Carrying head for wafer processing and chemical mechanical polishing apparatus

Abstract

The application provides a carrier head for wafer processing and a chemical mechanical polishing device. The carrier head comprises a carrier head body, a retaining ring arranged on the side of the carrier head body facing the wafer, the retaining ring defining the wafer therein, the retaining ring being configured with a mounting hole axially penetrating therethrough, and an anti-skid piece mechanism at least partially arranged in the mounting hole, the anti-skid piece mechanism comprising an anti-skid piece seat axially penetrating therethrough and an anti-skid piece body penetrating through the anti-skid piece seat; the anti-skid piece body is configured to be axially telescopic, so as to be retracted into the mounting hole when the retaining ring abuts against a polishing unit, and to be extended out of the retaining ring to block the wafer from sliding out of the retaining ring when the retaining ring is axially separated from the polishing unit. According to the technical scheme of the application, the wafer sliding out is effectively avoided, and the risk of wafer breakage is reduced.

Description

TECHNICAL FIELD

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

[0002] Chemical mechanical polishing (CMP) is a kind of global planarization ultra-precision surface processing technology. Chemical mechanical polishing usually sucks the wafer to the bottom surface of the carrier head (also known as the polishing head), and limits the wafer radially with the retaining ring at the lower part of the carrier head. The side to be polished of the wafer is pressed against the upper surface of the polishing pad, and the carrier head is rotated relative to the polishing pad under the actuation of the driving assembly and gives the wafer a downward load; 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 joint action of chemical and mechanical. However, sometimes the wafer slips out of the carrier head, resulting in damage to the wafer. SUMMARY

[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 provided on the side of the carrier head body facing the wafer, the retaining ring limiting the wafer therein, the retaining ring being configured with a mounting hole axially penetrating; and an anti-slip piece mechanism at least partially disposed in the mounting hole, the anti-slip piece mechanism comprising an anti-slip piece seat axially penetrating and an anti-slip piece body penetrating the anti-slip piece seat; the anti-slip piece body is configured to be axially telescopic, so as to retract into the mounting hole when the retaining ring abuts against a polishing unit, and to extend out of the retaining ring to block the wafer from slipping out of the retaining ring when the retaining ring is axially separated from the polishing unit.

[0005] Optionally or alternatively, the anti-slip piece body comprises an axially extending rod and a ball assembly connected to one end of the rod facing the polishing unit, and the anti-slip piece body is in rolling contact with the polishing unit through the ball assembly.

[0006] Optionally or alternatively, the ball assembly comprises a connecting block and a ball, the connecting block being configured with a hemispherical rolling cavity open towards the polishing unit, the ball being partially contained in the rolling cavity and being rollable in various directions relative to the rolling cavity.

[0007] Optionally or alternatively, the ball assembly further comprises one or more auxiliary balls arranged between the inner wall of the rolling cavity and the balls, the diameter of the auxiliary ball being equal to the difference between the inner radius of the rolling cavity and the outer radius of the ball.

[0008] Optionally or alternatively, the rolling cavity is configured with a retaining ring extending radially inward from the periphery thereof, the ball being partially accommodated in the rolling cavity through the retaining ring, the inner diameter of the retaining ring being adapted to the outer diameter of the ball.

[0009] Optionally or alternatively, the connecting block is threadedly connected to the rod member at one end thereof.

[0010] Optionally or alternatively, the connecting block is configured with a threaded hole recessed away from the rod member at one end thereof, the rod member is configured with an external thread matched with the threaded hole at one end thereof, and the connecting block and the rod member are threadedly connected via the threaded hole and the external thread.

[0011] Optionally or alternatively, the anti-skid sheet body is elastically abutted to the load head body via an elastic member, the anti-skid sheet body compresses the elastic member to retract into the mounting hole, and the anti-skid sheet body extends out of the retaining ring via the extension of the elastic member.

[0012] Optionally or alternatively, the mounting hole comprises a first hole section and a second hole section successively away from the load head body, the first hole section is configured to accommodate the anti-skid sheet seat, and the second hole section is configured for the anti-skid sheet body to pass through.

[0013] Optionally or alternatively, the anti-skid sheet seat comprises an axially extending accommodating cavity, the bottom of the accommodating cavity opposite to the load head body is configured with a through hole; the rod member comprises a first rod section, a second rod section and a third rod section successively away from the load head body; the outer diameter of the second rod section is greater than the outer diameter of the first rod section and the third rod section respectively, and the outer diameter of the second rod section is greater than the inner diameter of the through hole so that the second rod end is defined in the accommodating cavity; the first rod section and the second rod section are axially movably accommodated in the accommodating cavity, and the third rod section is connected with the ball assembly.

[0014] Optionally or alternatively, the elastic member is a spring, the spring is wrapped outside the first rod section, one end of the spring is abutted to the second rod section, and the other end of the spring is abutted to the load head body.

[0015] Optionally or alternatively, the anti-skid sheet seat comprises a first seat section fitted in the load head body and a second seat section fitted in the mounting hole.

[0016] Optionally or alternatively, the carrier head body is configured with a fitting hole facing the retaining ring opening, the fitting hole matching the first seat section in size and position, and the fitting hole threadedly mating with the first seat section.

[0017] Optionally or alternatively, the carrier head comprises a plurality of the anti-skid piece mechanisms distributed along the circumference of the retaining ring.

[0018] Optionally or alternatively, the plurality of the anti-skid piece mechanisms are evenly distributed along the circumference of the retaining ring.

[0019] Optionally or alternatively, the retaining ring is configured with a plurality of grooves on the side facing the polishing unit, the plurality of grooves being evenly distributed along the circumference of the retaining ring, one anti-skid piece mechanism being arranged between two adjacent grooves, or two or more anti-skid piece mechanisms being evenly spaced between two adjacent grooves.

[0020] According to another aspect of the present application, there is provided a chemical mechanical polishing apparatus comprising the carrier head according to the foregoing aspect.

[0021] According to the carrier head and the chemical mechanical polishing apparatus for wafer processing of the present application, by arranging the axially extendable anti-skid piece mechanism at the retaining ring, when the retaining ring and the polishing unit are axially separated, causing the wafer to have a tendency to slide radially outwards, the anti-skid piece body of the anti-skid piece mechanism can extend from the retaining ring to block the wafer, thereby avoiding the risk of wafer sliding out, reducing 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 the control flexibility and accuracy of the chemical mechanical polishing apparatus, and thereby improving the effectiveness and precision of wafer processing. BRIEF DESCRIPTION OF DRAWINGS

[0022] 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 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 based on these drawings.

[0023] Figure 1 A schematic view of a chemical mechanical polishing apparatus according to an embodiment of the present application;

[0024] Figure 2 A sectional view of a chemical mechanical polishing apparatus;

[0025] Figure 3 A sectional view of a chemical mechanical polishing apparatus; Figure 2 An enlarged view of A in FIG. 4;

[0026] Figure 4 is a sectional view of a carrier head according to an embodiment of the present application;

[0027] Figure 5 is an enlarged view of B in Figure 4

[0028] Figure 6 is an enlarged view of the ball assembly of the carrier head in Figure 5

[0029] Figure 7 is a schematic sectional view of the carrier head in Figure 4

[0030] Figure 8 is an enlarged view of C in Figure 7

[0031] Figure 9 is a schematic sectional view of the carrier head in Figure 4

[0032] Figure 10 is an enlarged view of D in Figure 9

[0033] Figure 11 is a bottom view of the retaining ring of the carrier head in Figure 4

[0034] Reference signs :

[0035] chemical mechanical polishing apparatus 1000, polishing unit 1100, carrier head 100, polishing pad 200, polishing disk 300, conditioner 400, liquid supply part 500,

[0036] carrier head body 110, gas distribution base 111, main base 112, connecting flange 113, carrier disk 114, first cover plate 1151, second cover plate 1152, elastic membrane 116, diaphragm 117, compression ring 118, assembly hole 1101,

[0037] retaining ring 120, mounting hole 121, first hole section 1211, second hole section 1212, groove 122,

[0038] ​​​​​​​Anti-slip piece mechanism 130, anti-slip piece seat 131, first seat section 131a, second seat section 131b, accommodating cavity 1311, through hole 1312, anti-slip piece body 132, rod piece 1321, first rod section 1321a, second rod section 1321b, third rod section 1321c, ball assembly 1322, connecting block 1322a, ball 1322b, auxiliary ball 1322c, rolling cavity 1322d, stop ring 1322e, elastic piece 133,

[0039] Wafer W, axis Ax. DETAILED DESCRIPTION

[0040] In order to make the personnel in the art 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 some of the embodiments of the present application, not all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application should belong to the scope of protection of the present application.

[0041] In the description of the present application, it should be understood that the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the present application and simplify the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0042] In addition, in the description of the present application, unless otherwise specified and limited, it should be noted that the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be mechanical connection or electrical connection, it can be the communication between two elements, it can be directly connected, or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0043] Figure 1This is a schematic diagram of a chemical mechanical polishing (CMP) apparatus 1000 according to one embodiment of this application. The CMP apparatus 1000 may include a polishing unit 1100, a support head 100, a dresser 400, and a liquid supply unit 500. Specifically, the polishing unit 1100 may 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 with it along the axis Ax. The horizontally movable support 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 dressing arm and a dressing head, which is disposed on one side of the polishing disc 300. The dressing arm drives the rotating dressing 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 distribute the polishing liquid onto the surface of the polishing pad 200.

[0044] Figure 2 This is a schematic cross-sectional view of a chemical mechanical polishing device 1000. Figure 3 for Figure 2 Enlarged view at point A. For simplicity, only the carrier head 100, polishing unit 1100, and wafer W are shown. Typically, by adjusting the pressure of the retaining ring 120 of the carrier head 100, the polishing pad 200 can be locally deformed, thereby controlling the edge removal rate of the wafer W. Figure 2 and Figure 3 A schematic diagram of the wafer sliding out of the carrier head 100 is shown. During wafer polishing, the pressure of the retaining ring 120 is usually continuously adjusted. In some processes, when the pressure of the retaining ring 120 is low, the retaining ring 120 may partially separate axially from the polishing unit 1100, causing the wafer W to slide out of the carrier head 100 (specifically, from the retaining ring 120). To prevent slippage, 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 can easily exacerbate the glazing of the polishing pad 200 (i.e., 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, creating a gap between the retaining ring 120 and the polishing unit 1100, thus causing the wafer to slide out of the carrier head.

[0045] Therefore, the pressure control range of the retaining ring is small. If the pressure is too small, there are problems such as (1) the retaining ring and the polishing unit are not in close axial contact, which leads to slippage. If the pressure is too large, there are problems such as (1) the polishing pad is easily glazed, which leads to slippage, and (2) the friction is too large, which leads to the retaining ring being skewed, which causes slippage.

[0046] To solve one or more of the above problems, Figure 4 A cross-sectional view of a carrier head 100 according to one embodiment of this application is shown, which can be used for Figure 1The chemical mechanical polishing apparatus 1000 is shown. As Figure 4 , the carrier head 100 mainly comprises a carrier head body 110 and a retaining ring 120, the carrier head body 110 can comprise a gas distribution base 111, a main base 112, a connecting flange 113 for connection, a carrier disk 114, a first cover plate 1151, a second cover plate 1152 and an elastic membrane 116. The gas distribution base 111 is connected with the main base 112 through a diaphragm 117, and the elastic membrane 116 is connected to the bottom of the carrier disk 114 through a compression ring 118. The retaining ring 120 is arranged on the side of the carrier head body 110 facing the wafer W, i.e. the lower side of the carrier head body 110 in Figure 4 . The retaining ring 120 is arranged around the outer periphery of the elastic membrane 116, the elastic membrane 116 carries the wafer W and presses the wafer W against the polishing pad 200 of the polishing unit 1100, and the retaining ring 120 radially defines the wafer W therein and abuts against the polishing pad 200 together with the wafer W for wafer polishing. The retaining ring 120 is configured with an axially through mounting hole 121.

[0047] Figure 5 For Figure 4 , the enlarged view of B in FIG. 10B can be seen, the carrier head 100 according to an embodiment of the present application further comprises an anti-slip piece mechanism 130 arranged at least partially in the mounting hole 121, as shown in Figure 5 , the anti-slip piece mechanism 130 comprises: an anti-slip piece seat 131, an anti-slip piece body 132 extending axially and passing through the anti-slip piece seat 131, the anti-slip piece body 132 can be elastically abutted to the carrier head body 110, for example, via an elastic member 133, such as a spring or a damper, so as to be axially telescopic, so as to be retracted into the mounting hole 121 when the retaining ring 120 abuts against the polishing unit 1100 (see Figure 7 , Figure 8 ), or to be axially extended from the retaining ring 120 to block the wafer from slipping out of the retaining ring 120 when the retaining ring 120 is axially separated from the polishing unit 1100 (i.e. not completely tightly abutting, including partially separating or completely separating) (see Figure 9 , Figure 10 ). Specifically, the anti-slip piece body 132 is pressed 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 is stretched) to extend from the retaining ring 120 when the retaining ring 120 is axially separated from the polishing unit 1100, so that the anti-slip piece body 132 can block the wafer W when the wafer W is about to slip out of the gap between the retaining ring 120 and the polishing unit 1100. The anti-slip piece mechanism 130 can be made of a corrosion-resistant material to reduce the corrosion of the polishing liquid to the anti-slip piece mechanism 130.

[0048] According to the technical solution of the present application, by arranging the anti-skid piece mechanism 130 which can axially extend and retract at the retaining ring 120, when the pressure between the retaining ring 120 and the polishing unit 1100 is small and the wafer W has a tendency to slide radially due to the axial separation, or when the bearing head 100 is deflected due to the large friction between the retaining ring 120 and the polishing unit 1100, causing the wafer W to have a tendency to slide radially, the anti-skid piece body 132 of the anti-skid piece mechanism 130 can extend from the retaining ring 120 to block the wafer W, thereby avoiding the risk of wafer sliding and reducing wafer breakage. At the same time, the pressure of the retaining ring 120 can have a higher upper limit and a lower lower limit to prevent the wafer from sliding, thereby expanding the adjustment range of the pressure of the retaining ring 120, improving the polishing adjustment range, control flexibility and accuracy of the chemical mechanical polishing equipment 1000, and further improving the effectiveness and precision of wafer processing.

[0049] In addition, the anti-skid piece mechanism 130 can be made of a corrosion-resistant material, thereby reducing the corrosion of the polishing liquid on the anti-skid piece mechanism 130, ensuring the effectiveness of the anti-skid piece mechanism 130, prolonging its service life, and reducing the pollution caused by the corrosion of the anti-skid piece mechanism 130 to the polishing environment, ensuring the efficient progress of the chemical mechanical polishing process.

[0050] As shown in the enlarged view of Figure 5 and Figure 6 , the anti-skid piece body 132 can include an axially extending rod 1321 and a ball assembly 1322 connected to one end (i.e. the lower end shown in the figure) of the rod 1321 facing the polishing unit 1100. The anti-skid piece body 132 is in rolling contact with the polishing unit 1100 through the ball assembly 1322, thereby reducing the friction between the anti-skid piece body 132 and the polishing pad 200, and further reducing the wear of the polishing pad 200 caused by the anti-skid piece body 132, improving the service life of the anti-skid piece body 132 and the polishing pad 200, and ensuring the wafer polishing efficiency.

[0051] In a specific embodiment, the ball assembly 1322 can include a connecting block 1322a and balls 1322b, the connecting block 1322a is configured with a hemispherical rolling cavity 1322d opening towards the polishing unit 1100, the balls 1322b are partially (e.g. half of the balls 1322b) contained in the rolling cavity 1322d and can roll in various directions relative to the rolling cavity 1322d, thereby forming a universal ball. The ball assembly 1322 can also include one or more auxiliary balls 1322c disposed between the inner wall of the rolling cavity 1322d and the balls 1322b, the diameter of the auxiliary balls 1322c is equal to the difference between the inner radius of the rolling cavity 1322d and the outer radius of the balls 1322b, i.e. the auxiliary balls 1322c are respectively tangent to the rolling cavity 1322d and the balls 1322b. By providing auxiliary balls 1322c, the rolling connection between the balls 1322b and the rolling cavity 1322d can be achieved, the rolling friction between the balls 1322b and the rolling cavity 1322d can be reduced, the wear between the two can be reduced, and the smoothness of the rolling of the balls 1322b can be improved, thereby improving the smoothness of the relative movement between the anti-slip sheet mechanism 130 and the polishing unit 1100.

[0052] According to the arrangement of the ball assembly 1322 of the present application, the anti-slip sheet body 132 is in rolling contact with the polishing unit 1100, thereby reducing the friction between the anti-slip sheet body 132 and the polishing pad 200, thereby reducing the wear of the polishing pad 200 caused by the anti-slip sheet body 132, improving the service life of the anti-slip sheet body 132 and the polishing pad 200, and ensuring the polishing efficiency of the wafer. Further, the arrangement of the ball assembly 1322 changes the sliding friction between the retaining ring 120 and the polishing unit 1100 to rolling friction at least partially, reduces the contact area between the retaining ring 120 and the polishing pad 200, and reduces the friction therebetween, thereby reducing the wear of the polishing pad 200 by the retaining ring 120, 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.

[0053] In a preferred embodiment, the balls 1322b have smooth and dense surfaces to prevent the accumulation of contaminants, such as debris generated by wafer polishing, on their surfaces, ensuring their cleanliness and surface smoothness. The balls 1322b can be made of a first plastic material, which includes one or more of polyether ether ketone (PEEK), polyphenylene sulfide (PPS), polyimide (PAI), polyethylene terephthalate (PET-P), and polytetrafluoroethylene (PTFE), which have good wear resistance and chemical corrosion resistance, which is beneficial to reducing the wear and chemical corrosion of the balls 1322b, ensuring the surface smoothness and rolling smoothness of the balls, and reducing the pollution of the wafer polishing environment by the wear or corrosion debris of the balls.

[0054] In addition, the connecting block 1322a and the rod member 1321 can also be made of the same or different plastic materials as the ball. For example, the rod member 1321 can be made of polyether ether ketone (PEEK) or polyphenylene sulfide (PPS). The auxiliary ball 1322c can also be made of, for example, a smooth and dense material to have a smooth and dense surface.

[0055] In a further embodiment, the rolling cavity 1322d is configured with a retaining ring 1322e extending radially inward from the periphery thereof, and the auxiliary ball 1322c is partially accommodated in the rolling cavity 1322d through the retaining ring 1322e. Figure 6 In the embodiment of the connecting block 1322a, the retaining ring 1322e can be integrally formed on the connecting block 1322a, and in other embodiments, it can also be formed separately from the connecting block 1322a. The ball 1322b is partially accommodated in the rolling cavity 1322d through the retaining ring 1322e, the inner diameter of the retaining ring 1322e is adapted to the outer diameter of the ball 1322b, for example, allowing the two to relatively roll with a small gap. The retaining ring 1322e can have a certain thickness in the up-down direction, the position of the middle of the thickness is matched with the diameter position of the ball 1322b, and the radially inward side of the retaining ring 1322e can be a curved torus surface matched with 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 provision of the retaining ring 1322e can limit the auxiliary ball 1322c in the rolling cavity 1322d, prevent the auxiliary ball 1322c from falling out of the rolling cavity 1322d, and the retaining ring 1322e can also block the polishing liquid or other contaminants from entering the rolling cavity 1322d to a greater extent, ensuring the cleanliness of the rolling cavity 1322d and reducing the failure of the rolling cavity 1322d due to pollution. Figure 6 In the embodiment of the connecting block 1322a, the retaining ring 1322e can be integrally formed on the connecting block 1322a, and in other embodiments, it can also be formed separately from the connecting block 1322a. The ball 1322b is partially accommodated in the rolling cavity 1322d through the retaining ring 1322e, the inner diameter of the retaining ring 1322e is adapted to the outer diameter of the ball 1322b, for example, allowing the two to relatively roll with a small gap. The retaining ring 1322e can have a certain thickness in the up-down direction, the position of the middle of the thickness is matched with the diameter position of the ball 1322b, and the radially inward side of the retaining ring 1322e can be a curved torus surface matched with 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 provision of the retaining ring 1322e can limit the auxiliary ball 1322c in the rolling cavity 1322d, prevent the auxiliary ball 1322c from falling out of the rolling cavity 1322d, and the retaining ring 1322e can also block the polishing liquid or other contaminants from entering the rolling cavity 1322d to a greater extent, ensuring the cleanliness of the rolling cavity 1322d and reducing the failure of the rolling cavity 1322d due to pollution.

[0056] In a preferred embodiment, the end of the connecting block 1322a towards the rod member 1321 can be threadedly connected with the rod member 1321. Specifically, the end of the connecting block 1322a towards the rod member 1321 can be configured with a threaded hole recessed away from the rod member 1321, for example Figure 6 the upwardly open hole in the upper part of the connecting block 1322a. The end of the rod member 1321 towards the connecting block 1322a can be configured with an external thread matched with the threaded hole, and the connecting block 1322a and the rod member 1321 are threadedly connected via the threaded hole and the external thread.

[0057] Also see 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 in sequence away from the carrier head body 110, the first hole section 1211 is configured to accommodate the anti-skid piece seat 131, and the second hole section 1212 is configured to pass through the anti-skid piece body 132. The anti-skid piece seat 131 includes an axially extending accommodation cavity 1311, which is open towards the carrier head body 110, and the bottom of the accommodation cavity 1311 opposite to the carrier head body 110 is configured with a through hole 1312. The rod 1321 of the anti-skid piece body 132 includes a first rod section 1321a, a second rod section 1321b and a third rod section 1321c in sequence away from the carrier head body 110; the outer diameter of the second rod section 1321b is greater than the outer diameters of the first rod section 1321a and the third rod section 1321c respectively, and the outer diameter of the second rod section 1321b is greater than the inner diameter of the through hole 1312, so that the second rod section 1321b is defined in the accommodation cavity 1311 without being pulled out of the accommodation cavity 1311. The first rod section 1321a and the second rod section 1321b are axially movably accommodated in the accommodation cavity 1311, and the third rod section 1321c is connected with the ball assembly 1322, for example, is threadedly connected with the connecting block 1322a of the ball assembly 1322. In Figure 5 In the embodiment shown in the middle, the elastic member 133 is a spring, which is wrapped outside the first rod section 1321a, and one end of the spring abuts against the second rod section 1321b, and the other end abuts against the carrier head body 110, for realizing the axial expansion and contraction of the anti-skid piece body 132.

[0058] In the preferred embodiment, the spring can be made of a second plastic material, which can be, for example, polyamide (PA, commonly known as nylon), polyether ether ketone (PEEK) or polytetrafluoroethylene (PTFE). The spring is made of a plastic material, which reduces the chemical corrosion of the spring, ensures the stability of the elastic performance, and further ensures the effectiveness of the elastic effect, so that the anti-skid piece mechanism 130 can timely and effectively perform the anti-skid piece operation to prevent the wafer from sliding out. It should be understood that the first plastic material and the second plastic material can be the same or different.

[0059] From the outside structure, the anti-skid piece seat 131 can include a first seat section 131a assembled in the carrier head main body 110 and a second seat section 131b assembled in the mounting hole 121. The outer diameter of the first seat section 131a can be greater than the outer diameter of the second seat section 131b, and a chamfer or a smooth transition structure can be arranged therebetween to reduce stress concentration and improve structural strength. Correspondingly, the carrier head main body 110 (specifically, the main base body 112) can be configured with an assembly hole 1101 opening towards the retaining ring 120, the assembly hole 1101 matching the first seat section 131a in size and position, and the assembly hole 1101 can be threadedly matched with the first seat section 131a. The elastic piece 133 can abut against the bottom of the assembly hole 1101 towards the carrier head main body 110. In the preferred embodiment, the edge portion of the assembly hole 1101 can also be designed as a transition structure matching 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-skid piece seat 131 being partially arranged in the mounting hole 121 and partially arranged in the assembly hole 1101 as shown in the figure, in alternative embodiments, the anti-skid piece seat 131 can also be entirely arranged in the mounting hole 121, at which time the carrier head main body 110 can not be provided with the assembly hole 1101, and the elastic piece 133 directly abuts against the bottom surface of the carrier head main body 110.

[0060] Figure 7 For Figure 4 a schematic cross-sectional view of the carrier head 100 in the polishing unit 1100 in axial abutment; Figure 8 For Figure 7 an enlarged view of C in the polishing unit 1100. It can be seen that the retaining ring 120 is in axial abutment with the polishing unit 1100, at which time the wafer W is retained in the retaining ring 120, and the anti-skid piece mechanism 130 is retracted in the mounting hole 121 of the retaining ring 120. Figure 9 For Figure 4 a schematic cross-sectional view of the carrier head 100 in the polishing unit 1100 in axial separation; Figure 10 For Figure 9 an enlarged view of D in the polishing unit 1100. 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 in the axial direction, at which time the wafer W has a tendency to slide radially out of the retaining ring 120, and the anti-skid piece mechanism 130 is extended axially outward from the mounting hole 121 of the retaining ring 120 under the action of the elastic piece 133, and the sidewall on the radially inner side of the connecting block 1322a of the ball assembly 130 radially blocks the wafer W. In the subsequent process of carrier head rotation, the wafer W will be brought back into the retaining ring 120, thereby avoiding wafer sliding out and the resulting wafer breakage, while allowing adjustment to a smaller pressure when actively adjusting the retaining ring 120 pressure, thus achieving a larger adjustment range of the retaining ring 120 pressure, improving the flexibility and accuracy of polishing control.

[0061] In a preferred embodiment, the carrier head 100 can include a plurality of anti-skid mechanisms 130 distributed along the circumference of the retaining ring 120. Figure 11 For Figure 4 A bottom view schematic diagram of the retaining ring 120 of the carrier head 100 in FIG. 1, showing a plurality of anti-skid mechanisms 130 distributed along the circumference of the retaining ring 120. In the illustrated embodiment, the retaining ring 120 is configured on the side facing the polishing unit 1100 with a plurality of grooves 122 recessed from the surface of the retaining ring 120 away from the polishing unit 1100, which penetrates the outer side and the inner side of the retaining ring 120 in the radial direction, thereby forming channels for the flow of polishing liquid or debris into or out of the retaining ring 120. The plurality of grooves 122 can be evenly distributed along the circumference of the retaining ring 120, or in alternative embodiments, one anti-skid mechanism 130 can be provided between adjacent two grooves 122, or two or more anti-skid mechanisms 130 can be evenly spaced along the circumference between adjacent two grooves 122, i.e. the number of anti-skid mechanisms 130 can be an integer multiple of the number of grooves 122.

[0062] In addition, in the embodiments shown in Figure 4 , 5 or Figure 8 , the anti-skid mechanism 130 can be biased towards the radial inner side of the retaining ring 120 in the radial direction, for example, arranged within 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-skid mechanism 130 described herein can be understood as the position of the central axis of the anti-skid mechanism 130 or the position of the vertical axis of the ball 1322b.

[0063] The following briefly describes an exemplary assembly method of the carrier head 100 shown in Figure 4 or Figure 5 .

[0064] S1: Assembling the anti-skid mechanism 130, which can specifically include:

[0065] S1-1: Inserting the rod member 1321 into the anti-skid seat 131;

[0066] S1-2: Connecting the ball assembly to the rod member 1321;

[0067] S1-3: Assembling the elastic member 133 to the rod member 1321;

[0068] S2: Assembling the anti-skid mechanism 130 to the carrier head body 110, specifically to the assembly hole 1101.

[0069] S3: Assemble the retaining ring 120 to the carrier head body 110, specifically, make the mounting hole 121 of the retaining ring 120 sleeved outside the anti-skid piece mechanism 130, namely: make the anti-skid piece mechanism 130 inserted into the mounting hole 121.

[0070] It should be understood that the above assembly method is only exemplary, and when the carrier head 100 has other structural forms, the specific operation of assembly or the operation sequence of each step can be adjusted as appropriate.

[0071] The above embodiments are only used to illustrate the present application, and are not intended to limit the present application. 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 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 processing, characterized in that, Comprising: a carrier head body; a retaining ring disposed on a side of the carrier head body facing a wafer, the retaining ring defining the wafer therein, the retaining ring being configured with a mounting hole extending axially therethrough; a wafer edge removal rate being regulated by adjusting a pressure of the retaining ring to locally deform a polishing pad under the carrier head; an anti-skid piece mechanism disposed at least partially in the mounting hole, the anti-skid piece mechanism comprising an anti-skid piece seat extending axially therethrough and an anti-skid piece body passing through the anti-skid piece seat; the anti-skid piece body being configured to be axially retractable into the mounting hole when the retaining ring abuts against a polishing unit and to be axially extendable out of the retaining ring when the retaining ring is axially separated from the polishing unit due to a relatively small pressure therebetween causing a wafer to have a tendency to slide radially out of the retaining ring or a relatively large frictional force therebetween causing the carrier head to be deflected and thus causing the wafer to have a tendency to slide radially out of the retaining ring, so as to block the wafer from sliding out of the retaining ring and to expand a pressure adjustment range of the retaining ring.

2. The load head of claim 1 wherein, The anti-skid piece body comprises an axially extending rod and a ball assembly connected to an end of the rod facing the polishing unit, the anti-skid piece body being in rolling contact with the polishing unit via the ball assembly.

3. The load head of claim 2 wherein, The ball assembly comprises a connecting block and a ball, the connecting block being configured with a hemispherical rolling cavity opening towards the polishing unit, the ball being partially accommodated in the rolling cavity and being rollable in respective directions relative to the rolling cavity.

4. The load head of claim 3 wherein, The ball assembly further comprises one or more auxiliary balls disposed between inner walls of the rolling cavity and the ball, the auxiliary balls having a diameter equal to a difference between an inner radius of the rolling cavity and an outer radius of the ball.

5. The load head of claim 4 wherein, The rolling cavity is configured with a retaining ring extending radially inwardly from a periphery thereof, the ball being partially accommodated in the rolling cavity via the retaining ring, an inner diameter of the retaining ring being adapted to an outer diameter of the ball.

6. The load head of claim 2 wherein, An end of the connecting block facing the rod is threadedly connected to the rod.

7. The load head of claim 6 wherein, An end of the connecting block facing the rod is configured with a threaded hole recessed away from the rod, an end of the rod facing the connecting block is configured with an external thread matching the threaded hole, the connecting block and the rod being threadedly connected via the threaded hole and the external thread.

8. The load head of any of claims 2-7, wherein, The anti-skid piece body is elastically abutted to the carrier head body via an elastic member, the anti-skid piece body compressing the elastic member to retract into the mounting hole, and the anti-skid piece body extending out of the retaining ring via an extension of the elastic member.

9. The load head of claim 8 wherein, The mounting hole comprises a first hole section and a second hole section successively away from the carrier head body, the first hole section being configured to accommodate the anti-skid piece seat, the second hole section being configured for the anti-skid piece body to pass through.

10. The load head of claim 9, wherein The anti-skid piece seat comprises an accommodation cavity extending axially, a bottom of the accommodation cavity facing away from the carrier head body being configured with a through hole; The rod includes a first rod segment, a second rod segment and a third rod segment in sequence away from the carrier head body; an outer diameter of the second rod segment is greater than outer diameters of the first rod segment and the third rod segment respectively, and the outer diameter of the second rod segment is greater than an inner diameter of the through hole so that the second rod end is defined in the accommodating cavity; the first rod segment and the second rod segment are accommodated in the accommodating cavity in an axially movable manner, and the third rod segment is connected with the ball assembly.

11. The load head of claim 10 wherein, The elastic member is a spring, the spring is wrapped outside 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.

12. The load head of any one of Claims 1-7, wherein, The anti-skid sheet seat includes a first seat segment assembled in the carrier head body and a second seat segment assembled in the mounting hole.

13. The load head of claim 12, wherein, The carrier head body is configured with a mounting hole facing the retaining ring opening, the mounting hole matches the first seat segment in size and position, and the mounting hole is threadedly connected with the first seat segment.

14. The load head of any one of claims 1-7, wherein, The carrier head includes a plurality of anti-skid sheet mechanisms distributed along the circumference of the retaining ring.

15. The load head of claim 14 wherein, The plurality of anti-skid sheet mechanisms are uniformly distributed along the circumference of the retaining ring.

16. The load head of claim 14 wherein, The retaining ring is configured with a plurality of grooves on a side facing the polishing unit, the plurality of grooves are uniformly distributed along the circumference of the retaining ring, one anti-skid sheet mechanism is arranged between two adjacent grooves, or two or more anti-skid sheet mechanisms are uniformly arranged at intervals between two adjacent grooves.

17. A chemical mechanical polishing apparatus, characterized in that, The chemical mechanical polishing equipment includes the carrier head according to any one of claims 1-16.

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