TW202243809A - Polishing system - Google Patents

Abstract

Various embodiments of the present disclosure are directed towards a chemical mechanical polishing (CMP) system including a first CMP head and a second CMP head. The first CMP head is configured to retain a workpiece and comprises a first plurality of pressure elements disposed across a first pressure control plate. The second CMP head is configured to retain the workpiece. The second CMP head comprises a second plurality of pressure elements disposed across a second pressure control plate. A distribution of the first plurality of pressure elements across the first pressure control plate is different from a distribution of the second plurality of pressure elements across the second pressure control plate.

Description

Polishing system

The embodiments of the present invention relate to a polishing system and a method for chemical mechanical polishing of workpieces.

The semiconductor integrated circuit (IC) industry has experienced rapid growth. Technological advances in IC materials and design have produced several generations of ICs, each with smaller and more complex circuits than the previous generation. However, these advances have increased the complexity of handling and manufacturing ICs, and to enable these advances, IC processing and manufacturing have evolved. For example, planarization techniques, such as chemical mechanical polishing (CMP) processes, have been implemented to planarize the wafer or one or more layers of features on the wafer in order to reduce the thickness of the wafer, thereby The treated surface removes excess material or prepares the treated surface for subsequent manufacturing processes.

According to an embodiment of the present invention, a chemical mechanical polishing (CMP) system includes a first CMP head configured to hold a workpiece, wherein the first CMP head includes a plurality of first pressure plates disposed across a first pressure control plate an element; and a second CMP head configured to hold the workpiece, wherein the second CMP head includes a plurality of second pressure elements disposed across a second pressure control plate, wherein the first pressure control plate is straddled The distribution of the plurality of first pressure elements is different from the distribution of the plurality of second pressure elements across the second pressure control plate.

According to an embodiment of the present invention, a polishing system for performing a polishing process includes: a first polishing device including a first platen and a first chemical mechanical polishing (CMP) head, wherein the first CMP head is configured to The surface to be polished of the workpiece performs a first CMP process, wherein the first CMP head includes a plurality of first concentric pressure elements and a first annular retaining ring surrounding the plurality of first concentric pressure elements in the lateral direction; the second Polishing equipment, including a second platen and a second CMP head, wherein the second CMP head is configured to perform a second CMP process on the surface to be polished of the workpiece, wherein the second CMP head includes a plurality of A second concentric pressure element and a second annular ring laterally surrounding the plurality of second concentric pressure elements, wherein the widths of the plurality of second concentric pressure elements are respectively different from those of the plurality of first concentric pressure elements width; surface measurement equipment positioned on the first platen and the second platen, wherein the surface measurement equipment is configured to perform real-time while performing the first CMP process and the second CMP process measuring the flatness of the surface to be polished of the workpiece, wherein the pressure applied by the plurality of second concentric pressure elements during the second CMP process is based on the to-be-polished surface after the first CMP process the measured flatness of a surface; and a transport device configured to transport the workpiece between the first polishing device and the second polishing device.

According to an embodiment of the present invention, a method for chemical mechanical polishing (CMP) of a workpiece includes: performing a first CMP process on the front side surface of the workpiece using a first CMP head, the first CMP head having a a first distribution of a plurality of first pressure elements of the first CMP head; measuring the flatness of the front side surface of the workpiece; and performing a second CMP process on the front side surface of the workpiece using a second CMP head , the second CMP head has a second distribution across a plurality of second pressure elements of the second CMP head, wherein the pressure exerted by the plurality of second pressure elements is based on the front side of the workpiece The measured flatness of a surface, and wherein the second distribution is different from the first distribution.

The present disclosure provides many different embodiments, or examples, for implementing different features of the disclosure. Specific examples of components and arrangements are set forth below to simplify the present disclosure. Of course, these are examples only and are not intended to be limiting. For example, in the following description, forming a first feature on or over a second feature may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which the first and second features are formed in direct contact. An embodiment in which an additional feature may be formed between a feature and a second feature such that the first feature and the second feature may not be in direct contact. Additionally, this disclosure may repeat reference numbers and/or letters in various instances. Such re-use is for simplicity and clarity and does not in itself indicate a relationship between the various embodiments and/or configurations discussed.

In addition, for ease of description, for example, "beneath", "below", "lower", "above", etc. may be used herein. Spatially relative terms such as "upper" and similar terms describe the relationship of one element or feature to another (other) element or feature illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The device may be at other orientations (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

Also, for ease of description, "first," "second," "third," etc. may be used herein to distinguish between different elements of a figure or series of figures. "First", "second", "third", etc. are not intended to recite corresponding elements, but are merely general identifiers. For example, the "first dielectric layer" described in connection with the first figure may not necessarily correspond to the "first dielectric layer" described in connection with some embodiments, but may correspond to the "second dielectric layer" in other embodiments. dielectric layer".

According to some chemical mechanical polishing (CMP) systems, a platen is covered by a polishing pad and configured to rotate the polishing pad. A polishing head is disposed over the polishing pad and is configured to support and rotate a workpiece. The polishing head includes a plurality of pressure elements disposed across a concentric pressure zone of the polishing head. The plurality of pressure elements are configured to press corresponding concentric surfaces on the front side of the workpiece into the polishing pad with varying force. These concentric surfaces on the front side of the workpiece may be referred to as workpiece surfaces to be polished. The pressure of the plurality of pressure elements can be adjusted to achieve a desired workpiece thickness. A slurry distribution system includes one or more nozzles disposed over the polishing pad and configured to provide slurry to the polishing pad through the nozzles. Slurries include chemical components and abrasive components. Due to the pressing force and the slurry, the surface of the workpiece to be polished undergoes chemical polishing and mechanical polishing.

One challenge of the aforementioned CMP systems is that the multiple pressure elements may not distribute pressure evenly across the corresponding concentric pressure zones. This is attributable in part to process tool limitations of the pressure elements and results in variations in the thickness of the workpiece's surface to be polished corresponding to the concentric pressure zones. For example, the pressure exerted by the first pressure element of the CMP head may be greater in the central region of the first concentric pressure zone than in the peripheral region of the first concentric pressure zone. Consequently, depending on the applied pressure, regions of the front side of the workpiece between adjacent concentric pressure zones may experience more or less polishing, resulting in these regions of the workpiece having undesirably different workpiece thicknesses. This can result in workpieces with poor workpiece thickness uniformity and significantly large total thickness variation (TTV) (eg, greater than about 0.35 micrometers (um)). A significantly large TTV may cause problems in subsequent processing steps such as insufficient etching, poor bonding interface, etc., which may lead to device failure and/or alter the electrical properties of electronic devices disposed on/over the workpiece.

Various embodiments of the present invention are directed to an improved CMP system and an associated method for polishing a workpiece to improve workpiece thickness uniformity. The CMP system includes a first CMP head configured to perform a first CMP process on a workpiece and a second CMP head configured to perform a second CMP process on the workpiece. The first CMP head includes a plurality of first pressure elements distributed across a first plurality of concentric pressure zones on a first pressure control plate. Additionally, the second CMP head includes a second plurality of pressure elements distributed across a second plurality of concentric pressure zones on the second pressure control plate. The distribution of the plurality of first pressure elements across the first pressure control plate is different from the distribution of the plurality of second pressure elements across the second pressure control plate.

During operation of the CMP system, a first CMP head performs a first CMP process on a workpiece to achieve a desired workpiece thickness. Consequently, regions of the workpiece between adjacent concentric pressure zones of the plurality of first concentric pressure zones may experience more or less polishing, depending on the applied pressure. These regions of the workpiece have undesirably different workpiece thicknesses, thereby causing the workpiece to have a significantly large TTV (eg, greater than about 0.35 um) after the first CMP process. Subsequently, the second CMP head performs a second CMP process on the workpiece. Since the second plurality of pressure elements has a different distribution than the first plurality of pressure elements, the second CMP head is configured to compensate for an undesired workpiece thickness achieved during the first CMP process. For example, each pressure element of the second plurality of pressure elements may extend continuously over an area between adjacent pressure elements of the first plurality of pressure elements. Accordingly, the second CMP head may compensate for an undesired workpiece thickness in a region of the workpiece located between the adjacent concentric pressure zones of the plurality of first concentric pressure zones. This, in part, results in a more precise planarization of the workpiece, which in turn causes the TTV of the workpiece after the second CMP process to be significantly smaller (eg, less than about 0.3 um).

1A-1C illustrate some embodiments of various views of a chemical mechanical polishing (CMP) system 100 including a first CMP head 106 and a second CMP head 114 . FIG. 1A shows a schematic diagram of some embodiments of a CMP system 100 . FIG. 1B shows a cross-sectional view of some embodiments of the first CMP head 106 . FIG. 1C shows a cross-sectional view of some embodiments of the second CMP head 114 .

The CMP system 100 includes a first polishing apparatus 102 including a first platen 104 and a first CMP head 106 . The first CMP head 106 is attached to a first end of a first support arm 108 extending above the first platen 104, and a second end of the first support arm 108 is anchored adjacent to the first platen 104. point (eg, anchored to the housing of the CMP system 100). The first CMP head 106 is configured, for example, to perform a first CMP process on a workpiece 105 (eg, a semiconductor wafer) when the workpiece 105 is positioned on the first platen 104 . In such an embodiment, the workpiece 105 is positioned between the first CMP head 106 and the first platen 104 during the first CMP process. Furthermore, the second polishing apparatus 110 is laterally adjacent to the first polishing apparatus 102 and includes a second platen 112 and a second CMP head 114 . A second CMP head 114 is attached to a first end of a second support arm 116 extending above the second platen 112, and a second end of the second support arm 116 is anchored adjacent to the second platen 112. point (eg, anchored to the housing of the CMP system 100). The second CMP head is configured, for example, to perform a second CMP process on the workpiece 105 while the workpiece 105 is positioned on the second platen 112 . In such an embodiment, the workpiece 105 is positioned between the second CMP head 114 and the second platen 112 during the second CMP process. In some embodiments, the first support arm 108 and the second support arm 116 may be telescopic, for example. The first polishing apparatus 102 and the second polishing apparatus 110 define a polishing station 118 . In some embodiments, any number of polishing stations may be provided and/or polishing station 118 may include any number of polishing devices. For example, a second polishing station 119 may be disposed adjacent to polishing station 118 . In various embodiments, the first CMP head 106 and the second CMP head 114 of the second polishing station 119 may be different from the first CMP head 106 and the second CMP head 114 of the polishing station 118 .

Referring to FIG. 1B , the first CMP head 106 includes an upper housing 138 , an annular retaining ring 136 , a first pressure control plate 139 , and a plurality of first pressure elements 140 a to 140 e disposed across the first pressure control plate 139 . In addition, a polishing pad 107 is provided on the first platen 104 between the first CMP head 106 and the first platen 104 . The first CMP head 106 is configured to retain the workpiece 105 between sidewalls of an annular retaining ring 136 . The plurality of first pressure elements 140 a - 140 e are disposed above the workpiece 105 and configured to apply independent amounts of suction or pressure onto corresponding concentric regions of the backside of the workpiece 105 . This suction or pressure applies a force to the workpiece 105 , which in turn causes the front side of the workpiece 105 to press against the polishing pad 107 . The force with which the workpiece 105 is pressed against the polishing pad 107 will control the rate of removal of material disposed on the front side of the workpiece 105 . In addition, the plurality of first pressure elements 140a to 140e are disposed across the first pressure control plate 139 in the plurality of first concentric pressure zones A1 to A5, respectively. For example, the first pressure element 140a of the first CMP head 106 is arranged in the concentric pressure zone A1 and the second pressure element 140b of the first CMP head 106 is arranged at the first pressure laterally surrounding the first CMP head 106 In the concentric pressure zone A2 of element 140a, the third pressure element 140c is arranged in the concentric pressure zone A3 of the second pressure element 140b laterally surrounding the first CMP head 106, and so on. The plurality of first concentric pressure zones A1 to A5 correspond to concentric surfaces on the front side of the workpiece 105 that may be polished during a corresponding CMP process. These concentric surfaces on the front side of workpiece 105 may be referred to as workpiece surfaces to be polished.

Referring to FIG. 1C , the second CMP head 114 includes an upper housing 138 , an annular retaining ring 136 , a second pressure control plate 142 , and a plurality of second pressure elements 144 a to 144 e disposed across the second pressure control plate 142 . In addition, a polishing pad 107 is provided on the second platen 112 between the second CMP head 114 and the second platen 112 . Second CMP head 114 is configured to retain workpiece 105 between sidewalls of annular retaining ring 136 . The plurality of second pressure elements 144 a - 144 e are disposed over the workpiece 105 and configured to apply independent amounts of suction or pressure onto corresponding concentric regions of the backside of the workpiece 105 . In addition, the plurality of second pressure elements 144a to 144e are disposed across the second pressure control plate 142 in the plurality of second concentric pressure zones B1 to B5, respectively. For example, the first pressure element 144a of the second CMP head 114 is arranged in the concentric pressure zone B1, and the second pressure element 144b of the second CMP head 114 is arranged at the first pressure surrounding the second CMP head 114 in the lateral direction. In the concentric pressure zone A2 of element 144a, the third pressure element 144c is arranged in the concentric pressure zone A3 of the second pressure element 144b laterally surrounding the second CMP head 114, and so on. The plurality of second concentric pressure zones B1 to B5 correspond to concentric surfaces on the front side of the workpiece 105 that may be polished during a corresponding CMP process.

In various embodiments, the diameter of the first pressure control plate 139 is equal to the diameter of the second pressure control plate 142, so that the plurality of first pressure elements 140a to 140e straddle the plurality of second pressure elements 144a to 140e 144e same area for distribution. In a further embodiment, the distribution of the plurality of first pressure elements 140a to 140e across the first pressure control plate 139 is different from the distribution of the plurality of second pressure elements 144a to 144e across the second pressure control plate 142 distributed.

In some embodiments, during operation of the CMP system 100 , the first CMP head 106 is configured to perform a first CMP process on the workpiece 105 such that each of the plurality of first pressure elements 140 a - 140 e is positioned on the back of the workpiece 105 Apply force to the side. The pressure of the plurality of first pressure elements 140a to 140e may be adjusted to achieve a desired workpiece thickness. For example, the pressure may be selected such that sufficient force is exerted by the plurality of first pressure elements 140a-140e to cause the workpiece 105 to be pressed down on the polishing pad 107 and planarized to a predetermined degree. In various embodiments, pressure elements in the plurality of first pressure elements 140a - 140e may not be able to distribute pressure evenly across the corresponding concentric pressure zones A1 - A5 due to process tool limitations. For example, the pressure applied by the first pressure element 140a of the first CMP head 106 may be higher in the central region of the concentric pressure zone A1 than in the peripheral region of the concentric pressure zone A1 (e.g., in the first CMP head 106 near the circumferential edge of the first pressure element 140a) large. Consequently, depending on the applied pressure, regions of the front side of the workpiece 105 between adjacent concentric pressure zones A1 to A5 may undergo more or less polishing, thereby rendering these regions of the workpiece 105 undesirably different. Workpiece thickness. This may result in workpiece 105 having a significantly large TTV (eg, greater than about 0.35 um) after the first CMP process.

Therefore, in some embodiments, to avoid undesired workpiece thicknesses, the second CMP head 114 is configured to perform the second CMP process after performing the first CMP process. The plurality of second pressure elements 144 a - 144 e each exert a force on the backside of the workpiece 105 during the second CMP process. In some embodiments, the pressure of the plurality of second pressure elements 144a-144e is adjusted to achieve a desired workpiece thickness, and may be configured to compensate for an undesired workpiece thickness achieved during the first CMP process. For example, pressure elements of the plurality of second pressure elements 144a to 144e may extend continuously over an area between adjacent pressure elements of the plurality of first pressure elements 140a to 140e, thereby The plurality of second pressure elements 144a to 144e is such that it can compensate for an undesired workpiece thickness in the region of the front side of the workpiece 105 between adjacent concentric pressure zones A1 to A5. This, in part, results in a more precise planarization of the workpiece 105, which in turn causes the TTV of the workpiece 105 after the second CMP process to be significantly smaller (eg, less than about 0.3 um). Therefore, since the distribution of the plurality of second pressure elements 144a to 144e is different from the distribution of the plurality of first pressure elements 140a to 140e, uniform planarization may be achieved, resulting in a significantly smaller TTV of the workpiece 105 .

In addition, the plurality of first pressure elements 140a to 140e have a plurality of first widths 141a to 141e, respectively. In some embodiments, the first pressure element 140a of the first CMP head 106 can be configured as a circular pressure element, and the second pressure element, the third pressure element, the fourth pressure element and the fifth pressure element of the first CMP head 106 The pressure elements 140b to 140e may be respectively configured as annular pressure elements (ie, annular pressure elements). Thus, the first width 141 a of the plurality of first widths 141 a to 141 e may eg correspond to the diameter of the first pressure element 140 a of the first CMP head 106 . In addition, the second width, the third width, the fourth width and the fifth width 141b to 141e among the plurality of first widths 141a to 141e may correspond to the second pressure element, the third The annular ring width of the pressure element, the fourth pressure element and the fifth pressure element 140b to 140e. In various embodiments, the second, third, fourth, and fifth widths 141b to 141e of the plurality of first widths 141a to 141e may be equal to each other. In yet other embodiments, the radius of the first pressure element 140a of the first CMP head 106 may be equal to the second width, the third width, the fourth width, and the fifth width 141b to 141e, respectively. In some embodiments, the center of the first pressure control plate 139 may be aligned with the center of the workpiece 105 during the first CMP process. In a further embodiment, the inner diameter of the second pressure element 140b of the first CMP head 106 is arranged along the circumferential edge of the first pressure element 140a of the first CMP head 106, and the inner diameter of the third pressure element 140c of the first CMP head 106 The inner diameter is set along the circumferential edge of the second pressure element 140b of the first CMP head 106, and so on.

In addition, the plurality of second pressure elements 144a to 144e have a plurality of second widths 145a to 145e, respectively. In some embodiments, the first pressure element 144a of the second CMP head 144 can be configured as a circular pressure element, and the second pressure element, the third pressure element, the fourth pressure element and the fifth pressure element of the second CMP head 114 The pressure elements 144b to 144e may be respectively configured as annular pressure elements (ie, annular pressure elements). Thus, the first width 145a of the plurality of second widths 145a to 145e may eg correspond to the diameter of the first pressure element 144a of the second CMP head 114 . In addition, the second width, the third width, the fourth width and the fifth width 145b to 145e among the plurality of second widths 145a to 145e may correspond to the second pressure element, the third The annular ring width of the pressure element, the fourth pressure element and the fifth pressure element 144b to 144e. In various embodiments, the second, third, fourth and fifth widths 145b to 145e of the plurality of second widths 145a to 145e may be different from each other. In yet other embodiments, the center of the second pressure control plate 142 may be aligned with the center of the workpiece 105 during the second CMP process. In a further embodiment, the inner diameter of the second pressure element 144b of the second CMP head 114 is arranged along the peripheral edge of the first pressure element 144a of the second CMP head 114, and the inner diameter of the third pressure element 144c of the second CMP head 114 The inner diameter is set along the circumferential edge of the second pressure element 144b of the second CMP head 114, and so on.

In some embodiments, the distribution of the plurality of first pressure elements 140 a - 140 e across the first pressure control plate 139 is different than the distribution of the plurality of second pressure elements 144 a - 144 e across the second pressure control plate 142 . In such an embodiment, the plurality of first widths 141a-141e are respectively different from corresponding widths of the plurality of second widths 145a-145e. For example, the first width 141a of the first pressure element 140a of the first CMP head 106 is different from the first width 145a of the first pressure element 144a of the second CMP head 114 (eg, the first width 141a is smaller than the first width 145a ), the second width 141b of the second pressure element 140b of the first CMP head 106 is different from the second width 145b of the second pressure element 144b of the second CMP head 114 (eg, the second width 141b is greater than the second width 145b), and so on.

In a further embodiment, the pressure elements in the plurality of first pressure elements 140a to 140e and the plurality of second pressure elements 144a to 144e may each be or include, for example, arranged in corresponding concentric pressure zones A1 to A5 , fluid-filled bladders in B1 to B5. The pressure of each fluid-filled bladder controls the downward force applied to the workpiece 105 and may be controlled, for example, by a pump driven by a motor of the CMP system, where the controller 134 is configured to control the pump and motor. In still other embodiments, the pressure elements of the plurality of first pressure elements 140a to 140e and the plurality of second pressure elements 144a to 144e may be driven, for example, by a drive system configured to apply force directly to the workpiece 105. motor to implement. In various embodiments, the pressure elements in the plurality of first pressure elements 140a to 140e and the plurality of second pressure elements 144a to 144e may each be or include a pressure element arranged in a corresponding concentric pressure zone A1 to A5, B1 to the concentric chamber in B5. In such an embodiment, the pressure applied by each concentric chamber may be controlled, for example, by a pump driven by a motor of the CMP system.

Referring back to FIG. 1A , the CMP system 100 also includes a surface measurement device 120 configured to measure one or more parameters of the workpiece 105, such as, for example, thickness, polishing uniformity, or other parameters related to the surface of the workpiece 105. other parameters of the link. For example, the surface measurement device 120 is configured to detect the thickness, evenness, planarity and/or roughness of the surface of the workpiece 105 before, during or after the corresponding CMP process. For example, lack of uniformity on the surface of workpiece 105 and interfaces of various materials associated with a CMP process may be monitored by surface measurement device 120 . Surface measurement device 120 may, for example, be configured to provide optical sensing, electrical sensing, thermal sensing, pressure sensing, and/or acoustic sensing. Surface measurement apparatus 120 may be associated with first CMP head 106 and/or second CMP head 114 . For example, surface measurement device 120 may be configured to detect vibration, motor feedback, or temperature before, during, and/or after a corresponding CMP process. In yet other embodiments, the surface measurement device 120 can be configured to report one or more parameters of the workpiece 105 to the controller 134 in real time, where the controller 134 can base the one or more parameters of the workpiece 105 (e.g., based on The measured flatness of the workpiece 105) to adjust parameters (eg, pressure settings) of the first CMP head 106 and/or the second CMP head 114 . In various embodiments, surface measurement equipment 120 may be disposed on and/or within first platen 104 and second platen 112 .

In some embodiments, the controller 134 may be configured to adjust the pressures of the plurality of first pressure elements 140a to 140e during the first CMP process and adjust the pressures of the plurality of first pressure elements 140a to 140e during the second CMP process according to the measurement of the surface measurement device 120. The pressure of the plurality of second pressure elements 144a to 144e. For example, if the workpiece surface to be polished of the workpiece 105 is relatively high, the pressure of the corresponding pressure element may be increased relative to adjacent pressure elements. Conversely, if the workpiece surface to be polished of the workpiece 105 is relatively low, the pressure of the corresponding pressure element may be reduced relative to adjacent pressure elements. Thus, the pressure of each pressure element 140a-140e, 144a-144e can be varied independently in a continuous and continuous manner to tailor its respective polishing rate during the corresponding CMP process to provide uniform planarization. In yet other embodiments, the controller 134 may be configured to, during the second CMP process, be based on measurements taken by the surface measurement device 120 during and/or after the first CMP process (e.g., based on the first flatness during and/or after the CMP process) to adjust the pressure of the plurality of second pressure elements 144a to 144e. This facilitates, in part, that the workpiece 105 has a significantly small TTV (eg, less than about 0.3 um).

Furthermore, a loading device 124 is arranged next to the polishing station 118 . Loading device 124 is configured to transport workpiece 105 between one of a plurality of front opening unified pods (FOUPs) 122 and transport device 126 . A transport device 126 is disposed laterally adjacent to the first polishing device 102 and the second polishing device 110 , wherein the transport device 126 is configured to transport the workpiece 105 between the first polishing device 102 and the second polishing device 110 . For example, the transportation device 126 can transport the workpiece 105 to the first polishing device 102 , so that the first CMP head 106 can perform the first CMP process on the workpiece 105 . After the first CMP process, the transportation device 126 can transport the workpiece 105 to the second polishing device 110 , so that the second CMP head 114 can perform the second CMP process on the workpiece 105 .

In some embodiments, the transport equipment 126 includes a wafer truck 132 and a robot 128 . Robot 128 is configured, for example, to selectively transport workpiece 105 between two or more of first polishing apparatus 102 , second polishing apparatus 110 , and/or another (other) polishing apparatus (not shown). Additionally, robot 128 is, for example, operably coupled to track 130 , where robot 128 is configured to translate along track 130 between first polishing apparatus 102 , second polishing apparatus 110 , and/or another (other) polishing apparatus. Additionally, robot 128 may be configured to move workpiece 105 from loading facility 124 , first polishing facility 102 , second polishing facility 110 , and/or another (other) polishing facility to wafer cart 132 . In some embodiments, the wafer cart 132 has drive mechanisms such as rollers, gears, belts, conveyors, or magnets that can move workpieces between the various assemblies in the CMP system 100 105. Additionally, first CMP head 106 and/or second CMP head 114 may each be configured to move workpiece 105 between each other and/or toward transport device 126 via first support arm 108 and/or second support arm 116 .

The controller 134 is configured to control the first polishing apparatus 102 , the second polishing apparatus 110 , the transport apparatus 126 and/or the loading apparatus 124 . For example, the controller 134 is configured to direct the loading device 124 to transfer the workpieces 105 from the plurality of FOUPs 122 to the transport device 126 . Additionally, controller 134 is configured to direct robot 128 to selectively transport workpiece 105 to first polishing apparatus 102 and/or second polishing apparatus 110 . Additionally, the controller 134 is configured to adjust a parameter of the first CMP head 106 and/or the second CMP head 114 based on the one or more parameters of the workpiece 105 provided by the surface measurement device 120 .

FIG. 2A shows some embodiments of a top view of a workpiece 105 with a plurality of first pressure elements 140a to 140e disposed proximate to the workpiece 105 . In some embodiments, the plurality of first pressure elements 140a to 140e correspond to pressure elements of a first CMP head (first CMP head 106 shown in FIGS. 1A to 1C ). In a further embodiment, said plurality of first pressure elements 140a to 140e are disposed across said plurality of first concentric pressure zones A1 to A5. In a further embodiment, the plurality of first pressure elements 140a to 140e may be configured as concentric pressure elements that are concentric with respect to each other and/or each are concentric with respect to the center point 105c of the workpiece 105 . In still other embodiments, the circumferential edge of the fifth pressure element 140e of the plurality of first pressure elements 140a - 140e is aligned with the circumferential edge 105e of the workpiece 105 . Furthermore, the radius R of the workpiece 105 is defined from the center point 105c of the workpiece 105 to the circumferential edge 105e of the workpiece 105 . It should be understood that while FIG. 2A shows five pressure elements and five concentric pressure zones, any number of concentric pressure zones and pressure elements may be provided across the workpiece 105 .

FIG. 2B shows some embodiments of a top view of a workpiece 105 with a plurality of second pressure elements 144a to 144e disposed proximate to the workpiece 105 . In some embodiments, the plurality of second pressure elements 144a to 144e correspond to pressure elements of a second CMP head (second CMP head 114 shown in FIGS. 1A to 1C ). In a further embodiment, the plurality of second pressure elements 144a to 144e are disposed across the plurality of second concentric pressure zones B1 to B5. In a further embodiment, the plurality of second pressure elements 144a to 144e may be configured as concentric pressure elements that are concentric with respect to each other and/or each are concentric with respect to the center point 105c of the workpiece 105 . In yet other embodiments, the circumferential edge of the fifth pressure element 144e of the plurality of second pressure elements 144a - 144e is aligned with the circumferential edge 105e of the workpiece 105 . It should be understood that while FIG. 2B shows five pressure elements and five concentric pressure zones, any number of concentric pressure zones and pressure elements may be provided across the workpiece 105 .

FIG. 3A illustrates some embodiments of cross-sectional views of the first CMP head 106 and the second CMP head 114 and a plurality of graphs 302 through 306 illustrating the CMP system shown in FIGS. 1A through 1C The removal rate of the first CMP head 106 and the second CMP head 114 during operation of 100 . In some embodiments, the y-axis of the plurality of graphs 302-306 corresponds to the normalized removal rate of material from the workpiece during the corresponding polishing process, and the x-axis of the plurality of graphs 302-306 corresponds to the distance from the center (center 105c shown in FIG. 2A or 2B ) of the workpiece (workpiece 105 shown in FIG. 2A or 2B ).

The first removal rate graph 302 illustrates some embodiments of removal rate values spanning the plurality of first concentric pressure zones A1 - A5 during a CMP process performed by the first CMP head 106 . The x-axis of the first removal rate graph 302 is aligned with the center of the first concentric pressure zone A1, the center of the first pressure element 140a of the first CMP head 106, and/or the center of the workpiece. The first upper curve 308 depicts an upper limit for the removal rate of material from the surface of the workpiece to be polished corresponding to the plurality of first concentric pressure zones A1 - A5 . The first lower curve 310 depicts the lower limit of the removal rate of material from the surface of the workpiece to be polished corresponding to the plurality of first concentric pressure zones A1 - A5 . A first horizontal line 309 is depicted, for example, at a normalized removal rate of about one. In some embodiments, the first upper curve 308 may correspond to when the pressure applied by each of the plurality of first pressure elements 140a - 140e is, for example, about +20 hectopascals (hPa) or another suitable The value of is the rate at which material is removed from the surface of the workpiece to be polished. In a further embodiment, the first lower curve 310 may correspond to when the pressure applied by each of the plurality of first pressure elements 140a to 140e is, for example, about -20 hPa or another suitable value The rate at which material is removed from the surface of the workpiece to be polished. Thus, in some embodiments, the pressure applied by each pressure element of the plurality of first pressure elements 140a to 140e may, for example, be in the range of about -20 hPa to +20 hPa. It should be understood that other pressure values applied by the plurality of first pressure elements 140a to 140e are also within the scope of the present disclosure. Therefore, by adjusting the pressure applied by the plurality of first pressure elements 140a to 140e during the CMP process, the span and the plurality of first concentric curves can be adjusted between the first upper curve 308 and the first lower curve 310. Removal rates for pressure zones A1 to A5.

In some embodiments, the first upper curve 308 may decrease continuously from the center of the width of the corresponding concentric pressure zone A1 - A5 to the outer and/or inner edge of the corresponding concentric pressure zone A1 - A5 . In a further embodiment, the first lower curve 310 may increase continuously from the center of the width of the corresponding concentric pressure zone A1 to A5 to the outer and/or inner edge of the corresponding concentric pressure zone A1 to A5 . For example, when the pressure exerted by the first pressure element 140a is at the maximum value (for example, +20 hPa), the removal rate in the first concentric pressure zone A1 at this moment can be changed from that of the first concentric pressure zone A1 to The center decreases toward a first horizontal line 320a, where the first horizontal line 320a is aligned with the outer edge of the first concentric pressure zone Al. Therefore, even if the pressure applied by a corresponding one of the plurality of first pressure elements 140a to 140e remains constant, the removal rate value during the first CMP process can vary across each concentric pressure zone A1 to A5. fluctuation. This is partly attributable to the processing tool limitations of the pressure elements, and can lead to difficulties across the surface to be polished of the workpiece (particularly in those located between adjacent concentric pressure zones A1 to A5 where the pressure exerted by the corresponding pressure element is not easy). at the controlled area) thickness variation. For example, the first horizontal line 320a is disposed at the junction between the outer edge of the first concentric pressure zone A1 and the inner edge of the second concentric pressure zone A2. In some embodiments, due to the processing tool limitations of the pressure elements, the first concentric pressure zone A1 and the second pressure zone A1 are separated even when the pressure applied by the first pressure element 140a and the second pressure element 140b is at a maximum value (eg, +20 hPa). The normalized removal rate at the junction between the two concentric pressure zones A2 is also, for example, about one. In contrast, in such an embodiment, the normalized removal rate is at a maximum at the center of the width of the first pressure element 140a and the second pressure element 140b. This results in poor workpiece thickness uniformity at regions between adjacent surfaces of the workpiece to be polished that correspond to regions located between adjacent concentric pressure zones A1 to A5.

The second removal rate graph 304 illustrates some embodiments of removal rate values spanning the plurality of second concentric pressure zones B1 to B5 during a CMP process performed by the second CMP head 114 . The second upper curve 312 depicts an upper limit for the removal rate of material from the surface of the workpiece to be polished corresponding to the plurality of second concentric pressure zones B1 to B5. The second lower curve 314 depicts the lower limit of the removal rate of material from the surface of the workpiece to be polished corresponding to the plurality of second concentric pressure zones B1 to B5. A second horizontal line 309 is depicted, for example, at a normalized removal rate of about one. In some embodiments, the second upper curve 312 may correspond to a material pressure when the pressure applied by each of the plurality of second pressure elements 144a-144e is, for example, about +20 hPa or another suitable value. The rate of removal from the surface of the workpiece to be polished. In a further embodiment, the second lower curve 314 may correspond to when the pressure applied by each pressure element of the plurality of second pressure elements 144a to 144e is, for example, about -20 hPa or another suitable value The rate at which material is removed from the surface of a workpiece to be polished. Thus, in some embodiments, the pressure applied by each pressure element of the plurality of second pressure elements 144a to 144e may, for example, be in the range of about -20 hPa to +20 hPa. It should be understood that other pressure values applied by the plurality of second pressure elements 144a to 144e are also within the scope of the present disclosure. Thus, by adjusting the pressure applied by the plurality of second pressure elements 144a to 144e during the CMP process, the spanning of the plurality of second concentric pressures can be adjusted between the second upper curve 312 and the second lower curve 314. Removal rates for zones B1 to B5.

In some embodiments, the second upper curve 312 may decrease continuously from the center of the width of the corresponding concentric pressure zone B1-B5 to the outer and/or inner edge of the corresponding concentric pressure zone B1-B5. In a further embodiment, the second lower curve 314 may increase continuously from the center of the width of the corresponding concentric pressure zone B1-B5 to the outer and/or inner edge of the corresponding concentric pressure zone B1-B5. For example, when the pressure applied by the second pressure element 144a is at a maximum value (eg, +20 hPa), the removal rate in the second concentric pressure zone B1 at this time can be changed from that of the second concentric pressure zone B1 to The center decreases toward a second horizontal line 320b, which is aligned with the outer edge of the second concentric pressure zone B1. Therefore, even if the pressure applied by the corresponding one of the plurality of second pressure elements 144a to 144e remains constant, the removal rate value during the CMP process performed by the second CMP head 114 can span each concentric pressure Bands B1 to B5 fluctuate.

The third removal rate graph 306 illustrates some examples of removal rate values across a workpiece surface during a multi-CMP head polishing process that includes a first The CMP head 106 performs a first CMP process and then the second CMP head 114 performs a second CMP process. In some embodiments, during a multi-CMP head polishing process, the removal rate and/or removal profile of material from the surface of the workpiece by the first CMP head 106 may be comparable to the removal of material from the workpiece by the second CMP head 114. The removal rates and/or removal profiles of the surfaces are deconstructively combined. This results in the formation of a plurality of third concentric pressure zones 322a-322i disposed across the surface of the workpiece. In some embodiments, the plurality of third concentric pressure zones 322a-322i may correspond to a plurality of surfaces of the workpiece to be polished. In addition, the pressure exerted on each of the concentric pressure zones of the plurality of third concentric pressure zones 322a to 322i corresponds to the pressure exerted by the plurality of first pressure elements 140a to 322i during the first CMP process. The sum of the pressure applied by 140e and the pressure applied by the plurality of second pressure elements 144a to 144e during the second CMP process.

In some embodiments, the pressure applied by the plurality of second pressure elements 144a to 144e is based on the pressure applied by the plurality of first pressure elements 140a to 140e during the first CMP process and/or based on the pressure applied by the plurality of first pressure elements 140a to 140e during the execution The measured flatness of the surface to be polished of the workpiece after the first CMP process. The pressure applied by the plurality of second pressure elements 144a to 144e may be configured to compensate for an undesired thickness achieved by the first CMP process. In such an embodiment, the removal rate and/or removal profile achieved by the plurality of first pressure elements 140a-140e may be comparable to the removal rate and/or removal profile achieved by the plurality of second pressure elements 144a-144e. /or remove outline deconstructively compose. For example, the third upper curve 316 may correspond to an upper limit for the removal rate of material from the surface of the workpiece to be polished corresponding to the plurality of third concentric pressure zones 322a - 322i after performing the multi-CMP head polishing process. In some embodiments, the third upper curve 316 may correspond to the sum of the first upper curve 308 of the first removal rate graph 302 and the second lower curve 314 of the second removal rate graph 304 . Additionally, the third lower curve 318 may correspond to a lower limit on the removal rate of material from the surface of the workpiece to be polished corresponding to the plurality of third concentric pressure zones 322a - 322i after performing the multi-CMP head polishing process. In a further embodiment, the third lower curve 318 may correspond to the sum of the first lower curve 310 of the first removal rate graph 302 and the second upper curve 312 of the second removal rate graph 304 .

In a further embodiment, said plurality of second pressure elements 144a to 144d respectively extend laterally beyond the circumference of a corresponding one of said plurality of first pressure elements 140a to 140d located in a corresponding outer zone 324a to 324d edge. For example, the first pressure element 144a of the second CMP head 114 extends outward beyond the circumferential edge of the first pressure element 140a of the first CMP head 106 located in the first outer region 324a, the second pressure element 144a of the second CMP head 114 The pressure element 144b extends outward beyond the circumferential edge of the second pressure element 140b of the first CMP head 106 in the second outer region 324b, and so on. Accordingly, the pressure elements within the plurality of second pressure elements 144a to 144d respectively extend continuously beyond corresponding regions between adjacent pressure elements in the plurality of first pressure elements 140a to 140e. For example, the first pressure element 144a of the second CMP head 144 extends continuously beyond the region between the first pressure element 140a and the second pressure element 140b within the first outer region 324a. In some embodiments, the inner or outer edges of the concentric pressure zones of the plurality of third concentric pressure zones 322a to 322i that extend laterally into the plurality of outer regions 324a to 324d are disposed on the corresponding outer At the midpoint of zones 324a to 324d. For example, the outer edge of the first concentric pressure zone 322a is disposed at the midpoint of the first outer zone 324a.

Accordingly, the distribution of the plurality of first pressure elements 140a to 140e across the workpiece is different than the distribution of the plurality of second pressure elements 144a to 144e across the workpiece. This facilitates in part the second CMP head 114 to compensate for the undesired thickness achieved in the peripheral region of each concentric pressure zone A1 - A5 after performing the first CMP process. Due to the difference between the distribution of the plurality of first pressure elements 140a to 140e and the plurality of second pressure elements 144a to 144e across the workpiece, the plurality of third concentric pressure zones 322a to 322i The fluctuation of the removal rate value of each concentric pressure zone of can be reduced. This results in a more accurate planarization of the workpiece such that the TTV of the workpiece after the second CMP process is significantly small (eg, less than about 0.3 um). In addition, the number of concentric pressure zones in the plurality of third concentric pressure zones 322a to 322i is greater than the number of pressure elements in the first CMP head 106 or the second CMP head 114 by performing a multi-CMP head polishing process. Since the removal rate can be individually controlled in each of the concentric pressure zones 322a-322i, a more precise planarization process can be performed on the workpiece.

FIG. 3B shows some embodiments of a layout of a workpiece 105 with a plurality of pressure elements disposed proximate to the workpiece 105 . For example, FIG. 3B shows the layout of pressure elements overlying the workpiece 105 from a first CMP head (first CMP head 106 shown in FIG. 3A ) and pressure elements from a second CMP head (second CMP head 106 shown in FIG. The layout of the pressure elements overlying the workpiece 105 of the head 114 ). In some embodiments, the concentric circles 326 correspond to the inner and/or outer edges of the pressure elements within the plurality of first pressure elements (the plurality of first pressure elements 140a to 140e shown in FIG. 3A ), and the concentric circles 328 corresponds to the inner and/or outer edges of pressure elements within the plurality of second pressure elements (the plurality of second pressure elements 144a to 144e shown in FIG. 3A ). The outer regions 324a to 324d of the concentric circles 328 correspond to portions of the second plurality of pressure elements (the plurality of second pressure elements 144a to 144e shown in FIG. 3A ) extending laterally beyond the first plurality of pressure elements ( FIG. 3A ). 3A , among the plurality of first pressure elements 140 a to 140 d ), the area corresponding to the outer edge of the pressure element.

FIG. 3C illustrates some embodiments of a layout of a workpiece 105 with multiple concentric pressure zones disposed across the workpiece 105 . In some embodiments, the concentric circles 330 correspond to inner and/or outer edges of the plurality of third concentric pressure zones 322a - 322i shown in FIG. 3A .

FIG. 4 illustrates some embodiments of a block diagram of a polishing apparatus 400 including a CMP head 408 disposed above a platen 402 .

The polishing apparatus 400 further includes a polishing pad 404 , a slurry arm 406 and a conditioning disk 410 . In some embodiments, polishing apparatus 400 may be configured to process workpieces (eg, wafers) (not shown) having diameters of approximately 200 millimeters (mm), 300 mm, 450 mm, or other suitable values. CMP head 408 is configured to receive a workpiece during a CMP process such that the workpiece is disposed between CMP head 408 and polishing pad 404 . Controller 134 is configured to control elements of polishing apparatus 400 during a CMP process. In some embodiments, the controller 134 includes an operating routine 417 and a feedback path 416 . In various embodiments, operating routine 417 includes real-time surface profile analyzer 436 and multi-zone pressure controller 440 , and feedback path 416 includes memory 428 and CMP controller 414 .

In some embodiments, the slurry arm 406 dispenses a slurry 411 comprising abrasive slurry particles onto the polishing surface 412 of the polishing pad 404 prior to workpiece planarization. CMP controller 414 is configured to rotate platen 402 and polishing pad 404 about polishing pad axis 420 (eg, via platen spindle 418 ) as indicated by first angular velocity arrow 422 . CMP controller 414 may be configured to perform rotation by means of a motor assembly (not shown). As polishing pad 404 rotates, conditioning disk 410 (which is pivotable by scan arm 424 and rotates about disk axis 444 ) traverses over polishing pad 404 such that conditioning surface 426 of conditioning disk 410 aligns with the polishing surface of polishing pad 404 . Surface 412 is in frictional engagement. In such an embodiment, the conditioning disk 410 continuously scratches or "rough up" the polishing surface 412 during polishing to facilitate consistent and uniform planarization of the workpiece. CMP controller 414 is further configured to simultaneously rotate the workpiece housed within CMP head 408 about wafer axis 421 (eg, through CMP head spindle 430 ) as indicated by second angular velocity arrow 432 . While this dual rotation occurs (eg, as indicated by first angular velocity arrow 422 and second angular velocity arrow 432 ), the workpiece is pressed against slurry 411 and Polished surface 412. For example, the downward force exerted by the CMP head 408 may be generated by a plurality of pressure elements (eg, the plurality of first pressure elements 140a to 140e or the plurality of second pressure elements 144a shown in FIGS. 1A to 1C ). to 144e) apply. The combination of abrasive slurry 411, dual rotation, and downward force planarizes the front side of the workpiece until the end of the CMP process is reached.

In some embodiments, the surface measurement device 120 is configured to measure the surface condition of the polishing pad 404, the conditioning disc 410, and/or the workpiece in real time during the CMP process. For example, surface measurement device 120 may be configured to measure the flatness of a corresponding surface of a workpiece to be polished. Furthermore, as the platen 402 (eg, the platen 402 to which the surface measurement device 120 is mounted) and the CMP head 408 undergo dual rotations, the surface measurement device 120 follows a path 434 that traverses the surface of the workpiece to be polished. Thus, as the platen 402 and CMP head 408 rotate relative to each other during the CMP process, the surface measurement apparatus 120 naturally passes in time the corresponding surfaces to be polished, and can continuously monitor the height of these surfaces as it passes over them.

Additionally, a feedback path 416 operably couples the surface measurement device 120 to the CMP controller 414 and to the operating routine 417 . The memory 428 is configured to store instructions from the measurement and operating routines 417 of the surface measurement device 120 . The immediate surface profile analyzer 436 of the operation routine 417 analyzes the flatness of the workpiece surface to be polished as measured by the surface measurement device 120 . Based on the flatness (or lack thereof) of the corresponding surface of the workpiece to be polished, the multi-zone pressure controller 440 may vary the pressure of the respective pressure control elements proximate to the respective surface of the workpiece to be polished via the CMP controller 414 . Since the removal rate of the CMP process (eg, the CMP polishing rate) is proportional to pressure, this surface-by-surface pressure control scheme facilitates precise planarization of the workpiece. Thus, the pressure of each pressure element can be varied independently in a continuous and sustained manner to tailor its respective removal rate during the CMP process to provide uniform planarization.

In some embodiments, the first polishing device (the first polishing device 102 shown in FIG. 1A ) and the second polishing device (the second polishing device 110 shown in FIG. 1A ) can be respectively configured as a polishing device 400, wherein the first polishing The CMP head 408 of the apparatus (the first polishing apparatus 102 shown in FIG. 1A ) is configured as the first CMP head 106 shown in FIG. 1B , and the CMP head 408 of the second polishing apparatus (the second polishing apparatus 110 shown in FIG. 1A ) is configured as It is configured as the second CMP head 114 shown in FIG. 1C. In such an embodiment, the operating routine 417 and the feedback path 416 are operatively coupled to both the first polishing apparatus and the second polishing apparatus (first polishing apparatus 102, second polishing apparatus 110 shown in FIG. 1A ), thereby Such that the operation routine 417 and the feedback path 416 are configured to control the first polishing apparatus and the second polishing apparatus (the first polishing apparatus 102 and the second polishing apparatus 110 shown in FIG. 1A ) as shown and/or described above. Additionally, the controller 134 is configured to perform a first CMP process by means of a CMP head 408 of a first polishing apparatus (the first polishing apparatus 102 shown in FIG. The CMP head 408 of the second polishing device 110) performs the second CMP process. In such an embodiment, measurements of surface measurement device 120 (eg, measurements of flatness) made during and/or after the first CMP process may be stored in memory 428 and multi-zone pressure controller 440 may During the second CMP process, the pressure elements in the CMP head 408 of the second polishing apparatus (the second polishing apparatus 110 shown in FIG. 1C shows the pressure of the pressure elements 144a to 144e).

Figure 5 illustrates some embodiments of a cross-sectional view of a plurality of CMP heads. The plurality of CMP headers includes a first CMP header 106 , a second CMP header 114 , a third CMP header 502 and a fourth CMP header 510 . In some embodiments, first CMP head 106 , second CMP head 114 , third CMP head 502 , and fourth CMP head 510 may each be disposed in a polishing apparatus as shown and/or described in FIG. 4 . In such an embodiment, a polishing apparatus may be provided in a CMP system as shown and/or described in FIG. 1A. For example, the first CMP head 106 and the second CMP head 114 can be disposed in a polishing system (polishing system 118 shown in FIG. 1A ), and the third CMP head 502 and the fourth CMP head 510 can be disposed in the second polishing system (polishing system 119 shown in FIG. 1A ).

The first CMP head 106 includes a plurality of first pressure elements 140a to 140e, and the plurality of first pressure elements 140a to 140e are respectively disposed across the first pressure control plate 139 in the plurality of first concentric pressure zones A1 to in A5. The second CMP head 114 includes a plurality of second pressure elements 144a to 144e, and the plurality of second pressure elements 144a to 144e are respectively disposed across the second pressure control plate 142 in the plurality of second concentric pressure zones B1 to B5. The third CMP head 502 includes a plurality of third pressure elements 506a to 506e disposed across the third pressure control plate 504 in a plurality of third concentric pressure zones C1 to C5, respectively. . In addition, the fourth CMP head 510 includes a plurality of fourth pressure elements 514a to 514e, and the plurality of fourth pressure elements 514a to 514e are respectively disposed in a plurality of fourth concentric pressure zones D1 to 514e across the fourth pressure control plate 512. D5. In some embodiments, the first CMP head 106, the second CMP head 114, the third CMP head 502, and the fourth CMP head 510 can each include an annular retaining ring 136 and an upper housing 138, and can be attached to to the corresponding support arm (not shown) shown and/or described in Figure 1C. In some embodiments, the diameters of the first pressure control plate 139, the second pressure control plate 142, the third pressure control plate 504, and the fourth pressure control plate 512 are respectively equal to each other, so that the multiple The first pressure elements 140a to 140e, the plurality of second pressure elements 144a to 144e, the plurality of third pressure elements 506a to 506e and the plurality of fourth pressure elements 514a to 514e respectively span the same area to distribute.

In addition, the plurality of first pressure elements 140a to 140e respectively have a plurality of first widths 141a to 141e, the plurality of second pressure elements 144a to 144e respectively have a plurality of second widths 145a to 145e, and the plurality of The third pressure elements 506a-506e have a plurality of third widths 508a-508e, respectively, and the plurality of fourth pressure elements 514a-514e have a plurality of fourth widths 516a-516e, respectively. In some embodiments, the plurality of first pressure elements 140a-140e, the plurality of second pressure elements 144a-144e, the plurality of third pressure elements 506a-506e, and the plurality of fourth pressure elements 514a to 514e have different distributions across and corresponding pressure control plates, respectively. In such an embodiment, the plurality of first widths 141a-141e, the plurality of second widths 145a-145e, the plurality of third widths 508a-508e, and the plurality of fourth widths 516a-516e are different from each other. For example, the first width 141a of the first pressure element 140a of the first CMP head 106, the first width 145a of the first pressure element 144a of the second CMP head 114, the first width 145a of the first pressure element 506a of the third CMP head 502 The first width 508a and the first width 516a of the first pressure element 514a of the fourth CMP head 510 are different from each other, and so on.

In various embodiments, during operation of the CMP system including the plurality of CMP heads, the first CMP head 106 is configured to perform The first CMP process. Subsequently, the second CMP head 114 is configured to perform a second CMP process on the workpiece, the third CMP head 502 is configured to perform a third CMP process on the workpiece, and/or the fourth CMP head 510 is configured to perform a fourth CMP process on the workpiece. CMP process. Since the plurality of first pressure elements 140a to 140e, the plurality of second pressure elements 144a to 144e, the plurality of third pressure elements 506a to 506e, and the plurality of fourth pressure elements 514a to 514e span and corresponding pressure plates have different distributions, so the pressure exerted by each pressure element of the plurality of CMP heads can be adjusted to achieve a desired wafer thickness, and can be configured to compensate for the pressure achieved during a previous CMP process. undesired wafer thickness. For example, the pressure elements 144a to 144e of the second CMP head 114 can compensate for an undesired wafer thickness at a region between adjacent pressure elements in the plurality of first pressure elements 140a to 140e (as shown in FIG. 3A shown and/or described in ). Thus, the removal rate and/or removal profile of material from the surface to be polished of the workpiece achieved by each of the first CMP head 106, the second CMP head 114, the third CMP head 502, and the fourth CMP head 510 Can be configured to increase planarization of the workpiece such that the TTV of the workpiece after the fourth CMP process is significantly small (eg, less than about 0.3 um).

In yet other embodiments, the first CMP head 106 , the second CMP head 114 , the third CMP head 502 , and the fourth CMP head 510 may each have the same number of pressure elements. It should be understood that although FIG. 5 shows five pressure elements and five concentric pressure zones per CMP head, any number of concentric pressure zones and pressure elements may be provided across the corresponding CMP head. In yet other embodiments, the plurality of first pressure elements 140a to 140e, the plurality of second pressure elements 144a to 144e, the plurality of third pressure elements 506a to 506e, and the plurality of fourth pressure elements 514a to 514e may be, for example, respectively Or comprise a fluid filled bladder as described in Figures 1A to 1C, a motor to drive the system, concentric chambers or the like.

In some embodiments, during operation of the CMP system including the plurality of CMP heads, the first CMP head 106 performs a first CMP process on the workpiece, and then the second CMP head 114 performs a second CMP process on the workpiece. In a further embodiment, during operation of the CMP system, the first CMP head 106 performs a first CMP process on the workpiece, the second CMP head 114 performs a second CMP process on the workpiece, and then the third CMP head 502 performs The third CMP process. In yet other embodiments, during operation of the CMP system, the first CMP head 106 performs a first CMP process on the workpiece, the second CMP head 114 performs a second CMP process on the workpiece, and the third CMP head 502 performs a third CMP process on the workpiece. CMP process, and then the fourth CMP head 510 performs a fourth CMP process on the workpiece.

Fig. 6 shows some embodiments of cross-sectional views of a plurality of CMP heads according to some alternative embodiments of the plurality of CMP heads shown in Fig. 5, wherein the plurality of CMP heads may, for example, have a different number of pressure elements.

In some embodiments, the first CMP head 106 includes a plurality of first pressure elements 140a to 140e, and the plurality of first pressure elements 140a to 140e are respectively disposed on the plurality of first pressure elements 140a to 140e across the first pressure control plate 139. Concentric pressure zones A1 to A5. The second CMP head 114 includes a plurality of second pressure elements 144a to 144g disposed across the second pressure control plate 142 in a plurality of second concentric pressure zones B1 to B7, respectively. . In various embodiments, the number of pressure elements in the plurality of second pressure elements 144a-144g is greater than the number of pressure elements in the plurality of first pressure elements 140a-140e. The third CMP head 502 includes a plurality of third pressure elements 506a to 506h disposed across the third pressure control plate 504 in a plurality of third concentric pressure zones C1 to C8, respectively. . In some embodiments, the number of pressure elements in the plurality of third pressure elements 506a-506h is greater than the number of pressure elements in the plurality of first pressure elements 140a-140e and/or the plurality of second pressure elements 144a-144g Number of pressure elements. In addition, the fourth CMP head 510 includes a plurality of fourth pressure elements 514a to 514h disposed across the fourth pressure control plate 512 in a plurality of fourth concentric pressure zones D1 to 514h, respectively. D8. In a further embodiment, the number of pressure elements in the plurality of fourth pressure elements 514a to 514h is greater than the pressure in the plurality of first pressure elements 140a to 140e and/or the plurality of second pressure elements 144a to 144g number of components. In some embodiments, the first CMP head 106, the second CMP head 114, the third CMP head 502, and the fourth CMP head 510 can each include an annular retaining ring 136 and an upper housing 138, and can be attached to to the support arm (not shown) shown and/or described in Figure 1C. In some embodiments, the diameters of the first pressure control plate 139, the second pressure control plate 142, the third pressure control plate 504, and the fourth pressure control plate 512 are respectively equal to each other, so that the multiple The first pressure elements 140a to 140e, the plurality of second pressure elements 144a to 144g, the plurality of third pressure elements 506a to 506h and the plurality of fourth pressure elements 514a to 514h respectively span the same area to distribute.

In addition, the plurality of first pressure elements 140a to 140e respectively have a plurality of first widths 141a to 141e, the plurality of second pressure elements 144a to 144g respectively have a plurality of second widths 145a to 145g, and the plurality of The third pressure elements 506a-506h have a plurality of third widths 508a-508h, respectively, and the plurality of fourth pressure elements 514a-514h have a plurality of fourth widths 516a-516h, respectively. In some embodiments, the plurality of first pressure elements 140a-140e, the plurality of second pressure elements 144a-144g, the plurality of third pressure elements 506a-506h, and the plurality of fourth pressure elements 514a through 514h have different distributions across and corresponding pressure control plates, respectively. In such an embodiment, the plurality of first widths 141a-141e, the plurality of second widths 145a-145g, the plurality of third widths 508a-508h, and the plurality of fourth widths 516a-516h are different from each other. In still other embodiments, the largest width of the plurality of fourth pressure elements 514a to 514h is smaller than the smallest width of the plurality of first widths 141a to 141e.

Since the plurality of first pressure elements 140a to 140e, the plurality of second pressure elements 144a to 144g, the plurality of third pressure elements 506a to 506h and the plurality of fourth pressure elements 514a to 514h span and corresponding pressure plates have different distributions, so the pressure exerted by each pressure element of the plurality of CMP heads can be adjusted to achieve a desired wafer thickness, and can be configured to compensate for the pressure achieved during a previous CMP process. undesired wafer thickness. For example, the pressure elements 144a to 144g of the second CMP head 114 can compensate for an undesired wafer thickness at a region between adjacent pressure elements in the plurality of first pressure elements 140a to 140e (as shown in FIG. 3A ). shown and/or described in ).

In yet other embodiments, the first CMP head 106, the second CMP head 114, the third CMP head 502, and/or the fourth CMP head 510 may have different numbers of pressure elements. It should be understood that while FIG. 6 shows the first CMP head 106 having five pressure elements and five concentric pressure zones, the second CMP head 114 having seven pressure elements and seven concentric pressure zones, and the third CMP head 502 having Eight pressure elements and eight concentric pressure zones and the fourth CMP head 510 has eight pressure elements and eight concentric pressure zones, however any number of concentric pressure zones and pressure elements may be provided across a corresponding CMP head.

In some embodiments, during operation of the CMP system including the plurality of CMP heads, the first CMP head 106 performs a first CMP process on the workpiece, and then the second CMP head 114 performs a second CMP process on the workpiece. In a further embodiment, during operation of the CMP system, the first CMP head 106 performs a first CMP process on the workpiece, the second CMP head 114 performs a second CMP process on the workpiece, and then the third CMP head 502 performs The third CMP process. In yet other embodiments, during operation of the CMP system, the first CMP head 106 performs a first CMP process on the workpiece, the second CMP head 114 performs a second CMP process on the workpiece, and the third CMP head 502 performs a third CMP process on the workpiece. CMP process, and then the fourth CMP head 510 performs a fourth CMP process on the workpiece. In various embodiments, during operation of the CMP system, the first CMP head 106 performs a first CMP process on the workpiece, the fourth CMP head 510 performs a second CMP process on the workpiece, and the first CMP head 106 performs a third CMP process on the workpiece. process, and then the fourth CMP head 510 performs a fourth CMP process on the workpiece.

FIG. 7 shows some embodiments of a block diagram of a CMP system 700 . The CMP system includes a first polishing apparatus 702 , a second polishing apparatus 704 and a flatness tool 708 . In some embodiments, during use of the CMP system 700, the first polishing apparatus 702 is applied to the workpiece 706 and the second polishing apparatus 704 is subsequently applied to the first planarized workpiece 706′ to achieve a substantially planar workpiece 706''. Advantageously, by performing the second planarization after the first planarization, the second planarization minimally affects the throughput of the first polishing apparatus 702 .

Flatness tool 708 is associated with first polishing apparatus 702 and/or second polishing apparatus 704 . In some embodiments, the flatness tool 708 may be independent of the first polishing apparatus 702 and/or the second polishing apparatus 704 . In yet other embodiments, the flatness tool 708 may include a surface measurement device integrated with the first polishing device 702 and/or the second polishing device 704 (for example, the surface measurement device 120 shown in FIG. 1A and/or FIG. 4 ). ). The flatness tool 708 is configured to measure the flatness of the surface to be polished of the workpiece 706 and the first planarized workpiece 706' so that the degree of unevenness (i.e., a region having an undesired workpiece thickness) on the surface to be polished can be identified. Location. The flatness tool 708 may measure the flatness of the workpiece 706 and the first planarized workpiece 706', for example, using optical sensing, electrical sensing, thermal sensing, pressure sensing, and/or acoustic sensing.

In a further embodiment, during use of the CMP system 700 , the flatness tool 708 measures the flatness of the workpiece 706 instantaneously during the first planarization performed on the workpiece 706 by the first polishing apparatus 702 . In some embodiments, a parameter (eg, applied pressure) of each pressure element in first polishing apparatus 702 may be adjusted on the fly based on an instant flatness measurement of flatness tool 708 during the first planarization. Subsequently, the second polishing apparatus 704 is configured to perform a second planarization on the first planarized workpiece 706'. The flatness tool 708 measures the flatness of the first planarized workpiece 706' in real time during the second planarization process. In some embodiments, a parameter (eg, applied pressure) of each pressure element in second polishing apparatus 704 can be adjusted on the fly based on an instant flatness measurement of flatness tool 708 during the second planarization. Additionally, during use of the CMP system 700, in some embodiments, the flatness tool 708 measures the flatness of the second planarized workpiece 706" after the second planarization. In such an embodiment, the second planarization may be repeated until the planarity of the second planarized workpiece 706'' satisfies a predetermined criterion. For example, the second planarization may be repeated until the second planarized workpiece 706'' has less than a predetermined number of uneven regions and/or has a TTV less than a predetermined TTV value (eg, less than about 0.30 um). In a further embodiment, each repeated second planarization may comprise using another CMP head than the one used in the first planarization or the second planarization, and/or using a Or the same CMP head used in the second planarization. Furthermore, the flatness measurement can be used for any repeated planarization.

In some embodiments, the first polishing apparatus 702 may be configured, for example, as the polishing apparatus 400 shown in FIG. 4 and/or may include the first CMP head 106 shown in FIG. 1B , FIG. 3A , FIG. 5 , or FIG. 6 . In yet other embodiments, the second polishing apparatus may be configured, for example, as the polishing apparatus 400 shown in FIG. 4 and/or may include the second CMP head 114 shown in FIG. 1B, FIG. 3A, FIG. 5 or FIG. The third CMP head 502 shown in FIG. 6 and/or the fourth CMP head 510 shown in FIG. 5 or FIG. 6 .

FIG. 8 shows a flow diagram providing some embodiments of a method 800 of planarizing a surface to be polished of a workpiece using a first CMP head and a second CMP head having cross and corresponding CMP heads. Different distribution of pressure elements. Although method 800 is shown and/or described as a series of acts or events, it is to be understood that the method is not limited to the shown order or acts. Accordingly, in some embodiments, the actions described may be performed in an order different from that shown, and/or may be performed concurrently. Furthermore, in some embodiments, an illustrated act or event may be subdivided into multiple acts or events that may be performed at a single time or concurrently with other acts or sub-acts. In some embodiments, some illustrated acts or events may be omitted, and other not illustrated acts or events may be included.

At act 802, a workpiece is provided. The workpiece can be, for example, a semiconductor wafer (eg, a crystalline silicon substrate, a silicon-on-insulator (SOI) substrate, or the like) supporting electronic circuitry under fabrication.

At act 804, in some embodiments, a thinning process is performed on the front side surface of the workpiece. The thinning process may, for example, include performing a mechanical grinding process or another suitable thinning process.

At act 806, a first chemical mechanical polishing (CMP) process is performed on a frontside surface of the workpiece. A first CMP process is performed using a first CMP head having a first distribution across a plurality of first pressure elements of the first CMP head. The first CMP process may be performed by, for example, the first CMP head 106 shown in FIG. 1A to FIG. 1B , FIG. 3A , FIG. 5 or FIG. 6 . In some embodiments, the first CMP process may include performing actions 808 and 810 .

At act 808, the flatness of the front side surface of the workpiece is measured. In some embodiments, the flatness of the front side surface of the workpiece is measured to identify the location of uneven regions (ie, regions of undesired workpiece thickness) on the front side surface of the workpiece. The flatness of the front side surface may be measured, for example, by optical sensors, electrical sensors, thermal sensors, pressure sensors and/or acoustic sensors. Furthermore, the flatness of the frontside surface can be measured, for example, before the first CMP process and/or instantaneously during the first CMP process.

At act 810 , parameters of the plurality of first pressure elements are adjusted based on the flatness measurement of act 808 . In some embodiments, parameters of the plurality of first pressure elements are adjusted on the fly during the first CMP process based on an on-the-fly measurement of the flatness of the front side surface of the workpiece. For example, the pressure applied by each pressure element of the plurality of first pressure elements can be adjusted in real time during the first CMP process based on the real time measurement of the flatness of the front side surface of the workpiece.

At act 812, a second CMP process is performed on the front side surface of the workpiece. A second CMP process is performed using a second CMP head having a second distribution of a plurality of second pressure elements across the second CMP head, wherein the second distribution is different from the first distribution. In a further embodiment, a second CMP process is performed based on the measured planarity of the frontside surface (eg, based on the identified location of the uneven region). For example, the initial pressure applied by each pressure element of the plurality of second pressure elements during the second CMP process may be based on a measured flatness of the front side surface of the workpiece after and/or during the first CMP process . The second CMP process may be performed by the second CMP head 114 as shown in, for example, FIG. 1A , FIG. 1C , FIG. 3A , FIG. 5 or FIG. 6 . In various embodiments, the second CMP process may include performing acts 814 and 816 .

At act 814, the flatness of the front side surface of the workpiece is measured. In some embodiments, the flatness of the frontside surface of the workpiece is measured to identify the location of remaining uneven regions (ie, regions having an undesired workpiece thickness) on the frontside surface of the workpiece. The flatness of the front side surface may be measured, for example, by optical sensors, electrical sensors, thermal sensors, pressure sensors and/or acoustic sensors. Furthermore, the flatness of the frontside surface may be measured, for example, prior to the second CMP process and/or instantaneously during the second CMP process.

At act 816 , parameters of the plurality of second pressure elements are adjusted based on the flatness measurement of act 814 . In some embodiments, parameters of the plurality of second pressure elements are adjusted on the fly during the second CMP process based on an on-the-fly measurement of the flatness of the front side surface of the workpiece. For example, the pressure applied by each pressure element of the plurality of second pressure elements can be adjusted in real time during the second CMP process based on the real time measurement of the flatness of the front side surface of the workpiece.

At act 818, in some embodiments, act 812 is repeated until the flatness of the front side surface of the workpiece meets a predetermined specification. Another (other) CMP head may for example be comprised of a second CMP head, a first CMP head or another (other) distribution of pressure elements having a different (other) distribution than the first and/or second distribution across the other (other) CMP head The CMP head performs a repeated second CMP process. For example, act 812 may be repeated until the TTV of the frontside surface of the workpiece is about zero or otherwise less than a predetermined number (eg, less than 0.30 um). In some embodiments, the repeated second CMP process may be performed by, for example, the third CMP head 502 shown in FIG. 5 or 6 and/or the fourth CMP head 510 shown in FIG. 5 or 6 .

9-14 show cross-sectional views 900-1400 of some embodiments of structures illustrating the actions of method 800 shown in FIG. 8 . Although the cross-sectional views 900 through 1400 shown in FIGS. 9 through 14 are described with reference to the method, it should be understood that the structures shown in FIGS. 9 through 14 are not limited to the method described, but may be established independently of the method described. . Furthermore, while FIGS. 9-14 are illustrated as a series of acts, it should be understood that these acts are not limiting, as the order of acts can be altered in other embodiments and the disclosed methods are applicable to other structures as well. In other embodiments, some acts shown and/or described may be omitted in whole or in part. In addition, although the method is described with respect to the structures shown in FIGS. 9 to 14, it should be understood that the method is not limited to the structures, but may stand alone.

FIG. 9 shows a cross-sectional view 900 of some embodiments corresponding to act 802 . As shown in Figure 9, a workpiece 902 is provided. In some embodiments, workpiece 902 includes semiconductor structure 906 overlying carrier substrate 904 . In various embodiments, the semiconductor structure 906 may include an interconnect structure (not shown) disposed along a semiconductor substrate (not shown). In yet other embodiments, workpiece 902 may be, for example, or include a semiconductor wafer supporting electronic circuitry under fabrication. Furthermore, the frontside surface 902f of the workpiece 902 may be bounded, for example, by the top surface of the semiconductor structure 906 .

FIG. 10 shows a cross-sectional view 1000 of some embodiments corresponding to act 804 . As shown in FIG. 10 , a thinning process is performed on the front side surface 902f of the workpiece 902 . In some embodiments, the thinning process includes performing a mechanical grinding process into the top surface of the semiconductor structure 906 to reduce the thickness of the semiconductor structure 906 from the initial thickness Ti to the first thickness Ts1. In yet other embodiments, the TTV of the workpiece 902 along the frontside surface 902f may be significantly larger (eg, a TTV greater than about 0.35 um) after performing the thinning process. Additionally, the front side surface 902f of the workpiece 902 may correspond to the surface of the workpiece 902 to be polished.

FIG. 11 shows a cross-sectional view 1100 of some embodiments corresponding to actions 806 and 808 . As shown in FIG. 11 , a first chemical mechanical polishing (CMP) process is performed on the front side surface 902f of the workpiece 902 . In some embodiments, during the first CMP process, the workpiece 902 is placed in the first CMP head 106 with the front side surface 902f of the workpiece 902 (ie, referred to as the surface to be polished of the workpiece 902) facing down. , and the workpiece 902 is rotated about the axis of the CMP head spindle 430 coupling the first CMP head 106 to the motor. Furthermore, the front side surface 902 f of the workpiece 902 is pressed against the polishing pad 404 . A polishing pad 404 is disposed on the platen 402 and rotated about an axis of a platen spindle 418 that couples the platen 402 to a motor.

The slurry arm (slurry arm 406 shown in FIG. 4 ) provides slurry (slurry 411 shown in FIG. 4 ) to the polishing pad 404 following the double rotation of the polishing pad 404 and the workpiece 902 . A slurry may, for example, include abrasive components and chemical components. In addition, a plurality of first pressure elements 140 a - 140 e are disposed proximate to the workpiece 902 and are configured to apply independent amounts of suction to corresponding concentric regions of the backside surface 902 b of the workpiece 902 or stress. The concentric region of the backside surface 902 b of the workpiece 902 corresponds to the plurality of first concentric pressure zones A1 to A5 distributed across the first CMP head 106 . Suction or pressure applies a force to the workpiece 902 , thereby causing the front side surface 902 f of the workpiece 902 to press against the polishing pad 404 . Due to the pressing force against the workpiece 902 and the abrasive components, the workpiece 902 undergoes mechanical polishing. In addition, workpiece 902 also undergoes chemical polishing due to the chemical composition of the slurry. In yet other embodiments, the first CMP head 106 has a first distribution of the plurality of first pressure elements 140 a - 140 e across the first CMP head 106 and/or across the backside surface 902 b of the workpiece 902 .

In some embodiments, pressure elements in the plurality of first pressure elements 140a - 140e may not be able to distribute pressure evenly across the corresponding concentric pressure zones A1 - A5 due to processing tool limitations. For example, the pressure applied by the first pressure element 140a of the first CMP head 106 may be higher in the central region of the concentric pressure zone A1 than in the peripheral region of the concentric pressure zone A1 (e.g., in the first CMP head 106 near the circumferential edge of the first pressure element 140a) large. Therefore, depending on the applied pressure, regions of the front side surface 902f of the workpiece 902 between the adjacent concentric pressure zones A1 to A5 may undergo more or less polishing, thereby causing these regions of the workpiece 902 to have undesired different wafer thicknesses.

Additionally, surface measurement device 120 is disposed on platen 402 and/or polishing pad 404 and configured to measure the surface condition of workpiece 902 before, during and/or after the first CMP process. For example, the surface measurement apparatus 120 is configured to measure the flatness of the front side surface 902f of the workpiece 902 to identify uneven areas (i.e., areas with an undesired workpiece thickness or with hillocks and and/or valley area) location. Surface measurement device 120 may be configured, for example, to provide optical sensing, electrical sensing, thermal sensing, pressure sensing, and/or acoustic sensing. In some embodiments, when the surface measurement device 120 measures the flatness of the front side surface 902f of the workpiece 902 during the first CMP process, the pressure of the plurality of first pressure elements 140a to 140e may be adjusted according to the flatness measurement. The pressure applied by each pressure element to achieve the desired workpiece thickness.

FIG. 12 illustrates a cross-sectional view 1200 corresponding to some embodiments of workpiece 902 after performing act 806 . As shown in FIG. 12, after performing the first CMP process, the thickness of the workpiece 902 is reduced from the first thickness Ts1 to the second thickness Ts2. In yet other embodiments, the flatness of the front side surface 902f of the workpiece 902 may be measured after performing the first CMP process. Flatness may be measured, for example, by a flatness detection system of the first polishing apparatus or by an external flatness tool. Furthermore, flatness may be measured, for example, using eddy currents, laser pulses, ultrasonic pulses, white light interferometry, or another suitable method.

FIG. 13 shows a cross-sectional view 1300 of some embodiments corresponding to acts 810 and 812 . As shown in FIG. 13 , a second CMP process is performed on the front side surface 902f of the workpiece 902 . In some embodiments, during the second CMP process, the workpiece 902 is placed in the second CMP head 114 with the front side surface 902f of the workpiece 902 facing downward, and the second CMP head 114 is coupled to the motor The axis of the CMP head spindle 430 rotates the workpiece 902 . Furthermore, the front side surface 902 f of the workpiece 902 is pressed against the polishing pad 404 . A polishing pad 404 is disposed on the platen 402 and rotated about an axis of a platen spindle 418 that couples the platen 402 to a motor.

The slurry arm (slurry arm 406 shown in FIG. 4 ) provides slurry (slurry 411 shown in FIG. 4 ) to the polishing pad 404 following the double rotation of the polishing pad 404 and the workpiece 902 . A slurry may, for example, include abrasive components and chemical components. Additionally, a plurality of second pressure elements 144a-144e are disposed proximate to the workpiece 902 and configured to apply independent amounts of suction to corresponding concentric regions of the backside surface 902b of the workpiece 902. or stress. The concentric region of the backside surface 902 b of the workpiece 902 corresponds to the plurality of second concentric pressure zones B1 to B5 distributed across the second CMP head 114 . Suction or pressure applies a force to the workpiece 902 , thereby causing the front side surface 902 f of the workpiece 902 to press against the polishing pad 404 . Due to the pressing force against the workpiece 902 and the abrasive components, the workpiece 902 undergoes mechanical polishing. In addition, workpiece 902 also undergoes chemical polishing due to the chemical composition of the slurry. In some embodiments, the pressure of the plurality of second pressure elements 144a-144e is adjusted during the second CMP process to achieve a desired workpiece thickness based on flatness measurements taken during and/or after the first CMP process. .

The second CMP head 114 has a second distribution of the plurality of second pressure elements 144 a - 144 e across the second CMP head 114 and/or across the backside surface 902 b of the workpiece 902 . In various embodiments, the second distribution is different than the first distribution. In addition, when the center of the first CMP head (the first CMP head 106 shown in FIG. Corresponding areas between adjacent ones of the plurality of first pressure elements 140a to 140e overlap. Therefore, in some embodiments, the plurality of second pressure elements 144a to 144e can compensate for the difference between the front side surface 902f of the workpiece 902 and the plurality of first concentric pressure zones ( FIG. 11 ) during the first CMP process. The undesired wafer thickness achieved in the region corresponding to the region between adjacent concentric pressure zones of the illustrated plurality of first concentric pressure zones A1 to A5 ). This, in part, results in a more accurate planarization of the workpiece 902, which in turn enables the TTV of the frontside surface 902f of the workpiece 902 after the second CMP process to be significantly smaller (eg, less than about 0.3 um). Thus, since the distribution of the plurality of second pressure elements 144a to 144e is different from the distribution of the plurality of first pressure elements 140a to 140e, uniform planarization may be achieved, resulting in a significantly smaller TTV for the workpiece 902. In yet other embodiments, the second CMP head 114 may be configured as shown and/or described in FIG. 6 , wherein the second CMP head 114 includes seven pressure elements.

Additionally, surface measurement device 120 is disposed on platen 402 and/or polishing pad 404 and configured to re-measure the surface condition of workpiece 902 before, during and/or after the second CMP process. For example, the surface measurement apparatus 120 is configured to re-measure the flatness of the front side surface 902f of the workpiece 902 to identify areas of unevenness (i.e., areas with an undesired workpiece thickness or with hillocks) on the front side surface 902f of the workpiece 902. and/or valley area) location. Surface measurement device 120 may be configured, for example, to provide optical sensing, electrical sensing, thermal sensing, pressure sensing, and/or acoustic sensing. In some embodiments, when the surface measurement device 120 re-measures the flatness of the front side surface 902f of the workpiece 902 during the second CMP process, the pressure of the plurality of second pressure elements 144a to 144e may be adjusted according to the flatness measurement. The pressure applied by each pressure element to achieve the desired workpiece thickness.

FIG. 14 illustrates a cross-sectional view 1400 corresponding to some embodiments of workpiece 902 after performing act 810 . In yet other embodiments, the flatness of the front side surface 902f of the workpiece 902 may be re-measured after the second CMP process is performed. Flatness may be remeasured, for example, by the flatness detection system of the first polishing apparatus or by an external flatness tool. Furthermore, flatness may be measured, for example, using eddy currents, laser pulses, ultrasonic pulses, white light interferometry, or another suitable method.

In some embodiments, to further increase the flatness of the front side surface 902f of the workpiece 902, one or more additional CMP processes may be performed on the workpiece 902 after the second CMP process. In an embodiment, after performing the second CMP process shown in FIG. 13 , a third CMP process is performed on the front side surface 902 f of the workpiece 902 by the third CMP head. In such an embodiment, the third CMP head may be configured as the third CMP head 502 shown in FIG. 5 or FIG. 6, and the third CMP process may be performed through a process substantially similar to that described above in FIG. to execute. In another embodiment, after the second CMP process shown in FIG. 13 is performed, the third CMP process is performed on the front side surface 902f of the workpiece 902 by the third CMP head, and then the front side surface 902f of the workpiece 902 is treated by the fourth CMP head. 902f executes the fourth CMP process. In such an embodiment, the third CMP head may be configured as the third CMP head 502 shown in FIG. 5 or FIG. 6 , the fourth CMP head may be configured as the fourth CMP head 510 shown in FIG. 5 or FIG. 6 , and The third CMP process and the fourth CMP process may each be performed by a process substantially similar to that described above in FIG. 13 .

Accordingly, in some embodiments, the present disclosure relates to a CMP system including a first CMP head configured to perform a first CMP process on a workpiece and configured to perform a second CMP head on the workpiece after performing the first CMP process. The second CMP head of the second CMP process. The distribution of pressure elements across the second CMP head is different than the distribution of pressure elements across the first CMP head.

In some embodiments, the present invention provides a chemical mechanical polishing (CMP) system comprising: a first CMP head configured to hold a workpiece, wherein the first CMP head includes a span and A plurality of first pressure elements disposed across the first pressure control plate; and a second CMP head configured to hold the workpiece, wherein the second CMP head includes a plurality of second pressure elements disposed across the second pressure control plate elements, wherein the distribution of the plurality of first pressure elements across the first pressure control plate is different from the distribution of the plurality of second pressure elements across the second pressure control plate.

In some embodiments, the plurality of first pressure elements are respectively concentric with respect to each other and with respect to the center of the first pressure control plate, wherein the plurality of second pressure elements are respectively relative to each other and with respect to the The center of the second pressure control plate is concentric.

In some embodiments, the number of pressure elements in the first plurality of pressure elements is equal to the number of pressure elements in the second plurality of pressure elements.

In some embodiments, the number of pressure elements in the first plurality of pressure elements is less than the number of pressure elements in the second plurality of pressure elements.

In some embodiments, the diameter of the first pressure control plate is equal to the diameter of the second pressure control plate.

In some embodiments, a diameter of an innermost pressure element of the first plurality of pressure elements is smaller than a diameter of an innermost pressure element of the second plurality of pressure elements.

In some embodiments, widths of the plurality of first pressure elements are respectively different from widths of the plurality of second pressure elements.

In some embodiments, the chemical mechanical polishing system further includes: a third chemical mechanical polishing head configured to hold the workpiece, wherein the third chemical mechanical polishing head includes multiple a third pressure element, wherein the distribution of the plurality of third pressure elements across the third pressure control plate is different from the distribution of the first plurality of pressure elements and the distribution of the second plurality of pressure elements The distribution of .

In some embodiments, the plurality of first pressure elements and the plurality of second pressure elements each include concentric chambers configured to provide independent pressure to corresponding regions of the workpiece.

In some embodiments, the present invention provides a polishing system for performing a polishing process. The polishing system includes: a first polishing device including a first platen and a first chemical mechanical polishing (CMP) head, wherein the first A CMP head is configured to perform a first CMP process on a surface to be polished of a workpiece, wherein the first CMP head includes a plurality of first concentric pressure elements and a first pressure element laterally surrounding the plurality of first concentric pressure elements. An annular retaining ring; a second polishing apparatus comprising a second platen and a second CMP head, wherein the second CMP head is configured to perform a second CMP process on the surface to be polished of the workpiece, wherein the The second CMP head includes a plurality of second concentric pressure elements and a second annular ring surrounding the plurality of second concentric pressure elements laterally, wherein the widths of the plurality of second concentric pressure elements are respectively different from those of the plurality of second concentric pressure elements. a width of a first concentric pressure element; a surface measuring device positioned on the first platen and the second platen, wherein the surface measuring device is configured to perform the first CMP process and the Simultaneously measuring the flatness of the surface to be polished of the workpiece during the second CMP process, wherein the pressure applied by the plurality of second concentric pressure elements during the second CMP process is based on the first the measured flatness of the surface to be polished after a CMP process; and a transport device configured to transport the workpiece between the first polishing device and the second polishing device.

In some embodiments, the polishing system further includes: a third polishing device including a third platen and a third chemical mechanical polishing head, wherein the third chemical mechanical polishing head is configured to performing a third chemical mechanical polishing process on the surface to be polished, wherein the third chemical mechanical polishing head includes a plurality of third concentric pressure elements and a third annular ring surrounding the plurality of third concentric pressure elements laterally, wherein the The widths of the plurality of third concentric pressure elements are respectively different from the widths of the plurality of first concentric pressure elements and the plurality of second concentric pressure elements.

In some embodiments, the innermost concentric pressure element of the first chemical mechanical polishing head has a width greater than the innermost concentric pressure element of the first chemical mechanical polishing head laterally surrounding the first chemical mechanical polishing head. The width of the concentric pressure element of the pressure element, and wherein the width of the innermost concentric pressure element of the third chemical mechanical polishing head is smaller than the width of the innermost concentric pressure element of the first chemical mechanical polishing head.

In some embodiments, the width of the second innermost concentric pressure element of the third chemical mechanical polishing head is greater than the width of the innermost concentric pressure element of the third chemical mechanical polishing head.

In some embodiments, the number of concentric pressure elements in the plurality of first concentric pressure elements is less than the number of concentric pressure elements in the second plurality of concentric pressure elements, and the number of concentric pressure elements in the third plurality of concentric pressure elements The number of concentric pressure elements is greater than the number of concentric pressure elements in the second plurality of concentric pressure elements.

In some embodiments, the polishing system further includes: a fourth polishing device including a fourth platen and a fourth chemical mechanical polishing head, wherein the fourth chemical mechanical polishing head is configured to A fourth chemical mechanical polishing process is performed on the surface to be polished, wherein the fourth chemical mechanical polishing head includes a plurality of fourth concentric pressure elements and a fourth annular ring surrounding the plurality of fourth concentric pressure elements laterally, wherein the The widths of the plurality of fourth concentric pressure elements are respectively different from the widths of the plurality of first concentric pressure elements, the plurality of second concentric pressure elements, and the plurality of third concentric pressure elements.

In some embodiments, the plurality of first concentric pressure elements, the plurality of second concentric pressure elements, the plurality of third concentric pressure elements, and the plurality of fourth concentric pressure elements each comprise the same number of Concentric pressure element.

In some embodiments, the present invention provides a method for chemical mechanical polishing (CMP) of a workpiece, the method comprising: using a first CMP head to perform a first CMP process on the front side surface of the workpiece, the first A CMP head having a first distribution of a plurality of first pressure elements across the first CMP head; measuring the flatness of the front side surface of the workpiece; and measuring the front side of the workpiece with a second CMP head performing a second CMP process on the surface, the second CMP head having a second distribution across a plurality of second pressure elements of the second CMP head, wherein pressure exerted by the plurality of second pressure elements is based on the The measured flatness of the front side surface of the workpiece, and wherein the second distribution is different from the first distribution.

In some embodiments, the width of the innermost pressure element of the first chemical mechanical polishing head is smaller than the width of the innermost pressure element of the second chemical mechanical polishing head.

In some embodiments, the method further includes: performing a third chemical mechanical polishing process on the front side surface of the workpiece using a third chemical mechanical polishing head, the third chemical mechanical polishing head having a A third distribution of a plurality of third pressure elements of three chemical mechanical polishing heads, wherein the third distribution is different from the first distribution and the second distribution.

In some embodiments, the method further includes: performing a fourth chemical mechanical polishing process on the front side surface of the workpiece using a fourth chemical mechanical polishing head, the fourth chemical mechanical polishing head having A fourth distribution of a plurality of fourth pressure elements of four chemical mechanical polishing heads, wherein the fourth distribution is different from the first distribution, the second distribution and the third distribution.

The foregoing outlines features of several embodiments so that those skilled in the art may better understand the various aspects of the present disclosure. Those skilled in the art should appreciate that they can readily use this disclosure as a basis for designing or modifying other processes and structures to carry out the same purposes and/or implement the embodiments described herein. example with the same advantages. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and they can make various changes, substitutions and alterations herein without departing from the spirit and scope of the present disclosure. .

100,700: chemical mechanical polishing (CMP) systems 102,702: First polishing equipment 104: The first board 105,706,902: Artifacts 105c: center point 105e: Circumferential edge 106: The first CMP header 107,404: Polishing pads 108: The first support arm 110,704: Second polishing equipment 112: The second platen 114: The second CMP header 116: second support arm 118:Polishing station 119: The second polishing station 120: Surface measurement equipment 122:Front opening unified box (FOUP) 124: Loading equipment 126: Transport equipment 128: Robot 130: track 132: Wafer car 134: Controller 136: ring retaining ring 138: Upper shell 139: The first pressure control board 140a,140b,140c,140d,140e,144a,144b,144c,144d,144e,144f,144g,506a,506b,506c,506d,506e,506f,506g,506h,514a,514b,514c,514d,514e, 514f, 514g, 514h: pressure components 141a,141b,141c,141d,141e,145a,145b,145c,145d,145e,145f,145g,508a,508b,508c,508d,508e,508f,508g,508h,516a,516b,516c,516d,516e, 516f, 516g, 516h: width 142: Second pressure control board 302, 304, 306: graphs 308: First upper curve 309,320a: first horizontal line 310: First lower curve 312: second upper curve 314: second lower curve 316: third upper curve 318: third lower curve 320b: second horizontal line 322a, 322b, 322c, 322d, 322e, 322f, 322g, 322h, 322i, A1, A2, A3, A4, A5, B1, B2, B3, B4, B5, B6, B7, C1, C2, C3, C4, C5, C6, C7, C8, D1, D2, D3, D4, D5, D6, D7, D8: Concentric pressure zones 324a, 324b, 324c, 324d: outer area 326,328,330: concentric circles 400: Polishing equipment 402: platen 406: slurry arm 408: CMP header 410: Adjustment dial 411: slurry 412: polished surface 414: CMP controller 416: Feedback path 417: Operation routine 418: Platen spindle 420: polishing pad axis 421: Wafer Axis 422: The first angular velocity arrow 424:Scan arm 426: Regulating surface 428: memory 430: CMP head spindle 432: The second angular velocity arrow 434: path 436:Instant Surface Profile Analyzer 440:Multi-zone pressure controller 444: disk axis 502: The third CMP header 504: The third pressure control board 510: The fourth CMP head 512: The fourth pressure control board 706': The first planarized workpiece 706'': Artifact 708: Flatness tool 800: method 802,804,806,808,810,812,814,816,818: action 900,1000,1100,1200,1300,1400: cutaway view 902b: dorsal surface 902f: Front side surface 904: carrier substrate 906:Semiconductor Structures R: Radius Ti: initial thickness Ts1: first thickness Ts2: second thickness

Aspects of the present disclosure are best understood from the following detailed description when read with the accompanying figures. It should be noted that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion. 1A-1C illustrate some embodiments of various diagrams of a chemical mechanical polishing (CMP) system including first and second CMP heads each having a plurality of pressure elements. 2A-2B illustrate some embodiments of top views of a workpiece with a plurality of pressure elements disposed proximate to the workpiece. 3A illustrates some embodiments of graphs illustrating removal rates of a first CMP head and a second CMP head during operation of the CMP system shown in FIGS. 1A-1C . Figure 3B illustrates some embodiments of a layout of a workpiece with a plurality of pressure elements disposed proximate to the workpiece. Figure 3C illustrates some embodiments of a layout of a workpiece provided with multiple concentric pressure zones spanning the workpiece. Figure 4 shows some embodiments of a block diagram of a polishing apparatus with a CMP head. Figure 5 illustrates some embodiments of a cross-sectional view of a plurality of CMP heads. 6 illustrates some embodiments of a cross-sectional view of a plurality of CMP heads according to some alternative embodiments of the plurality of CMP heads shown in FIG. 5 . Figure 7 shows some embodiments of a block diagram of a CMP system. Figure 8 illustrates some embodiments of a method of polishing a surface to be polished of a workpiece using multiple CMP heads. 9 to 14 show cross-sectional views of some embodiments of structures illustrating the method shown in FIG. 8 .

106: The first CMP header

114: The second CMP header

139: The first pressure control board

140a, 140b, 140c, 140d, 140e, 144a, 144b, 144c, 144d, 144e: pressure element

142: Second pressure control board

302, 304, 306: graphs

308: First upper curve

309,320a: first horizontal line

310: First lower curve

312: second upper curve

314: second lower curve

316: third upper curve

318: third lower curve

320b: second horizontal line

322a, 322b, 322c, 322d, 322e, 322f, 322g, 322h, 322i: Concentric pressure zones

324a, 324b, 324c, 324d: outer area

Claims (1)

A chemical mechanical polishing system comprising: a first chemical mechanical polishing head configured to hold a workpiece, wherein the first chemical mechanical polishing head includes a plurality of first pressure elements disposed across the first pressure control plate; and A second chemical mechanical polishing head configured to hold the workpiece, wherein the second chemical mechanical polishing head includes a plurality of second pressure elements disposed across a second pressure control plate, wherein the first pressure control plate A distribution of the first plurality of pressure elements of the plate is different than a distribution of the second plurality of pressure elements across the second pressure control plate.

Images