Top ring and substrate polishing device

Abstract

Provided are a top ring or a substrate polishing device capable of making the polishing profile of a substrate uniform.　Proposed is a top ring for holding a substrate, said top ring comprising: a base member connected to a rotary shaft; a substrate suctioning body that has a substrate suctioning surface for suctioning the substrate and that is in communication with a vacuum module; a shielding member that is configured to shield the surface of the substrate suctioning body on the reverse side from the substrate suctioning surface and that defines at least one cavity in communication with a supply module for supplying vacuum or pressure; and an elastic membrane configured to form, between the base member and the shielding member, a pressurization chamber that is in communication with a fluid supply source.

Description

Top ring, and substrate polishing apparatus

[0001] This application relates to a top ring and a substrate polishing apparatus.

[0002] In the manufacture of semiconductor devices, a chemical mechanical polishing (CMP) apparatus is used to planarize the surface of a substrate. The substrates used in the manufacture of semiconductor devices are often disc-shaped. Also, not limited to semiconductor devices, the requirements for flatness when planarizing the surfaces of rectangular substrates such as CCL substrates (Copper Clad Laminate substrates), PCB (Printed Circuit Board) substrates, photomask substrates, and display panels are increasing. Also, the requirements for planarizing the surface of a package substrate on which electronic devices such as PCB substrates are arranged are increasing.

[0003] A substrate polishing apparatus includes a top ring for holding a substrate. For example, as described in Patent Document 1, the top ring includes a rotating shaft, a flange connected to the rotating shaft, a suction plate fitted into an opening formed on the lower surface of the flange, and a shielding plate attached to the upper surface of the suction plate. Further, the top ring includes an elastic film arranged so as to form a pressurizing chamber between the flange and the shielding plate, and a fluid supply source is connected to the elastic film. This top ring is configured to adsorb the substrate via the suction plate by vacuum suction, and to press the substrate against the polishing pad by supplying fluid to the pressurizing chamber to apply pressure to the shielding plate.

[0004] Japanese Patent Application Laid-Open No. 2022-59509

[0005] In the substrate polishing apparatus described in Patent Document 1, the pressing of the substrate against the polishing pad is adjusted by supplying fluid to a plurality of concentric pressurizing chambers formed by the elastic film. However, even in such a substrate polishing apparatus, there may be a portion where the uniformity of the polishing surface profile is impaired. This includes cases where the reason is that the unevenness of the substrate to be polished is large, or cases where the reason is the structure of the top ring. Therefore, in addition to or instead of supplying fluid to the pressurizing chamber formed by the elastic film, it is considered to provide a mechanism for adjusting the pressing of the substrate against the polishing pad.

[0006] In light of the above circumstances, one of the objectives of this application is to provide a top ring or substrate polishing apparatus that can make the polishing profile uniform on the central side and the outer edge side of a rectangular substrate.

[0007] According to one embodiment, a top ring for holding a substrate is proposed, comprising: a base member connected to a rotating shaft; a substrate adsorbent having a substrate adsorption surface for adsorbing a substrate and communicating with a depressurization module; a shielding member configured to shield the surface of the substrate adsorbent opposite to the substrate adsorption surface and defining at least one cavity communicating with a supply module for depressurization or pressurization; and an elastic membrane configured to form a pressurization chamber communicating with a fluid supply source between the base member and the shielding member.

[0008] In another embodiment, a top ring for holding a substrate is proposed, comprising: a substrate adsorbent having a substrate adsorption surface for adsorbing the substrate and communicating with a depressurization module; and a shielding member configured to shield the surface of the substrate adsorbent opposite to the substrate adsorption surface and defining a cavity communicating with a supply module for depressurization or pressurization, wherein the surface of the substrate adsorbent opposite to the substrate adsorption surface is bonded to the shielding member except in the area in which the cavity is defined.

[0009] This is a plan view showing the overall configuration of a substrate polishing apparatus according to one embodiment. This is a perspective view schematically showing the configuration of a polishing unit according to one embodiment. This is a schematic cross-sectional view showing the top ring of one embodiment. This is a diagram showing an enlarged view of a part of the top ring shown in Figure 3. This is a diagram schematically showing an enlarged view of the area around the cavity in the shielding member of this embodiment. This is a diagram showing an example of cavity arrangement. This is a diagram showing another example of cavity arrangement. This is a diagram illustrating an example of a method for manufacturing a shielding member with a cavity formed thereon. This is a diagram illustrating another example of a method for manufacturing a shielding member with a cavity formed thereon. This is a diagram illustrating an example of a shielding member with a cavity having a triangular cross-section. This is a schematic cross-sectional view showing a modified top ring. This is a schematic cross-sectional view showing a modified top ring.

[0010] Embodiments of the present invention will be described below with reference to the drawings. In the drawings described below, the same or corresponding components are denoted by the same reference numerals, and redundant descriptions are omitted.

[0011] Figure 1 is a plan view showing the overall configuration of a substrate polishing apparatus 1000 according to one embodiment. The substrate polishing apparatus 1000 shown in Figure 1 includes a load unit 100, a transport unit 200, a polishing unit 300, a drying unit 500, and an unload unit 600. In the illustrated embodiment, the transport unit 200 has two transport units 200A and 200B, and the polishing unit 300 has two polishing units 300A and 300B. Note that one or more transport units 200 and polishing units 300 may be provided. In one embodiment, each of these units can be formed independently. By forming these units independently, substrate polishing apparatuses 1000 with different configurations can be easily formed by arbitrarily combining the number of each unit. Furthermore, the substrate polishing apparatus 1000 is equipped with a controller 900, and each component of the substrate polishing apparatus 1000 is controlled by the controller 900. In one embodiment, the controller 900 can be composed of a general-purpose computer equipped with input / output devices, an arithmetic unit, a storage device (storage medium), etc. The controller 900 functions as the main unit for controlling the substrate polishing apparatus 1000. The controller 900 performs various processes by reading and executing a program stored in the storage device, etc. The program may be obtained from a recording medium such as a DVD-ROM, or it may be obtained via a network.

[0012] <Load Unit> The load unit 100 is a unit for introducing substrates WF into the substrate polishing apparatus 1000 before processing such as polishing and cleaning. In one embodiment, the load unit 100 is configured to conform to the SMEMA (Surface Mount Equipment Manufacturers Association) mechanical equipment interface standard (IPC-SMEMA-9851).

[0013] In the illustrated embodiment, the transport mechanism of the load unit 100 has a plurality of transport rollers 202 and a plurality of roller shafts 204 to which the transport rollers 202 are attached. In the embodiment shown in Figure 1, three transport rollers 202 are attached to each roller shaft 204. The substrate WF is placed on the transport rollers 202, and the substrate WF is transported by the rotation of the transport rollers 202. The mounting position of the transport rollers 202 on the roller shafts 204 can be any position that allows for stable transport of the substrate WF. However, since the transport rollers 202 come into contact with the substrate WF, it is preferable to position the transport rollers 202 so that they come into contact with an area of ​​the substrate WF that will not cause any problems even if it comes into contact with the substrate WF to be processed. In one embodiment, the transport rollers 202 of the load unit 100 can be made of a conductive polymer. In one embodiment, the transport rollers 202 are electrically grounded via the roller shafts 204, etc. This is to prevent the substrate WF from becoming charged and damaging the substrate WF. In one embodiment, the load unit 100 may also be provided with an ionizer (not shown) to prevent the substrate WF from becoming charged.

[0014] <Transport Unit> The substrate polishing apparatus 1000 shown in Figure 1 is equipped with two transport units 200A and 200B. Since the two transport units 200A and 200B can have the same configuration, they will be described collectively as the transport unit 200 below.

[0015] The illustrated transport unit 200 is equipped with a plurality of transport rollers 202 for transporting substrates WF. By rotating the transport rollers 202, the substrates WF on the transport rollers 202 can be transported in a predetermined direction. The transport rollers 202 of the transport unit 200 may be formed from a conductive polymer or from a non-conductive polymer.

[0016] In one embodiment, the transport unit 200 has a cleaning nozzle 284. The cleaning nozzle 284 is connected to a source of cleaning fluid (not shown). The cleaning nozzle 284 is configured to supply cleaning fluid to the substrate WF being transported by the transport roller 202.

[0017] <Polishing Unit> Figure 2 is a schematic perspective view showing the configuration of a polishing unit 300 according to one embodiment. The substrate polishing apparatus 1000 shown in Figure 1 includes two polishing units 300A and 300B. The two polishing units 300A and 300B can have the same configuration, so they will be described collectively as the polishing unit 300 below.

[0018] As shown in Figure 2, the polishing unit 300 comprises a polishing table 350 and a top ring 302 which constitutes a polishing head that holds the substrate to be polished and presses it against the polishing surface on the polishing table 350. The polishing table 350 is connected via a table shaft 351 to a polishing table rotation motor (not shown) located below it, and is rotatable around the table shaft 351. A polishing pad 352 is attached to the upper surface of the polishing table 350, and the surface 352a of the polishing pad 352 constitutes the polishing surface for polishing the substrate.

[0019] A polishing fluid supply nozzle 354 is installed above the polishing table 350, and this nozzle supplies polishing fluid to the polishing pad 352 on the polishing table 350. As shown in Figure 2, the polishing table 350 and the table shaft 351 are provided with a passage 353 for supplying polishing fluid. The passage 353 communicates with an opening 355 on the surface of the polishing table 350. A through hole 357 is formed in the polishing pad 352 at a position corresponding to the opening 355 of the polishing table 350, and the polishing fluid passing through the passage 353 is supplied to the surface of the polishing pad 352 from the opening 355 of the polishing table 350 and the through hole 357 of the polishing pad 352. Note that the opening 355 of the polishing table 350 and the through hole 357 of the polishing pad 352 may be one or more, or they may not be provided at all. Furthermore, the positions of the opening 355 in the polishing table 350 and the through-hole 357 in the polishing pad 352 are arbitrary, but in one embodiment they are positioned near the center of the polishing table 350. In one embodiment, during polishing of the substrate, the substrate WF held by the top ring 302 is moved so as to pass near the center of the polishing table 350 (so as to cover the through-hole 357).

[0020] Although not shown in Figure 2, in one embodiment, the polishing unit 300 includes an atomizer 358 for spraying a liquid or a mixed fluid of liquid and gas toward the polishing pad 352 (see Figure 1). The liquid sprayed from the atomizer 358 is, for example, pure water, and the gas is, for example, nitrogen gas.

[0021] The top ring 302 is connected to the top ring shaft 18, which moves up and down relative to the oscillating arm 360 by a vertical movement mechanism 319. This vertical movement of the top ring shaft 18 causes the entire top ring 302 to move up and down relative to the oscillating arm 360, thereby positioning it. The top ring shaft 18 is rotated by a top ring rotation motor (not shown). The rotation of the top ring shaft 18 causes the top ring 302 to rotate around the top ring shaft 18.

[0022] The top ring 302 is configured to hold a circular or rectangular substrate on its lower surface. In this embodiment, "rectangular substrate" refers to a substrate having a triangular, quadrilateral, or polygonal surface with five or more sides. The oscillating arm 360 is configured to pivot about a pivot shaft 362. By rotating the oscillating arm 360, the top ring 302 can move between the substrate transfer position of the transport unit 200 and above the polishing table 350. By lowering the top ring shaft 18, the top ring 302 can be lowered to press the substrate against the surface (polishing surface) 352a of the polishing pad 352. At this time, the top ring 302 and the polishing table 350 are rotated, and polishing fluid is supplied onto the polishing pad 352 from a polishing fluid supply nozzle 354 provided above the polishing table 350 and / or from an opening 355 provided in the polishing table 350. In this way, the substrate can be pressed against the polishing surface 352a of the polishing pad 352 and the surface of the substrate can be polished. As described above, during polishing of the substrate WF, the arm 360 may be fixed or swung so that the top ring 302 passes through the center of the polishing pad 352 (covering the through hole 357 of the polishing pad 352).

[0023] The vertical movement mechanism 319, which moves the top ring shaft 18 and the top ring 302 up and down, comprises a bridge 28 that rotatably supports the top ring shaft 18 via a bearing 321, a ball screw 32 attached to the bridge 28, a support base 29 supported by a support column 130, and an AC servo motor 38 provided on the support base 29. The support base 29 that supports the servo motor 38 is fixed to the swing arm 360 via the support column 130.

[0024] The ball screw 32 comprises a screw shaft 32a connected to the servo motor 38 and a nut 32b into which the screw shaft 32a is screwed. The top ring shaft 18 moves up and down together with the bridge 28. Therefore, when the servo motor 38 is driven, the bridge 28 moves up and down via the ball screw 32, and this causes the top ring shaft 18 and the top ring 302 to move up and down.

[0025] A polishing unit 300 according to one embodiment includes a dressing unit 356 for dressing the polishing surface 352a of a polishing pad 352. The dressing unit 356 includes a dresser 50 that slides against the polishing surface 352a, a dresser shaft 51 to which the dresser 50 is connected, an air cylinder 53 provided at the upper end of the dresser shaft 51, and a swing arm 55 that rotatably supports the dresser shaft 51. The lower part of the dresser 50 is composed of a dressing member 50a, and needle-shaped diamond particles are attached to the lower surface of this dressing member 50a. The air cylinder 53 is positioned on a support base 57 supported by support columns 56, and these support columns 56 are fixed to the swing arm 55.

[0026] The oscillating arm 55 is driven by a motor (not shown) and is configured to pivot around a pivot shaft 58. The dresser shaft 51 rotates due to the drive of a motor (not shown), and the rotation of this dresser shaft 51 causes the dresser 50 to rotate around the dresser shaft 51. The air cylinder 53 moves the dresser 50 up and down via the dresser shaft 51 and presses the dresser 50 against the polishing surface 352a of the polishing pad 352 with a predetermined pressing force.

[0027] The polishing surface 352a of the polishing pad 352 is dressed as follows. The dresser 50 is pressed against the polishing surface 352a by an air cylinder 53, and at the same time, pure water is supplied to the polishing surface 352a from a pure water supply nozzle (not shown). In this state, the dresser 50 rotates around the dresser shaft 51 and the oscillating arm 55 oscillates on the polishing surface 352a, causing the lower surface (diamond particles) of the dressing member 50a to slide against the rotating polishing surface 352a. In this way, the polishing pad 352 is scraped off by the dresser 50 and the polishing surface 352a is dressed.

[0028] <Drying Unit> The drying unit is a device for drying the substrate WF. In the substrate polishing apparatus 1000 shown in Figure 1, the drying unit 500 dries the substrate WF that has been polished by the polishing unit 300 and then cleaned in the cleaning section of the transport unit 200. As shown in Figure 1, the drying unit 500 is located downstream of the transport unit 200. The drying unit 500 has a nozzle 530 for injecting gas toward the substrate WF being transported on the transport rollers 202. The gas can be, for example, compressed air or nitrogen. The substrate WF can be dried by blowing away water droplets on the transported substrate WF with the drying unit 500.

[0029] <Unloading Unit> The unloading unit 600 is a unit for transporting the substrate WF after processing such as polishing and cleaning to the outside of the substrate polishing apparatus 1000. In the substrate polishing apparatus 1000 shown in Figure 1, the unloading unit 600 receives the substrate after it has been dried in the drying unit 500. As shown in Figure 1, the unloading unit 600 is located downstream of the drying unit 500. In one embodiment, the unloading unit 600 is configured to conform to the SMEMA (Surface Mount Equipment Manufacturers Association) mechanical equipment interface standard (IPC-SMEMA-9851).

[0030] <Top Ring> Next, the top ring 302 in the polishing unit 300 according to one embodiment will be described. Figure 3 is a schematic cross-sectional view showing the top ring 302 of one embodiment, and Figure 4 is an enlarged view showing a part of the top ring 302 shown in Figure 3. As shown in Figures 3 and 4, the top ring 302 includes a base member 301 connected to the top ring shaft (rotating shaft) 18. As a specific example, the base member 301 is composed of a flange 303 connected to the top ring shaft 18, an upper guide member 305 attached to the lower surface of the flange 303, and a lower guide member 306 provided on the lower surface of the upper guide member 305. The flange 303 and the upper guide member 305 are fixed together by bolts 307 (see Figure 4). The upper guide member 305 and the lower guide member 306 are fixed together by bolts 326 with an elastic member (elastic membrane) 340 in between (see Figure 4). The elastic member 340 can be made of rubber materials such as silicone rubber, EPDM (ethylene propylene diene rubber), or FKM (fluororubber), but is not limited to these. The lower guide member 306 is provided in a frame shape on the peripheral edge of the lower surface of the upper guide member 305.

[0031] Furthermore, the top ring 302 includes a substrate adsorption member 330 for adsorbing the back surface of the substrate WF when the surface to be polished is facing downwards. The substrate adsorption member 330 is positioned below the base member 301. The substrate adsorption member 330 includes a substrate adsorption body 334. The substrate adsorption body 334 can be any member capable of vacuum adsorbing the substrate WF by vacuuming using a depressurization module (vacuum source) 36. The substrate adsorption body 334 can be made of a resin porous material (porous material) in which a large number of pores are formed in a resin such as PE (polyethylene), PP (polypropylene), PTFE (polytetrafluoroethylene), or PVC (polyvinyl chloride). In this embodiment, the substrate adsorption body 334 is formed in a plate shape, and its lower surface defines a substrate adsorption surface 334a for adsorbing the substrate WF.

[0032] Furthermore, the substrate adsorption member 330 includes a shielding member 332. The shielding member 332 can be any airtight member that can shield the flow of gas, and can be formed from a resin plate such as a relatively soft PE (polyethylene), PP (polypropylene), PTFE (polytetrafluoroethylene), or PVC (polyvinyl chloride). In this embodiment, the shielding member 332 is formed to shield the surface 334b ​​of the substrate adsorption body 334 that is opposite to the substrate adsorption surface 334a. In one embodiment, the shielding member 332 and the surface 334b ​​of the substrate adsorption body 334 can be fixed by any means such as adhesive or double-sided tape. Also, the shielding member 332 has a suction passage 312 that communicates with the surface 334b ​​or side surface 334c of the substrate adsorption body 334 (see Figure 3).

[0033] The shielding member 332 of this embodiment includes a frame-shaped elastic sealing member 336 that covers the side surface 334c of the substrate adsorbent 334. The elastic sealing member 336 may be attached to the shielding member 332 by any means, such as double-sided tape. The elastic sealing member 336 can be any material that is elastic and can shield the flow of gas. For example, the elastic sealing member 336 can be a soft material that is chemical resistant, has good elasticity, and has a skin surface. For example, as the elastic sealing member 336, a silicone sponge, silicone rubber, or NORSEAL® made of soft polyvinyl chloride can be used. In the example shown in Figures 3 and 4, the elastic sealing member 336 has a lip portion that extends outward from the lower end. However, it is not limited to this example, and the elastic sealing member 336 may have, for example, a rectangular cross-section or a circular cross-section. Also, the shielding member 332 does not have an elastic sealing member 336 and may be formed to shield the side surface 334c of the substrate adsorbent 334.

[0034] By providing the shielding member 332, when the substrate adsorbent 334 is evacuated by the depressurization module (vacuum source) 36, negative pressure can be efficiently formed on the substrate adsorption surface 334a. As a result, the substrate WF can be reliably adsorbed onto the substrate adsorption member 330, preventing the substrate WF from flying out (slipping out) during polishing, even without providing a retainer member around the substrate WF. Furthermore, if the substrate WF is rectangular in shape, the corners of the substrate WF may come into contact with the retainer member during polishing, potentially causing damage to the substrate WF or top ring. In contrast, according to this embodiment, the substrate WF can be pressed against the polishing pad 352 while being vacuum-adsorbed by the substrate adsorption member 330, thereby preventing the substrate WF from slipping out during polishing and preventing damage to the substrate WF or top ring during polishing.

[0035] Furthermore, the shielding member 332 of this embodiment defines a cavity 338. In one embodiment, the cavity 338 is formed inside the integrally formed shielding member 332. In other words, the shielding member 332 defines both the surface of the cavity 338 on the substrate adsorbent 334 side and the surface on the side away from the substrate adsorbent 334 (the base member 301 side). That is, the shielding member 332 is a hollow body in which the cavity 338 is formed. However, the invention is not limited to this example, and another member may define the surface of the cavity 338 on the base member 301 side. Figure 5 is a schematic, enlarged view of the area around the cavity 338 in the shielding member 332 of this embodiment. As shown in Figure 5, the cavity 338 is in communication with a supply module 37 via a flow path 339. The supply module 37 has a pressure adjustment function that adjusts the pressure inside the cavity 338 by depressurizing or pressurizing the cavity 338. Any fluid, such as air, can be used for depressurization or pressurization. While not limited to these, in the example shown in Figure 5, positive or negative pressure supplied from the supply module 37 is supplied to the cavity 338 through the sensor 37a and valve 37b. For example, sensor 37a may be a pressure sensor or a flow sensor. Valve 37b may be a control valve or an on-off valve. The controller 900 may adjust the pressure in the cavity 338 by controlling valve 37b based on control commands based on a predetermined recipe and signals from sensor 37a. The supply module 37 may be, for example, a depressurization source or a pressurization source, and may consist of at least one of a pressure adjustment unit 35 and a depressurization module 36. By adjusting the pressure in the cavity 338 with the supply module 37, the shielding member 332 can be deformed, allowing a force to be applied in the direction of pushing or pulling the substrate adsorbent 334. This allows for localized adjustment of the pressure exerted by the pressurizing chamber formed by the elastic membrane 320 (described later), thereby controlling the pressing force of the substrate WF against the polishing pad 352 via the substrate adsorbent 334.

[0036] In this embodiment, the shielding member 332 has a plurality of cavities 338 formed therein. Figure 6 is a diagram showing an example of the arrangement of the cavities 338, and Figure 7 is a diagram showing another example of the arrangement of the cavities 338. In the examples shown in Figures 6 and 7, the shape of the substrate WF is rectangular (see the dashed lines in the figures). In the example shown in Figure 6, the cavities 338 are formed in a four-corner frame shape along the four corner edges of the substrate WF. In the example shown in Figure 7, the cavities 338 are formed in a four-corner triangular shape along the four corner edges of the substrate WF. In the examples shown in Figures 6 and 7, the cavities 338 are formed including an area outside the outer shape of the substrate WF. However, the invention is not limited to these examples, and the cavities 338 may be provided only in an area inside the outer shape of the substrate WF, that is, in an area that overlaps with the substrate WF when viewed from a direction perpendicular to the substrate adsorption surface 334a. Furthermore, the location where the cavity 338 is formed can be determined by experiment or simulation, and it may be formed at any location, such as the center of the substrate WF, instead of along the edge of the substrate WF, or in addition to that. For example, the cavity 338 is arranged rotationally symmetrically around the rotation axis of the top ring 302. Note that the shielding member 332 is not limited to having multiple cavities 338 formed in it, and may have a single cavity formed in it.

[0037] Here, an example of a method for manufacturing a shielding member 332 having a cavity 338 formed therein will be described. As shown in Figure 8, the shielding member 332 can be integrally constructed by surface joining a first member 332-1 having a groove 338a defining the cavity 338 and a thin plate-shaped second member 332-2. Here, surface joining can be by adhesive, double-sided tape or other adhesive, chemical bonding, or welding. In this embodiment, the first member 332-1 is in contact with the substrate adsorbent 334 side, and the second member 332-2 is positioned on the opposite side from the substrate adsorbent 334, but this is not limited to this. Also, in this embodiment, the first member 332-1 has a flow path 339 that extends along the substrate adsorption surface 334a and communicates with the groove 338a (cavity 338). However, the flow path 339 may also be formed in the second member 332-2. Furthermore, the channel 339 may be hollow, or a porous material 339a with numerous pores may be placed in the channel 339. By providing the porous material 339a in the channel 339, the strength of the portion of the shielding member 332 in which the channel 339 is formed can be improved. The porous material 339a may be made of the same material as the material forming the shielding member 332, or a material having similar rigidity. Figure 9 is a diagram illustrating another example of a method for manufacturing a shielding member 332 in which a cavity 338 is formed. As shown in Figure 9, the shielding member 332 may be integrally constructed by joining a first member 332-1 in which a groove 338a defining the cavity 338 is formed, and a lid member 332-3 that matches the shape of the groove 338a of the first member 332-1. Here, the joining can be various adhesives, similar to surface joining. Furthermore, the shielding member 332 is not limited to being formed by bonding the first member 332-1 to the second member 332-2 or the lid member 332-3, but may be manufactured by other methods such as injection molding or AM (Additive Manufacturing) technology. In addition, the shielding member 332 may be formed by welding the joint surfaces of the first member 332-1 to the second member 332-2 or the lid member 332-3 and flattening the weld bead with a grinder or the like.

[0038] Furthermore, in the examples shown in Figures 8 and 9, the cavity 338 formed in the shielding member 332 is formed to have a trapezoidal cross-section, being narrower closer to the substrate adsorbent 334 (downward) and wider further away from the substrate adsorbent 334 (upward). This allows the deformation of the cavity 338 when the pressure inside the cavity 338 is adjusted to be distributed smoothly, being larger in the center and smaller at the edges. This suppresses excessive force being applied to the edges of the cavity 338 due to deformation, allowing force to be applied to the substrate adsorbent 334. However, the cavity 338 formed in the shielding member 332 is not limited to a trapezoidal cross-section that is narrower closer to the substrate adsorbent 334; as shown in Figure 10, the cross-section may be triangular, rectangular, or any other shape. The shape of the cavity 338 may also be determined by experiment or simulation.

[0039] The shielding member 332, in which the cavity 338 is formed, can be fixed to the substrate adsorbent 334 by any means such as adhesive or double-sided tape. In one embodiment, as shown in Figure 5, the shielding member 332 is bonded to the substrate adsorbent 334 in the region 332a where the cavity 338 is not formed, but is not bonded to the substrate adsorbent 334 in the region 332b where the cavity 338 is formed. The region 332b in which the cavity 338 is formed can also be described as the region of the shielding member 332 sandwiched between the cavity 338 and the substrate adsorbent 334. This is based on the fact that the region 332b in the shielding member 332 in which the cavity 338 is formed is deformed by the pressure adjustment of the cavity 338. In other words, by not bonding the region 332b in the shielding member 332 in which the cavity 338 is formed to the substrate adsorbent 334, the shielding member 332 can be suitably deformed.

[0040] Refer again to Figures 3 and 4. The substrate adsorption member 330 includes a frame member 344 provided on the shielding member 332 so as to surround at least a portion of the base member 301 (specifically, the upper guide member 305 and the lower guide member 306). The frame member 344 includes a lower frame member 343 provided in a frame shape on the periphery of the upper surface of the shielding member 332, a frame-shaped upper frame member 342 provided on the lower frame member 343, and a stopper 346 provided on the upper frame member 342. As an example, the shielding member 332 and the frame member 344 are fixed together by bolts 308 (see Figure 4). The upper frame member 342 and the lower frame member 343 are connected by an elastic member 340. The stopper 346 overlaps with the upper guide member 305 in at least a portion of the area when the top ring 302 is viewed from above (viewed from a direction perpendicular to the substrate adsorption surface 334a). This allows the height movement of the substrate adsorption member 330 to be restricted by contact between the stopper 346 and the upper guide member 305.

[0041] The top ring 302 includes an elastic membrane 320 configured to form a pressurizing chamber for pressurizing the substrate WF between the base member 301 and the substrate adsorption member 330. In this embodiment, the elastic membrane 320 includes a plurality of elastic membranes 320-1, 320-2, and 320-3 that are stacked and have different areas. Each of the elastic membranes 320-1, 320-2, and 320-3 includes a central portion that contacts the upper surface of the shielding member 332 and an end portion that extends from the central portion and is fixed to different positions on the lower surface of the upper guide member 305. As an example, each of the ends of the plurality of elastic membranes 320-1, 320-2, and 320-3 is fixed to the upper guide member 305 by a bolt 325. Multiple elastic membranes 320-1, 320-2, and 320-3 form multiple concentric pressure chambers between the base member 301 and the multiple elastic membranes 320-1, 320-2, and 320-3 for pressurizing the substrate WF. In addition, the outermost pressure chamber is formed by elastic membrane 320-3 and elastic member 340. Each of the multiple pressure chambers is in communication with a pressure adjustment unit (fluid supply source) 35 via a pressure passage 313. The pressure adjustment unit 35 has a pressure adjustment function that adjusts the pressure of the pressurized fluid supplied to each pressure chamber. By forming multiple pressure chambers, the pressing force of the substrate WF against the polishing pad 352 via the substrate adsorption member 330 can be controlled area by area. In this embodiment, the pressure chambers formed by the elastic membrane 320 are arranged to overlap with the cavity 338 of the shielding member 332 when viewed from a direction perpendicular to the substrate adsorption surface 334a. This allows the pressing force on the substrate WF to be controlled by utilizing the pressurizing chamber formed by the elastic membrane 320 and the cavity 338 of the shielding member 332. The top ring 302 is not limited to having multiple concentric pressurizing chambers, but may also have multiple pressurizing chambers divided in the circumferential direction. Furthermore, the elastic membrane 320 is not limited to being composed of multiple laminated sheets, but may have partitions separating the multiple pressurizing chambers, and as an example, an elastic membrane formed by a mold as disclosed in Japanese Patent No. 7074606 may be used. In addition, the top ring 302 may have a single pressurizing chamber.

[0042] In one embodiment, the top ring 302 further includes a band 345 connecting the outer surface of the base member 301 and the outer surface of the frame member 344. In the example shown in Figures 3 and 4, the band 345 is specifically attached from the outer surface of the flange 303 to the outer surface of the upper frame member 342. The band 345 allows displacement of the substrate adsorption member 330 relative to the base member 301 and prevents polishing fluid or the like from entering the space between the substrate adsorption member 330 and the base member 301.

[0043] The top ring 302 can evacuate the substrate adsorbent 334 using a vacuum module (vacuum source) 36, allowing the substrate WF to be adsorbed onto the substrate adsorption surface 334a. The pressure adjustment unit 35 pressurizes the pressurizing chamber formed by the elastic film 320, and the supply module 37 adjusts the pressure in the cavity 338 of the shielding member 332, thereby controlling the force pressing the substrate WF against the polishing pad 352. At this time, the controller 900 may control the pressure supply to the pressurizing chamber and cavity 338 so that the film thickness distribution of the substrate WF becomes a target distribution. As an example, the controller 900 may control the pressure adjustment unit 35 and the supply module 37 based on a predetermined recipe based on the characteristics of the substrate WF. Alternatively, a sensor for measuring the film thickness of the substrate WF may be provided inside the polishing table 350, and the controller 900 may acquire information from the sensor during substrate polishing and control the pressure adjustment unit 35 and the supply module 37 based on the acquired information. Furthermore, an eddy current sensor, an optical sensor, or a microwave sensor can be used as the sensor for measuring the film thickness of the substrate WF. In addition, the controller 900 may modify the subsequent control of the pressure adjustment unit 35 and the supply module 37 based on the polishing profile of the substrate WF after polishing.

[0044] <Modification Example 1> Fig. 11 is a cross-sectional view schematically showing the top ring of the modification example. The top ring 302A of the modification example is substantially the same as the above-described top ring 302 except that it includes an airbag 337, and redundant descriptions are omitted. In Fig. 11, for the sake of clarity of the drawing, the line for supplying pressure to the pressure chamber formed by the elastic membrane 320 and the cavity 338 formed in the shielding member 332 is shown omitted. The top ring 302A of the modification example has an airbag 337 provided in the outermost peripheral side pressure chamber formed by the elastic membrane 320-3 and the elastic member 340. However, the airbag 337 may be provided in other pressure chambers formed by the elastic membranes 320-1, 320-2, and 320-3. The airbag 337 may be provided in a frame shape continuous in the circumferential direction along the outer shape of the substrate WF, or may be formed in a four-corner frame shape along the four-corner edge portions of the substrate WF as shown in Fig. 6. Note that the airbag 337 may be arranged so as to overlap the cavity 338 of the shielding member 332 when viewed from a direction perpendicular to the substrate adsorption surface 334a, or may not overlap the cavity 338. The airbag 337 communicates with a fluid supply source (positive pressure source) 33. The fluid supply source 33 may be the same as the pressure adjustment unit 35, but it is preferably configured such that the pressure adjustment of the pressure chamber and the pressure adjustment of the airbag 337 can be controlled individually. The airbag 337 is arranged so as to contact the base member 301 and the substrate adsorption member 330, and can press the substrate adsorption member 330 according to the internal pressure.

[0045] According to the modified top ring 302A, the force pressing the substrate WF against the polishing pad 352 can be controlled by adjusting the pressure in the pressurizing chamber formed by the elastic film 320, the pressure in the cavity 338 of the shielding member 332, and the pressure in the airbag 337. At this time, the controller 900 may control the pressure supply to the pressurizing chamber, cavity 338, and airbag 337 so that the film thickness distribution of the substrate WF becomes a target distribution. As an example, the controller 900 may control the pressure adjustment unit 35, the supply module 37, and the fluid supply source 33 based on a recipe predetermined based on the characteristics of the substrate WF. Alternatively, a sensor for measuring the film thickness of the substrate WF may be provided inside the polishing table 350, and the controller 900 may acquire information from the sensor during substrate polishing and control the pressure adjustment unit 35, the supply module 37, and the fluid supply source 33 based on the acquired information. Furthermore, the controller 900 may modify the subsequent control of the pressure adjustment unit 35, the supply module 37, and the fluid supply source 33 based on the polishing profile of the substrate WF after polishing.

[0046] <Modification 2> Figure 12 is a schematic cross-sectional view showing the modified top ring. The modified top ring 302B is generally identical to the top ring 302 described above, except that it does not have an elastic membrane 320, so redundant explanations will be omitted. The modified top ring 302B does not have an elastic membrane 320, and a single pressurized chamber is formed by an elastic member (elastic membrane) 340. The pressurization of the pressurized chamber by the elastic member (elastic membrane) 340 is locally adjusted by adjusting the pressure in a cavity 338 formed in the shielding member 332, and this is configured to control the force that presses the substrate WF against the polishing pad 352. Since this modified top ring 302B does not have multiple elastic membranes 320, bolts 325 for fixing the elastic membranes 320 are not required, and the top ring 302B can be made into a simple structure. In Figure 12, the shielding member 332 is configured with multiple cavities 338 formed at positions corresponding to the entire surface of the substrate WF, and the supply module 37 can individually control the pressure within the multiple cavities 338. The shielding member 332 may have multiple cavities 338 formed concentrically, or it may have cavities 338 formed in any arrangement as described in the above embodiment. Furthermore, the shielding member 332 may have cavities 338 formed at positions corresponding to the entire surface of the substrate WF, or it may have cavities 338 formed only at positions corresponding to a portion of the surface of the substrate WF. The matters described in the above embodiment regarding the shielding member 332 can be applied to the shielding member 332 in the modified top ring 302B, insofar as they do not contradict each other. For example, the shielding member 332 of the top ring 302B is bonded to the substrate adsorbent 334 in areas where the cavity 338 is not formed, but does not need to be bonded to the substrate adsorbent 334 in areas where the cavity 338 is formed.

[0047] The present invention can also be described in the following forms. [Aspect 1] According to Aspect 1, a top ring for holding a substrate, comprising: a base member connected to a rotating shaft; a substrate adsorber having a substrate adsorption surface for adsorbing the substrate and communicating with a decompression module; a shielding member configured to shield a surface of the substrate adsorber opposite to the substrate adsorption surface and defining at least one cavity communicating with a supply module for decompression or pressurization; and an elastic film configured to form a pressurization chamber communicating with a fluid supply source between the base member and the shielding member. According to Aspect 1, the cavity can be decompressed or pressurized to equalize the polishing profile of the substrate.

[0048] [Aspect 2] According to Aspect 2, a top ring for holding a substrate, comprising: a substrate adsorber having a substrate adsorption surface for adsorbing the substrate and communicating with a decompression module; and a shielding member configured to shield a surface of the substrate adsorber opposite to the substrate adsorption surface and defining a cavity communicating with a supply module for decompression or pressurization, wherein the surface of the substrate adsorber opposite to the substrate adsorption surface is adhered to the shielding member except for a region where the cavity is defined. According to Aspect 2, the cavity can be decompressed or pressurized to equalize the polishing profile of the substrate.

[0049] [Aspect 3] According to Aspect 3, in Aspect 1 or 2, a plurality of cavities are defined in the shielding member along the substrate adsorption surface. According to Aspect 3, the plurality of cavities can be decompressed or pressurized to equalize the polishing profile of the substrate.

[0050] [Aspect 4] According to Aspect 4, in Aspect 1, the surface of the substrate adsorber opposite to the substrate adsorption surface is adhered to the shielding member except for a region where the cavity is defined. According to Aspect 4, in the region where the cavity is defined, the substrate adsorber and the shielding member are not adhered, and the cavity can be decompressed or pressurized to preferably deform the shielding member.

[0051] [Embodiment 5] According to embodiment 5, in embodiments 1 to 4, the cavity defined in the shielding member is formed to include an area outside the outer shape of the substrate held by the top ring. According to embodiment 5, the polishing profile of the substrate can be made uniform, including around the edges of the substrate.

[0052] [Embodiment 6] In embodiment 6, in embodiments 1 to 5, the shielding member is formed by bonding together a first member having a groove that defines the cavity and a second member that covers the groove.

[0053] [Embodiment 7] According to embodiment 7, in embodiment 6, the shielding member has a flow path formed therein, one end of which extends along the substrate adsorption surface and is connected to the groove, and the other end of which communicates with the supply module. According to embodiment 7, a flow path through which a fluid for depressurization or pressurization flows can be provided in the shielding member.

[0054] [Embodiment 8] According to embodiment 8, in embodiment 7, a porous material is placed in the flow channel. According to embodiment 8, the strength of the portion where the flow channel is formed can be improved.

[0055] [Embodiment 9] According to embodiment 9, in embodiment 7 or 8, the cross-sectional shape of the groove is rectangular, trapezoidal, or triangular.

[0056] [Embodiment 10] According to embodiment 10, in embodiment 2, an elastic membrane is further provided between the base member and the shielding member, configured to form a pressurized chamber communicating with a fluid supply source.

[0057] [Embodiment 11] According to embodiment 11, in embodiments 1, 3 to 10 in which a pressurized chamber is formed, an elastic membrane is provided that is configured to form a plurality of pressurized chambers, including the pressurized chamber, concentrically between the base member and the shielding member. According to embodiment 11, by supplying fluid to the plurality of concentrically formed pressurized chambers, the polishing profile of the substrate can be made uniform.

[0058] [Embodiment 12] According to embodiment 12, in embodiments 1, 3 to 11 in which a pressurized chamber is formed, an airbag is provided which is placed in the pressurized chamber and is configured to form a local pressurized chamber that communicates with a fluid supply source. According to embodiment 12, fluid can be supplied to the airbag to homogenize the polishing profile of the substrate.

[0059] [Embodiment 13] In embodiment 13, in embodiments 1 to 12, the substrate adsorbent is formed of a porous material.

[0060] [Embodiment 14] According to embodiment 14, a substrate polishing apparatus is proposed comprising the top ring of embodiments 1 to 13 and a table configured to hold a polishing pad. According to embodiment 14, the same effects as those of the embodiments described above can be achieved.

[0061] While embodiments of the present invention have been described above, the embodiments of the invention described above are for the purpose of facilitating understanding of the present invention and do not limit it. The present invention can be modified and improved without departing from its spirit, and of course, the present invention includes equivalents thereof. Furthermore, any combination of embodiments and modifications is possible to the extent that at least some of the above-mentioned problems can be solved or at least some of the effects can be achieved, and any combination or omission of each component described in the claims and specification is possible.

[0062] This application claims priority under Japanese Patent Application No. 2024-230679, filed on 26 December 2024. All disclosures of Japanese Patent Application No. 2024-230679, including the specification, claims, drawings, and abstract, are incorporated herein by reference. All disclosures of Japanese Patent Publication No. 2022-59509 (Patent Document 1), including the specification, claims, drawings, and abstract, are incorporated herein by reference.

[0063] WF...Substrate 33...Fluid supply source 35...Pressure adjustment unit 36...Depressurization module 37...Supply module 100...Load unit 200...Transport unit 300...Polishing unit 301...Base member 302, 302A, 302B...Top ring 303...Flange 305...Upper guide member 306...Lower guide member 307...Bolt 308...Bolt 312...Suction passage 313...Pressure passage 319...Vertical movement mechanism 320...Elastic membrane 325...Bolt 326...Bolt 330...Substrate adsorption member 332...Shielding member 332-1...First member 332-2...Lid member 332-3...Second member 334...Substrate adsorption body 334a...Substrate adsorption surface 336...Elastic seal member 337...Airbag 338...Cavity 339...Flow path 339a...Porous material 340...Elastic member (elastic film) 342...Upper frame member 343...Lower frame member 344...Frame member 345...Band 346...Stopper 350...Polishing table 500...Drying unit 600...Unloading unit 900...Controller 1000...Substrate polishing device

Claims

1. A top ring for holding a substrate, comprising: a base member connected to a rotating shaft; a substrate adsorbent having a substrate adsorption surface for adsorbing a substrate and communicating with a depressurization module; a shielding member configured to shield the surface of the substrate adsorbent opposite to the substrate adsorption surface and defining at least one cavity communicating with a supply module for depressurization or pressurization; and an elastic membrane configured to form a pressurization chamber communicating with a fluid supply source between the base member and the shielding member.

2. A top ring for holding a substrate, comprising: a substrate adsorbent having a substrate adsorption surface for adsorbing a substrate and communicating with a depressurization module; and a shielding member configured to shield the surface of the substrate adsorbent opposite to the substrate adsorption surface and defining a cavity communicating with a supply module for depressurization or pressurization, wherein the surface of the substrate adsorbent opposite to the substrate adsorption surface is bonded to the shielding member, except in the area where the cavity is defined.

3. The top ring according to claim 1 or 2, wherein the shielding member has a plurality of cavities defined along the substrate adsorption surface.

4. The top ring according to claim 1, wherein the surface of the substrate adsorbent opposite to the substrate adsorption surface is bonded to the shielding member, except for the region in which the cavity is defined.

5. The top ring according to claim 1 or 2, wherein the cavity defined in the shielding member is formed to include a region outside the outer shape of the substrate held by the top ring.

6. The top ring according to claim 1 or 2, wherein the shielding member is formed by bonding together a first member having a groove that defines the cavity and a second member that covers the groove.

7. The top ring according to claim 6, wherein the shielding member has a flow path formed therein, one end of which extends along the substrate adsorption surface and is connected to the groove, and the other end of which communicates with the supply module.

8. The top ring according to claim 7, wherein a porous material is arranged in the flow path.

9. The top ring according to claim 6, wherein the cross-sectional shape of the groove is rectangular, trapezoidal, or triangular.

10. The top ring according to claim 2, further comprising: a base member connected to a rotating shaft; and an elastic membrane configured to form a pressurized chamber communicating with a fluid supply source between the base member and the shielding member.

11. The top ring according to claim 1 or 10, comprising an elastic membrane configured to form a plurality of pressurized chambers, including the pressurized chamber, concentrically between the base member and the shielding member.

12. The top ring according to claim 1 or 10, comprising an airbag disposed within the pressurized chamber and configured to form a local pressurized chamber communicating with a fluid supply source.

13. The top ring according to claim 1 or 2, wherein the substrate adsorbent is formed of a porous material.

14. A substrate polishing apparatus comprising: a top ring according to claim 1 or 2; and a table configured to hold a polishing pad.

Images