Chemical mechanical polishing device and fixing ring for chemical mechanical polishing device

Abstract

A chemical mechanical polishing device and a retaining ring for a chemical mechanical polishing device are provided. The chemical mechanical polishing device comprises a polishing pad; a polishing head configured to receive a wafer and hold the wafer on a polishing pad; and a fixing ring configured to engage with the polishing head, where the fixing ring is formed with a plurality of channels configured to allow slurry to flow from an exterior of the fixing ring to an interior of the fixing ring in a flow direction, where a flow cross-sectional area of the channels decreases in the flow direction.

Description

Technical Field

[0001] The present disclosure relates to a chemical mechanical polishing device, and more particularly to a fixing ring used in a chemical mechanical polishing device. Background Art

[0002] Semiconductor or integrated circuit (IC) devices are built using complex manufacturing processes that form multiple different layers stacked on top of each other. These multiple layers are patterned using lithography, where light-sensitive photoresist materials are selectively exposed to light. For example, lithography is used to define back-end metallization layers that are formed on top of each other. In order to ensure that the formed metallization layers have good structural definition, the patterned light must be properly focused. In order to properly focus the patterned light, the workpiece must be substantially planar to avoid depth of focus issues.

[0003] Chemical mechanical polishing (CMP) is a widely used process that uses chemical and mechanical forces to flatten the semiconductor workpiece as a whole. Flattening prepares the workpiece for the formation of subsequent layers. A typical CMP tool includes a rotating platen covered with a polishing pad. A slurry distribution system is configured to provide a polishing mixture having a chemical component and an abrasive component to the polishing pad. The workpiece is then brought into contact with the rotating polishing pad to flatten the workpiece. CMP is a popular process because CMP can achieve global flattening of the entire wafer surface. The CMP process is used to polish and remove material on the wafer and is applicable to a variety of material surfaces. In addition, the CMP process avoids the use of hazardous gases and / or is generally a low-cost process. Utility Model Content

[0004] One aspect of the present disclosure relates to a chemical mechanical polishing device, comprising: a polishing pad; a polishing head configured to receive a wafer and hold the wafer on the polishing pad; and a fixing ring configured to engage with the polishing head, wherein the fixing ring is formed with a channel, and the channel is configured to allow slurry to flow from the outside of the fixing ring to the inside of the fixing ring along a flow direction, wherein the flow cross-sectional area of ​​the channel decreases along the flow direction.

[0005] Another aspect of the present disclosure relates to a fixed ring for surrounding a wafer in a chemical mechanical polishing device, the fixed ring comprising an annular wall surrounding the wafer and having an outer surface and an inner surface; and a channel extending from the outer surface to the inner surface, wherein the channel has a first flow cross-sectional area adjacent to the outer surface, wherein the channel has a second flow cross-sectional area adjacent to the inner surface, and wherein the second flow cross-sectional area is smaller than the first flow cross-sectional area.

[0006] Another aspect of the present disclosure relates to a chemical mechanical polishing device, comprising: a polishing pad; a polishing head configured to receive a wafer and hold the wafer on the polishing pad; and a fixed ring configured to engage with the polishing head, wherein the fixed ring is formed with a channel, the channel is configured to allow slurry to flow from the outside of the fixed ring to the inside of the fixed ring along a flow direction, wherein the channel has an inner channel wall formed with a curvature radius, wherein the curvature radius is 5 to 50 mm. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] When read in conjunction with the accompanying drawings, the various aspects of the present disclosure can be best understood from the following detailed description. It should be noted that, in accordance with industry standard practices, various features may not be drawn to scale. In fact, for the sake of clarity of discussion, the size of various features may be increased or decreased arbitrarily.

[0008] Figure 1 is a schematic diagram of a chemical mechanical polishing (CMP) system according to some embodiments;

[0009] Figure 2 According to some embodiments Figure 1 A CMP tool perspective of the system;

[0010] Figure 3 According to some embodiments Figure 2 A cross-sectional view of a CMP tool;

[0011] Figure 4 According to some embodiments Figure 2 , Figure 3 A schematic top view of a fixing ring of a tool;

[0012] Figure 5 According to some embodiments Figure 4 A perspective view of a portion of a retaining ring;

[0013] Figure 6 According to some embodiments Figure 5 An outer side view of the fixing ring;

[0014] Figure 7 According to some embodiments Figure 5 An inner side view of a fixing ring;

[0015] Figure 8 According to some embodiments Figure 4 A perspective view of a portion of a retaining ring;

[0016] Fig. 9 According to some embodiments Figure 4 A perspective view of a portion of a retaining ring;

[0017] Fig.10 According to some embodiments Fig. 9An outer side view of the fixing ring;

[0018] Fig.11 According to some embodiments Fig. 9 An inner side view of a fixing ring;

[0019] Fig.12 According to some embodiments Figure 4 A perspective view of a portion of a retaining ring;

[0020] Fig.13 According to some embodiments Figure 4 A perspective view of a portion of a retaining ring;

[0021] Figures 14 to 16 Alternative embodiment of the interception through the baffle Fig.13 A cross-sectional view of a portion of a retaining ring;

[0022] Fig.17 According to some embodiments Figure 4 A perspective view of a portion of a retaining ring;

[0023] Fig.18 It is cut through the baffle Fig.17 A cross-sectional view of a portion of a retaining ring;

[0024] Fig.19 According to some embodiments Figure 4 A perspective view of a portion of a retaining ring;

[0025] Fig. 20 According to some embodiments Fig.19 an inner side view of a portion of a retaining ring;

[0026] Figure 21 to Figure 23 According to some embodiments Figure 4 A top view of an alternative embodiment of a portion of a retaining ring.

[0027]

Explanation of symbols

[0028] 1: System

[0029] 5: Wafer

[0030] 10: Tools

[0031] 12: Rinse module

[0032] 13,14: Cleaning module

[0033] 15: Rinse, spin and / or dry module

[0034] 16:Transmission module

[0035] 19: Axis

[0036] 30: Platform

[0037] 40: Platform motor

[0038] 50: Wafer holder assembly

[0039] 56: Axis

[0040] 60: Fixed ring

[0041] 99: Slurry

[0042] 110: Base

[0043] 120,120a,120b,120c: Polishing pad

[0044] 121a, 121b, 121c: Pad adjuster

[0045] 122,122a,122b,122c: Slurry supply arm

[0046] 130: Loading cup

[0047] 132: Lower surface

[0048] 134: Elastic member

[0049] 139: Internal volume

[0050] 140: Head rotation unit

[0051] 141: Carrying head / polishing head

[0052] 141a,141b,141c,141d: Polishing head

[0053] 152: Back

[0054] 153: Peripheral edge

[0055] 154: Front

[0056] 161:Robotic Arm

[0057] 165: Carrier

[0058] 301: Inner surface

[0059] 302: Outer surface

[0060] 303: Top surface

[0061] 304: Bottom surface

[0062] 400: Channel

[0063] 401: Inner opening

[0064] 402: External opening

[0065] 411: Side wall

[0066] 412: Side wall

[0067] 413:Up the wall

[0068] 421: Internal

[0069] 422: External

[0070] 423: Interface

[0071] 450: Baffle

[0072] 460: Baffle

[0073] 555: Part

[0074] A1:Angle

[0075] L1: Length

[0076] D3,D4: diameter

[0077] H1,H2: Height

[0078] R1, R2: Radius

[0079] R3, R4: radius of curvature

[0080] W1,W2: Width DETAILED DESCRIPTION

[0081] It should be understood that the following disclosure provides many different embodiments or examples for implementing the different features of the present disclosure. Specific embodiments or examples of components and configurations are described below to simplify the present disclosure. Of course, these are merely examples and are not intended to be limiting.

[0082] For the sake of brevity, conventional techniques associated with conventional semiconductor device manufacturing will not be described in detail herein. In addition, the various operations and processes described herein may be incorporated into a more comprehensive process or process having additional functions not described in detail herein. Specifically, the various processes in semiconductor device manufacturing are well known, and therefore, for the sake of brevity, many conventional processes will only be briefly mentioned herein or will be omitted entirely without providing well-known process details. It will be readily apparent to those skilled in the art after a complete reading of this disclosure that the structures disclosed herein can be used with a variety of technologies and can be incorporated into a variety of semiconductor devices and products. In addition, it should be noted that the semiconductor device structure includes a varying number of components, and a single component shown in the illustrations may represent multiple components.

[0083] In addition, for ease of description, the present disclosure may use spatially relative terms such as "below", "under", "lower", "above", "upper", etc. to describe the relationship between an element or feature and one or more other elements or features, as shown in the accompanying drawings. Spatially relative terms are intended to cover different orientations of the device in use or operation in addition to the orientations illustrated in the accompanying drawings. Therefore, the exemplary term "below" can cover both above and below. This device can be oriented in other ways (rotated 90 degrees or in other orientations), and the spatially relative descriptors used herein can also be interpreted accordingly. When spatially relative terms such as those listed above are used to describe a first element relative to a second element, the first element can be directly on another element, or there can be an intermediate element or layer. When an element or layer is referred to as being "on" another element or layer, it is directly on another element or layer and in contact with another element or layer.

[0084] In addition, the present disclosure may repeat reference numerals and / or letters in various examples. This repetition is for the purpose of simplicity and clarity, and does not in itself define the relationship between the various embodiments and / or configurations discussed.

[0085] Embodiments herein relate to CMP processing, and in particular to retaining CMP slurry at the interface of a wafer and a polishing pad during a CMP process. The post-CMP profile of a wafer is closely related to the flow field of the slurry on the CMP platform. The flow field is generated by a combination of polishing pad grooves, slurry arm performance, and a retaining ring. Here, the retaining ring is provided with grooves that are designed to promote the slurry to enter the wafer while inhibiting the slurry from leaving the wafer. Therefore, during the CMP process, the slurry can be retained within the retaining ring, thereby providing a more efficient use of the slurry in the CMP process.

[0086] Figure 1 1 is a schematic diagram of a processing system 1 for processing a semiconductor wafer 5 according to some embodiments. In some embodiments, the processing system 1 is a chemical mechanical polishing (CMP) system. The CMP system 1 includes a CMP module or tool 10, a rinse module 12, a plurality of cleaning modules, such as cleaning modules 13 and 14, a rinse, spin and / or dry module 15, and a plurality of transfer modules 16. Elements of the CMP system 1 may be added or omitted, and the present disclosure should not be limited by the embodiments.

[0087] The semiconductor wafer 5 can be made of silicon or other semiconductor materials. Alternatively or additionally, the semiconductor wafer 5 can include other elemental semiconductor materials, such as germanium (Ge). In some embodiments, the semiconductor wafer 5 is made of compound semiconductors such as silicon carbide (SiC), gallium arsenide (GaAs), indium arsenide (InAs) or indium phosphide (InP). In some embodiments, the semiconductor wafer 5 is made of alloy semiconductors, such as silicon germanium (SiGe), silicon germanium carbide (SiGeC), gallium arsenide phosphide (GaAsP) or gallium indium phosphide (GaInP). In some embodiments, the semiconductor wafer 5 includes an epitaxial layer. For example, the semiconductor wafer 5 has an epitaxial layer covering the main semiconductor. In some other embodiments, the semiconductor wafer 5 can be a silicon-on-insulator (SOI) or a germanium-on-insulator (GOI) substrate.

[0088] The semiconductor wafer 5 may have various device elements. Examples of device elements formed in the semiconductor wafer 5 include transistors (e.g., metal-oxide semiconductor field effect transistors (MOSFET), complementary metal-oxide-semiconductor transistors (CMOS) transistors, bipolar junction transistors (BJT), high voltage transistors, high frequency transistors, p-channel and / or n-channel field effect transistors (PFET / NFET), etc.), diodes and / or other applicable elements. Various processes are performed to form the device elements, such as deposition, etching, implantation, lithography, annealing and / or other suitable processes. In some embodiments, a shallow trench isolation (STI) layer, an inter-layer dielectric (ILD) or an intermetallic dielectric layer covers the device elements formed on the semiconductor wafer 5.

[0089] The CMP module 10 is configured to perform a planarization process on a semiconductor wafer 5 in a semiconductor manufacturing process. In some embodiments, the CMP module 10 includes a substrate 110, a plurality of polishing pads 120a, 120b, and 120c, a plurality of loading cups 130, and a head rotation unit 140. Elements of the CMP module 10 may be added or omitted, and the present disclosure should not be limited by the embodiments.

[0090] In some embodiments, polishing pads 120a, 120b and 120c are disposed on substrate 110. The three polishing pads 120a, 120b and 120c are conducive to processing multiple wafers simultaneously in a short time. Each polishing pad is mounted on a rotatable turntable (not shown in the figure). Pad conditioners 121a, 121b and 121c are disposed on substrate 110 and can sweep across each polishing pad 120a, 120b and 120c to adjust the polishing pads 120a, 120b and 120c. Slurry supply arms 122a, 122b and 122c are also disposed on substrate 110 for supplying slurry to the surface of each polishing pad 120a, 120b and 120c.

[0091] The loading cup 130 is configured to load and unload the semiconductor wafer 5. In some embodiments, each loading cup 130 includes a circular base on which the semiconductor wafer 5 is placed for loading the semiconductor wafer 5 onto the polishing pads 120a, 120b, and 120c and for unloading the semiconductor wafer 5 from the polishing pads 120a, 120b, and 120c.

[0092] The head rotation unit 140 has a plurality of carriers or polishing heads 141a, 141b, 141c and 141d for holding and fixedly rotating the semiconductor wafer 5 on the polishing pads 120a, 120b and 120c. The polishing heads 141a, 141b, 141c and 141d of the head rotation unit 140 are mounted on respective rotation axes (not shown in the figure), which are rotated by a driving mechanism within the head rotation unit 140. The polishing heads 141a, 141b, 141c and 141d hold the respective semiconductor wafers 5 and press the semiconductor wafers 5 against the top surfaces of the respective polishing pads 120a, 120b and 120c. In this way, a material layer is removed from each semiconductor wafer 5.

[0093] According to some embodiments, the transfer module 16 includes one or more drive elements (not shown) and a plurality of robotic arms 161. The drive element, such as a motor, is controlled by the control module and connected to the robotic arms 161. The robotic arms 161 are driven by the drive element to provide radial and rotational motion within a fixed plane to pick up, transfer, and transfer the semiconductor wafer 5 from one location to another within the CMP system 1. For example, using the transfer module 16, the semiconductor wafer 5 is transferred between a carrier 165 such as a FOUP and the CMP module 10. Alternatively, the semiconductor wafer 5 is transferred between the CMP module 10 and the rinse module 12 through the transfer module 16. Alternatively, the semiconductor wafer 5 is transferred between the rinse, spin, and / or dry module 15 and the carrier 165.

[0094] Figure 2 For example, from Figure 1Schematic diagram of a CMP polishing tool or module 10 of a system 1. The tool 10 is configured to perform a CMP process on a wafer 5 in a semiconductor manufacturing process. As shown, according to some embodiments, the tool 10 includes a polishing pad 120, a platform 30, a platform motor 40, and a wafer holder assembly 50. Elements of the polishing tool 10 may be added or omitted, and the present disclosure should not be limited by the embodiments.

[0095] The platform 30 is configured to receive the polishing pad 120 and rotate about the central axis 19. In some embodiments, the shape of the platform 30 is circular. The diameter of the platform 30 is within a range that is significantly larger than the diameter of the wafer 5 to be polished. The platform motor 40 rotates the platform 30 about the axis 19. The platform motor 40 can be electrically connected to a control module in the CMP tool and can be started and operated by the control module.

[0096] In one embodiment, a polishing pad 120 is fixed to the platform 30. The polishing pad 120 can be a consumable used in a semiconductor wafer manufacturing process. The polishing pad 120 can be a hard and incompressible pad or a soft pad. For polishing oxide, a hard and more rigid pad is usually used to achieve flatness. Softer pads are often used in other polishing processes to achieve improved uniformity and smooth surfaces. Hard and soft pad components can also be combined into arrangements for custom applications.

[0097] The wafer holder assembly 50 is used to support the wafer 5. In some embodiments, the wafer holder assembly 50 may include a shaft having a drive motor (not shown), a carrier head 141, and a fixed ring 60. The drive motor is configured to control the rotational movement of the carrier head 141 and the fixed ring 60 around the rotation axis 56. The rotation axis 56 is different from the rotation axis 19. In some embodiments, the drive motor is an electric motor that converts electrical energy into mechanical energy to drive the carrier head 141 and the fixed ring 60 to rotate. In some embodiments, the carrier head 141 and the fixed ring 60 are driven to rotate around the rotation axis 56 by an external force (e.g., the friction force generated between the polishing pad 120 and the wafer 5).

[0098] Figure 3 Provides a Figure 2 1 and 120. As shown, the slurry 99 is delivered to the polishing pad 120.

[0099] In addition, the wafer 5 is located below the wafer holder assembly 50. In some embodiments, the wafer 5 is attached to an elastic member 134 (e.g., a backing film) that is located between the wafer 5 and the lower surface 132 of the carrier head 141. Specifically, the back side 152 of the wafer 5 is attached to the elastic member 134. In addition, the wafer 5 has a front side 154 that is to be polished by the slurry 99 and the polishing pad 120. As shown, the wafer 5 is generally cylindrical and has a peripheral edge 153.

[0100] In the illustrated embodiment, the retaining ring 60 is formed as an annular wall having an inner surface 301 and an outer surface 302. As shown, the retaining ring 60 extends downward from a top surface 303 adjacent to the carrier head 141 to a bottom surface 304. As shown. Figure 3 As shown, the bottom surface 304 of the retaining ring 60 can contact the polishing pad 120. The retaining ring 60 defines an internal volume 139 that can accommodate the wafer 5. As shown, the inner surface 301 of the retaining ring 60 can be spaced a distance from the peripheral edge 153 of the wafer 5. By surrounding the wafer 5, the retaining ring 60 ensures that the wafer 5 remains under the carrier head 141 during the polishing process.

[0101] During operation of the CMP tool 10, the wafer 5 is placed face down with the front side 154 against the polishing pad 120. As the wafer 5 moves, the polishing pad 120 and slurry 99 remove material from the front side 154. The retaining ring 60 can be pressed against the polishing pad 120 with an adjustable down force.

[0102] The embodiments herein facilitate the entry of the slurry 99 into the interior volume 139 where the wafer 5 is located. In addition, the embodiments herein inhibit the slurry 99 from escaping from the interior volume 139 where the wafer 5 is located. Therefore, the slurry 99 can be trapped in the interior volume 139 during the CMP process, thereby providing more efficient use of the slurry 99 in the CMP process.

[0103] Reference now Figure 4 , providing a top view of the retaining ring 60. As shown, the retaining ring 60 includes channels 400 extending from the outer surface 302 to the inner surface 301. Although the retaining ring 60 is shown as including twelve channels 400, any suitable number of channels 400 may be used. In addition, it should be noted that the top surface 303 of the retaining ring 60 is Figure 4 The channel 400 is transparent to allow viewing of the channel 400.

[0104] Figure 5 supply Figure 4 60, wherein the internal passage 400 can be seen through the retaining ring 60. As shown, the portion 555 includes the passage 400 extending from the outer surface 302 to the inner surface 301 of the retaining ring 60. Figure 6is a side view of outer surface 302 of retaining ring 60 in portion 555 . Figure 7 is a side view of the inner surface 301 of the retaining ring 60 in the portion 555 .

[0105] For reference Figures 5 to 7 , it can be seen that the channel 400 forms an outer opening 402 at the outer surface 302 and an inner opening 401 at the inner surface 301. In addition, the channel 400 is in fluid communication with the bottom surface 304, so that the bottom end of the channel 400 should not be restricted by the fixing ring 60. Instead, the channel 400 is defined by the first side wall 411, the second side wall 412 and the upper wall 413.

[0106] As shown, passage 400 has a radial length L1 from outer opening 402 to inner opening 401. Length L1 can be 0.5 to 50 millimeters (mm). For example, length L1 can be at least 0.5, at least 1, at least 2, at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, at least 40, or at least 45 millimeters (mm). In addition, length L1 can be at most 1, at most 2, at most 5, at most 10, at most 15, at most 20, at most 25, at most 30, at most 35, at most 40, at most 45, or at most 50 millimeters (mm).

[0107] As shown, the channel 400 has a flow cross-sectional area that decreases from the outer surface 302 to the inner surface 301. Figures 5 to 7 In the embodiment of the present invention, the flow cross-sectional area decreases continuously, that is, in a smooth manner. At the outer opening 402, the channel 400 has a width W2 extending from the side wall 411 to the side wall 412. In addition, at the outer opening 402, the channel 400 has a height H2 extending from the bottom surface 304 to the upper wall 413. Therefore, at the outer opening 402, the channel 400 has a flow cross-sectional area A2 equal to the product of the width W2 and the height H2.

[0108] At the inner opening 401, the channel 400 has a width W1 extending from the side wall 411 to the side wall 412. In addition, at the inner opening 401, the channel 400 has a height H1 extending from the bottom surface 304 to the upper wall 413. Therefore, at the inner opening 402, the channel 400 has a flow cross-sectional area A1 equal to the product of the width W1 and the height H1.

[0109] In some embodiments, the maximum flow cross-sectional area of ​​the channel 400 is the flow cross-sectional area A2 at the outer opening 402. In some embodiments, the minimum flow cross-sectional area of ​​the channel 400 is the flow cross-sectional area A1 at the inner opening 401.

[0110] In some embodiments, the maximum cross-sectional flow area is 5 to 500 millimeters (mm). For example, the maximum cross-sectional flow area can be at least 5, at least 10, at least 25, at least 50, at least 100, at least 150, at least 200, at least 250, at least 300, at least 350, at least 400, or at least 450 millimeters (mm). In addition, the maximum cross-sectional flow area can be at most 10, at most 25, at most 50, at most 100, at most 150, at most 200, at most 250, at most 300, at most 350, at most 400, at most 450, or at most 500 millimeters (mm).

[0111] In some embodiments, the minimum flow cross-sectional area is 5% to 95% of the maximum flow cross-sectional area. For example, the minimum flow cross-sectional area can be at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, or at least 90% of the maximum flow cross-sectional area. In addition, the minimum flow cross-sectional area can be at most 10%, at most 15%, at most 20%, at most 25%, at most 30%, at most 35%, at most 40%, at most 45%, at most 50%, at most 55%, at most 60%, at most 65%, at most 70%, at most 75%, at most 80%, at most 85%, at most 90%, or at most 95% of the maximum flow cross-sectional area.

[0112] The flow rate of the slurry 99 that can pass through the channel 400 from the outer opening 402 to the inner opening 401 ( Figure 3 ) is equal to the product of the flow cross-sectional area of ​​the channel and the flow velocity. During the CMP process, the slurry supply arm 122 ( Figure 1 ) supplies a fixed flow of slurry 99( Figure 3 As the passage 400 decreases in cross-sectional flow area from the outer opening 402 to the inner opening 401, the flow rate of the slurry 99 must increase as the slurry 99 travels through the passage 400. It is believed that the increase in flow rate can suppress the amount of slurry 99 that flows outward from the inner opening 401 to the outer opening 402. Therefore, the slurry 99 is retained within the retaining ring 60.

[0113] Although Figure 5 A channel having a continuously decreasing rectangular flow cross-sectional area is shown, but other embodiments are contemplated.

[0114] For example, Figure 8 Shows Figure 4 Another embodiment of the portion 555 of the fixing ring 60. Similar to Figure 5 , Figure 8 The internal passage 400 is shown visible through the retaining ring 60. Figure 8, the channel 400 has a steady flow cross-sectional area from the outer opening 402 through the outer portion 422. Likewise, the channel 400 has a steady flow cross-sectional area from the inner opening 401 through the inner portion 421. At the interface 423 between the outer portion 422 and the inner portion 421, the flow cross-sectional area changes dramatically, i.e., in a step-wise manner, from the maximum flow cross-sectional area of ​​the outer opening 402 to the minimum flow cross-sectional area of ​​the inner opening 401. Figure 8 The maximum and minimum cross-sectional flow areas and other dimensions of the embodiments may be the same as described above.

[0115] Figures 9 to 11 Show Figure 4 Another embodiment of a portion 555 of a fixing ring. Fig. 9 supply Figure 4 60, wherein the internal passage 400 can be seen through the retaining ring 60. As shown, the portion 555 includes the passage 400 extending from the outer surface 302 to the inner surface 301 of the retaining ring 60. Fig.10 is a side view of outer surface 302 of retaining ring 60 in portion 555 . Fig.11 is a side view of the inner surface 301 of the retaining ring 60 in the portion 555 .

[0116] exist Figures 9 to 11 In the embodiment, the channel 400 has a circular flow cross-sectional area that decreases smoothly from the outer opening 402 to the inner opening 401. At the outer opening 402, the channel 400 has a radius R2. Therefore, at the outer opening 402, the channel 400 has a radius equal to π(R2) 2 The cross-sectional flow area A2 is the product of the product of. At the inner opening 401, the channel 400 has a radius R1. Therefore, at the inner opening 401, the channel 400 has a radius equal to π(R1) 2 The product of the flow cross-sectional area A1.

[0117] Figures 9 to 11 The maximum and minimum cross-sectional flow areas and other dimensions of the embodiments may be the same as described above.

[0118] In some embodiments, the maximum flow cross-sectional area of ​​the channel 400 is the flow cross-sectional area A2 at the outer opening 402. In some embodiments, the minimum flow cross-sectional area of ​​the channel 400 is the flow cross-sectional area A1 at the inner opening 401.

[0119] In some embodiments, the maximum cross-sectional flow area is 5 to 500 millimeters (mm). For example, the maximum cross-sectional flow area can be at least 5, at least 10, at least 25, at least 50, at least 100, at least 150, at least 200, at least 250, at least 300, at least 350, at least 400, or at least 450 millimeters (mm). In addition, the maximum cross-sectional flow area can be at most 10, at most 25, at most 50, at most 100, at most 150, at most 200, at most 250, at most 300, at most 350, at most 400, at most 450, or at most 500 millimeters (mm).

[0120] In some embodiments, the minimum flow cross-sectional area is 5% to 95% of the maximum flow cross-sectional area. For example, the minimum flow cross-sectional area can be at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, or at least 90% of the maximum flow cross-sectional area. In addition, the minimum flow cross-sectional area can be at most 10%, at most 15%, at most 20%, at most 25%, at most 30%, at most 35%, at most 40%, at most 45%, at most 50%, at most 55%, at most 60%, at most 65%, at most 70%, at most 75%, at most 80%, at most 85%, at most 90%, or at most 95% of the maximum flow cross-sectional area.

[0121] The flow rate of the slurry 99 that can pass through the channel 400 from the outer opening 402 to the inner opening 401 ( Figure 3 ) is equal to the product of the flow cross-sectional area of ​​the channel and the flow velocity. During the CMP process, the slurry supply arm 122 ( Figure 1 )Supply a fixed flow of slurry 99( Figure 3 As the passage 400 decreases in cross-sectional flow area from the outer opening 402 to the inner opening 401, the flow rate of the slurry 99 must increase as the slurry 99 travels through the passage 400. It is believed that the increase in flow rate can suppress the amount of slurry 99 that flows outward from the inner opening 401 to the outer opening 402. Therefore, the slurry 99 is retained within the retaining ring 60.

[0122] Reference now Fig.12 , showing Figure 4 Another embodiment of the portion 555 of the fixing ring 60. Similar to Figure 5 , Fig.12 The internal passage 400 is shown visible through the retaining ring 60. Figure 8In the figure, the channel 400 has a stable flow cross-sectional area from the outer opening 402 through the outer portion 422. Similarly, the channel 400 has a stable flow cross-sectional area from the inner opening 401 through the inner portion 421. At the interface 423 between the outer portion 422 and the inner portion 421, the flow cross-sectional area changes sharply, that is, in a step-wise manner, from the maximum flow cross-sectional area of ​​the outer opening 402 to the minimum flow cross-sectional area of ​​the inner opening 401. As shown in the figure. Fig.12 As shown, the outer portion 422 of the channel 400 has a rectangular cross-sectional flow area, while the inner portion 421 has a circular cross-sectional flow area. Fig.12 The maximum and minimum cross-sectional flow areas and other dimensions of the embodiments may be the same as described above.

[0123] Fig.13 Shows Figure 4 Another embodiment of the portion 555 of the fixing ring 60. Similar to Figure 5 , Fig.13 The internal passage 400 is shown visible through the retaining ring 60. Fig.13 In the embodiment, the channel 400 is formed with side walls 411 and 412 and an upper wall 413 of constant size. However, a baffle 450 is located in the channel 400 to provide a constriction to reduce the flow cross-sectional area. In such an embodiment, the flow cross-sectional area is equal to the difference between the channel area (the product of width and height) and the area of ​​the baffle (the product of width and height). Fig.13 In FIG. 4 , the baffles 450 are periodically arranged and are arranged equidistant from one another along the length L1 of the channel 400 ; however, other arrangements are also contemplated.

[0124] Figures 14 to 16 Show Fig.13 Different embodiments of channel 400. Figures 14 to 16 A cross-sectional view taken through a respective baffle 450 is provided to illustrate the cross-sectional flow area. In various embodiments, the baffle 450 is connected to the upper wall 413, however other configurations are also contemplated. Fig.14 In the example shown in FIG. 1 , baffle 450 reduces the flow cross-sectional area by 10%. Fig.15 In the embodiment of FIG. 4 , similarly sized baffles 450 are provided with different shapes. Fig.16 In the embodiment of FIG. 4 , baffle 450 reduces the cross-sectional flow area by 25%.

[0125] exist Figures 13 to 16 , the baffle 450 is arranged at a right angle to the upper wall 413. Figure 17 to Figure 18 , another embodiment having a baffle 450 is shown.

[0126] Fig.17 Shows Figure 4 Another embodiment of the portion 555 of the fixing ring 60. Similar to Figure 5, Fig.17 The internal passage 400 is shown visible through the retaining ring 60 . Fig.18 A cross-sectional view taken through a portion of a particular baffle 450 is provided.

[0127] exist Figure 17 to Figure 18 In the embodiment of the present invention, the baffle 450 is again used to reduce the flow cross-sectional area of ​​the channel 400. However, the baffle 450 is mounted to the upper wall 413 at an angle A1. In some embodiments, as shown in the figure, the angle A1 is an acute angle when viewed from the inner opening 401.

[0128] The baffle 450 can be considered to be formed at an angle A1 of 1-90 degrees, for example at least 1 degree, at least 5 degrees, at least 10 degrees, at least 15 degrees, at least 20 degrees, at least 25 degrees, at least 30 degrees, at least 35 degrees, at least 40 degrees, at least 45 degrees, at least 50 degrees, at least 55 degrees, at least 60 degrees, at least 65 degrees, at least 70 degrees, at least 75 degrees, at least 80 degrees or at least 85 degrees, for example at most 5 degrees, at most 10 degrees, at most 15 degrees, at most 20 degrees, at most 25 degrees, at most 30 degrees, at most 35 degrees, at most 40 degrees, at most 45 degrees, at most 50 degrees, at most 55 degrees, at most 60 degrees, at most 65 degrees, at most 70 degrees, at most 75 degrees, at most 80 degrees, at most 85 degrees, or at most 90 degrees.

[0129] Fig.19 A perspective view of another embodiment of a portion 555 of a retaining ring 60 having a channel 400 is shown. Figure 5 , Fig.19 The internal passage 400 is shown visible through the retaining ring 60 . Fig. 20 A side view from the inner opening 401 is provided.

[0130] In FIGS. 19 and 20, baffles 450 are mounted to upper wall 413. In addition, side baffles 460 are mounted to opposite side walls 411 and 412. In the illustrated embodiment, baffles 450 are periodically arranged at equal intervals along length L1, and side baffles 460 are located only at inner opening 401. Although this configuration is shown, other configurations are possible.

[0131] exist Figures 13 to 20 In the embodiment of the present invention, each baffle 450 or 460 may have a size of 0.1 to 250 square millimeters (mm) in the plane of the flow area. 2 ). For example, each baffle 450 or 460 may have a cross-sectional area of ​​at least 0.1, at least 0.5, at least 1, at least 2, at least 5, at least 10, at least 25, at least 50, at least 100, at least 150, or at least 200 square millimeters (mm) in the plane of the flow area. 2), and at most 0.5, at most 1, at most 2, at most 5, at most 10, at most 25, at most 50, at most 100, at most 150, at most 200 or at most 250 square millimeters (mm 2 ).

[0132] The cross-sectional area of ​​each baffle 450 or 460 in the plane of the flow area may be 1% to 50% of the flow cross-sectional area, for example at least 1%, at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, or at least 45% of the flow cross-sectional area; and at most 5%, at most 10%, at most 15%, at most 20%, at most 25%, at most 30%, at most 35%, at most 40%, at most 45%, or at most 50% of the flow cross-sectional area.

[0133] In addition, each baffle 450 or 460 may be formed with a length, width or depth of 0.5 to 50 millimeters (mm). For example, the baffle length, width or depth may be at least 0.5, at least 1, at least 2, at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, at least 40, or at least 45 millimeters (mm), and at most 1, at most 2, at most 5, at most 10, at most 15, at most 20, at most 25, at most 30, at most 35, at most 40, at most 45, or at most 50 millimeters (mm).

[0134] Figures 5 to 20 The embodiment provides that the cross-sectional flow area decreases from the outer surface 302 to the inner surface 301 of the retaining ring 60. Therefore, the flow rate of the slurry can be increased, and the reverse flow of the slurry, that is, from the interior of the retaining ring 60 to the exterior of the retaining ring 60, can be eliminated or reduced. In such embodiments, the channel 400 can be linear, for example, along a radial path through the retaining ring 60.

[0135] Figure 21 to Figure 23 An embodiment having a curved channel 400 is provided. Figure 21 to Figure 23 In the embodiment of the present invention, the curved shape of the channel 400 can extend the path of the channel 400 to reduce the reverse flow of the slurry 99 out of the retaining ring 60. Figure 21 to Figure 22 shows a channel having a smoothly formed curved shape, while Fig.23 Shows a channel formed in stages by straight line segments.

[0136] Figure 21 to Figure 23 4 is a cross-sectional view taken along a horizontal plane passing through the passage 400 and the portion 555 of the retaining ring 60 and looking downward. Fig.21, the channel 400 extends from an outer opening 402 formed in the outer surface 302 to an inner opening 401 formed in the inner surface 301. As shown, the channel 400 is formed with a radius of curvature R3 and a diameter D3. In addition, the channel 400 forms an angle A2 of about 90 degrees with the outer surface 302.

[0137] exist Fig. 22 , the channel 400 extends from an outer opening 402 formed in the outer surface 302 to an inner opening 401 formed in the inner surface 301. As shown, the channel 400 is formed with a radius of curvature R4 and a diameter D4.

[0138] The average flow velocity V of the slurry is expressed by the following formula:

[0139]

[0140] Where R is the radius of curvature, d is the diameter, ΔP is the pressure difference, and ρ is the fluid density.

[0141] When the average flow rate V is fixed to the slurry supply arm 122 ( Figure 1 ) flow rate, when the radius of curvature decreases, the channel diameter must decrease. In some embodiments, the radius of curvature may be 5 to 50 millimeters (mm). For example, the radius of curvature may be at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, at least 40, or at least 45 millimeters (mm). In addition, the radius of curvature may be at most 10, at most 15, at most 20, at most 25, at most 30, at most 35, at most 40, at most 45, or at most 50 millimeters (mm). In some embodiments, the diameter may be 2 to 20 millimeters (mm). For example, the diameter may be at least 2, at least 5, at least 10, or at least 15 millimeters (mm). In addition, the radius of curvature may be at most 5, at most 10, at most 15, or at most 20 millimeters (mm).

[0142] Although Figure 21 to Figure 23 The channels 400 are each shown having a counter-clockwise configuration, but it is contemplated that the channels can curve in the opposite clockwise direction.

[0143] Various embodiments of retaining ring 60 for use in a CMP process are provided herein that are provided with channels 400 that facilitate the flow of slurry 99 into retaining ring 60 while preventing or hindering the flow of slurry 99 out of retaining ring 60. Thus, the CMP process can utilize slurry 99 more efficiently.

[0144] The embodiments herein may reduce the cross-sectional flow area of ​​the channel 400 by reducing the height, width, and / or radius of the channel 400 as the channel 400 moves from the outer surface 302 to the inner surface 301 of the retaining ring 60. Alternatively or additionally, a baffle 450 or 460 or other constriction may be located in the channel 400 to prevent the slurry 99 from flowing back out of the retaining ring 60 and reduce the cross-sectional flow area of ​​the channel 400. Alternatively or additionally, the channel may be formed with a curved path to further reduce the reverse flow of the slurry 99 out of the retaining ring 60.

[0145] Although various features have been described with respect to the illustrated embodiments, it is contemplated that these features may be combined even if these combinations of features are not explicitly shown.

[0146] It is worth noting that the cross-section of the channel 400 can change continuously (i.e., smoothly), or change sharply (i.e., change in stages). In addition, the cross-section can be any shape, such as circular, rectangular, square, triangular or other suitable shapes. In addition, a single channel 400 can have sections with different cross-sectional shapes.

[0147] Furthermore, baffles 450 and 460 may be provided in any suitable shape and may be designed to extend into the channel from either side wall or from the upper wall.

[0148] The chemical mechanical polishing method includes engaging the polishing head 141 with the retaining ring 60. The retaining ring 60 includes or is an annular wall having an inner surface 301 and an outer surface 302 and a channel 400 extending from the outer surface 302 to the inner surface 301. The method also includes receiving the wafer 5 with the polishing head 141 so that the annular wall surrounds the wafer 5. The method also includes holding the wafer 5 on the polishing pad 120. Moreover, the method includes rotating the polishing pad 120 about the axis 19 and / or rotating the polishing head 141 and the retaining ring 60 about the axis 56. The method also includes distributing the slurry 99 on the polishing pad 120 and promoting the slurry 99 to enter the internal volume 139 where the wafer 5 is located, while preventing the slurry 99 from leaving the internal volume 139 where the wafer 5 is located.

[0149] In one embodiment, a chemical mechanical polishing device includes: a polishing pad; a polishing head configured to receive a wafer and hold the wafer on the polishing pad; and a fixed ring configured to engage with the polishing head, wherein the fixed ring is formed with a channel, and the channel is configured to allow slurry to flow from the outside of the fixed ring to the inside of the fixed ring along a flow direction, wherein the flow cross-sectional area of ​​the channel decreases along the flow direction.

[0150] In some embodiments of the device, each cross-sectional flow area decreases by 5% to 95% along the flow direction.

[0151] In some embodiments of the device, the maximum flow cross-sectional area of ​​each channel is 5 to 500 square millimeters (mm2 ).

[0152] In some embodiments of the device, each channel has a length of 0.5 to 50 millimeters (mm).

[0153] In some embodiments of the device, the cross-sectional flow area of ​​each channel decreases continuously.

[0154] In some embodiments of the device, the flow cross-sectional area of ​​each channel decreases in stages.

[0155] In some embodiments of the device, each channel includes a baffle for reducing the cross-sectional flow area.

[0156] In some embodiments of the device, each channel extends along a respective linear direction.

[0157] In some embodiments of the device, each channel extends along a respective curvilinear direction.

[0158] In another embodiment, a fixed ring for surrounding a wafer in a chemical mechanical polishing device includes an annular wall surrounding the wafer and having an outer surface and an inner surface; and a channel extending from the outer surface to the inner surface, wherein the channel has a first flow cross-sectional area adjacent to the outer surface, wherein the channel has a second flow cross-sectional area adjacent to the inner surface, and wherein the second flow cross-sectional area is smaller than the first flow cross-sectional area.

[0159] In some embodiments of the retaining ring, the second cross-sectional flow area is 5% to 95% of the first cross-sectional flow area.

[0160] In some embodiments of the retaining ring, the first flow cross-sectional area is 5 to 500 square millimeters (mm 2 ).

[0161] In some embodiments of the retaining ring, the channel has a length of 0.5 to 50 millimeters (mm).

[0162] In some embodiments of the retaining ring, the channel includes a baffle adjacent the inner surface.

[0163] In some embodiments of the retaining ring, the channel is linear.

[0164] In some embodiments of the retaining ring, the channel is curvilinear.

[0165] In another embodiment, a chemical mechanical polishing method includes: receiving a wafer with a polishing head; holding the wafer on a polishing pad; and engaging the polishing head with a retaining ring, wherein the retaining ring includes: an annular wall surrounding the wafer and having an outer surface and an inner surface; and a channel extending from the outer surface to the inner surface.

[0166] In some embodiments of the method, the channel has an inner channel wall formed with a radius of curvature, wherein the radius of curvature is from 5 to 50 millimeters.

[0167] In some embodiments of the method, the channel is formed with a diameter, and wherein the diameter is 2 to 20 millimeters.

[0168] In some embodiments of the method, the channel is formed at an angle of about 90 degrees to the outer surface.

[0169] In another embodiment, a chemical mechanical polishing device includes a polishing pad; a polishing head configured to receive a wafer and hold the wafer on the polishing pad; and a retaining ring configured to engage with the polishing head, wherein the retaining ring is formed with a channel, the channel is configured to allow slurry to flow from the outside of the retaining ring to the inside of the retaining ring along a flow direction, wherein the channel has an inner channel wall formed with a curvature radius, wherein the curvature radius is 5 to 50 mm.

[0170] The features of several embodiments are summarized above so that those skilled in the art can better understand the various aspects of the content of the present disclosure. It should be understood by those skilled in the art that the content of the present disclosure can be easily used as a basis for designing or modifying other processes and structures for performing the same purpose and / or achieving the same advantages of the embodiments introduced herein. It should also be appreciated by those skilled in the art that such equivalent structures do not depart from the spirit and scope of the present disclosure, and those skilled in the art may make various changes, substitutions and modifications herein.

Claims

1. A chemical mechanical polishing device, characterized in that: include: a polishing pad; a polishing head configured to receive a wafer and hold the wafer on the polishing pad; and A fixing ring is configured to engage with the polishing head, wherein the fixing ring is formed with a plurality of channels, and the plurality of channels are configured to allow a slurry to flow from the outside of the fixing ring to the inside of the fixing ring along a flow direction, wherein a flow cross-sectional area of ​​the plurality of channels decreases along the flow direction.

2. The chemical mechanical polishing device according to claim 1, characterized in that: The flow cross-sectional area is reduced by 5% to 95% along the flow direction.

3. The chemical mechanical polishing device according to claim 1, characterized in that: A maximum flow cross-sectional area of ​​each of the plurality of channels is 5 to 500 square millimeters.

4. The chemical mechanical polishing device according to claim 1, characterized in that: The length of each of the plurality of channels is 0.5 to 50 mm.

5. The chemical mechanical polishing device according to claim 1, characterized in that: The flow cross-sectional area of ​​each of the plurality of channels decreases continuously.

6. A fixing ring for surrounding a wafer in a chemical mechanical polishing device, characterized in that: The retaining ring includes: an annular wall surrounding the wafer and having an outer surface and an inner surface; and A channel extends from the outer surface to the inner surface, wherein the channel has a first flow cross-sectional area adjacent to the outer surface, wherein the channel has a second flow cross-sectional area adjacent to the inner surface, and wherein the second flow cross-sectional area is smaller than the first flow cross-sectional area.

7. The fixing ring according to claim 6, characterized in that: The channel includes a baffle adjacent to the inner surface.

8. The fixing ring according to claim 6, characterized in that: The channel is linear.

9. The fixing ring according to claim 6, characterized in that: The channel is in a curved shape.

10. A chemical mechanical polishing device, characterized in that: include: a polishing pad; a polishing head configured to receive a wafer and hold the wafer on the polishing pad; and A retaining ring is configured to engage with the polishing head, wherein the retaining ring forms a channel, the channel is configured to allow a slurry to flow from the outside of the retaining ring to the inside of the retaining ring along a flow direction, wherein the channel has an inner channel wall formed with a curvature radius, wherein the curvature radius is 5 to 50 mm.

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