Polishing head with local wafer pressure

Abstract

A polishing system includes a carrier arm having an actuator disposed on a lower surface of the carrier arm. The actuator includes a piston and a roller coupled to a distal end of the piston. The polishing system includes a polishing pad and a substrate carrier suspended from the carrier arm and configured to apply pressure between a substrate and the polishing pad. The substrate carrier includes a housing, a clasp, and a membrane. The substrate carrier includes an upper load ring disposed in the housing. The roller of the actuator is configured to contact the upper load ring during relative rotation between the substrate carrier and the carrier arm. The actuator is configured to apply a load to a portion of the upper load ring, thereby changing the pressure applied between the substrate and the polishing pad.

Description

Background Technology Technical Field

[0002] The embodiments of this disclosure generally relate to apparatus and methods for polishing and / or planarizing substrates. More specifically, embodiments of this disclosure relate to polishing heads for chemical mechanical polishing (CMP).

[0003] Related technical specifications

[0004] Chemical mechanical polishing (CMP) is commonly used in the fabrication of semiconductor devices to planarize or polish material layers disposed on the surface of a polycrystalline silicon (Si) substrate. In a typical CMP process, the substrate is held in a substrate carrier (e.g., a polishing head), which presses the substrate against a rotating polishing pad in the presence of a polishing slurry. Generally, the polishing slurry comprises an aqueous solution of one or more chemical components and nanoscale abrasive particles suspended in the aqueous solution. Material is removed from the surface of the substrate material layer in contact with the polishing pad through a combination of chemical and mechanical activity provided by the polishing slurry and the relative motion between the substrate and the polishing pad.

[0005] The substrate carrier comprises a membrane having multiple radial regions that contact the substrate. The membrane may include three or more regions, such as 3 to 11 regions, for example, 3, 5, 7, or 11 regions. The regions are typically labeled from the outside to the inside (e.g., for a membrane with 11 regions, from region 1 on the outer side to region 11 on the inner side). Using different radial regions, the pressure applied to the chamber bounded by the back side of the membrane can be selectively controlled to control the center-to-edge profile of the force applied by the membrane to the substrate, thereby controlling the center-to-edge profile of the force applied by the substrate to the polishing pad. Even with different radial regions, a persistent problem in CMP is the occurrence of edge effects, i.e., over-polishing or under-polishing of the outermost 5-10 mm of the substrate. Edge effects can be caused by a sharp increase in pressure around the periphery of the substrate between the substrate and the polishing pad, due to a knife-edge effect where the leading edge of the substrate is scraped along the upper surface of the polishing pad. Current methods of applying pressure to different radial regions result in a force distribution across a large area of ​​the substrate. This distribution of load applied over a large area cannot prevent the aforementioned edge effects.

[0006] To mitigate edge effects and improve the resulting surface finish and smoothness of the substrate, the polishing head includes a retainer surrounding a film. The retainer has a bottom surface for contacting the polishing pad during polishing and a top surface that is secured to the polishing head. By moving the area of ​​increased pressure from under the substrate to under the retainer, the pre-compression of the polishing pad below the bottom surface of the retainer reduces the pressure increase at the periphery of the substrate. However, the improvement in the uniformity of the substrate's periphery is typically limited and has proven insufficient for many applications.

[0007] Therefore, there is a need in the art for apparatus and methods to solve the above problems. Summary of the Invention

[0008] The embodiments of this disclosure generally relate to apparatus and methods for polishing and / or planarizing substrates. More specifically, embodiments of this disclosure relate to polishing heads for chemical mechanical polishing (CMP).

[0009] In one embodiment, a polishing system includes a support arm having an actuator disposed on a lower surface of the support arm, the actuator including: a piston; and a roller coupled to a distal end of the piston; a polishing pad; and a substrate carrier suspended from the support arm and configured to apply pressure between a substrate and the polishing pad, the substrate carrier including: a housing; a retaining ring coupled to the housing; a membrane coupled to the housing and spanning an inner diameter of the retaining ring, the membrane having a bottom portion configured to contact a substrate and a side portion extending orthogonally to the bottom portion, wherein the side portion includes an annular groove formed along an outer edge of the side portion, and wherein an annular sleeve is disposed in the annular groove; and an upper load ring disposed in the housing, wherein the actuator... The rollers are configured to contact the upper load ring during relative rotation between the substrate carrier and the bracket arm; a plurality of load pins are circumferentially disposed in the housing, each of the plurality of load pins having a proximal end coupled to the upper load ring and a distal end coupled to the lower load ring; and the lower load ring is disposed in the housing, the lower load ring having a flange portion coupled to the distal end of each of the plurality of load pins and a body portion extending orthogonally relative to the flange portion, wherein the body portion contacts an annular sleeve disposed in the membrane; wherein actuation of the actuator is configured to apply a load to a portion of the upper load ring, one or more of the plurality of load pins, the lower load ring, the annular sleeve, and the outer edge region of the membrane, thereby changing the pressure applied between the substrate and the polishing pad. Attached Figure Description

[0010] To gain a more detailed understanding of the features described above, the present disclosure, which has been briefly summarized above, can be described in more detail with reference to embodiments, some of which are illustrated in the accompanying drawings. However, it should be noted that the drawings only illustrate exemplary embodiments of the present disclosure and should therefore not be construed as limiting the scope of the disclosure, as other equivalent embodiments are permissible.

[0011] Figure 1A This is a schematic side view of an exemplary polishing station that can be used to practice the methods described herein, according to one or more embodiments.

[0012] Figure 1B This is a schematic plan view of a part of a multi-station polishing system that can be used to practice the methods described herein, according to one or more embodiments.

[0013] Figure 2A It can be used Figure 1B A schematic side view of an embodiment of a substrate carrier in a polishing system.

[0014] Figure 2B yes Figure 2A An enlarged side sectional view of a portion of the image.

[0015] Figure 2C yes Figure 2A A magnified isometric view of a portion of the image.

[0016] Figure 3A It can be used Figure 1B A side cross-sectional view of yet another embodiment of the substrate carrier in the polishing system.

[0017] Figure 3B yes Figure 3A A schematic top view of the substrate carrier.

[0018] Figure 3C and Figure 3D yes Figure 3B An enlarged side sectional view of a portion of the internal actuators according to two different embodiments.

[0019] Figure 4 It can be used Figure 1B A side cross-sectional view of yet another embodiment of the substrate carrier in the polishing system.

[0020] To facilitate understanding, the same reference numerals are used where possible to indicate common elements in the figures. It is contemplated that elements and features of one embodiment can be advantageously combined in other embodiments without further description. Detailed Implementation

[0021] Before describing several exemplary embodiments of the apparatus and method, it should be understood that this disclosure is not limited to the details of the construction or process steps set forth in the following specific embodiments. It is conceivable that some embodiments of this disclosure may be combined with other embodiments.

[0022] Figure 1A This is a schematic side view of a polishing station 100a according to one or more embodiments, which can be used to practice the methods described herein. Figure 1B This is a schematic plan view of a multi-station polishing system 101 comprising multiple polishing stations 100a-c, wherein each of the polishing stations 100b-c is associated with... Figure 1AThe polishing station 100a described herein is essentially similar. Figure 1B In order to reduce visual clutter, the details on multiple polishing stations 100a-c are not shown. Figure 1A At least some of the components described in the description of polishing station 100a. Polishing systems suitable for benefiting from this disclosure include LK and The LKPRIME planarization system, among others, is available from Applied Materials, Inc. in Santa Clara, California.

[0023] like Figure 1A As shown, the polishing station 100a includes a platform 102, a first actuator 104 coupled to the platform 102, a polishing pad 106 disposed on and fixed to the platform 102, a fluid delivery arm 108 disposed above the polishing pad 106, a substrate carrier 110 (shown in cross-section), and a pad adjuster assembly 112. Here, the substrate carrier 110 is self-supporting to the bracket assembly 114 (… Figure 1B The bracket arm 113 suspends the substrate carrier 110, such that the substrate carrier 110 is positioned above and facing the polishing pad 106. The bracket assembly 114 is rotatable about the bracket axis C to position the substrate carrier loading station 103 of the multi-station polishing system 101. Figure 1B The substrate carrier 110 is moved between the substrate carrier 100a-c and / or the polishing stations 100a-c, thereby moving the substrate 122 held in place in the substrate carrier 110. The substrate carrier loading station 103 includes a load cup 150 (shown in dashed lines) for loading the substrate 122 onto the substrate carrier 110.

[0024] During substrate polishing, a first actuator 104 rotates a stage 102 about stage axis A, and a substrate carrier 110 is positioned above and facing the stage 102. The substrate carrier 110 pushes the surface of the substrate 122 (shown in dashed lines) to be polished against the polishing surface of the polishing pad 106 while rotating about carrier axis B. Here, the substrate carrier 110 includes a housing 111, an annular retaining ring 115 coupled to the housing 111, and a membrane 117 spanning the inner diameter of the retaining ring 115. The retaining ring 115 surrounds the substrate 122 and prevents the substrate 122 from slipping out of the substrate carrier 110 during polishing. The membrane 117 applies a downward force to the substrate 122 and loads (clamps) the substrate into the substrate carrier 110 during substrate loading operations and / or between substrate polishing stations. For example, during polishing, pressurized gas is supplied to the carrier chamber 119 to apply a downward force on the membrane 117, and thus a downward force on the substrate 122 in contact with the membrane 117. Before and after polishing, a vacuum can be applied to the chamber 119 to deflect the membrane 117 upward, creating a low-pressure pocket between the membrane 117 and the substrate 122, thereby securing the substrate 122 into the substrate carrier 110.

[0025] During polishing, the substrate 122 is pressed onto the pad 106 in the presence of polishing slurry supplied by the fluid delivery arm 108. The rotating substrate carrier 110 oscillates between the inner and outer radii of the stage 102 to partially reduce uneven wear on the surface of the polishing pad 106. Here, the substrate carrier 110 is rotated using a first actuator 124 and oscillated using a second actuator 126.

[0026] Here, the pad adjuster assembly 112 includes a fixed abrasive adjustment disc 120 (e.g., a diamond-coated disc) that can be pushed against the polishing pad 106 to restore the surface of the polishing pad 106 and / or remove polishing byproducts or other debris from the polishing pad 106. In other embodiments, the pad adjuster assembly 112 may include a brush (not shown).

[0027] The operation of the multi-station polishing system 101 and / or each polishing station 100a-c of the multi-station polishing system 101 is controlled by the system controller 136. Figure 1A The system controller 136 includes a programmable central processing unit (CPU 140) that operates in conjunction with memory 142 (e.g., non-volatile memory) and support circuitry 144. Support circuitry 144 is conventionally coupled to CPU 140 and includes caches, clock circuitry, input / output subsystems, power supplies, and combinations thereof coupled to various components of the polishing system 101 to facilitate control of the substrate polishing process. For example, in some embodiments, CPU 140 is one of any form of general-purpose computer processor (such as a programmable logic controller (PLC)) used in an industrial environment to control various polishing system components and subprocessors. Memory 142 coupled to CPU 140 is non-transient and includes one or more readily available memories, such as random access memory (RAM), read-only memory (ROM), floppy disk drives, hard disks, or any other form of local or remote digital storage.

[0028] Here, memory 142 is in the form of a computer-readable storage medium (e.g., non-volatile memory) containing instructions that, when executed by CPU 140, facilitate the operation of polishing system 101. The instructions in memory 142 are in the form of a program product (such as a program implementing the methods of this disclosure (e.g., middleware application, device software application, etc.)). The program code may conform to any of several different programming languages. In one example, this disclosure may be implemented as a program product stored on a computer-readable storage medium for use with a computer system. The program(s) of the program product define the functionality of the embodiments (including the methods described herein).

[0029] Illustrative computer-readable storage media include, but are not limited to: (i) non-writable storage media that permanently store information thereon (e.g., read-only memory devices within a computer, such as CD-ROM disks readable by a CD-ROM drive, flash memory, ROM chips, or any type of solid-state non-volatile semiconductor memory); and (ii) writable storage media that store variable information thereon (e.g., floppy disks or hard disk drives within a floppy disk drive, or any type of solid-state random access semiconductor memory). Such computer-readable storage media are embodiments of this disclosure when carrying computer-readable instructions that direct the functionality of the methods described herein.

[0030] Figure 2A It can be used Figure 1B A schematic side view of an embodiment of the substrate carrier 110 in the polishing system 101. Figure 2B yes Figure 2A An enlarged side sectional view of a portion of the image. Figure 2C yes Figure 2A A magnified isometric view of a portion. Figure 2C In this design, the housing 111 and the retaining ring 115 are removed to more clearly show the internal components of the substrate carrier 110. The membrane 117 includes a bottom portion 117a spanning the inner diameter of the retaining ring 115 and a side portion 117b extending substantially parallel to the inner wall 115a of the retaining ring 115. An external actuator 202 (e.g., a linear actuator) is coupled to the bracket arm 113. The external actuator 202 is disposed between the bracket arm 113 and the housing 111 of the substrate carrier 110. Although... Figures 2A to 2C Only one external actuator 202 is shown, but it should be understood that multiple external actuators 202 may be arranged circumferentially about the carrier axis B. In some embodiments, the number of external actuators 202 may be 1 to 12, such as 1 to 4, 4 to 12, or 4 to 8.

[0031] The external actuator 202 includes a cylindrical housing 204 coupled to the underside of the carrier arm 113. The cylindrical housing 204 is oriented substantially longitudinally along the z-axis (e.g., aligned in the direction of gravity). A piston 206 is partially disposed within the cylindrical housing 204. The piston 206 is actuable to extend and retract substantially along the z-axis relative to the cylindrical housing 204 (e.g., vertically movable). In one embodiment, a roller 208 is coupled to the distal end of the piston 206 using fasteners (e.g., clamps). The roller 208 is configured to contact the housing 111 to transfer a load from the external actuator 202 to the housing 111 or to one or more components of the housing, as described in detail below. The roller 208 enables the transfer of a load to the carrier head 110 during operation (e.g., when the external actuator 202 is stationary and the carrier head 110 is rotating).

[0032] The rollers 208 contact the upper load ring 210 disposed in the housing 111. The upper load ring 210 is an annular ring having an upper surface 212 and a plurality of lower surfaces 214 opposite to the upper surface 212. In some embodiments, the upper load ring 210 has a continuous annular upper surface. The upper surface 212 is exposed through the top of the housing 111 to maintain contact with the rollers 208 during rotation of the carrier head 110. In some other embodiments (not shown), the upper load ring 210 includes a plurality of arcuate segments having a plurality of upper surfaces 212. A plurality of load pins 216 are located below the upper load ring 210 and are circumferentially disposed about the bracket axis B of the substrate carrier 110. Each of the plurality of load pins 216 is oriented substantially longitudinally along the z-axis. Figure 2C The multiple load pins 216 are depicted more clearly in the text. For example... Figure 2C As shown, a plurality of load pins 216 are evenly spaced apart. In some embodiments, the plurality of load pins 216 may include 6 to 36 load pins, such as 12 to 24 load pins.

[0033] A plurality of load pins 216 are vertically disposed between the flange portions 220 of the upper load ring 210 and the lower load ring 218. The proximal end of each of the plurality of load pins 216 contacts one of the plurality of lower surfaces 214 of the upper load ring 210. The distal end of each of the plurality of load pins 216 is coupled to the flange portion 220 of the lower load ring 218 by a fastener (e.g., a machine screw). The lower load ring 218 includes a body portion 222 extending orthogonally to the flange portion 220. The body portion 222 extends substantially along the z-axis. The body portion 222 is radially disposed between the side portion 117b of the membrane 117 and the housing 111. The inner diameter of the body portion 222 is configured to engage the side portion 117b of the membrane 117. The body portion 222 includes a plurality of arcuate segments 224 with gaps 226 between adjacent segments 224. Figure 2C Segment 224 is circumferentially aligned with each of the plurality of load pins 216. Gaps 226 are spaced apart between adjacent load pins 216. In some other embodiments (not shown), the body portion 222 may be a continuous annular ring without gaps 226.

[0034] The side portion 117b of the membrane 117 includes an annular groove 117c formed along the outer edge of the side portion 117b. The outer diameter of the groove 117c is smaller than the outer diameter of the side portion 117b. An annular sleeve 228 is disposed in the groove 117c. The inner diameter of the sleeve 228 is configured to match the outer diameter of the groove 117c. The outer diameter of the sleeve 228 is larger than the outer diameter of the side portion 117b. The distal end of the body portion 222 of the lower load ring 218 engages the top edge of the sleeve 228, and the sleeve 228 is radially exposed outside the groove 117c. A segment 224 of the lower load ring 218 concentrates the load applied by each of the plurality of load pins 216 to the circumferential portion of the lower sleeve 228. Gap 226 ( Figure 2C This increases the compliance of the lower load ring 218 in the z-direction. The side portion 117b of the film 117 surrounding the groove 117c is partially disposed along the z-axis between the bottom edge of the sleeve 228 and the substrate 122. The lower end of the side portion 117b contacts the edge of the substrate 122. Therefore, applying a downward force to the sleeve 228 increases the pressure between the edge of the substrate 122 and the polishing pad 106.

[0035] In operation, actuation of the external actuator 202 causes the piston 206 to extend downward, thereby applying downward pressure to the upper load ring 210 via the roller 208. The downward pressure applied to the upper load ring 210 is ultimately transmitted to the edge of the substrate 112 via a load path that passes through multiple load pins 216, the lower load ring 218, the sleeve 228, and the side portion 117b of the membrane 117. Therefore, actuation of the external actuator 202 causes the outer radial portion of the membrane 117 to receive the load within a narrow region at the outer edges of the membrane 117 and the substrate 122, which may tend to tilt the bottom portion 117a relative to the xy-plane. Specifically, the narrowly distributed load on the outer edge of the membrane 117 and / or the subsequent tilting of the membrane 117 will tend to create a negative taper corresponding to a greater downward deflection of the bottom portion 117a from the central axis to the outer edge of the membrane 117. The narrowly distributed load on the outer edge of the membrane 117 changes the pressure applied between the substrate 122 and the polishing pad 106.

[0036] In some embodiments, the pressure applied to the edge of substrate 122 can be locally controlled. In other words, the pressure applied by each of the external actuators 202 can be positioned to an arcuate region of substrate 122, which is located below one or more active, load-applying external actuators 202. In some embodiments, the length of the arcuate region corresponding to local pressure control can be about 90° or less, such as about 60° or less, such as about 45° or less, such as about 30° or less, such as about 30° to about 90°. Thus, the pressure between substrate 122 and polishing pad 106 can be locally controlled within different circumferential regions by the timing actuation of each of the plurality of external actuators 202. By orienting and positioning the external actuators 202 in a desired position or orientation relative to stage 102 and / or bracket assembly 114, the pressure applied by the external actuators 202 can be applied to one or more desired regions of membrane 117 at any time during processing. In one example, one or more desired regions may include portions of the membrane that are close to the leading or trailing edge of the carrier head 110 at any given time as the carrier head 110 rotates and moves across the polishing pad 106 during processing. As disclosed herein, the carrier head 110 may move in a direction along the radius of the platform, in a direction tangential to the radius of the platform, or in an arcuate direction relative to the radius of the platform.

[0037] In some other embodiments (not shown) that can be combined with other embodiments described herein, the plurality of load pins 216 may be linear actuators or piezoelectric actuators configured to independently apply a downward force to the lower load ring 218.

[0038] In some embodiments (not shown), the upper load ring 210 is coupled to the annular sleeve 228. In such embodiments, the upper load ring 210, the plurality of load pins 216, and the lower load ring 218 form a continuous structure or component extending from the load application axis of the external actuator 202 to the annular sleeve 228.

[0039] Figure 3A It can be used Figure 1B An enlarged side cross-sectional view of another embodiment of the substrate carrier 300 in the polishing system 101. In this example, the substrate carrier 300 includes a decoupled membrane assembly 302. A flexible plate 304 is disposed between the housing 111 and the base assembly 116 for flexibly coupling the membrane assembly 302 to the housing 111. The flexible plate 304 is an annular plate. The flexible plate 304 has an inner flange 306 for coupling the flexible plate 304 to the housing 111. The flexible plate 304 has an outer flange 308 for coupling the flexible plate 308 to the inner tube 320.

[0040] Typically, the inner tube 320 (described in more detail below) is operable to apply a downward force along the z-axis to the outer flange 308 of the flexible plate 304. The flexible plate 304 also has a flexible portion 310 and a main body portion 312, which are radially adjacent to each other and extend between the inner flange 306 and the outer flange 308. The flexible portion 310 is thinner than each of the inner flange 306, the outer flange 308, and the main body portion 312, such that bending of the flexible plate 304 is concentrated primarily within the flexible portion 310.

[0041] An inner tube 320 is disposed within the housing 111 of the substrate carrier 300. The inner tube 320 is annular or arc-shaped. The inner tube 320 includes an upper clamp 322 and a lower clamp 324, which engage with each other to form a pressurized airbag. A connecting element 326 has an upper end that contacts the lower clamp 324 and a lower end that contacts the outer flange 308 of the flexible plate 304. Pressurization of the inner tube 320 applies a downward force to the outer flange 308 of the flexible plate 304, thereby generating torque in the flexible plate 304 and deflecting the outer flange 308 and the main body portion 312 toward the decoupled membrane assembly 302. Specifically, an annular protrusion 314 formed along the bottom surface of the flexible plate 304 contacts the upper portion 317d of the decoupled membrane assembly 302. Therefore, applying a downward force to the flexible plate 304 causes the outer radial portion of the membrane assembly 302 (including its bottom portion 317a) to receive the load within a narrow region at the outer edges of the membrane 317 and the substrate 122, which may tend to cause the bottom portion 317a to tilt relative to the xy plane. Specifically, the narrowly distributed load on the outer edge of the membrane 317 and / or the subsequent tilt of the membrane 317 will tend to form a negative taper corresponding to a greater downward deflection of the bottom portion 317a as it moves radially outward from the central axis to the outer edge of the membrane 317. In some embodiments, the narrowly distributed load received by the membrane assembly 302 can be locally controlled to produce a selectively distributed load on the substrate 122 along the outer radial portion of the membrane 317.

[0042] although Figure 3A Only one inner tube 320 is shown, but it should be understood that multiple inner tubes 320 may be arranged circumferentially around the carrier axis B. Figure 3B yes Figure 3A A schematic top view of the substrate carrier 300, showing the positions of multiple inner tubes 320. (Reference) Figure 3BThe substrate carrier 300 includes 12 individual arc-shaped inner tubes 320. However, other numbers of inner tubes 320 are also considered. In some embodiments, the number of inner tubes 320 can be 1 to 16, such as 1 to 4, 4 to 16, or 8 to 12. In some embodiments, the length of each inner tube 320 can be about 90° or less, such as about 60° or less, such as about 45° or less, such as about 30° or less, or such as about 30° to about 90°.

[0043] exist Figures 3A to 3B In some embodiments shown, the pressure applied to the edge of the substrate 122 can be locally controlled. In other words, the pressure can be localized to an arcuate region of the substrate 122 located below one or more pressurized inner tubes 320. Thus, as the carrier head 110 rotates about axis B during processing, the pressure between the substrate 122 and the polishing pad 106 can be locally controlled in different circumferential regions by timed pressurization of each of the plurality of inner tubes 320.

[0044] refer to Figure 3B The substrate carrier 300 includes a plurality of internal actuators 330 arranged circumferentially around the carrier axis B. Although Figure 3B Twelve internal actuators 330 are shown, but other numbers of internal actuators 330 are also considered. In some embodiments, the number of internal actuators 330 can be from one to sixteen, such as one to four, four to sixteen, or eight to twelve. (Reference) Figure 3B The number of internal actuators 330 in the substrate carrier is equal to the number of internal tubes 320. However, in some other embodiments (not shown), the number of internal actuators 330 and internal tubes 320 are different.

[0045] Multiple internal actuators 330 are structurally and functionally similar to external actuators 202. Typically, the multiple internal actuators 330 include a cylindrical housing 332 and a piston 334. The piston 334 is partially disposed within the cylindrical housing 332. The piston 334 is actuable to extend and retract substantially along the z-axis relative to the cylindrical housing 332.

[0046] Figure 3C and Figure 3D yes Figure 3B An enlarged side sectional view of a portion of the internal actuator 330 according to two different embodiments. Common Reference Figure 3C and 3D Each of the internal actuators 330c-d is configured to contact the upper portion 317d of the decoupled membrane assembly 302. The distal end of the piston 334 contacts the upper portion 317d of the membrane 317 to apply a downward force thereto. (Reference) Figure 3CThe piston 334 of the internal actuator 330c extends through a hole formed in the flexible plate 304 to contact the upper portion 317d of the membrane 317. On the other hand, refer to... Figure 3D Each of the plurality of internal actuators 330d is disposed between the flexible plate 304 and the upper portion 317d of the membrane 317. Specifically, a cylindrical housing 332 is fixedly coupled to the flexible plate 304. The cylindrical housing 332 is at least partially disposed in a corresponding groove formed in the bottom surface of the outer flange 308 of the flexible plate 304. A piston 334 extends below the bottom surface of the outer flange 308 of the flexible plate 304 and contacts the upper portion 317d of the membrane 317.

[0047] exist Figure 3C and 3D In this embodiment, the effect of the plurality of internal actuators 330c-d allows for the application of a narrowly distributed load to the outer edges of the membrane 317 and the substrate 122, which may cause the membrane assembly 302 to tilt, similar to the plurality of inner tubes 320 described above. Compared to using only one or the other of the plurality of inner tubes 320 or the internal actuators 330c-d, the plurality of inner tubes 320 and the internal actuators 330c-d can be actuated independently to provide more precise pressure control between the substrate 122 and the polishing pad 106.

[0048] although Figure 3C and Figure 3D The overall effect of the embodiments may be similar, but the force coupling mechanism between the multiple inner tubes 320 and the internal actuators 330c-d is different. Figure 3C In this configuration, the forces applied by multiple inner tubes 320 and internal actuators 330c are decoupled from each other, meaning that each force is applied independently. However, in Figure 3D In this process, these forces are not decoupled from each other. In other words, even if the multiple inner tubes 320 and the internal actuators 330d are actuated independently, the applied forces are actually coupled to each other through the flexible plate 304. For example, a downward force applied to the membrane 317 by one or more internal actuators 330d results in an equal and opposite reaction force applied in the upward direction to the bottom surface of the flexible plate 304. The resulting upward force acts in the opposite direction to the downward force applied to the flexible plate 304 by one or more inner tubes 320.

[0049] Figure 3C and Figure 3D Each of the embodiments described has certain unique advantages. (Go to...) Figure 3CIn this embodiment, because the multiple internal actuators 330c act on the flexible plate 304 rather than directly on the membrane 317, the multiple internal actuators 330c can be disposed within the housing 111, where there is sufficient space to accommodate significant design modifications to the multiple internal actuators 330c. Furthermore, positioning the multiple internal actuators 330c above the flexible plate 304 makes them less susceptible to slurry contamination. In some embodiments (not shown), additional sealing mechanisms can be incorporated into the substrate carrier 300 to prevent slurry contamination. For example, one or more sliding seals can be disposed between the piston 334 of the internal actuator 330c and the flexible plate 304 to enhance the seal between them. Now turning to Figure 3D In this embodiment, because the multiple internal actuators 330d act directly on the membrane 317 rather than on the flexible plate 304, the multiple internal actuators 330d can generate the same narrowly distributed load on the outer edge of the membrane 317 and / or produce tilting of the membrane 317, while the displacement of the piston 334 is small, which allows for the use of shorter actuators.

[0050] Figure 4 It can be used Figure 1B A side cross-sectional view of another embodiment of the substrate carrier 410 in the polishing system 101. Figure 4 The embodiments described herein can be combined with other embodiments. The substrate carrier 410 includes an internal actuator 430 coupled to the base assembly 116. The internal actuator 430 may be structurally and functionally similar to the external actuator 202 and / or the internal actuators 330, 340. Typically, the internal actuator 430 includes a cylindrical housing 432 and a piston 434. The cylindrical housing 432 is coupled to the bottom side of the base assembly 116. The piston 434 is partially disposed within the cylindrical housing 432. The piston 434 is actuable to extend and retract substantially along the z-axis relative to the cylindrical housing 432. The piston 434 is configured to contact the bottom portion 117a of the membrane 117 to transfer a load from the internal actuator 430 to the substrate 122 via the membrane 117.

[0051] although Figure 4Only one internal actuator 430 is shown, but it should be understood that multiple internal actuators 430 may be arranged in one or more concentric rings around the carrier axis B. In some embodiments (not shown), the number of internal actuators 430 in each concentric ring may be 1 to 12 external actuators, such as 1 to 4 external actuators, such as 4 to 12 external actuators, such as 4 to 8 external actuators. In some other embodiments (not shown), the multiple internal actuators 430 comprise an array of internal actuators 430 arranged at different radial distances from the carrier axis B. In some embodiments (not shown), one or more pressure regions of the membrane 117 comprise a ring of internal actuators 430. In some embodiments, the pressure between the substrate 122 and the polishing pad 106 can be locally controlled in different circumferential and radial regions by timing actuation of each of the multiple internal actuators 430.

[0052] While the foregoing relates to embodiments of this disclosure, other and further embodiments of this disclosure may be devised without departing from the basic scope of this disclosure, the scope of which is defined by the appended claims.

Claims

1. A substrate carrier configured to be attached to a polishing system for polishing a substrate, the substrate carrier comprising: a housing; a clasp coupled to the housing; a membrane disposed within the housing and spanning an inner diameter of the clasp, the membrane having: a bottom portion configured to contact the substrate; an upper portion opposite the bottom portion; and a side portion extending orthogonally between the bottom portion and the upper portion, wherein an outer edge connects the side portion to the bottom portion; and an actuator disposed on the outer edge of the membrane and configured to apply a load to the outer edge of the membrane toward the substrate, thereby varying a pressure applied between the substrate disposed in the substrate carrier and a polishing pad, wherein the side portion includes an annular groove formed along an outer edge of the side portion, an annular sleeve is disposed in the annular groove, and the load applied to the outer edge of the membrane is applied via the annular sleeve, and wherein the actuator includes a piston that engages the upper portion of the membrane, wherein the load applied to the outer edge of the membrane is applied by the piston applying a load to the upper portion of the membrane.

2. The substrate carrier of claim 1, further comprising a flex plate coupled to the housing.

3. The substrate carrier of claim 2, wherein the piston of the actuator is disposed through an aperture formed in the flex plate.

4. The substrate carrier of claim 2, wherein the actuator is disposed on a lower surface of the flex plate, wherein the load applied to the upper portion of the membrane is applied via the annular sleeve.

5. The substrate carrier of claim 1, further comprising: an upper load ring configured to contact the housing; a lower load ring disposed in the housing, and a plurality of load pins disposed circumferentially in the housing, each of the plurality of load pins having a proximal end coupled to the upper load ring and a distal end coupled to the lower load ring; wherein the load applied by the piston is applied to the outer edge of the membrane via a portion of the upper load ring, one or more of the plurality of load pins, the lower load ring, and the annular sleeve.

6. The substrate carrier of claim 5, wherein the upper load ring is disposed in the housing. a flange portion coupled to a distal end of each of the plurality of load pins; 7. The substrate carrier of claim 6, wherein the lower load ring comprises: and a body portion extending orthogonally relative to the flange portion, wherein the body portion contacts the annular sleeve disposed in the membrane.

8. A substrate carrier configured to be attached to a polishing system for polishing a substrate, the substrate carrier comprising: a housing; a clasp coupled to the housing; a membrane disposed within the housing and spanning an inner diameter of the clasp, the membrane having: a bottom portion configured to contact the substrate; an upper portion opposite the bottom portion; and a side portion extending orthogonally between the bottom portion and the upper portion, wherein an outer edge connects the side portion to the bottom portion; and an actuator disposed on the outer edge of the membrane and configured to apply a load to the outer edge of the membrane toward the substrate, thereby varying a pressure applied between the substrate disposed in the substrate carrier and a polishing pad, wherein the side portion includes an annular groove formed along an outer edge of the side portion, an annular sleeve is disposed in the annular groove, and the load applied to the outer edge of the membrane is applied via the annular sleeve, and wherein the actuator includes a piston that engages the upper portion of the membrane, wherein the load applied to the outer edge of the membrane is applied by the piston applying a load to the upper portion of the membrane. a membrane disposed within the housing and spanning an inner diameter of the clasp ring, the membrane having: a bottom portion configured to contact the substrate; an upper portion opposite the bottom portion; and a side portion extending orthogonally between the bottom portion and the upper portion, with an outer edge connecting the side portion to the bottom portion; an actuator disposed on the outer edge of the membrane and configured to apply a load to the outer edge of the membrane toward the substrate, thereby varying a pressure applied between the substrate disposed in the substrate carrier and a polishing pad; and a flexure plate coupled to the housing, wherein: the side portion includes an annular groove formed along an outer edge of the side portion, an annular sleeve is disposed in the annular groove, the load applied to the outer edge of the membrane is applied via the annular sleeve, the actuator includes an inner tube disposed within the housing, and the inner tube is configured to apply the load to a portion of the flexure plate, thereby varying the pressure applied between the substrate disposed in the substrate carrier and the polishing pad.

9. The substrate carrier of claim 8, wherein a protrusion of the flexure plate engages the upper portion of the membrane to apply the load.

10. A substrate carrier configured to be attached to a polishing system for polishing a substrate, the substrate carrier comprising: a housing; a clasp ring coupled to the housing; a membrane disposed within the housing and spanning an inner diameter of the clasp ring, the membrane having: a bottom portion configured to contact the substrate; an upper portion opposite the bottom portion; and a side portion extending orthogonally between the bottom portion and the upper portion, with an outer edge connecting the side portion to the bottom portion; an actuator disposed on the outer edge of the membrane and configured to apply a load to the outer edge of the membrane toward the substrate, thereby varying a pressure applied between the substrate disposed in the substrate carrier and a polishing pad, wherein: the actuator is disposed between the membrane and a base of the substrate carrier; and the pressure between the substrate disposed in the substrate carrier and the polishing pad is configured to be controlled within different circumferential zones and radial zones by timed actuation of the actuator.

11. The substrate carrier of claim 10, wherein: the polishing system includes a plurality of actuators, wherein each actuator of the plurality of actuators is disposed between the membrane and the base of the substrate carrier, and the pressure is controlled by timed actuation of the plurality of actuators; and the plurality of actuators are disposed in a plurality of concentric rings about a central axis of the substrate carrier.

12. A polishing system comprising: a carrier arm having an actuator coupled to the carrier arm; and the substrate carrier of any of claims 1-11. ​ ​ 13. The polishing system of claim 12, wherein the actuator further comprises: a load application axis configured to apply the load to a portion of the upper load ring, the annular sleeve, and the outer edge of the membrane.

14. The polishing system of claim 13, wherein the actuator further comprises: a roller coupled to a distal end of the load application axis, wherein the roller of the actuator is configured to contact the upper load ring during relative rotation between the substrate carrier and the cradle arm.

15. The polishing system of claim 14, further comprising: the lower load ring disposed in the housing.

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