

[0007] In a possible implementation, the end ring comprises a base contact surface and an inner ring surface, the base contact surface is in contact with the base, the inner ring surface is opposite to the air film assembly, and the inner ring surface is adjacent to the base contact surface; the liquid storage groove is provided at the intersection of the inner ring surface and the base contact surface.

[0008] In a possible implementation, the end ring further comprises a retaining ring contact surface, the retaining ring contact surface is in contact with the retaining ring, and the retaining ring contact surface is adjacent to the inner ring surface; a distance between a point on the bottom surface of the liquid storage groove and the rotation axis of the base is positively correlated with a distance between the point and the retaining ring contact surface, and the retaining ring contact surface is perpendicular to the rotation axis of the base.

[0009] In a possible implementation, for any cross-sectional curve on the bottom surface of the liquid storage groove, distances between points on the cross-sectional curve and the rotation axis of the base are equal, and a distance between a second point on the cross-sectional curve and a first point on the cross-sectional curve is positively correlated with a distance between the second point and the retaining ring contact surface, and the first point is a point on the cross-sectional curve that is closest to the retaining ring contact surface.

[0010] In a possible implementation, the liquid storage groove is symmetrical about a middle plane, the middle plane is in the same plane as the rotation axis of the base; an extension groove is arranged at an intersection between the inner ring surface and the base contact surface, the extension groove is in communication with the liquid storage groove, and in the rotation direction of the end ring, the extension groove is located behind the liquid storage groove.

[0011] In a possible implementation, a sealing ring is arranged between the base and the end ring.

[0012] In a possible implementation, the end ring is made of metal or nonmetal.

[0013] In a possible implementation, a first mounting hole and a second mounting hole are arranged on the end ring; the end ring is connected to the base by a first mounting member passing through the first mounting hole; and the retaining ring is connected to the base by a second mounting member passing through the second mounting hole.

[0014] According to a second aspect of the embodiment of the present application, a polishing device is provided, comprising the carrier head in any of the preceding embodiments.

[0015] According to a third aspect of the embodiment of the present application, a polishing method applied to the polishing device is provided, comprising: abutting a wafer against a polishing pad of the polishing device by a gas film assembly of a carrier head of the polishing device, and supplying a polishing liquid to the polishing pad by a liquid supply device of the polishing device; controlling the carrier head and the polishing pad to rotate, and polishing the wafer; wherein when the polishing liquid enters an annular accommodating cavity surrounded by the gas film assembly, the base and the detachable end ring in the carrier head, the polishing liquid will be in contact with the end ring under the centrifugal force of the rotation of the carrier head.

[0016] In the embodiment of the present application, the bearing head comprises a gas film assembly, an end ring, a retaining ring and a base, the gas film assembly is located in the end ring and the retaining ring, there is a gap between the gas film assembly and the end ring and the retaining ring, the end ring, the base and the gas film assembly enclose an annular accommodating cavity, and an outer annular cavity wall of the annular accommodating cavity comprises an inner wall of the end ring; when polishing the wafer, the polishing liquid enters the gap between the gas film assembly and the end ring and the accommodating cavity, and can mainly contact the end ring under the centrifugal force of the rotation of the bearing head, thereby reducing the contact area of the polishing liquid with the base, and the base can be prevented from being corroded by the polishing liquid and abraded by the wafer debris and other impurities in the polishing liquid. The end ring can bear the sacrifice function, the end ring can bear the corrosion of the polishing liquid and the abrasion caused by the wafer debris and other impurities in the polishing liquid, damage to the base is avoided, and in most cases, the damage of the bearing head caused by the polishing liquid can be solved by replacing the end ring, instead of replacing the base, thereby reducing the use cost of the bearing head. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments described in the embodiments of the present application, and other drawings can also be obtained by those skilled in the art according to these drawings.

[0018] Figure 1 is a structural schematic diagram of a bearing head for wafer polishing provided by an optional embodiment of the present application;

[0019] Figure 2 is an enlarged view of part A in Figure 1

[0020] Figure 3 is a cross-sectional schematic diagram of an end ring provided by an optional embodiment of the present application;

[0021] Figure 4 is a cross-sectional schematic diagram of another end ring provided by an optional embodiment of the present application;

[0022] Figure 5 is a structural schematic diagram of a bearing head for wafer polishing provided by another optional embodiment of the present application;

[0023] Figure 6 is an enlarged view of part B in Figure 5

[0024] Figure 7 is a structural front view of an end ring provided by an optional embodiment of the present application;

[0025] Figure 8 is a structural perspective view of an end ring provided by an optional embodiment of the present application; ​​

[0026] Figure 9 This is a cross-sectional schematic diagram of another end ring provided in an optional embodiment of this application;

[0027] Figure 10 This is a schematic diagram of another carrier head for wafer polishing provided in an optional embodiment of this application;

[0028] Figure 11 yes Figure 10 Enlarged view of section C;

[0029] Figure 12 This is a front view of another end ring structure provided in an optional embodiment of this application;

[0030] Figure 13 This is a three-dimensional view of another end ring structure provided in an optional embodiment of this application;

[0031] Figure 14 This is a cross-sectional schematic diagram of another end ring provided in an optional embodiment of this application;

[0032] Figure 15 This is a front view of another end ring structure provided in an optional embodiment of this application;

[0033] Figure 16 This is a schematic diagram of the structure of a polishing device provided in an optional embodiment of this application.

[0034] Figure 17 This is a flowchart of a polishing method provided in an optional embodiment of this application.

[0035] Figure label:

[0036] 10. Bearing head; 11. Air film assembly; 12. End ring; 121. Liquid storage tank; 122. Base contact surface; 123. Inner ring surface; 124. Retaining ring contact surface; 125. First mounting hole; 126. Second mounting hole; 127. Extension groove; 13. Retaining ring; 14. Base; 15. Annular receiving cavity; 16. Sealing ring; 20. Polishing equipment; 21. Polishing disc; 22. Liquid supply device; 23. Dresser; 24. Polishing pad. Detailed Implementation

[0037] To enable those skilled in the art to better understand the technical solutions in the embodiments of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art should fall within the protection scope of the embodiments of this application.

[0038] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in this 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 be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0039] It should be understood that, although the terms first, second, third, etc. can be used herein to describe various information, the information should not be limited to these terms. These terms are only used to differentiate one piece of information from another. For example, a first information can also be termed a second information, similarly, a second information can also be termed a first information without departing from the scope of the present application. Depending on the context, the word "if' as used herein can be interpreted as meaning "when" or "in response to determining" or "in response to ascertaining".

[0040] In the present application, the chemical mechanical polishing (CMP) is also called as "chemical mechanical planarization (CMP)", which is a global planarization ultra-precision surface processing technology, and can make the wafer complete chemical mechanical polishing under the joint action of chemical and mechanical.

[0041] According to a first aspect of the embodiments of the present application, a carrier head 10 for wafer polishing is provided to solve the above problems. The carrier head 10 can be applied to the polishing equipment of the second aspect, and the specific structure of the polishing equipment can be seen in the embodiments of the second aspect. Of course, the carrier head 10 can be applied to other suitable polishing equipment, which are all within the protection scope of the embodiments of the present application.

[0042] The following refers to the accompanying drawings that Figures 1-16 The carrier head 10 for wafer polishing provided by the embodiments of the present application is described in detail.

[0043] As shown in Figure 1 and Figure 2 The embodiments of the present application provide a carrier head 10 for wafer polishing, which comprises: an air film assembly 11, an end ring 12, a retaining ring 13 and a base 14.

[0044] The end ring 12 is detachably mounted between the base 14 and the retaining ring 13. The end ring 12 can be detachably mounted by screws, buckles or other structures. The application does not limit the detachable mounting mode of the end ring 12. The air film assembly 11 is connected to the base 14. The air film assembly 11 and the base 14 can be fixedly connected or detachably connected, which are both within the protection scope of the embodiments of the application. Moreover, the air film assembly 11 is located in the end ring 12 and the retaining ring 13. There is a gap between the air film assembly 11 and the end ring 12, and there is also a gap between the air film assembly 11 and the retaining ring 13. The two gaps are in communication with each other.

[0045] The gap between the air film assembly 11 and the end ring 12 and the retaining ring 13 is used to ensure the movement space of the air film assembly 11, so as to avoid that the end ring 12 and the retaining ring 13 hinder the deformation or movement of the air film assembly 11. It should be understood that the gap between the air film assembly 11 and the end ring 12 and the retaining ring 13 should not be too large, as long as it does not affect the movement of the air film assembly 11, so as to save space.

[0046] The air film assembly 11 is used to abut the wafer against the polishing pad when the wafer is polished. In some feasible embodiments, the air pressure in the air film assembly 11 is adjustable, and the air film assembly 11 can also adsorb the wafer. After the air film assembly 11 adsorbs the wafer, the air pressure in the air film assembly 11 can be adjusted to apply pressure to the wafer, so as to abut the wafer against the polishing pad when the wafer is polished. When the wafer is polished, the polishing liquid is usually supplied to the polishing pad and the wafer by the liquid supply device. Part of the polishing liquid enters the gap between the air film assembly 11 and the retaining ring 13, and the gap between the air film assembly 11 and the end ring 12. In the embodiments of the application, when the wafer is polished, the polishing head carrier 10 can rotate relative to the polishing pad, and the wafer can be driven to rotate relative to the polishing pad by the air film assembly 11, so as to improve the polishing efficiency.

[0047] As shown in FIGS. 1, 2 and 3, the end ring 12 can be rectangular or approximately rectangular in cross section, or can be trapezoidal or approximately trapezoidal, so that the polishing liquid can flow down along the side wall of the end ring 12. Figure 3 Figure 4 The end ring 12, the base 14 and the air film assembly 11 surround the annular accommodating cavity 15, and the outer annular cavity wall of the annular accommodating cavity 15 is the side wall of the end ring 12.

[0048] As shown in FIGS. 1, 2 and 3, the end ring 12, the base 14 and the air film assembly 11 leave a cavity therebetween. The cavity or part of the cavity can form the annular accommodating cavity 15. The outer annular cavity wall of the annular accommodating cavity 15 is the side wall of the end ring 12, so that the outer annular side of the annular accommodating cavity 15 mainly contacts the end ring 12. Figure 2

[0049] ​​In the embodiment of the present application, the carrier head 10 comprises a gas film assembly 11, an end ring 12, a retaining ring 13 and a base 14, the gas film assembly 11 is located in the end ring 12 and the retaining ring 13, and there is a gap between the gas film assembly 11 and the end ring 12 and the retaining ring 13, the end ring 12, the base 14 and the gas film assembly 11 enclose an annular accommodating cavity 15, and the outer annular cavity wall of the annular accommodating cavity 15 is the side wall of the end ring 12. When the wafer is polished, the polishing liquid enters the gap between the gas film assembly 11 and the end ring 12 and the accommodating cavity, and can mainly contact the end ring 12 under the centrifugal force of the rotation of the carrier head 10, thereby reducing the contact area of the polishing liquid with the base 14, and preventing the base 14 from being corroded by the polishing liquid and abraded by the wafer debris and other impurities in the polishing liquid. The end ring 12 can bear the sacrifice function, and the end ring 12 can bear the corrosion of the polishing liquid and the abrasion caused by the wafer debris and other impurities in the polishing liquid, so as to avoid damage to the base 14, so that in most cases, the part damage of the carrier head 10 caused by the polishing liquid can be solved by replacing the end ring 12, without replacing the base 14, thereby reducing the use cost of the carrier head 10.

[0050] As shown in Figures 5-8 In some optional embodiments, a liquid storage groove 121 is formed in the end ring 12 and communicates with the annular accommodating cavity 15. The liquid storage groove 121 can be located at the inner annular surface 123 of the end ring 12, or at the intersection of the inner annular surface 123 of the end ring 12 and the base contact surface 122, or at other suitable positions, all of which are within the protection scope of the embodiment of the present application.

[0051] In the embodiment of the present application, the liquid storage groove 121 is formed in the end ring 12 and communicates with the annular accommodating cavity 15, and the polishing liquid entering the gap between the gas film assembly 11 and the end ring 12 and the accommodating cavity will rotate under the rotation of the carrier head 10 and concentrate in the liquid storage groove 121 under the action of the centrifugal force, thereby further reducing the contact area of the polishing liquid with the base 14 and avoiding damage to the base 14.

[0052] As shown in Figure 9 In some optional embodiments, the end ring 12 comprises a base contact surface 122 and an inner annular surface 123, the base contact surface 122 is attached to the base 14, the inner annular surface 123 is opposite to the gas film assembly 11 and can serve as the outer annular cavity wall of the annular accommodating cavity 15 above, and the inner annular surface 123 is adjacent to the base contact surface 122 respectively; the liquid storage groove 121 is formed at the intersection of the inner annular surface 123 and the base contact surface 122, so that the liquid storage groove 121 can penetrate into the inner annular surface 123 and the base contact surface 122 of the end ring 12.

[0053] Figure 8In the illustrated embodiment, the liquid storage tank 121 has a symmetrical structure and is located at the junction of the inner ring surface 123 and the base contact surface 122. Specifically, the line connecting the center of the end ring 12 and the center of the liquid storage tank 121 is the axis of symmetry of the liquid storage tank 121; simultaneously, the depth of the liquid storage tank 121 along the thickness direction of the end ring 12 is equal to the depth of the liquid storage tank 121 along the radial direction of the end ring 12. The symmetrical liquid storage tanks 121 formed by the end ring 12 are uniformly distributed circumferentially along the end ring 12 to uniformly store the composition of liquid and particulate matter formed during the polishing process.

[0054] As one aspect of this embodiment, the depth of the liquid storage tank 121 along the thickness direction of the end ring 12 is 3-8mm to ensure the liquid storage capacity of the liquid storage tank 121; at the same time, the setting of the liquid storage tank 121 also reduces the self-weight of the end ring 12 to a certain extent, thereby ensuring the mechanical performance of the end ring 12 and the base 14 forming the assembly.

[0055] In this embodiment, the liquid storage tank 121 is located at the junction of the inner ring surface 123 and the base contact surface 122. That is, the liquid storage tank 121 can penetrate into the inner ring surface 123 of the end ring 12 and the base contact surface 122. This allows the polishing liquid in contact with the inner ring surface 123 to be concentrated in the liquid storage tank 121 during wafer polishing, and also allows the polishing liquid in contact with the base 14 to be concentrated in the liquid storage tank 121. This further reduces the contact area between the polishing liquid and the base 14, and reduces the damage of the polishing liquid to the base 14.

[0056] like Figure 9 As shown, in some optional embodiments, the end ring 12 further includes a retaining ring contact surface 124, which fits against the retaining ring 13 and is adjacent to the inner ring surface 123. The distance between a point on the bottom surface of the reservoir 121 and the rotation axis of the base 14 is positively correlated with the distance between that point and the retaining ring contact surface 124. The retaining ring contact surface 124 is perpendicular to the rotation axis of the base 14. When the rotation axis of the base 14 is a vertical line, the retaining ring contact surface 124 can be a horizontal plane. It should be understood that the "rotation axis" of each component in this application refers to the rotation axis of each component during wafer polishing, which will not be elaborated further below.

[0057] During wafer polishing, the base 14 rotates together with the other parts of the carrier head 10, and the axis of rotation of the base 14 is the same as the axis of rotation of the carrier head 10. Furthermore, the axis of rotation of the base 14 can be the central axis of the end ring 12 and the retaining ring 13.

[0058] In this embodiment, when the bearing head 10 is erected vertically along a vertical line, with the base 14 on top and the end ring 12 on the bottom (e.g.) Figure 5 and Figure 6When the distance between the point on the bottom surface of the reservoir 121 and the rotation axis of the base 14 is equal to the distance between the point and the retaining ring contact surface 124, the height of the point on the bottom surface of the reservoir 121 in the vertical direction gradually decreases with the decrease of the distance between the point and the rotation axis of the base 14, i.e., the height of the bottom surface of the reservoir 121 gradually decreases from the outer annular surface of the end ring 12 to the inner annular surface 123 of the end ring 12, so that the polishing liquid can be guided out to the gap between the end ring 12 and the air film assembly 11. When the polishing process is completed, the polishing liquid in the reservoir 121 can flow down along the bottom of the reservoir 121 under the influence of gravity and flow out of the polishing head, avoiding accumulation of the polishing liquid. Moreover, the polishing liquid flows down along the bottom of the reservoir 121, which can flush the wafer debris and other impurities carried in the polishing liquid, avoiding the wafer debris and other impurities from being stuck in the gap between the air film assembly 11 and the end ring 12 or the retaining ring 13, which affects the movement of the air film assembly 11.

[0059] In some optional embodiments, for any cross-sectional curve on the bottom surface of the reservoir 121, the distance between the point on the cross-sectional curve and the rotation axis of the base 14 is equal, and the distance between the second point on the cross-sectional curve and the first point on the cross-sectional curve is positively correlated with the distance between the second point and the retaining ring contact surface 124, and the first point is the point on the cross-sectional curve closest to the retaining ring contact surface 124.

[0060] It should be understood that the cross-sectional curve can be regarded as a curved surface composed of points with equal distances from the rotation axis of the base 14, and the curve is cut on the bottom surface of the reservoir 121. The second point on the cross-sectional curve is any point on the cross-sectional curve except the first point. In the embodiments of the present application, the shape of the cross-sectional curve can be various arcs or a plurality of straight lines, which are all within the protection scope of the embodiments of the present application.

[0061] In the embodiments of the present application, when the carrier head 10 is vertically arranged along the vertical line, the base 14 is on the top, and the end ring 12 is on the bottom, because the distance between the second point on the cross-sectional curve and the first point on the cross-sectional curve is positively correlated with the distance between the second point and the retaining ring contact surface 124, the height of the point on the bottom surface of the reservoir 121 in the vertical direction gradually increases with the decrease of the distance from the first point, and the line connecting the first points of all the cross-sectional curves on the bottom surface of the reservoir 121 can form a “valley line” of the reservoir 121, so that the polishing liquid in the reservoir 121 is concentrated to the “valley line” under the action of gravity, thereby facilitating the polishing liquid to flow out of the reservoir 121 along the “valley line”.

[0062] In some optional embodiments, the reservoir 121 is symmetrical about a middle plane, and the middle plane is in the same plane as the rotation axis of the base 14. As shown in FIG. 6, the middle plane is the plane of symmetry of the reservoir 121. Figures 10-14As shown, the intersection of the inner annular surface 123 and the base contact surface 122 can be provided with an extension groove 127, which is in communication with the liquid storage groove 121 and is located behind the liquid storage groove 121 in the rotation direction of the end ring 12.

[0063] The rotation direction of the end ring 12 is the rotation direction of the end ring 12 during polishing of the wafer. In the rotation direction of the end ring 12, the extension groove 127 is located behind the liquid storage groove 121. It can also be understood that the extension groove 127 extends from the liquid storage groove 121 connected thereto in a direction opposite to the rotation direction of the end ring 12.

[0064] In addition, the distance from a point on the bottom surface of the extension groove 127 to the middle plane can be positively correlated with the distance between the point and the retaining ring contact surface 124, so that when the carrier head 10 is vertically arranged along the plumb line with the base 14 on top and the end ring 12 on bottom, the height of the point on the bottom surface of the extension groove 127 in the vertical direction gradually decreases as the distance between the point and the middle plane decreases, so that the polishing liquid in the extension groove 127 can flow smoothly to the liquid storage groove 121.

[0065] The bottom surface of the extension groove 127 and the bottom surface of the liquid storage groove 121 are connected as a total bottom surface, and the distance from a point on the total bottom surface to the middle plane can be positively correlated with the distance between the point and the retaining ring contact surface 124, so that when the carrier head 10 is vertically arranged along the plumb line with the base 14 on top and the end ring 12 on bottom, the height of the point on the total bottom surface in the vertical direction gradually decreases as the distance between the point and the middle plane decreases, so that the polishing liquid can flow out of the extension groove 127 and the liquid storage groove 121.

[0066] In the embodiments of the present application, the liquid storage groove 121 is symmetrical about the middle plane, the intersection of the inner annular surface 123 and the base contact surface 122 is provided with the extension groove 127, which is in communication with the liquid storage groove 121, and through the extension groove 127, more polishing liquid can be stored, thereby enhancing the liquid storage capacity of the end ring 12. Moreover, when the carrier head 10 is vertically arranged along the plumb line with the base 14 on top and the end ring 12 on bottom, the extension groove 127 can have a relatively high height relative to the liquid storage groove 121, and when the wafer is polished, the polishing liquid will enter the extension groove 127 due to inertia, and the polishing liquid entering the extension groove 127 can be at a relatively high position, so that the polishing liquid flowing into the liquid storage groove 121 is more likely to flow out of the liquid storage groove 121.

[0067] In some embodiments, the extension groove 127 can be 2-5 mm higher than the liquid storage groove 121 in the vertical direction, so as to increase the potential energy of the stored liquid, thereby ensuring that the liquid towards the gap between the gas film assembly 11 and the retaining ring 13 has a relatively large speed, thereby ensuring the effect of liquid flushing and avoiding the residue of particulate matter in the gap.

[0068] AsFigure 2 , Figure 6 and Figure 11 As shown, in some optional embodiments, a sealing ring 16 is provided between the base 14 and the end ring 12, thereby sealing the gap between the base 14 and the end ring 12 and preventing the polishing liquid in the annular cavity 15 from seeping to other locations through the gap between the base 14 and the end ring 12.

[0069] The sealing ring 16 can be disposed at the end of the gap between the base 14 and the end ring 12 that is away from the annular receiving cavity 15, such as... Figure 2 , Figure 6 and Figure 11 As shown; it can also be set in the middle of the gap between the base 14 and the end ring 12 or in other positions, as long as it does not intersect with the liquid storage tank 121.

[0070] Due to the need for endpoint testing in certain processes, in some cases the material of the base 14 needs to be specially specified (such as non-metallic materials like PPS and PEEK) in the existing technology, which leads to the specialization of the polishing head and is not conducive to the standardization of the carrier head 10.

[0071] As a feasible implementation method, in this embodiment of the application, the end ring 12 is made of metal or non-metal.

[0072] The end ring 12 in this embodiment can be made of stainless steel, plastic, polymer, or other materials. Because the end ring 12 is independent, a configuration combining a single-material base 14 with end rings 12 made of multiple materials can be used to meet the needs of different manufacturing processes and application scenarios, reducing the variety of bases 14 and facilitating the standardization of the bearing head 10.

[0073] In some optional embodiments, a hydrophobic layer is provided on the surface of the liquid storage tank 121. It should be understood that the hydrophobic layer is a material layer formed of a hydrophobic material. In the embodiments of this application, the hydrophobic layer can be provided on the surface of the liquid storage tank 121 by spraying or coating, and the hydrophobic layer repels the polishing liquid, making it easier for the polishing liquid to flow out of the liquid storage tank 121.

[0074] like Figure 15 As shown, in some optional embodiments, the end ring 12 has a first mounting hole 125 and a second mounting hole 126. The end ring 12 is connected to the base 14 by a first mounting member passing through the first mounting hole 125, and the retaining ring 13 is connected to the base 14 by a second mounting member passing through the second mounting hole 126.

[0075] The first mounting hole 125 and the second mounting hole 126 can be mounting holes of the same size or mounting holes of different sizes, both of which are within the protection scope of the embodiments of the present application. The first mounting member and the second mounting member can be bolts, screws or other detachable connecting members, so as to detachably mount the end ring 12 and the retaining ring 13 on the base 14 through the first mounting member and the second mounting member respectively.

[0076] In the embodiments of the present application, the first mounting hole 125 and the second mounting hole 126 are formed in the end ring 12. The end ring 12 is connected with the base 14 through the first mounting member passing through the first mounting hole 125, and the retaining ring 13 is connected with the base 14 through the second mounting member passing through the second mounting hole 126. The end ring 12 and the retaining ring 13 can be mounted on the base 14 through different mounting holes and mounting members respectively, so that the fixation of the end ring 12 and the retaining ring 13 is relatively independent, which can avoid loosening of both the end ring 12 and the retaining ring 13 at the same time, and is beneficial to ensuring the fastening of the installation of the end ring 12 and the retaining ring 13.

[0077] In some optional embodiments, an adjusting ring with the same axis as the end ring 12 can also be arranged between the end ring 12 and the retaining ring 13. The adjusting ring is used to apply a force to the retaining ring 13, so that the retaining ring 13 generates a deflection torque relative to the second connecting member, so that the bottom surface of the retaining ring 13 forms a height difference in the radial direction. The height difference formed by the bottom surface of the retaining ring 13 is beneficial to shortening the running-in time of the carrier head 10, so that the retaining ring 13 can quickly adapt to the polishing process of the wafer, thereby accurately controlling the polishing pressure of the edge portion of the wafer, and improving the polishing uniformity of the wafer.

[0078] As shown in FIG. 1, Figure 16 According to the second aspect of the embodiments of the present application, a polishing device is also provided, which comprises the carrier head in any of the embodiments of the first aspect of the present application.

[0079] The polishing device of the embodiments of the present application can be applied to chemical mechanical polishing. As shown in FIG. 2, Figure 16 The polishing device 20 can comprise a carrier head 10, a polishing disc 21, a liquid supply device 22, a dresser 23 and a polishing pad 24. The carrier head 10 loads a wafer to be polished and abuts the wafer against the polishing pad 24 above the polishing disc 21, so as to polish the wafer by the polishing pad 24. The liquid supply device 22 supplies a polishing liquid towards the polishing pad 24 and the wafer. The dresser 23 is used to dress the surface of the polishing pad 24. The polishing pad 24 is placed on the polishing disc 21, and the carrier head 10 and the dresser 23 can be respectively located on the two sides of the polishing pad 24, so that the dressing disc of the dresser 23 can simultaneously dress the polishing pad 24 when the carrier head 10 polishes the wafer by the polishing pad 24.

[0080] It should be understood that the polishing apparatus 20 of the present embodiment is based on the same inventive concept as the aforementioned embodiments of the carrier head 10 for wafer polishing, and the specific implementation and advantages thereof can refer to the above embodiments, which will not be described here again.

[0081] As shown in Figure 17 According to a third aspect of the present application, a polishing method is also provided, which can be applied to the polishing apparatus of the second aspect, and the polishing method comprises the following steps:

[0082] S110, abutting the wafer against the polishing pad 24 of the polishing apparatus by the gas film assembly 11 of the carrier head 10, and supplying the polishing liquid to the polishing pad 24 by the liquid supply device 22 of the polishing apparatus 20.

[0083] S120, rotating the carrier head 10 and the polishing pad 24 to polish the wafer; wherein when the polishing liquid enters the annular accommodating cavity 15 surrounded by the gas film assembly 11, the base 14 and the detachable end ring 12 in the carrier head 10, the polishing liquid will contact the end ring 12 under the centrifugal force of the rotation of the carrier head 10.

[0084] The polishing method of the present embodiment is based on the same inventive concept as the aforementioned embodiments of the polishing apparatus, and the specific implementation and advantages thereof can refer to the above embodiments, which will not be described here again.

[0085] It should be noted that, according to the needs of implementation, each component / step described in the embodiments of the present application can be split into more components / steps, or two or more components / steps or part of the operation of the components / steps can be combined into a new component / step, to achieve the purpose of the embodiments of the present application.

[0086] Those skilled in the art can appreciate that the units and method steps of the examples described in combination with the embodiments disclosed herein can be realized by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are realized in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to realize the described functions for each specific application, but such implementation should not be considered beyond the scope of the embodiments of the present application.

[0087] The above embodiments are only used to illustrate the present application, and not to limit the present application, and those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present application, therefore all equivalent technical solutions also belong to the scope of the present application, and the patent protection scope of the present application should be defined by the claims.

Claims

1. A carrier head for wafer polishing, comprising: The application relates to a bearing head for a polishing device. The bearing head comprises a gas film assembly, an end ring, a retaining ring and a base. The end ring is detachably mounted between the base and the retaining ring, the gas film assembly is connected to the base, and the gas film assembly is located in the end ring and the retaining ring, and there is a gap between the gas film assembly and the end ring and the retaining ring. The gas film assembly is used for abutting a wafer against a polishing pad during polishing of the wafer. The end ring, the base and the gas film assembly form an annular accommodating cavity, and an outer annular cavity wall of the annular accommodating cavity comprises an inner wall of the end ring.

2. The load head of claim 1 wherein, The end ring comprises a base contact surface and an inner ring surface, the base contact surface is attached to the base, the inner ring surface is opposite to the gas film assembly, and the inner ring surface is adjacent to the base contact surface. The liquid storage groove is arranged at the joint of the inner ring surface and the base contact surface.

3. The load head of claim 2 wherein, The end ring further comprises a retaining ring contact surface, the retaining ring contact surface is attached to the retaining ring, and the retaining ring contact surface is adjacent to the inner ring surface.

4. The load head of claim 3 wherein, The distance between a point on the bottom surface of the liquid storage groove and the rotation axis of the base is positively correlated with the distance between the point and the retaining ring contact surface, and the retaining ring contact surface is perpendicular to the rotation axis of the base.

5. The load head of claim 2 wherein, For any cross-sectional curve on the bottom surface of the liquid storage groove, the distance between a point on the cross-sectional curve and the rotation axis of the base is equal, and the distance between a second point on the cross-sectional curve and a first point on the cross-sectional curve is positively correlated with the distance between the second point and the retaining ring contact surface, and the first point is the point on the cross-sectional curve closest to the retaining ring contact surface. The liquid storage groove is symmetrical about a middle plane, and the middle plane is in the same plane as the rotation axis of the base.

6. The carrier head of any one of claims 1-5, wherein, The joint of the inner ring surface and the base contact surface is provided with an extension groove, the extension groove is communicated with the liquid storage groove, and the extension groove is located behind the liquid storage groove in the rotation direction of the end ring.

7. The load head of any one of claims 1-5, wherein, A sealing ring is arranged between the base and the end ring.

8. The load head of any one of Claims 1-5, wherein, The end ring is made of metal or nonmetal.

9. A polishing apparatus characterized by comprising: The end ring is provided with a first mounting hole and a second mounting hole, the end ring is connected to the base through a first mounting member penetrating through the first mounting hole, and the retaining ring is connected to the base through a second mounting member penetrating through the second mounting hole.

10. A method of polishing, characterized by, The application further relates to a polishing device comprising the bearing head. The application further relates to a polishing method applied to the polishing device. The wafer is abutted against the polishing pad of the polishing device through the gas film assembly of the bearing head of the polishing device, and the polishing pad is supplied with polishing liquid through a liquid supply device of the polishing device. The bearing head and the polishing pad are controlled to rotate to polish the wafer, and when the polishing liquid enters the annular accommodating cavity formed by the gas film assembly, the base and the detachable end ring in the bearing head, the polishing liquid will contact the end ring under the centrifugal force generated by the rotation of the bearing head.

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