Bearing head for wafer processing and chemical mechanical polishing equipment

Abstract

The invention provides a bearing head for wafer processing and chemical mechanical polishing equipment. The bearing head comprises a bearing head main body; the retaining ring is arranged on one side, facing the wafer, of the bearing head main body, and the wafer is limited in the retaining ring; and an anti-slip sheet mechanism at least partially disposed in the retaining ring, the anti-slip sheet mechanism being configured to be axially retractable to retract into the retaining ring when the retaining ring abuts against the polishing unit and to protrude from the retaining ring when the retaining ring is axially separated from the polishing unit, the anti-slip sheet mechanism being made of a corrosion resistant material. According to the technical scheme, the wafer is effectively prevented from sliding out, the risk that the wafer is broken is reduced, and the effectiveness of the anti-slip sheet mechanism is guaranteed.

Description

Technical Field

[0001] The present application relates to the technical field of chemical mechanical polishing, and in particular, to a carrier head for wafer processing and a chemical mechanical polishing device. Background Art

[0002] Chemical Mechanical Polishing (CMP) is a global flattening ultra-precision surface processing technology. Chemical mechanical polishing usually sucks the wafer to the bottom surface of the carrier head (also called polishing head), and the retaining ring at the bottom of the carrier head radially limits the wafer. The side of the wafer to be polished is pressed against the upper surface of the polishing pad. The carrier head rotates relative to the polishing pad under the actuation of the drive assembly and applies a downward load to the wafer; at the same time, the 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 completes the chemical mechanical polishing of the wafer under the combined action of chemistry and mechanics. However, sometimes the wafer slips out of the carrier head, resulting in wafer damage. Summary of the invention

[0003] The present application provides a carrier head for wafer processing and a chemical mechanical polishing device to solve or alleviate at least some of the above-mentioned problems.

[0004] According to one aspect of the present application, a carrier head for wafer processing is provided, the carrier head comprising: a carrier head body; a retaining ring arranged on the side of the carrier head body facing the wafer, the retaining ring confining the wafer therein; an anti-slip sheet mechanism, which is at least partially arranged in the retaining ring, the anti-slip sheet mechanism is configured to be axially retractable so as to retract into the retaining ring when the retaining ring abuts against the polishing unit, and to extend from the retaining ring when the retaining ring is axially separated from the polishing unit, the anti-slip sheet mechanism being made of corrosion-resistant material.

[0005] Optionally or alternatively, the anti-skid sheet mechanism includes an axially through-going anti-skid sheet seat and an anti-skid sheet body passing through the anti-skid sheet seat; the anti-skid sheet seat is arranged in the retaining ring, and the anti-skid sheet body is configured to be axially movable relative to the sheet seat and capable of extending from the retaining ring; the anti-skid sheet body includes a ball assembly arranged at one end thereof facing the polishing unit, and the anti-skid sheet body is in rolling contact with the polishing unit through the ball assembly.

[0006] Optionally or alternatively, the anti-slip sheet body includes a ball assembly disposed at one end thereof facing the polishing unit, and the anti-slip sheet body is in rolling contact with the polishing unit through the ball assembly.

[0007] Optionally or alternatively, the ball assembly comprises a connection block and a ball rollingly connected to the connection block, wherein the ball has a smooth and dense surface that prevents accumulation of contaminants.

[0008] Optionally or alternatively, the ball is made of a first plastic material, and the first plastic material includes one or more of polyetheretherketone, polyphenylene sulfide, polyimide, polyethylene terephthalate, and polytetrafluoroethylene.

[0009] Optionally or alternatively, the connecting block is constructed with a hemispherical rolling cavity opening toward the polishing unit, and the ball is partially accommodated in the rolling cavity; the ball assembly also includes one or more auxiliary balls arranged between the inner wall of the rolling cavity and the ball, the diameter of the auxiliary ball is equal to the difference between the inner radius of the rolling cavity and the outer radius of the ball, and the ball has a smooth and dense surface to prevent the accumulation of contaminants.

[0010] Optionally or alternatively, the rolling cavity is configured with a retaining ring extending radially inward from the periphery thereof, the balls pass through the retaining ring and are partially accommodated in the rolling cavity, and the inner diameter of the retaining ring is adapted to the outer diameter of the balls.

[0011] Optionally or alternatively, the anti-slip sheet body elastically abuts against the carrier head body via an elastic member, the anti-slip sheet body compresses the elastic member to retract into the retaining ring, and the anti-slip sheet body extends from the retaining ring via extension of the elastic member.

[0012] Optionally or alternatively, the elastic member is a damper.

[0013] Optionally or alternatively, the elastic member is a spring, the spring is made of a second plastic material, and the second plastic material is polyamide, polyetheretherketone or polytetrafluoroethylene.

[0014] Optionally or alternatively, the anti-slip sheet body includes an axially extending rod member, the rod member includes a first rod segment, a second rod segment and a third rod segment that are sequentially away from the carrier head body; the outer diameter of the second rod segment is respectively larger than the outer diameters of the first rod segment and the third rod segment, and the anti-slip sheet body is axially limited relative to the anti-slip sheet seat by locking the second rod segment; the spring surrounds the outside of the first rod segment, and one end of the spring abuts against the second rod segment, and the other end abuts against the carrier head body.

[0015] Optionally or alternatively, the rod is made of polyetheretherketone or polyphenylene sulfide.

[0016] Optionally or alternatively, the carrier head includes a plurality of anti-slip sheet mechanisms distributed along the circumference of the retaining ring.

[0017] Optionally or alternatively, the anti-slip sheet mechanism is biased radially inwardly of the retaining ring in a radial direction.

[0018] Optionally or alternatively, the anti-slip sheet mechanism is arranged within a range of 1 / 5 to 1 / 3 of the radial width of the retaining ring from the radial inner side of the retaining ring.

[0019] According to another aspect of the present application, a chemical mechanical polishing device is provided, wherein the chemical mechanical polishing device comprises the carrier head according to the aforementioned aspect.

[0020] According to the carrier head and chemical mechanical polishing equipment for wafer processing of the present application, an axially retractable anti-slip sheet mechanism is provided at the retaining ring, so that when the retaining ring and the polishing unit are axially separated and the wafer has a tendency to slide out radially, the anti-slip sheet mechanism can extend from the retaining ring to block the wafer, thereby avoiding the risk of the wafer sliding out, reducing the wafer breakage, and allowing the retaining ring pressure to have a lower pressure lower limit without causing the wafer to slide out, expanding the adjustment range of the retaining ring pressure, improving the polishing adjustment range and control flexibility and accuracy of the chemical mechanical polishing equipment, and thus improving the effectiveness and accuracy of wafer processing. In addition, the anti-slip sheet mechanism is made of corrosion-resistant material, which reduces the corrosion of the anti-slip sheet mechanism by the polishing liquid, ensures the effectiveness of the anti-slip sheet mechanism, extends its service life, and reduces the pollution of the polishing environment caused by the corrosion and chipping of the anti-slip sheet mechanism, ensuring the efficient conduct of the chemical mechanical polishing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of the present application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0022] Figure 1 is a schematic diagram of a chemical mechanical polishing device according to an embodiment of the present application;

[0023] Figure 2 is a cross-sectional view of a chemical mechanical polishing device;

[0024] Figure 3 for Figure 2 The enlarged view of point A in the middle;

[0025] Figure 4 is a cross-sectional view of a carrier head according to an embodiment of the present application;

[0026] Figure 5 for Figure 4 The enlarged view of point B in FIG.

[0027] Figure 6 for Figure 5 An enlarged view of the ball assembly of the bearing head;

[0028] Figure 7 for Figure 4 A schematic cross-sectional view of the carrier head in the embodiment of the present invention when the carrier head is axially abutting against the polishing unit;

[0029] Figure 8 for Figure 7 The enlarged view of point C in FIG.

[0030] Fig. 9 for Figure 4 A schematic cross-sectional view of the carrier head when it is axially separated from the polishing unit;

[0031] Fig.10 for Fig. 9 A magnified view of D in FIG. 1 ; and

[0032] Fig.11 for Figure 4 Schematic bottom view of the retaining ring of the carrier head.

[0033] Reference numerals :

[0034] Chemical mechanical polishing equipment 1000, polishing unit 1100, carrier head 100, polishing pad 200, polishing plate 300, dresser 400, liquid supply unit 500,

[0035] The carrier head body 110, the gas distribution base 111, the main base 112, the connecting flange 113, the carrier plate 114, the first cover plate 1151, the second cover plate 1152, the elastic membrane 116, the diaphragm 117, the pressure ring 118, the assembly hole 1101,

[0036] Retaining ring 120, mounting hole 121, first hole section 1211, second hole section 1212, groove 122,

[0037] The anti-slip sheet mechanism 130, the anti-slip sheet seat 131, the first seat section 131a, the second seat section 131b, the accommodating chamber 1311, the through hole 1312, the anti-slip sheet body 132, the rod 1321, the first rod section 1321a, the second rod section 1321b, the third rod section 1321c, the ball assembly 1322, the connecting block 1322a, the ball 1322b, the auxiliary ball 1322c, the rolling chamber 1322d, the retaining ring 1322e, the elastic member 133,

[0038] Wafer W, axis Ax. DETAILED DESCRIPTION

[0039] In order to enable those skilled in the art to better understand the technical solutions in the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the embodiments of the present application should fall within the scope of protection of the embodiments of the present application.

[0040] In the description of the present application, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present 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 should not be understood as a limitation on the present application.

[0041] In addition, in the description of the present application, unless otherwise specified and limited, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal connection between two components. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.

[0042] Figure 1 Schematic diagram of a chemical mechanical polishing device 1000 according to an embodiment of the present application. The chemical mechanical polishing device 1000 may include a polishing unit 1100, a carrier head 100, a dresser 400 and a liquid supply unit 500. The polishing unit 1100 may specifically include a polishing disc 300 and a polishing pad 200. The polishing pad 200 is disposed on the upper surface of the polishing disc 300 and rotates along the axis Ax with the polishing disc 300; the horizontally movable carrier head 100 is disposed above the polishing pad 200, and its lower surface receives the wafer W to be polished. The dresser 400 includes a dresser arm and a dresser head, which is disposed on one side of the polishing disc 300. The dresser arm drives the rotating dresser head to swing to dress the surface of the polishing pad 200. The liquid supply unit 500 is disposed above the polishing pad 200 to spread the polishing liquid on the surface of the polishing pad 200.

[0043] Figure 2 is a schematic cross-sectional view of a chemical mechanical polishing device 1000, Figure 3 for Figure 2For the purpose of simplification, only the carrier head 100, the polishing unit 1100 and the wafer W are shown. Generally, by adjusting the pressure of the retaining ring 120 of the carrier head 100, the polishing pad 200 can be partially deformed, thereby achieving the regulation of the edge removal rate of the wafer W. Figure 2 and Figure 3 The schematic diagram of the wafer sliding out of the carrier head 100 is shown. During the wafer polishing process, it is usually necessary to continuously adjust the pressure of the retaining ring 120. In some processes, when the pressure of the retaining ring 120 is relatively low, the retaining ring 120 may be partially axially separated from the polishing unit 1100, thereby causing the wafer W to slide out of the carrier head 100 (specifically, slide out of the retaining ring 120). In order to prevent the wafer from sliding, the pressure of the retaining ring 120 is increased. At this time, the friction between the retaining ring 120 and the polishing pad 200 increases, which is easy to aggravate the glazing of the polishing pad 200 (that is, the surface of the polishing pad becomes smooth), making it easier for the wafer W to slide out. In addition, due to the large friction between the retaining ring 120 and the polishing pad 200, and between the wafer W and the polishing pad 200, the carrier head 100 may be slightly deflected, and a gap may be generated between the retaining ring 120 and the polishing unit 1100, thereby causing the wafer to slide out of the carrier head.

[0044] Therefore, the pressure control range of the retaining ring is small. If the pressure is too small, there will be problems such as (1) the axial contact between the retaining ring and the polishing unit is not tight, resulting in sliding of the sheet; if the pressure is too large, there will be problems such as (1) the polishing pad is easily glazed, resulting in sliding of the sheet, and (2) the friction is large, resulting in the deflection of the retaining ring, causing sliding of the sheet.

[0045] To address one or more of the above problems, Figure 4 A cross-sectional view of a carrier head 100 according to an embodiment of the present application is shown, which can be used for Figure 1 The chemical mechanical polishing apparatus 1000 shown in FIG. Figure 4 The carrier head 100 mainly includes a carrier head body 110 and a retaining ring 120. The carrier head body 110 may include a gas distribution substrate 111, a main substrate 112, a connecting flange 113 for connection, a carrier plate 114, a first cover plate 1151, a second cover plate 1152 and an elastic membrane 116. The gas distribution substrate 111 is connected to the main substrate 112 through a diaphragm 117, and the elastic membrane 116 is connected to the bottom of the carrier plate 114 through a pressure ring 118. The retaining ring 120 is arranged on the side of the carrier head body 110 facing the wafer W, that is, Figure 4 The retaining ring 120 is arranged around the outer circumference of the elastic membrane 116, and the elastic membrane 116 carries the wafer W and presses the wafer W to the polishing pad 200 of the polishing unit 1100. The retaining ring 120 radially confines the wafer W therein and presses against the polishing pad 200 together with the wafer W to perform wafer polishing. The retaining ring 120 is configured with an axially through mounting hole 121.

[0046] Figure 5 for Figure 4 From the enlarged view at B in FIG. 1 , it can be seen that the carrier head 100 according to one embodiment of the present application further includes an anti-slip sheet mechanism 130 at least partially disposed in the mounting hole 121, such as Figure 5 As shown, the anti-skid sheet mechanism 130 includes: an anti-skid sheet seat 131, an anti-skid sheet body 132 extending axially and passing through the anti-skid sheet seat 131, and the anti-skid sheet body 132 can be elastically abutted against the carrier head body 110 via an elastic member 133, such as a spring or a damper, so as to be axially retractable and retracted into the mounting hole 121 when the retaining ring 120 abuts against the polishing unit 1100 (see Figure 7 , Figure 8 ), or when the retaining ring 120 and the polishing unit 1100 are axially separated (ie, not completely tightly abutted, including partially separated or completely separated), the retaining ring 120 axially extends to prevent the wafer from sliding out of the retaining ring 120 (see Fig. 9 , Fig.10 Specifically, the anti-skid sheet body 132 presses the elastic member 133 to retract into the mounting hole 121 when the retaining ring 120 abuts against the polishing unit 1100, and is pressed by the elastic member 133 (the elastic member 133 stretches) to extend from the retaining ring 120 when the retaining ring 120 and the polishing unit 1100 are axially separated, so that when the wafer W is about to slide out of the gap between the retaining ring 120 and the polishing unit 1100, the anti-skid sheet body 132 can block the wafer W. The anti-skid sheet mechanism 130 can be made of a corrosion-resistant material to reduce the corrosion of the polishing liquid to the anti-skid sheet mechanism 130.

[0047] According to the technical solution of the present application, an axially retractable anti-slip sheet mechanism 130 is provided at the retaining ring 120, so that when the pressure between the retaining ring 120 and the polishing unit 1100 is small and the axial separation causes the wafer W to have a tendency to slide out radially, or when the friction between the retaining ring 120 and the polishing unit 1100 is large and the carrier head 100 is deflected, causing the wafer W to have a tendency to slide out radially, the anti-slip sheet mechanism 130, specifically the anti-slip sheet body 132, can extend from the retaining ring 120 to block the wafer W, thereby avoiding the risk of the wafer sliding out and reducing the wafer breakage. At the same time, the pressure of the retaining ring 120 can have a higher upper pressure limit and a lower pressure lower limit to keep the wafer from sliding out, thereby expanding the adjustment range of the pressure of the retaining ring 120, improving the polishing adjustment range and the control flexibility and accuracy of the chemical mechanical polishing equipment 1000, and thereby improving the effectiveness and accuracy of wafer processing. In addition, the anti-skid sheet mechanism 130 can be made of corrosion-resistant material, thereby reducing the corrosion of the anti-skid sheet mechanism 130 by the polishing liquid, ensuring the effectiveness of the anti-skid sheet mechanism 130, extending its service life, and reducing the pollution of the polishing environment caused by corrosion and chips of the anti-skid sheet mechanism 130, thereby ensuring the efficient implementation of the chemical mechanical polishing process.

[0048] like Figure 5 and Figure 6 As shown in the enlarged view, the anti-slip sheet body 132 may include an axially extending rod 1321 and a ball assembly 1322 connected to one end of the rod 1321 facing the polishing unit 1100 (i.e., the lower end shown in the figure). The anti-slip sheet body 132 is in rolling contact with the polishing unit 1100 through the ball assembly 1322, thereby reducing the friction between the anti-slip sheet body 132 and the polishing pad 200, thereby reducing the wear of the anti-slip sheet body 132 on the polishing pad 200, thereby improving the service life of the anti-slip sheet body 132 and the polishing pad 200, and ensuring the wafer polishing efficiency.

[0049] In a specific embodiment, the ball assembly 1322 may include a connecting block 1322a and a ball 1322b, wherein the connecting block 1322a is configured with a hemispherical rolling cavity 1322d opening toward the polishing unit 1100, and the ball 1322b is partially (e.g., half of the ball 1322b) accommodated in the rolling cavity 1322d, and can roll in all directions relative to the rolling cavity 1322d, thereby forming a universal ball. The ball assembly 1322 may also include one or more auxiliary balls 1322c disposed between the inner wall of the rolling cavity 1322d and the ball 1322b, wherein the diameter of the auxiliary ball 1322c is equal to the difference between the inner radius of the rolling cavity 1322d and the outer radius of the ball 1322b, that is, the auxiliary ball 1322c is disposed tangent to the rolling cavity 1322d and the ball 1322b, respectively. By setting the auxiliary ball 1322c, a rolling connection can be achieved between the ball 1322b and the rolling cavity 1322d, thereby reducing the rolling friction between the ball 1322b and the rolling cavity 1322d, reducing the wear between the two, and improving the smoothness of the rolling of the ball 1322b, thereby improving the smoothness of the relative movement between the anti-slip sheet mechanism 130 and the polishing unit 1100.

[0050] According to the configuration of the ball assembly 1322 of the present application, the anti-skid sheet body 132 and the polishing unit 1100 are in rolling contact, thereby reducing the friction between the anti-skid sheet body 132 and the polishing pad 200, thereby reducing the wear of the anti-skid sheet body 132 on the polishing pad 200, improving the service life of the anti-skid sheet body 132 and the polishing pad 200, and ensuring the wafer polishing efficiency. Furthermore, the configuration of the ball assembly 1322 changes the sliding friction between the retaining ring 120 and the polishing unit 1100 at least partially into rolling friction, reducing the contact area between the retaining ring 120 and the polishing pad 200, reducing the friction between the two, thereby reducing the wear of the retaining ring 120 on the polishing pad 200, slowing down the glazing effect or glazing speed of the polishing pad 200, and thereby reducing the risk of the wafer W slipping out due to the glazing of the polishing pad 200.

[0051] In a preferred embodiment, the ball 1322b has a smooth and dense surface to prevent the accumulation of pollutants on its surface and ensure its cleanliness and surface smoothness, and the pollutants are, for example, debris generated by wafer polishing, etc. The ball 1322b can be made of a first plastic material, and the first plastic material includes, for example, one or more of polyetheretherketone (PEEK), polyphenylene sulfide (PPS), polyimide (PAI), polyethylene terephthalate (PET-P), and polytetrafluoroethylene (PTFE). These plastic materials have good wear resistance and chemical corrosion resistance, which is conducive to reducing the wear and chemical corrosion of the ball 1322b, ensuring the surface smoothness and rolling smoothness of the ball, and reducing the pollution of the wafer polishing environment caused by the wear or corrosion of the ball.

[0052] In addition, the connecting block 1322a and the rod 1321 can also be made of the same or different plastic materials as the ball. The rod 1321 is made of polyetheretherketone (PEEK) or polyphenylene sulfide (PPS), for example. The auxiliary ball 1322c can also be made of a smooth and dense material, for example, to have a smooth and dense surface.

[0053] In a further embodiment, the rolling cavity 1322d is configured with a retaining ring 1322e extending radially inward from its periphery. Figure 6 In the embodiment, the retaining ring 1322e is integrally formed on the connecting block 1322a. In other embodiments, the retaining ring 1322e can be formed separately from the connecting block 1322a. The ball 1322b passes through the retaining ring 1322e and is partially accommodated in the rolling cavity 1322d. The inner diameter of the retaining ring 1322e is adapted to the outer diameter of the ball 1322b, for example, to allow a small gap between the two to roll relative to each other. The retaining ring 1322e can be Figure 6 The retaining ring 1322e has a certain thickness in the vertical direction, and the middle position of the thickness matches the diameter position of the ball 1322b. The radially inward side of the retaining ring 1322e can be a curved annular surface that matches the outer surface of the ball 1322b, thereby limiting the ball 1322b from falling out of the rolling cavity 1322d through the retaining ring 1322e. The setting of the retaining ring 1322e can limit the auxiliary ball 1322c in the rolling cavity 1322d to prevent the auxiliary ball 1322c from escaping from the rolling cavity 1322d, and the retaining ring 1322e can also largely block the polishing liquid or other contaminants from entering the rolling cavity 1322d, ensuring the cleanliness of the rolling cavity 1322d and reducing the failure of the rolling cavity 1322d due to contamination.

[0054] In a preferred embodiment, one end of the connection block 1322a facing the rod 1321 may be threadedly connected to the rod 1321. Specifically, one end of the connection block 1322a facing the rod 1321 may be configured with a threaded hole recessed away from the rod 1321, for example Figure 6 The end of the rod 1321 facing the connection block 1322a may be configured with an external thread matching the threaded hole, and the connection block 1322a and the rod 1321 are threadedly connected via the threaded hole and the external thread.

[0055] See also Figure 5In the illustrated embodiment, the mounting hole 121 of the retaining ring 120 includes a first hole section 1211 and a second hole section 1212 which are sequentially away from the carrier head body 110, the first hole section 1211 is configured to accommodate the anti-slip sheet seat 131, and the second hole section 1212 is configured to allow the anti-slip sheet body 132 to pass through. The anti-slip sheet seat 131 includes an axially extending accommodation cavity 1311, which is open toward the carrier head body 110, and a through hole 1312 is configured at the bottom of the accommodation cavity 1311 facing away from the carrier head body 110. The rod 1321 of the anti-slip sheet body 132 includes a first rod segment 1321a, a second rod segment 1321b and a third rod segment 1321c which are sequentially away from the bearing head body 110; the outer diameter of the second rod segment 1321b is larger than the outer diameters of the first rod segment 1321a and the third rod segment 1321c, respectively, and the outer diameter of the second rod segment 1321b is larger than the inner diameter of the through hole 1312, so that the second rod segment 1321b is confined in the accommodating cavity 1311 and does not escape from the accommodating cavity 1311. The first rod segment 1321a and the second rod segment 1321b are axially movably accommodated in the accommodating cavity 1311, and the third rod segment 1321c is connected to the ball assembly 1322, for example, it is threadedly connected to the connecting block 1322a of the ball assembly 1322. Figure 5 In the embodiment where the elastic member 133 is a spring, the spring is wrapped around the outside of the first rod segment 1321a, and one end of the spring abuts against the second rod segment 1321b, and the other end abuts against the carrier head body 110, so as to achieve axial expansion and contraction of the anti-slip sheet body 132.

[0056] In a preferred embodiment, the spring can be made of a second plastic material, which can be, for example, polyamide (PA, commonly known as nylon), polyetheretherketone (PEEK) or polytetrafluoroethylene (PTFE). The spring is made of plastic material, which reduces chemical corrosion of the spring, ensures the stability of the elastic performance, and further ensures the effectiveness of its elastic effect, so that the anti-slip sheet mechanism 130 can perform the anti-slip sheet operation in a timely and effective manner to prevent the wafer from slipping out. It should be understood that the first plastic material and the second plastic material can be the same or different.

[0057] From the perspective of the outer structure, the anti-slip sheet seat 131 may include a first seat section 131a assembled in the carrier head body 110 and a second seat section 131b assembled in the mounting hole 121. The outer diameter of the first seat section 131a may be greater than the outer diameter of the second seat section 131b, and a chamfer or smooth transition structure may be provided between the two to reduce stress concentration and improve structural strength. Correspondingly, the carrier head body 110 (specifically the main substrate 112) may be configured with an assembly hole 1101 opening toward the retaining ring 120, the size and position of the assembly hole 1101 match the first seat section 131a, and the assembly hole 1101 and the first seat section 131a may be threadedly matched. The elastic member 133 may abut against the bottom of the assembly hole 1101 toward the carrier head body 110. In a preferred embodiment, the edge of the assembly hole 1101 may also be designed as a transition structure that matches the transition structure between the first seat section 131a and the second seat section 131b. It should be understood that in addition to the anti-slip sheet seat 131 being partially set in the mounting hole 121 and partially set in the assembly hole 1101 as shown in the figure, in an optional embodiment, the anti-slip sheet seat 131 can also be completely set in the mounting hole 121. In this case, the carrier head body 110 may not be provided with the assembly hole 1101, and the elastic member 133 directly abuts against the bottom surface of the carrier head body 110.

[0058] Figure 7 for Figure 4 A schematic cross-sectional view of the carrier head 100 in axial abutment with the polishing unit 1100; Figure 8 for Figure 7 It can be seen that the retaining ring 120 is axially abutted against the polishing unit 1100 , at which time the wafer W is retained in the retaining ring 120 , and the anti-slip sheet mechanism 130 is contracted in the mounting hole 121 of the retaining ring 120 . Fig. 9 for Figure 4 Schematic cross-sectional view of the carrier head 100 when axially separated from the polishing unit 1100; Fig.10 for Fig. 9 The enlarged view of D in FIG. It can be seen that the carrier head 100 is slightly tilted, and the retaining ring 120 is slightly separated from the polishing unit 1100 axially. At this time, the wafer W tends to slide out radially from the retaining ring 120. The anti-slip sheet mechanism 130 extends axially outward from the mounting hole 121 of the retaining ring 120 under the action of the elastic member 133. The radially inner side wall of the connecting block 1322a of the ball assembly 130 radially blocks the wafer W. In the subsequent rotation of the carrier head, the wafer W will be driven back to the retaining ring 120, thereby avoiding the wafer from sliding out and the resulting wafer breakage. At the same time, when the pressure of the retaining ring 120 is actively adjusted, it is also allowed to adjust to a smaller pressure without causing the wafer to slide out, thereby achieving a larger adjustment range of the pressure of the retaining ring 120, and improving the flexibility and accuracy of polishing control.

[0059] In a preferred embodiment, the carrier head 100 may include a plurality of anti-slip sheet mechanisms 130 distributed along the circumference of the retaining ring 120 . Fig.11 for Figure 4 1 is a bottom view schematic diagram of the retaining ring 120 of the carrier head 100, wherein a plurality of anti-skid sheet mechanisms 130 distributed along the circumference of the retaining ring 120 are shown. In the illustrated embodiment, the retaining ring 120 is configured with a plurality of grooves 122 recessed from the surface of the retaining ring 120 away from the polishing unit 1100 on the side facing the polishing unit 1100, and the grooves 122 penetrate the outer side and the inner side of the retaining ring 120 in the radial direction, thereby forming a channel for the inside and outside of the retaining ring 120 to flow into or out of the retaining ring 120 for the polishing liquid or debris to flow into or out of the retaining ring 120. The plurality of grooves 122 may be evenly distributed along the circumference of the retaining ring 120, or in an optional embodiment, one anti-skid sheet mechanism 130 may be provided between two adjacent grooves 122, or two or more anti-skid sheet mechanisms 130 may be evenly spaced circumferentially between two adjacent grooves 122, that is, the number of the anti-skid sheet mechanisms 130 may be an integer multiple of the grooves 122.

[0060] In addition, Figure 4 , 5 or Figure 8 In the illustrated embodiment, the anti-slip sheet mechanism 130 may be offset in the radial direction toward the radial inner side of the retaining ring 120, for example, to be set within a range of 1 / 5 to 1 / 3 of the radial width of the retaining ring 120 from the radial inner side of the retaining ring 120, so as to be able to block the wafer more quickly and effectively. The position of the anti-slip sheet mechanism 130 described here may be understood as the position of the central axis of the anti-slip sheet mechanism 130 or the position of the vertical axis of the ball 1322b.

[0061] The following is a brief introduction Figure 4 or Figure 5 An exemplary method of assembling carrier head 100 is shown.

[0062] S1: Assembling the anti-slip sheet mechanism 130 may specifically include:

[0063] S1-1: insert the rod 1321 into the anti-slip sheet seat 131;

[0064] S1-2: Connect the ball assembly to the rod 1321;

[0065] S1-3: Assemble the elastic member 133 to the rod 1321;

[0066] S2: Assemble the anti-slip sheet mechanism 130 to the carrier head body 110 , specifically, to the assembly hole 1101 .

[0067] S3: Assemble the retaining ring 120 to the carrier head body 110 , specifically, sleeve the mounting hole 121 of the retaining ring 120 onto the outside of the anti-slip sheet mechanism 130 , that is, insert the anti-slip sheet mechanism 130 into the mounting hole 121 .

[0068] It should be understood that the above-mentioned assembly method is merely exemplary, and when the carrier head 100 has other structural forms, the specific assembly operations or the operation sequence of each step may be appropriately adjusted.

[0069] The above implementation methods are only used to illustrate the embodiments of the present application, and are not limitations on the embodiments of the present application. Ordinary technicians in the relevant technical field can make various changes and modifications without departing from the spirit and scope of the embodiments of the present application. Therefore, all equivalent technical solutions also belong to the scope of the embodiments of the present application. The scope of patent protection of the embodiments of the present application should be limited by the claims.

Claims

1. A carrier head for wafer processing, characterized in that: The carrier head comprises: A carrier head body; A retaining ring is arranged on a side of the carrier head body facing the wafer, and the retaining ring confines the wafer therein; An anti-slip sheet mechanism is at least partially disposed in the retaining ring, the anti-slip sheet mechanism being configured to be axially retractable so as to be retracted into the retaining ring when the retaining ring abuts against the polishing unit, and to be extended from the retaining ring when the retaining ring is axially separated from the polishing unit, the anti-slip sheet mechanism being made of a corrosion-resistant material.

2. The carrier head according to claim 1, characterized in that: The anti-skid sheet mechanism includes an axially-through anti-skid sheet seat and an anti-skid sheet main body passing through the anti-skid sheet seat; the anti-skid sheet seat is arranged in the retaining ring, and the anti-skid sheet main body is configured to be axially movable relative to the sheet seat and capable of extending from the retaining ring; the anti-skid sheet main body includes a ball assembly arranged at one end thereof facing the polishing unit, and the anti-skid sheet main body is in rolling contact with the polishing unit through the ball assembly.

3. The carrier head according to claim 2, characterized in that: The ball assembly includes a connection block and a ball rollingly connected to the connection block, wherein the ball has a smooth and dense surface that prevents contaminants from accumulating.

4. The carrier head according to claim 3, characterized in that: The ball is made of a first plastic material, and the first plastic material includes one or more of polyetheretherketone, polyphenylene sulfide, polyimide, polyethylene terephthalate, and polytetrafluoroethylene.

5. The carrier head according to claim 3, characterized in that: The connecting block is constructed with a hemispherical rolling cavity opening toward the polishing unit, and the ball is partially accommodated in the rolling cavity; the ball assembly also includes one or more auxiliary balls arranged between the inner wall of the rolling cavity and the ball, the diameter of the auxiliary ball is equal to the difference between the inner radius of the rolling cavity and the outer radius of the ball, and the ball has a smooth and dense surface to prevent the accumulation of contaminants.

6. The carrier head according to claim 5, characterized in that: The rolling cavity is configured with a retaining ring extending radially inward from the periphery thereof, the balls are partially accommodated in the rolling cavity through the retaining ring, and the inner diameter of the retaining ring is adapted to the outer diameter of the balls.

7. The carrier head according to any one of claims 2 to 6, characterized in that: The anti-slip sheet body elastically abuts against the carrier head body via an elastic member, the anti-slip sheet body compresses the elastic member to be retracted into the retaining ring, and the anti-slip sheet body protrudes from the retaining ring via extension of the elastic member.

8. The carrier head according to claim 7, characterized in that: The elastic member is a damper.

9. The carrier head according to claim 7, characterized in that: The elastic member is a spring, and the spring is made of a second plastic material. The second plastic material is polyamide, polyetheretherketone or polytetrafluoroethylene.

10. The carrier head according to claim 9, characterized in that: The anti-slip sheet body includes an axially extending rod, and the rod includes a first rod segment, a second rod segment and a third rod segment that are sequentially away from the bearing head body; the outer diameter of the second rod segment is respectively larger than the outer diameters of the first rod segment and the third rod segment, and the anti-slip sheet body is axially limited relative to the anti-slip sheet seat by locking the second rod segment; the spring surrounds the outside of the first rod segment, and one end of the spring abuts against the second rod segment, and the other end abuts against the bearing head body.

11. The carrier head according to claim 10, characterized in that: The rod is made of polyetheretherketone or polyphenylene sulfide.

12. The carrier head according to any one of claims 1 to 6, characterized in that: The carrier head includes a plurality of anti-slip sheet mechanisms distributed along the circumference of the retaining ring.

13. The carrier head according to any one of claims 1 to 6, characterized in that: The anti-slip sheet mechanism is biased radially inwardly of the retaining ring in a radial direction.

14. The carrier head according to claim 13, characterized in that: The anti-slip sheet mechanism is disposed within a range of 1 / 5 to 1 / 3 of the radial width of the retaining ring from the radial inner side of the retaining ring.

15. A chemical mechanical polishing device, characterized in that: The chemical mechanical polishing apparatus comprises a carrier head according to any one of claims 1-14.

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