Flexure mounted pad for chemical mechanical polishing

Abstract

The chemical mechanical polishing system includes an adsorption assembly with a suction cup for holding a substrate, a motor for rotating the suction cup about a first axis, and a pad carrier assembly. The pad carrier assembly includes a movable support, a lateral actuator connected to the support for radially moving the support, a flexible connector having a first end fixed to the support and a second end fixed to the bottom of the second end of the flexible connector for receiving and holding an polishing pad, a support arm extending from the support to above the flexible connector such that the support arm and the flexible connector move together radially, while the second end of the flexible connector is vertically movable relative to the support arm, and a pad carrier actuator fixed to the arm for applying downward pressure to the top of the flexible component.

Description

[Technical Field]

[0001] This disclosure relates to chemical mechanical grinding (CMP). [Previous Technology]

[0002] Integrated circuits are typically formed on a substrate by sequentially depositing conductive, semiconductive, or insulating layers on a silicon wafer. One manufacturing step involves depositing a filler layer on a non-planar surface and planarizing the filler layer. For some applications, the filler layer is planarized until the top surface of the patterned layer is exposed. For example, a conductive filler layer can be deposited on a patterned insulating layer to fill trenches or holes in the insulating layer. After planarization, the metal layer portions located between the raised patterns of the insulating layer form vias, plugs, and wiring, providing conductive paths for thin-film circuits on the substrate. For other applications, such as oxide polishing, the filler layer is planarized until a predetermined thickness is left on the non-planar surface. Furthermore, substrate surface planarization is often required for lithography.

[0003] Chemical mechanical polishing (CMP) is an accepted planarization method. This planarization method typically requires the substrate to be mounted on a carrier head or polishing head. The exposed surface of the substrate is typically placed on a rotating polishing pad. The carrier head applies a controlled load to the substrate, pushing it toward the polishing pad. Abrasive slurry is typically supplied to the surface of the polishing pad. [Summary of the Invention]

[0004] This disclosure provides an apparatus for performing "position-specific grinding" on a substrate; the contact area between the grinding pad and the substrate is smaller than the surface area of ​​the substrate, so the grinding of the substrate is limited to a specific area.

[0005] In one embodiment, the chemical mechanical polishing system includes: an adsorption assembly including a suction cup configured to hold a substrate during polishing operations; a motor for rotating the suction cup about a first axis; and a pad carrier assembly including a support movable radially relative to the first axis, a lateral actuator connected to the support for radially moving the support, a flexible connector having one end fixed to the support and a second end; a pad carrier / fastener fixed to the bottom of the second end of the flexible connector, configured to receive and hold a polishing pad; a support arm extending from the support beyond the flexible connector such that the support arm and the flexible connector move together radially and the second end of the flexible connector is vertically movable relative to the support arm; and a pad carrier actuator fixed to the support arm for applying downward pressure to the top of the flexible connector.

[0006] In another embodiment, the chemical mechanical polishing system includes: an adsorption assembly including a suction cup configured to hold a substrate during polishing operations; a motor for rotating the suction cup about a first axis; and a plurality of pad carrier assemblies arranged about the first axis. Each of the pad carrier assemblies may include a support that is radially movable relative to the first axis, a lateral actuator connected to the support for radially moving the support, a pad carrier / fastener supported on the support configured to receive and hold a polishing pad, and a pad carrier actuator for applying downward pressure to the pad carrier.

[0007] In another embodiment, the chemical mechanical polishing system includes: an adsorption assembly including a suction cup configured to fix a substrate during polishing operations; a motor for rotating the suction cup about a first axis; a pad carrier assembly including a support radially movable relative to the first axis, a lateral actuator connected to the support for radially moving the support, a pad carrier supported on the support configured to receive and fix a polishing pad, and a pad carrier for applying downward pressure to the pad carrier; and an adjustment ring concentrically placed with respect to the suction cup. The sweep range of the support can sweep from a first position to a second position, in which the polishing pad fixed to the pad carrier is positioned above the suction cup for polishing the substrate, and in the second position, the polishing pad is positioned above the adjustment ring for adjustment of the polishing pad.

[0008] In another embodiment, the chemical mechanical polishing system includes: an adsorption assembly including a suction cup configured to hold a substrate during polishing operations; a motor for rotating the suction cup about a first axis; a pad carrier assembly including a support that is radially movable relative to the first axis, a lateral actuator connected to the support for radially moving the support, a pad carrier supported from the support, configured to receive and hold a polishing pad, and a pad carrier for applying downward pressure to the pad carrier; a substrate transfer robot responsible for loading and / or unloading a substrate from the suction cup; and a vertical actuator for vertically moving the suction cup between a raised position and a lowered position, in which the substrate contacts the polishing pad, and in which the substrate on the suction cup can be contacted by the substrate transfer robot in the lowered position.

[0009] In another embodiment, the method includes: transferring a substrate onto a suction cup supported by a drive shaft while the suction cup is at a first height; raising the suction cup to a second height above the first height by a vertical actuator connected to the drive shaft, so that the top surface of the substrate contacts at least one polishing pad; polishing the substrate by the at least one polishing pad; lowering the suction cup to a third height below the second height by the vertical actuator; and removing the substrate from the suction cup.

[0010] Embodiments may include one or more of the following features. The actuator of the pad carrier may include a membrane fixed to the bottom of the arm to form a pressurizable chamber. The pad carrier actuator includes a membrane fixed to the bottom of the arm to form a pressurized chamber. The system may include a controller configured to cause a lateral actuator to radially oscillate the pad carrier and the polishing pad during polishing of the substrate by the polishing pad.

[0011] The system may include an adjustment ring concentrically positioned with the suction cup. The support can sweep from a first position to a second position in the radial direction, where an abrasive pad fixed to the pad carrier is positioned above the suction cup to abrade the substrate, and in the second position, the abrasive pad is positioned above the adjustment ring for adjustment. The adjustment ring can rotate about a first axis. A vertical actuator can vertically move the suction cup through a hole in the adjustment ring.

[0012] The vertical actuator can vertically move the chuck between a raised position and a lowered position, wherein the substrate is in contact with the polishing pad in the raised position, and the substrate is below the adjustment ring in the lowered position. The controller can be configured to move the pad carrier and polishing pad from a first position to a second position by the lateral actuator after the substrate polishing is completed. The controller can also be configured to radially oscillate the pad carrier and polishing pad by the lateral actuator while the polishing pad is polishing the substrate.

[0013] The substrate transfer robot can be configured to transfer substrates into and out of the system. A vertical actuator can vertically move a chuck between a raised position and a lowered position, in which the substrate is located in contact with a polishing pad, and in the lowered position, the substrate can be contacted by the substrate transfer robot. The chuck may include a lifting pin configured to rise from and retract from the chuck to transfer the substrate onto the substrate transfer robot.

[0014] A plurality of pad carrier assemblies may be arranged around a first axis at equal angular intervals. These plurality of pad carrier assemblies may be exactly four pad carrier assemblies. The controller may be configured to operate the lateral actuators of these plurality of pad carrier assemblies at the same radial distance as the first axis during substrate polishing. The controller may also be configured to cause the lateral actuators of these pad carrier assemblies to radially oscillate the pad carrier and polishing pad in a synchronous manner during substrate polishing.

[0015] Each pad carrier assembly may include a flexible connector having one end fixed to a support and the other end, and a support arm extending from the support beyond the flexible connector such that the support arm and the flexible connector move together in a radial direction, and a second end of the flexible connector is vertically movable relative to the support arm. A pad carrier / fastener may be fixed to the bottom of the second end of the flexible connector. An actuator of the pad carrier may be fixed to the support arm to apply downward pressure to the top of the flexible connector.

[0016] The controller can be configured to, after the substrate grinding is completed, cause a drive lateral actuator to move the pad carrier and grinding pad from a first position to a second position. A vertical actuator can vertically move the suction cup via a hole in an adjustment ring; in the raised position, the substrate contacts the grinding pad, and in the lowered position, the substrate is below the adjustment ring. The substrate transfer robot can be configured to load or unload the substrate in the lowered position. A horizontally extending support plate can support the pad carrier assembly. The lowered position can be below the horizontally extending support plate.

[0017] The substrate transfer robot may have an end effector for securing the substrate, which is movable along a horizontal axis. The movement of the end effector may be restricted to the horizontal axis. The support may have a sweeping range in the radial direction, sweeping from a first position to a second position, in which a grinding pad fixed to the pad carrier is positioned above the suction cup for grinding the substrate, and in the second position, the grinding pad is positioned above an adjustment ring for adjusting the grinding pad. A vertical actuator can vertically move the suction cup through a hole in the adjustment ring.

[0018] Grinding the substrate may include rotating a chuck by a rotary motor connected to a drive shaft, causing the substrate to rotate relative to at least one grinding pad. Grinding the substrate may also include oscillating at least one grinding pad in a radial direction by a sweeping arm. While oscillating at least one grinding pad in a radial direction, grinding the substrate may also include rotating the chuck by a rotary motor connected to a drive shaft. Oscillating at least one grinding pad in a radial direction includes operating a horizontal actuator engaged with a guide rail, which connects to and supports the sweeping arm. At least one grinding pad may include a first grinding pad and a second grinding pad, and oscillating at least one grinding pad in a radial direction may include oscillating the first grinding pad at a first rate and oscillating the second grinding pad at a second rate.

[0019] The sweeping arm can move the assembly connected to at least one abrasive pad in the radial direction such that at least one abrasive pad covers the adjustment ring, and at least one abrasive pad can be adjusted using the adjustment ring.

[0020] The removal of the substrate from the suction cup can be performed simultaneously with either the radial movement of at least one polishing pad or the adjustment of at least one polishing pad using an adjusting ring. Adjusting the at least one polishing pad may include rotating a rotary motor connected to a belt surrounding and contacting the adjusting ring and a rotary motor, such that rotation of the rotary motor causes the adjusting ring to rotate as well. Polishing the substrate may involve controlling the pressure of the at least one polishing pad on the substrate by changing the pressure within a pressure-bearing diaphragm connected to the at least one polishing pad, the pressure-bearing diaphragm being separated from the at least one polishing pad by a flexible connector. The polishing pad can be replaced without removing the pressure-bearing diaphragm.

[0021] Transferring the substrate onto and off the suction cup may include raising and lowering the lifting pin embedded in the suction cup to contact the substrate, while the robotic arm moves horizontally above the suction cup.

[0022] The advantages of the present invention may optionally include, but are not limited to, one or more of the following: Flexible support enables near 360° coverage of a set of arcuate pads on the substrate for grinding annular regions of the substrate, which can increase the grinding rate and thus enhance throughput. Non-uniform grinding of the substrate can be reduced, particularly at the substrate edges, and the flatness and surface finish of the substrate are improved. Furthermore, the apparatus and system allow substrate transfer below the grinding level, which can increase throughput.

[0023] Other aspects, features and advantages of the present invention will be apparent from the description and illustrations, as well as from the claims.

Implementation Method

[0034] Certain chemical mechanical polishing processes can cause uneven thickness on the substrate surface. For example, mass polishing processes may produce areas that are not sufficiently polished on the substrate. To address this issue, a "trimming" polishing process can be performed after mass polishing to focus on those insufficiently polished substrate areas, such as "position-specific polishing" (LSP).

[0035] Some high-volume polishing processes can lead to radial polishing inhomogeneities. Polishing pads rotating around the center of the substrate may compensate for the inhomogeneities of concentric rings, but their polishing rate may be relatively low. However, a set of small arc-shaped pads can orbit around the center of the substrate to compensate for radial polishing inhomogeneities while maintaining a relatively high throughput. Each arc-shaped pad can be mounted on a flexible connector connected to the sweeping mechanism, allowing the system to adapt to under-polishing at different radial positions. The pads and pressure control module can sweep outwards to contact a pad adjuster that can rotate around a central axis. A chuck can hold the wafer while rotating around the central axis and moving up and down in the vertical direction to facilitate wafer transfer under the pad adjuster. Therefore, pad adjustment and wafer transfer can be performed simultaneously.

[0036] This architecture also allows the abrasive pad to be separated from the pressurized chamber used to apply downward force. The ability to remove the abrasive pad separately from the actuation chamber reduces operating costs, as the abrasive pad typically needs to be replaced more frequently than the pressurized chamber.

[0037] Referring to FIG. 1, the polishing system 100 can be configured to polish a local area of ​​the substrate 10. The polishing system 100 may include an adsorption assembly 101 for loading the substrate 10, a polishing assembly 103 for polishing the substrate 10, an adjustment assembly 104 for adjusting the polishing pad of the polishing assembly 103, and a controller 90, such as a programmable computer, for controlling the components in the polishing system 100. The controller 90 may include a central processing unit 91, a memory 92, and support circuitry 93. The central processing unit 91 of the controller 90 executes instructions loaded from the memory 92 via the support circuitry 93, enabling the controller to receive inputs based on the environment and required polishing parameters, and to control various actuators and drive systems.

[0038] The processes of loading the wafer, grinding the wafer, unloading the wafer, and adjusting the grinding pad will be described next. Although some component symbols introduced in Figure 1 will not be discussed until later in the figures for clarity, these component symbols provide an illustration of the relationships between the various components. Loading

[0039] The system 100 includes a substrate transfer robot 114 having an end effector 107 at the end of a robotic arm 109a for horizontally moving the substrate 10 to load or unload the substrate from the adsorption assembly 101.

[0040] The adsorption assembly 101 includes a suction cup 105, a drive shaft 117, a motor 119a, and a vertical actuator 119b. The suction cup 105 is supported by the drive shaft 117, which is connected to the motor 119a and the vertical actuator 119b. The motor 119a can rotate the drive shaft 117 about its central axis 118a, while the vertical actuator 119b can raise or lower the suction cup 105 to control its vertical position, for example, via a hole 133 on an adjustment ring 112. The actuator 119b can raise the suction cup 105 so that the upper surface of the substrate 10 is at the same vertical height as the surface of the polishing pad. Although Figure 1 shows the vertical actuator 119b located above the surface, its position can be reversed.

[0041] The top surface 105a of the suction cup 105 provides a sufficiently large loading area to accommodate the substrate 10 to be processed. For example, the substrate 10 may be a substrate with a diameter of 200 to 450 mm. The top surface of the suction cup 105 contacts the back surface (i.e., the unpolished surface) of the substrate 10 and holds it in position.

[0042] In some embodiments, the radius of the suction cup 105 is approximately the same as or larger than that of the substrate 10. In some embodiments, the width of the suction cup 105 is slightly smaller than that of the substrate, for example, 1-2% of the substrate diameter. In this case, when the substrate 10 is placed on the suction cup 105, the edge of the substrate will slightly overhang the edge of the suction cup 105. This provides space for the edge-grabbing robot to place the substrate on the support. In some embodiments, the width of the suction cup 105 is greater than that of the substrate, for example, 1-10% of the substrate diameter. In either case, the suction cup 105 can contact most of the back surface of the substrate.

[0043] In some embodiments, a channel 115 in the suction cup 105 extends from a hole in the surface 105a of the suction cup 105 to a vacuum source 116. The vacuum source 116 can generate a pressure difference between the top and bottom surfaces of the substrate 10, thereby adsorbing the substrate onto the suction cup 105.

[0044] Figure 1 is a side view of the polishing system 100, showing the substrate 10 being loaded into the suction cup 105. Specifically, the suction cup 105 is located in a lowered first configuration below the polishing assembly 103, and the substrate 10 is initially supported by the end effector 107 of the robot 114. The end effector 107 is attached to the robotic arm 109a and can move at least horizontally to move the substrate, for example, to position the substrate 10 above the suction cup 105 from a transfer station.

[0045] In some embodiments, a lifting pin 111 embedded in the suction cup 105 can rise from the suction cup 105 to temporarily support the substrate 10 when the end effector 107 is positioned above the suction cup 105 and close enough that the lifting pin 111 can contact the substrate 10. When the lifting pin 111 supports the substrate 10, the robotic arm 109a can retract, for example, by moving horizontally away from the suction cup 105. The lifting pin 111 can then retract into the suction cup 105 until the substrate 10 contacts the top surface 105a of the suction cup 105.

[0046] Alternatively, if the suction cup 105 is narrower than the substrate and the end effector is an edge clamp or an edge support ring, the transfer of the substrate 10 to the top surface 105a of the suction cup 105 can be achieved simply by using a vertical actuator (e.g., a robotic arm 109a) to lift the suction cup 105.

[0047] Figure 2 is a side view of the polishing system 100, showing a second configuration. In this second configuration, the substrate 10 is in contact with the suction cup 105, and the lifting pin 111 is in a retracted position, for example, embedded in the suction cup 105. Polishing

[0048] The polishing assembly 103 includes polishing pads 200 positioned to be driven downward by a pressurized chamber 250. The pressurized chamber 250 is supported at the end of a horizontally movable support arm 135. The pressurized chamber 250 may be an actuator in the form of a pressurizable chamber 131, such as a bladder or a chamber formed by attaching a membrane 252 to the bottom of the support arm 135. The polishing surfaces 220 of the polishing pads 200 are supported in a downward orientation to contact the exposed surfaces of the substrate 10. Specifically, each polishing pad 200 is supported by a flexible connector 121 extending from the support arm 135.

[0049] The end of the flexible connector 121 is located below the pressurized chamber 250, such that the downward pressure of the pressurized chamber 250 on the flexible connector 121 causes the abrasive pad 200 to exert a downward force on the substrate 10. For example, when pressure is applied from the pressure source 80, the pressurized chamber 131 is inflated, which causes the membrane 252 to expand outward to contact the flexible connector 121.

[0050] Figure 3 is a side view of the polishing system 100, showing a third configuration in which the vertical actuator 119b has lifted the chuck 105 relative to Figure 2. In the lifted position, the substrate 10 contacts the polishing surface 220 of the polishing pad 200.

[0051] The polishing pad 200 may have a lateral width W along the radius of the substrate 10 (see Figure 4), which is smaller than the radius of the substrate 10. For example, the width W of the polishing pad 200 may be approximately 1-10% of the diameter of the substrate 10. For example, for a substrate 10 with a diameter ranging from 200 mm to 300 mm, the polishing pad surface 220 may have a width of 2-30 mm, such as 3-10 mm, or 3-5 mm. A narrower polishing pad 200 provides higher precision, but may be slower to use if the unpolished area is relatively wide.

[0052] The polishing pad 200 can be made of a material suitable for contacting the substrate 10 during chemical mechanical polishing. For example, the material of the polishing pad can include polyurethane, such as microporous polyurethane, such as IC-1000 material. The thickness of the polishing pad 200 can be from about 0.5 to 7 mm, for example, about 2 mm.

[0053] Each polishing pad 200 is secured to the bottom of a corresponding flexible connector 121 by fasteners 123 (e.g., pad retainers with adhesive, or one or more mechanical fasteners, such as clamps). Due to attachment to the flexible connector 121, each polishing pad 200 has a certain range of vertical movement. The range of vertical movement can depend on the lifespan of the pad, for example, this range can compensate for gaps caused by pad wear, such as 10 to 100 millisieverts. However, the flexible connector 121 prevents the polishing pad 200 from simply sinking down with the substrate 10 when the suction cup 105 is lowered to the loading position.

[0054] The flexible connector 121 is connected to the sweeping arm 125, allowing the flexible connector 121 to perform lateral sweeping. The sweeping arm 125 is supported by a drive motor 127, which engages with the guide rail 129, for example by means of a gear. The drive motor 127 can move the grinding assembly and the flexible connector 121 along a horizontal direction aligned with the guide rail 129.

[0055] When the actuator is supplied by the pressurized chamber 250, the grinding system 100 includes a controllable pressure source 80, such as a pump, to apply controllable pressure to the interior of the pressurized chamber 250. The pressure source 80 may be connected to the pressurized chamber 250 via a conduit 82 (such as a flexible conduit) that passes through the support arm 135. When the actuator is supplied by a motor, such as a linear screw actuator or a linear motor, a current source is connected to the actuator.

[0056] During the polishing process, a vertical actuator 119b, such as a motor 119b, can rotate a drive shaft 117, causing the suction cup 105 and the substrate 10 to rotate about the central axis 118a of the drive shaft 117. The polishing system 100 includes a port 66 for spraying polishing slurry 62 (e.g., polishing paste) onto the substrate 10. Optionally, the polishing system includes a reservoir 60 to store the polishing slurry 62. A conduit 64 (e.g., a flexible conduit) can deliver the polishing slurry 62 from the reservoir 60 to the port 66, where it flows onto the surface of the substrate 10. The reservoir 60 may include a pump to supply the polishing slurry at a controllable rate via the conduit 64. Assuming the polishing pad 200 has an arcuate shape, by spraying the polishing slurry 62 near the center of the substrate, the polishing pad can prevent the paste from sliding off the substrate 10 due to centripetal force during polishing.

[0057] After polishing, cleaning fluid 74 from a cleaning fluid source (e.g., reservoir 70) can flow from port 76 onto the substrate 10 to remove debris accumulated during the polishing process. Cleaning fluid 74 can be deionized water. For example, conduit 72 (e.g., flexible conduit) can be used to deliver cleaning fluid 74 from reservoir 70 to port 76, where it flows onto the surface of substrate 10.

[0058] Each of the reservoir 60, reservoir 70 and controllable pressure source 80 can be mounted on a support structure or on a separate frame to hold the various components of the grinding system 100.

[0059] Figure 4 shows a plan view of the substrate 10 and polishing pads 200 from the polishing system 100. Each polishing pad 200 may have an arcuate shape, such as an annular arc. Although four polishing pads 200 are depicted in this example, there may be fewer, such as two or three, or more, such as up to ten. In some embodiments, the polishing pads 200 are evenly angularly distributed. In this example, there are four polishing pads, so the centers of each polishing pad 200 are 90° apart (360 / 4=90). Each pad may have an included angle of 20-90° around the center of the substrate. Depending on the radial position of the pad surface 220, all pads together may have a total included angle of approximately 270-350° around the center of the substrate.

[0060] These polishing pads 200 may collectively form a ring, with gaps 401 in the annular region 400. These gaps 401 allow the polishing pads 200 to sweep along the radial direction B without contacting each other. The wafer rotates in the direction indicated by arrow A due to the rotation of motor 119a. In the configuration depicted in FIG4, polishing occurs in the annular region 400 having inner and outer diameters Di and Do.

[0061] In some embodiments, as shown in FIG4, the polishing pad 200 is positioned by an actuator such that both the outer diameter Do and the inner diameter Di of the annular region 400 are smaller than the diameter of the substrate 10. In some embodiments, the polishing pad 200 is positioned such that the outer diameter Do of the polishing pad 200 is aligned with the outer edge of the substrate 10. For example, the polishing pad 200 may be sized to locally polish the periphery 15 mm of the substrate 10. In some embodiments, the polishing pad 200 is positioned such that the outer diameter Do extends beyond the outer edge of the substrate 10; each polishing pad 200 will only partially contact the substrate 10.

[0062] When the abrasive pad 200 sweeps along the radial direction B, the radial position of the annular region 400 can be changed, either by increasing or decreasing the inner and outer diameters Do and Di of the annular region 400.

[0063] Despite the gaps 401 between the polishing pads 200, the substrate 10 is still uniformly polished within the annular region 400 due to the rotation of the substrate (as indicated by arrow A). The size of these gaps 401 depends on the radial positioning of the polishing pads 200; the gaps 401 decrease as the polishing pads 200 move toward the center of the substrate. The controller can maintain a minimum distance between the polishing pads 200 and the center of the substrate 10 to avoid collisions between the pads.

[0064] Because these gaps may be relatively small, for example, less than 90° of the substrate circumference, for example, less than 45°, for example, less than 25°, for example, less than 10°, a relatively high polishing rate can be achieved within the annular region 400.

[0065] In some embodiments, one or more polishing pads 200 may move laterally during polishing, for example, by oscillating in the radial direction. For example, the support 125 (e.g., sweeping arm 125) and the flexible connector 121 may slowly sweep one or more polishing pads 200 (compared to the rotational movement of the substrate 10) across the area to be polished. For example, the relative horizontal velocity between the substrate 10 and the polishing pads 200 may be less than 5%, for example less than 2%, compared to the instantaneous rotational speed provided by the substrate 10. On the other hand, in some embodiments, the polishing pads 200 may be held in a fixed lateral position during the polishing operation.

[0066] In some embodiments, one or more polishing pads 200 can move independently during polishing. For example, each of the four polishing pads 200 can move at different rates while oscillating in the radial direction. As another example, although the polishing pads 200 are at the same distance from the center of the substrate 10, each polishing pad 200 can be located at a different radial position relative to the center of the substrate 10.

[0067] In some embodiments, the cross-sectional shape of the abrasive pad 200 (parallel to the abrasive pad surface 220) can be almost any shape, such as circular, square, elliptical or arc-shaped.

[0068] FIG5 is a plan view of the substrate 10, fastener 123, flexible connector 121 (shown in dashed lines), support arm 135, and polishing pad 200. The cross-sectional lines indicate the correlation between FIG5 and the cross-sectional view of FIG6. Fastener 123 connects polishing pad 200 to flexible connector 121, which can move in the horizontal direction, for example, in the radial direction relative to substrate 10. Although only one polishing pad 200 is shown in the figure connected to fastener 123, flexible connector 121, and sweeping arm 125 and thus able to move laterally, all polishing pads 200 can be configured such that each has its own fastener 123, flexible connector 121, and sweeping arm 125.

[0069] Figure 6 is a side view of a single lateral actuator 600 and flexible connector 121. The lateral actuator 600 is a variation of the mechanism that provides the abrasive pad 200 with the ability to sweep in a horizontal direction. In some embodiments, the abrasive pad 200 is suspended below the expansion bladder 602a by the flexible connector 121. The flexible connector 121 is secured to a movable support 604 that engages with a fixed frame 606. The actuator 608 can push or drag the movable support in a horizontal direction indicated by an arrow on the fixed frame, thereby achieving lateral movement of the abrasive pad 200. For example, the actuator 608 may include a linear screw extending to the movable support 604. Another expansion bladder 602b is connected to a pressure control system via a support 610.

[0070] Due to the architecture of the polishing system 100, the pressurized chamber 131 (formed by the expansion bladder 602b or membrane 252) within the polishing assembly 103 is detached from the polishing pad 200. This allows the polishing pad 200 to be replaced without disturbing the pressurized chamber 131, and the lifespan of the pressurized chamber is typically longer than that of the polishing pad 200. Furthermore, due to the detachment of the pressurized chamber 250 from the polishing pad 200, the rigidity of the expansion bladder 602b or membrane 252 can be independent of the position of the polishing pad 200. For example, the pressurized chamber 250 may have specific requirements, such as rigidity, when the desired polishing profile requires the transmission of shear force from the polishing pad 200. However, by detachment, the membrane can be flexible.

[0071] Figure 7 shows a plan view of an example of the polishing assembly 103 in the polishing system 100. In this example, there are four arc-shaped polishing pads 200, and a flexible connector 121, a fastener 123, a sweeping arm 125, a drive motor 127, and a pressurized chamber 131 are shown for each polishing pad 200. Each polishing pad 200 is connected to the pressurized diaphragm 131 to control the pressure on the substrate 10 during polishing. Each polishing pad 200 is connected to the sweeping arm 125 (supported by the drive motor 127) via the flexible connector 121, which is connected to the polishing pad 200 via the fastener 123. As shown in Figure 7, each flexible connector may have an arc-shaped annular shape, such as an arc segment of an annular hole.

[0072] The four polishing pads 200 work together to achieve precise and accurate polishing. In some embodiments, a portion of the polishing pads 200 may be positioned above the substrate 10 during polishing to allow polishing of the center of the substrate 10, for example, an area of ​​the substrate 10 with an inner radius smaller than the minimum possible inner diameter when all polishing pads are in contact. Adjustment and wafer transfer

[0073] Figure 8 depicts a fourth configuration of the polishing system 100. After polishing, the substrate 10 can be lowered by the actuator 119b to the position below the polishing assembly 103 via the suction cup 105. The robotic arm 109a can then lift the substrate 10 from the suction cup 105 and transfer the polished substrate out of the polishing system 100. Generally, the loading steps can be performed in reverse order. For example, the lifting pin can raise the substrate 10, the end effector 107 can be inserted under the substrate 10 by the robotic arm 109a, and then the lifting pin can be retracted, allowing the substrate to be held by the end effector.

[0074] The polishing pad 200 can be adjusted by the adjustment assembly 104 before, after or simultaneously with the transfer substrate 10. The adjustment assembly 104 includes an adjustment ring 112 and a mechanism for rotating the adjustment ring 112 relative to the polishing pad 200.

[0075] In the configuration of FIG. 8, the drive motor 127 has moved the sweeping arm 125 and the polishing pad 200 radially outward relative to the polishing position, such that the polishing pad 200 is aligned with and above the adjusting ring 112. The adjusting ring 112 can wear down the polishing pad 200 to keep the polishing pad 200 in a consistent abrasive state. The polishing pad 200 and the adjusting ring 112 can be brought into contact by pressure applied by the pressurized chamber 250, and the substrate can be moved along the guide rail 129.

[0076] The inner diameter 112a of the adjusting ring 112 (see FIG. 9) is larger than the maximum outer diameter of the suction cup 105 and larger than the diameter of the substrate 10. This allows the suction cup 105 and the substrate 10 to pass through or be placed within the adjusting ring 112 (see FIG. 3) when the suction cup 105 is in the raised position for grinding operations. The adjusting ring 112 and the suction cup 105 may have a common central axis.

[0077] Figure 9 is a plan view of the adjustment assembly 104 in the polishing system 100. As shown in the plan view, during adjustment, the polishing pad 200 is positioned above the adjustment ring 112. The polishing pad 200 is fixed to the supporting flexible connector 121. During adjustment, the adjustment ring 112 rotates about the central axis (118b in Figure 2) to adjust the polishing pad 200.

[0078] In some embodiments, the rotation mechanism of the adjusting ring is a belt 139 engaged with the motor 141. When the motor 141 rotates about the central axis 118b, the motor 141 pulls a portion of the belt 139 in contact with the motor 141 in the direction of rotation, causing the entire belt 139 to rotate. As the belt 139 rotates, the belt 129 also pulls the adjusting ring 112 in the direction of rotation. Therefore, the grinding pad 200 is adjusted by the rotating adjusting ring 112. The rotation of the adjusting ring 112 can also be achieved by other drive mechanisms.

[0079] In some embodiments, the abrasive pad 200 oscillates radially as the adjusting ring 112 rotates to achieve additional control during the adjustment process. In some embodiments, the adjustment is accomplished by simply having the abrasive pad 200 rapidly oscillate the adjusting ring 112 while the adjusting ring 112 remains stationary. Since the abrasive pads 200 do not form concentric arcs in any lateral position, the width of the adjusting ring 112 is greater than the width of the abrasive pads 200 when they are in a concentric position.

[0080] Therefore, other embodiments are within the scope of the following claims. [Simplified Explanation of the Diagram]

[0024] Figure 1 is a side view of the grinding system in the first configuration.

[0025] Figure 2 is a side view of the second configuration of the grinding system in Figure 1.

[0026] Figure 3 is a side view of the third configuration of the grinding system in Figure 1.

[0027] Figure 4 is a plan view of the wafer and polishing pad of the polishing system in Figure 1.

[0028] Figure 5 is a plan view of the wafer, polishing pad and lateral actuator with flexible connector of the polishing system in Figure 1.

[0029] Figure 6 is a side view of a single lateral actuator and flexible connector.

[0030] Figure 7 is a plan view of the grinding pad support of the grinding system in Figure 1.

[0031] Figure 8 is a side view of the grinding system in Figure 1 in the fourth position.

[0032] Figure 9 is a plan view of the adjustment components of the grinding system in Figure 1.

[0033] The similar element symbols in each figure represent similar elements. [Biomaterial Storage]

[0082] Domestic Deposit Information (Please note in order of deposit institution, date, and number) None

[0083] Overseas Deposit Information (Please note in the order of deposit country, institution, date, and number) None

Claims

1. A chemical mechanical grinding system, comprising: An adsorption assembly including a suction cup configured to hold a substrate during a polishing operation; A motor configured to rotate the suction cup about a first axis; a pad carrier assembly including a support movable in a radial direction relative to the first axis, a lateral actuator connected to the support and configured to move the support in the radial direction, a flexible connector having a first end fixed to the support and a second end, including a pad carrier / fastener fixed to a bottom of the second end of the flexible connector, the pad carrier / fastener being configured to receive and hold an abrasive pad, a support arm extending from the support to above the flexible connector such that the support arm and the flexible connector move together in the radial direction and the second end of the flexible connector is movable up and down relative to the support arm, and a pad carrier actuator fixed to the arm and configured to apply a downward pressure to a top of the flexible connector.

2. The system as claimed in claim 1, wherein the pad carrier actuator includes a membrane fixed to a bottom of the arm to form a pressurizable chamber.

3. The system as described in claim 2, wherein, When the chamber is fully pressurized, an outer surface of the membrane comes into direct contact with the top surface of the flexible connector.

4. The system of claim 1, comprising a controller configured to cause the lateral actuator to radially oscillate the pad carrier and the polishing pad during the polishing pad polishing the substrate.

5. The system of claim 1, comprising an adjustment ring concentrically positioned with respect to the suction cup, wherein a scanning range of the support in the radial direction begins at a first position in which the polishing pad attached to the pad carrier is positioned above the suction cup for polishing the substrate; and a second position in which the polishing pad is positioned above the adjustment ring for adjusting the polishing pad.

6. The system as claimed in claim 5, wherein the adjusting ring is rotatable about the first axis.

7. The system as claimed in claim 5 includes a vertical actuator configured to vertically move the suction cup through an opening in the adjustment ring.

8. The system of claim 7, comprising a vertical actuator configured to vertically move the chuck between a raised position and a lowered position, wherein the raised position contacts the substrate with the polishing pad and the lowered position positions the substrate below the adjustment ring.

9. The system of claim 5, comprising a controller configured to, after polishing the substrate is completed, cause the lateral actuator to move the pad carrier and polishing pad from the first position to the second position.

10. The system of claim 9, wherein the controller is configured to cause the lateral actuator to radially oscillate the pad carrier and the polishing pad as the polishing pad polishes the substrate.

11. The system as claimed in claim 1, including a substrate transfer robot capable of transferring the substrate into or out of the system.

12. The system of claim 11, comprising a vertical actuator configured to vertically move the chuck between a raised position and a lowered position, wherein the raised position allows the substrate to contact the polishing pad and the lowered position allows the substrate to contact the polishing pad.

13. The system of claim 12, wherein the suction cup includes a lifting pin configured to be raised and retracted from the suction cup to transfer a substrate to the substrate transfer robot.

14. The system as claimed in claim 1, including the abrasive pad, wherein the abrasive pad is an arc-shaped abrasive pad.

15. A chemical mechanical grinding system, comprising: A suction cup assembly including a suction cup configured to hold a substrate in a polishing operation; A motor configured to rotate the suction cup about a first axis; and a plurality of pad carrier assemblies arranged around the first axis, wherein each of the pad carrier assemblies includes a support movable in a radial direction relative to the first axis, a lateral actuator connected to the support to move the support in the radial direction, a pad carrier / fastener supported by the support and configured to receive and clamp an abrasive pad, and a pad carrier actuator configured to apply a downward pressure to the pad carrier, wherein each pad carrier assembly includes a flexible connector having a first end fixed to the support and a second end, and a support arm extending from the support to above the flexible connector such that the support arm and the flexible connector move together in the radial direction, and the second end of the flexible connector is movable vertically relative to the support arm; and wherein the pad carrier / fastener is fixed to a bottom of the second end of the flexible connector, and the pad carrier actuator is fixed to the support arm to apply a downward pressure to a top of the flexible connector.

16. The system of claim 15, wherein the pad carrier assemblies are arranged at equal angular intervals around the first axis.

17. The system as described in claim 16, wherein there are exactly four pad carrier assemblies.

18. The system as claimed in claim 15, including the abrasive pad, wherein the abrasive pad is an arc-shaped abrasive pad.

19. The system of claim 15, comprising a controller configured to maintain the lateral actuators of the pad carrier assemblies at the same radial distance from the first axis during grinding of the substrate.

20. The system of claim 15, comprising a controller configured to cause the lateral actuators of the pad carrier assemblies to synchronously oscillate the pad carrier and the polishing pad during polishing of the substrate.

Images