Top ring and substrate polishing device

Abstract

Provided is a top ring or a substrate polishing device capable of making a polishing profile more uniform between the center of a square substrate and the outer edge side of the substrate.　This top ring, which is for holding a polygonal substrate, comprises: a base member connected to a rotary shaft; a substrate suction member that includes a substrate suction body having a substrate suction surface for suctioning the substrate, and communicates with a pressure-reduction module, a shielding member configured to shield a surface on the opposite side to the substrate suction surface of the substrate suction body, and a frame member connected to the shielding member so as to surround at least a part of the periphery of the base member; and a biasing mechanism that has a first end part in contact with the base member and a second end part in contact with the frame member, and applies a biasing force in a direction in which the base member and the frame member approaches or separates from each other.

Description

Top ring and substrate polishing apparatus

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

[0002] Chemical mechanical polishing (CMP) equipment is used to planarize the surface of a substrate in the manufacture of semiconductor devices. The substrates used in semiconductor device manufacture are often circular. Furthermore, there is a growing demand for flatness when planarizing the surfaces of rectangular substrates, such as copper clad laminate (CCL) substrates, printed circuit board (PCB) substrates, photomask substrates, and display panels, in addition to semiconductor devices. There is also a growing demand for planarization of the surfaces of package substrates, such as PCB substrates, on which electronic devices are mounted.

[0003] The substrate polishing apparatus includes a top ring for holding a substrate. As described in Patent Document 1, for example, the top ring includes a rotating shaft, a flange connected to the rotating shaft, a suction plate fitted into an opening formed in the underside of the flange, and a shield plate attached to the upper surface of the suction plate. The top ring is configured to suck the substrate via the suction plate by vacuum suction and to press the substrate against a polishing pad by applying pressure to the shield plate.

[0004] Japanese Patent Application Laid-Open No. 2023-57047

[0005] With the top ring described above, differences in substrate film thickness after polishing have been observed between the center and the outer edge of the substrate. In particular, when polishing rectangular substrates, the amount of polishing at the corners of the substrate may be smaller than the amount of polishing at the center of the substrate. This is thought to be due to the fact that when the top ring presses the substrate through the shielding plate, a force is generated in the corners of the substrate that causes the substrate to bend upward, resulting in a lower pressure at the corners than at the center of the substrate. Furthermore, as shown in FIG. 10 , in the substrate polishing apparatus 1000, polishing slurry PS is supplied to the center of the rectangular substrate WF held by the top ring 302 through the passage 353 (opening 355) formed in the polishing table 350. This polishing slurry PS may then spread along the surface of the substrate WF toward the outer edge, resulting in the polishing slurry PS being supplied to the outer edge of the substrate WF (see the dashed arrow). In this process, the amount of polishing slurry PS supplied may be less at the corners of the substrate than at the center, resulting in a lower amount of polishing at the corners of the substrate compared to the amount of polishing at the center of the substrate. Furthermore, depending on the polishing environment, the amount of polishing on the outer edge of the rectangular substrate may be greater than the amount of polishing on the central side of the substrate.

[0006] In view of the above circumstances, one of the objects of the present application is to provide a top ring or a substrate polishing apparatus that can make the polishing profile more uniform between the center side and the outer edge side of a rectangular substrate.

[0007] According to one embodiment, a top ring for holding a polygonal substrate is proposed, the top ring comprising: a base member connected to a rotating shaft; a substrate attracting member including a substrate attracting body having a substrate attracting surface for attracting a substrate and communicating with a decompression module; a shielding member configured to shield the surface of the substrate attracting body opposite the substrate attracting surface; and a frame member connected to the shielding member so as to surround at least a portion of the base member; and a biasing mechanism having a first end that contacts the base member and a second end that contacts the frame member, and applying a biasing force in a direction that brings the base member and the frame member closer to each other or in a direction that moves them apart.

[0008] FIG. 5 is a plan view showing the overall configuration of a substrate polishing apparatus according to an embodiment; FIG. 6 is a perspective view schematically showing the configuration of a polishing unit according to an embodiment; FIG. 7 is a cross-sectional view schematically showing a top ring according to an embodiment; FIG. 8 is a cross-sectional perspective view schematically showing a top ring according to an embodiment; FIG. 9 is a perspective view schematically showing a substrate suction member according to an embodiment; FIG. 10 is an enlarged view of region AA in FIG. 5; FIG. 11 is a diagram showing a contact location of a biasing mechanism in a modified example; FIG. 12 is a cross-sectional view schematically showing a top ring in a modified example; FIG. 13 is a diagram showing an example of a portion of a frame member with which a piston or an elastic body comes into contact; FIG. 14 is a diagram showing an example of a substrate polishing apparatus according to a reference example.

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the drawings described below, the same or corresponding components are designated by the same reference numerals, and redundant description will be omitted.

[0010] FIG. 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 FIG. 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 includes two transport units 200A and 200B, and the polishing unit 300 includes 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. The substrate polishing apparatus 1000 also includes 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 configured as a general computer equipped with an input / output device, an arithmetic unit, a storage device (storage medium) 900a, etc. The controller 900 functions as a main body of operations that controls the substrate polishing apparatus 1000. The controller 900 performs various processes by reading and executing programs stored in the storage device 900a, etc. The programs may be obtained by recording them on a recording medium such as a DVD-ROM, or may be obtained via a network.

[0011] <Load Unit> The load unit 100 is a unit for introducing a substrate WF before processing such as polishing and cleaning into the substrate polishing apparatus 1000. In one embodiment, the load unit 100 is configured to comply with the SMEMA (Surface Mount Equipment Manufacturers Association) Mechanical Device Interface Standard (IPC-SMEMA-9851).

[0012] In the illustrated embodiment, the transport mechanism of the load unit 100 includes 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 FIG. 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 transport rollers 202 may be attached at any position on the roller shaft 204 as long as they can stably transport 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 to be processed without causing any problems. In one embodiment, the transport rollers 202 of the load unit 100 may be made of a conductive polymer. In one embodiment, the transport rollers 202 are electrically grounded via the roller shafts 204 or the like. This is to prevent the substrate WF from being 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 being charged.

[0013] 1 includes two transport units 200 A and 200 B. The two transport units 200 A and 200 B can have the same configuration, and therefore will be collectively referred to as the transport unit 200 in the following description.

[0014] The transport unit 200 shown in the figure includes a plurality of transport rollers 202 for transporting the substrate WF. By rotating the transport rollers 202, the substrate 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 a non-conductive polymer.

[0015] In one embodiment, the transport unit 200 includes a cleaning nozzle 284. The cleaning nozzle 284 is connected to a cleaning liquid supply source (not shown). The cleaning nozzle 284 is configured to supply the cleaning liquid to the substrate WF transported by the transport rollers 202.

[0016] <Polishing Unit> Fig. 2 is a perspective view showing a schematic configuration of a polishing unit 300 according to one embodiment. The substrate polishing apparatus 1000 shown in Fig. 1 includes two polishing units 300A and 300B. The two polishing units 300A and 300B can have the same configuration, and therefore will be collectively referred to as the polishing unit 300 below.

[0017] 2, the polishing unit 300 includes a polishing table 350 and a top ring 302 constituting a polishing head that holds a substrate, which is an object to be polished, and presses it against the polishing surface on the polishing table 350. The polishing table 350 is connected to a polishing table rotation motor (not shown) disposed below the polishing table 350 via a table shaft 351, and is rotatable about the table shaft 351. A polishing pad 352 is affixed to the upper surface of the polishing table 350, and a surface 352a of the polishing pad 352 constitutes the polishing surface that polishes the substrate.

[0018] A polishing liquid supply nozzle 354 is installed above the polishing table 350, and this polishing liquid supply nozzle 354 supplies a polishing liquid onto a polishing pad 352 on the polishing table 350. Also, as shown in FIG. 2 , the polishing table 350 and the table shaft 351 are provided with a passage 353 for supplying the polishing liquid. The passage 353 communicates with an opening 355 in 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 in the polishing table 350, and the polishing liquid passing through the passage 353 is supplied to the surface of the polishing pad 352 through the opening 355 in the polishing table 350 and the through-hole 357 in the polishing pad 352. The opening 355 in the polishing table 350 and the through-hole 357 in the polishing pad 352 may be one, multiple, or none. 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 located 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) (see FIG. 10 ).

[0019] 2, in one embodiment, the polishing unit 300 includes an atomizer 358 (see FIG. 1) for spraying a liquid or a mixture of liquid and gas toward the polishing pad 352. The liquid sprayed from the atomizer 358 is, for example, pure water, and the gas is, for example, nitrogen gas.

[0020] The top ring 302 is connected to a top ring shaft 18, which is movable up and down relative to a swing arm 360 by a vertical movement mechanism 319. The vertical movement of the top ring shaft 18 moves the entire top ring 302 up and down relative to the swing 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.

[0021] The top ring 302 is capable of holding a rectangular substrate on its underside. In this embodiment, a "rectangular substrate" refers to a substrate having a triangular, rectangular, or polygonal surface with five or more sides. The swing arm 360 is rotatable about a support shaft 362. The swing arm 360 rotates to move the top ring 302 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 a polishing liquid is supplied onto the polishing pad 352 from a polishing liquid supply nozzle 354 provided above the polishing table 350 and / or an opening 355 provided in the polishing table 350. In this manner, the substrate can be pressed against the polishing surface 352a of the polishing pad 352 to polish the surface of the substrate. As described above, the arm 360 may be fixed or swung so that the top ring 302 passes through the center of the polishing pad 352 (so as to cover the through-hole 357 of the polishing pad 352) during polishing of the substrate WF (see Figure 10).

[0022] The up-and-down movement mechanism 319 that moves the top ring shaft 18 and the top ring 302 up and down includes 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 a swing arm 360 via the support column 130.

[0023] The ball screw 32 includes a screw shaft 32a connected to a servo motor 38 and a nut 32b onto which the screw shaft 32a is threaded. The top ring shaft 18 moves up and down integrally with the bridge 28. Therefore, when the servo motor 38 is driven, the bridge 28 moves up and down via the ball screw 32, which in turn moves the top ring shaft 18 and the top ring 302 up and down.

[0024] The polishing unit 300 according to one embodiment includes a dressing unit 356 that dresses the polishing surface 352a of the 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 attached to the upper end of the dresser shaft 51, and a swing arm 55 that rotatably supports the dresser shaft 51. The lower portion of the dresser 50 is formed by a dressing member 50a, and needle-shaped diamond particles are attached to the underside of the dressing member 50a. The air cylinder 53 is disposed on a support base 57 supported by struts 56, and the struts 56 are fixed to the swing arm 55.

[0025] The swing arm 55 is driven by a motor (not shown) and configured to rotate around a support shaft 58. The dresser shaft 51 is rotated by the drive of the motor (not shown), and the rotation of the 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.

[0026] The polishing surface 352a of the polishing pad 352 is dressed as follows: The dresser 50 is pressed against the polishing surface 352a by the air cylinder 53, and simultaneously, 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 swing arm 55 swings over 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 dresser 50 scrapes off the polishing pad 352, and the polishing surface 352a is dressed.

[0027] <Drying Unit> The drying unit is an apparatus for drying the substrate WF. In the substrate polishing apparatus 1000 shown in FIG. 1, the drying unit 500 dries the substrate WF that has been polished in the polishing unit 300 and then cleaned in the cleaning section of the transport unit 200. As shown in FIG. 1, the drying unit 500 is disposed downstream of the transport unit 200. The drying unit 500 has a nozzle 530 for spraying 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 having the drying unit 500 blow off water droplets on the substrate WF being transported.

[0028] <Unload Unit> The unload unit 600 is a unit for unloading 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 FIG. 1, the unload unit 600 receives the substrate after drying in the drying unit 500. As shown in FIG. 1, the unload unit 600 is disposed downstream of the drying unit 500. In one embodiment, the unload unit 600 is configured to comply with the SMEMA (Surface Mount Equipment Manufacturers Association) Mechanical Device Interface Standard (IPC-SMEMA-9851).

[0029] <Top Ring> Next, the top ring 302 in the polishing unit 300 according to one embodiment will be described. FIGS. 3 and 4 are a cross-sectional view and a cross-sectional perspective view, respectively, schematically illustrating the top ring 302 according to one embodiment. As shown in FIGS. 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 includes a flange 303 connected to the top ring shaft 18, a spacer 304 attached to the underside of the flange 303, an upper guide member 305 attached to the underside of the spacer 304, and a lower guide member 306 attached to the underside of the upper guide member 305. The flange 303, the spacer 304, and the upper guide member 305 are fixed together by bolts (not shown). The upper guide member 305 and the lower guide member 306 are fixed together by bolts (not shown), sandwiching an elastic member 340 therebetween. The elastic member 340 can be made of a rubber material such as, but not limited to, silicone rubber, EPDM (ethylene propylene diene rubber), FKM (fluoro rubber), etc. The lower guide member 306 is provided in a frame shape on the peripheral portion of the lower surface of the upper guide member 305.

[0030] The top ring 302 also includes a substrate suction member 330 for suctioning the backside of the substrate WF with its surface to be polished facing downward. The substrate suction member 330 is disposed below the base member 301. The substrate suction member 330 includes a substrate suction body 334. The substrate suction body 334 may be any member capable of vacuum-suctioning the substrate WF by vacuuming using the decompression module (vacuum source) 31. The substrate suction body 334 may be made of a resin porous material (porous material) having numerous pores formed in a resin such as PE (polyethylene), PP (polypropylene), PTFE (polytetrafluoroethylene), or PVC (polyvinyl chloride). In this embodiment, the substrate suction body 334 is formed in a plate shape, and its lower surface defines a substrate suction surface 334a for suctioning the substrate WF.

[0031] The substrate adsorption member 330 also includes a shielding member 332. The shielding member 332 may be any airtight member capable of blocking the flow of gas, and may be formed, for example, from a relatively soft resin plate such as PE (polyethylene), PP (polypropylene), PTFE (polytetrafluoroethylene), or PVC (polyvinyl chloride). In this embodiment, the shielding member 332 is formed so as to shield a surface 334b ​​of the substrate adsorption body 334 opposite to the substrate adsorption surface 334a. The shielding member 332 also has a suction path 312 formed therein so as to communicate with the surface 334b ​​or the side surface 334c of the substrate adsorption body 334.

[0032] The shielding member 332 of this embodiment includes a frame-shaped elastic seal member 336 that covers the side surface 334c of the substrate adsorbent 334. The elastic seal member 336 may be attached to the main body of the shielding member 332 by any means, such as double-sided tape. The elastic seal member 336 may be any material that is elastic and capable of blocking the flow of gas. For example, the elastic seal member 336 may be a soft material that is chemical-resistant, has good elasticity, and has a skin surface. For example, the elastic seal member 336 may be made of silicone sponge, silicone rubber, or Norseal, a soft polyvinyl chloride material. In the example shown in FIGS. 3 and 4 , the elastic seal member 336 has a lip portion extending outward from its lower end. However, this is not limited to this example, and the elastic seal member 336 may have, for example, a rectangular or circular cross section. Alternatively, the shielding member 332 may not include the elastic seal member 336 and may be formed to shield the side surface 334c of the substrate adsorbent 334.

[0033] By providing the shielding member 332, when the substrate attracting body 334 is evacuated by the decompression module (vacuum source) 31, a negative pressure can be efficiently generated on the substrate attracting surface 334a. This allows the substrate WF to be reliably attracted to the substrate attracting member 330, preventing the substrate WF from jumping outward (slipping out) during polishing even without providing a retainer member around the substrate WF. Furthermore, if the substrate WF has a rectangular shape, the corners of the substrate WF may come into contact with the retainer member during polishing, potentially resulting in damage to the substrate WF or the top ring. In contrast, according to this embodiment, the substrate WF can be pressed against the polishing pad 352 while being vacuum-attracted by the substrate attracting member 330, preventing the substrate WF from slipping out during polishing and preventing damage to the substrate WF or the top ring during polishing.

[0034] 3 and 4 , the substrate suction 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 peripheral portion of the upper surface of the shielding member 332, an upper frame member 342 provided in a frame shape 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 with bolts (not shown). The upper frame member 342 and the lower frame member 343 are connected with an elastic member 340 sandwiched therebetween.

[0035] Fig. 5 is a perspective view schematically showing a substrate suction member according to one embodiment, and Fig. 6 is an enlarged view of area AA in Fig. 5. For ease of understanding, Figs. 5 and 6 also show an upper guide member 305 on a base member 301. As shown in Fig. 5, in this embodiment, suction ports 314 are provided at four locations on the substrate suction member 330. Each suction port 314 is connected to a decompression module 31 (not shown) via a suction path 312 and a suction connector 311.

[0036] As shown in FIGS. 5 and 6 , the upper frame member 342 includes stoppers 346 provided at each of the four corners of the upper frame member 342. The stoppers 346 are configured to connect different locations of the upper frame member 342 in an arch shape across the interior of the frame. In this embodiment, the stoppers 346 are configured to connect two sides forming corners of the upper frame member 342 in an arch shape. Meanwhile, the upper guide member 305 of the base member 301 includes pads 309 provided at each of the four corners of the upper guide member 305. The pads 309 are provided at positions corresponding to the stoppers 346. The pads 309 are formed in a disk shape at the corners of the upper frame member 342 at a different height than the stoppers 346. The stoppers 346 and the pads 309 overlap each other in a predetermined area when the top ring 302 is viewed from above (as viewed perpendicular to the substrate suction surface 334 a). Therefore, contact between the stoppers 346 and the pads 309 can restrict vertical movement of the substrate suction member 330. The pad 309 is an example of a "contact portion" that contacts the stopper 346 to limit movement in the height direction relative to the base member 301.

[0037] 3 , the top ring 302 includes an elastic membrane 320 configured to form a pressure chamber for pressurizing the substrate WF between the base member 301 and the substrate suction member 330. In this embodiment, the elastic membrane 320 includes multiple 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 end portions that extend from the central portion and are fixed at different positions on the lower surface of the upper guide member 305. The multiple elastic membranes 320-1, 320-2, and 320-3 form multiple concentric pressure chambers for pressurizing the substrate WF between the base member 301 and the multiple elastic membranes 320-1, 320-2, and 320-3. Each of the multiple pressure chambers is connected to the pressure adjustment unit (fluid supply source) 30 via a pressure path 313. The pressure adjusting unit 30 has a pressure adjusting function for adjusting the pressure of the pressure fluid supplied to each pressurizing chamber. By forming multiple pressurizing chambers, the pressing force of the substrate WF against the polishing pad 352 via the substrate attracting member 330 can be controlled for each area. According to this embodiment, the substrate WF is attracted to the substrate attracting surface 334a by applying negative pressure to the substrate attracting body 334 using the decompression module 31, and the substrate WF is pressed against the polishing pad 352 via the substrate attracting member 330 by pressurizing the pressurizing chambers using the pressure adjusting unit 30. The top ring 302 is not limited to having multiple concentric pressurizing chambers, but may have multiple pressurizing chambers divided circumferentially. The elastic membrane 320 is not limited to being formed by stacking multiple membranes, but may have partitions separating the multiple pressurizing chambers. For example, an elastic membrane formed by a mold as disclosed in Japanese Patent No. 7074606 may be used. The top ring 302 may have a single pressurizing chamber without the elastic membrane 320.

[0038] As shown in FIGS. 3 and 4 , the top ring 302 includes a biasing mechanism 400 configured to bias the frame member 344 of the substrate suction member 330 in the vertical direction. In this embodiment, the biasing mechanism 400 is configured using a pneumatic actuator. Specifically, the biasing mechanism 400 includes a cylinder 401 attached to the base member 301, a diaphragm 408 disposed within the cylinder 401, and a piston 410 in contact with the frame member 344. The cylinder 401 is defined by an upper cylinder housing 402 attached to the lower surface of the outer periphery of the flange 303 of the base member 301 and a lower cylinder housing 404 attached to the lower surface of the upper cylinder housing 402. The upper cylinder housing 402 and the lower cylinder housing 404 are formed, for example, from polyphenylene sulfide (PPS) resin. The diaphragm 408 is formed, for example, from a rubber material and is sandwiched and fixed between the upper cylinder housing 402 and the lower cylinder housing 404. The internal space of the cylinder 401 is divided into an upper space and a lower space by a diaphragm 408. A piston 410 is disposed in the lower space of the cylinder 401. The upper end of the piston 410 contacts the lower surface of the diaphragm 408, and the lower end of the piston 410 protrudes from the lower side of the lower cylinder housing 404 and contacts the frame member 344. In one embodiment, the piston 410 is formed from a resin such as PPS resin, a metal, or ceramic. Forming the piston 410 from a resin is advantageous in that it can be made lighter.

[0039] In one embodiment, the top ring 302 includes multiple biasing mechanisms 400. As an example, each of the multiple biasing mechanisms 400 may be provided near a corner of the rectangular substrate WF. However, the biasing mechanisms 400 are not limited to being provided near all corners of the rectangular substrate WF, and may be provided near some of the corners. Furthermore, one end (second end) of the biasing mechanism 400 may contact the stopper 346 of the frame member 344. As an example, the piston 410 may be configured to contact the hatched region 346a in FIG. 6 (multiple locations for each stopper 346). However, this example is not limiting, and one end (second end) of the biasing mechanism 400 may be configured to directly contact the upper frame member 342 instead of or in addition to the stopper 346. FIG. 7 shows the contact location of the biasing mechanism 400 in a modified example. 7 , one end (second end) of the biasing mechanism 400 may be configured to contact the hatched region 342 a of the upper frame member 342. In other words, the biasing mechanism 400 may be configured to contact a region closer to the corner than the stopper 346, or may be configured to contact the upper frame member 342 in the vicinity of the stopper 346. Note that the end (first end) of the biasing mechanism 400 that contacts the base member 301 and the end (second end) that contacts the frame member 344 are preferably spaced apart from the pressure chamber formed by the elastic membrane 320 and / or the substrate attracting body 334 when the top ring 302 is viewed from above (as viewed perpendicular to the substrate attracting surface 334 a).

[0040] 3 and 4 , the upper cylinder housing 402 communicates with the pressure adjustment unit 30 via a pressure passage 413. By using the pressure adjustment unit 30 for pressurizing the substrate WF as the driving source of the biasing mechanism 400 in this manner, the number of parts in the top ring 302 can be reduced. However, the top ring 302 may have a pressure supply source as a driving source separate from the pressure adjustment unit 30 for pressurizing the substrate WF. When a working fluid (e.g., air or nitrogen) is supplied from the pressure adjustment unit 30 into the upper space of the cylinder 401, the diaphragm 408 expands downward, causing the piston 410 to move downward. The downward movement of the piston 410 can bias the frame member 344 downward.

[0041] 3 , the top ring 302 further includes a band 345 that connects the outer side surface of the base member 301 and the outer side surface of the frame member 344. In the example shown in FIG. 3 , the band 345 is specifically attached from the outer side surface of the upper cylinder housing 402 to the outer side surface of the upper frame member 342. The band 345 allows the substrate suction member 330 to be displaced relative to the base member 301 and prevents the polishing liquid and the like from entering the space between the substrate suction member 330 and the base member 301.

[0042] The top ring 302 can evacuate the substrate attracting member 334 using the decompression module (vacuum source) 31 and attract the substrate WF to the substrate attracting surface 334a. The pressure adjusting unit 30 then pressurizes the pressure chamber, thereby pressing the substrate WF against the polishing pad 352 via the substrate attracting member 330. At this time, the controller 900 may control the pressure supply to the pressure chamber so that the film thickness distribution of the substrate WF becomes a target distribution. As an example, the controller 900 may control the pressure adjusting unit 30 based on a recipe predetermined based on the characteristics of the substrate WF. Alternatively, the substrate polishing apparatus 1000 may be provided with a sensor for measuring the film thickness of the substrate WF, and the controller 900 may acquire information from the sensor during substrate polishing and control the pressure adjusting unit 30 based on the acquired information. The sensor for measuring the film thickness of the substrate WF may be an eddy current sensor, an optical sensor, or a microwave sensor. Furthermore, the controller 900 may modify the subsequent control of the pressure adjusting unit 30 based on the polishing profile of the polished substrate WF.

[0043] Furthermore, in this embodiment, the top ring 302 can press the substrate WF against the polishing pad 352 by using the biasing mechanism 400 to bias the frame member 344 of the substrate attracting member 330, in addition to the pressing of the substrate attracting body 334 by the elastic membrane 320. This allows the polishing amount at the outer edge of the substrate WF, where the polishing amount is more likely to vary compared to the center of the substrate WF, to be adjusted, thereby achieving a uniform polishing profile between the center and outer edge of a rectangular substrate. Specifically, the controller 900 may control the biasing force of the biasing mechanism 400 based on a predetermined recipe so that the film thickness distribution of the substrate WF becomes a target distribution. Alternatively, the substrate polishing apparatus 1000 may be provided with a sensor for measuring the film thickness of the substrate WF, and the controller 900 may acquire information from the sensor during substrate polishing and control the biasing mechanism 400 based on the acquired information. Furthermore, the controller 900 may modify subsequent control of the biasing mechanism 400 based on the polishing profile of the substrate WF after polishing.

[0044] <Modification 1> FIG. 8 is a cross-sectional view schematically illustrating a top ring according to a modification. The top ring 302A according to the modification is generally identical to the top ring 302 described above, except that it includes a biasing mechanism 400A different from the biasing mechanism 400, and therefore a redundant description will be omitted. The biasing mechanism 400A according to the modification is formed by an elastic body 410A. Various known elastic bodies, such as a coil spring, can be used as the elastic body 410A. The top ring 302A according to the modification has a lower flange 404A attached to the lower surface of the flange 303 of the base member 301. Collars 406A and 408A are fixed to the lower flange 404A of the base member 301 and the frame member 344. One end (first end) of the elastic body 410A is attached to the collar 406A, and the other end (second end) of the elastic body 410A is attached to the collar 408A. In the top ring 302A of this modified example, a compressively deformed elastic body 410A is inserted between the lower flange 404A (collar 406A) and the upper frame member 342 (collar 408A), thereby biasing the base member 301 and the frame member 344. The biasing force of the biasing mechanism 400A using the elastic body 410A is determined by the relative distance between the lower flange 404A (collar 406A) of the base member 301 and the upper frame member 342 (collar 408A). The biasing force that biases the frame member 344 toward the polishing table 350 can be adjusted by selecting the elastic body 410A or adjusting the amount of compressive deformation of the elastic body 410A through prior experiments or simulations. Thus, like the top ring 302 of the embodiment, the top ring 302A of the modified example can adjust the amount of polishing of the outer edge of the substrate WF by adjusting the pressing force of the outer edge of the substrate WF against the polishing table 350, thereby achieving a uniform polishing profile between the center and outer edges of a rectangular substrate. For example, the biasing mechanism 400A may be configured to change the elastic body 410A to an elastic body having a desired elastic modulus. The biasing mechanism 400A may also be configured to adjust the height positions of the collars 406A and 408A using spacers or the like. In the example shown in FIG. 8 , the elastic body 410A is attached to the lower flange 404A of the base member 301 and the upper frame member 342 of the frame member 344, but the present invention is not limited to this example.As an example, the elastic body 410A may be attached to the flange 303 of the base member 301 or to the stopper 346 of the frame member 344.

[0045] <Modification 2> In the above-described modification 1, the biasing mechanism 400A biases the frame member 344 and the base member 301 in a direction that moves the frame member 344 away from the base member 301, that is, in a direction that presses the substrate WF. However, in cases where the amount of polishing of the outer edge of the substrate WF is greater than the amount of polishing of the central portion, the biasing mechanism 400A may be configured to apply a biasing force in a direction that moves the frame member 344 closer to the base member 301.

[0046] <Modification 3> Figure 9 is a diagram showing an example of a contact portion of the piston 410 or elastic body 410A on the frame member 344. In the above-described embodiment and modification, the pistons 410 or elastic bodies 410A of the multiple biasing mechanisms 400, 400A are arranged to contact the vicinity of the corners of the rectangular substrate WF, i.e., the corner regions AC including the corners of the frame member 344. However, without being limited to this example, the biasing mechanisms 400, 400A may be arranged in the side regions AS of the frame member 344 (e.g., regions including the center of the side but excluding the corners) instead of or in addition to the corner regions AC of the frame member 344. In this example, as with the top ring 302 of the embodiment, the polishing amount of the outer edge of the substrate WF can be adjusted, and the polishing profile can be made uniform between the center and outer edge of the rectangular substrate.

[0047] The present invention can also be described as the following aspects. [Aspect 1] According to aspect 1, a top ring for holding a polygonal substrate is proposed, the top ring comprising: a base member connected to a rotating shaft; a substrate attracting member including a substrate attracting surface for attracting a substrate and communicating with a decompression module; a shielding member configured to shield the surface of the substrate attracting member opposite the substrate attracting surface; and a frame member connected to the shielding member so as to surround at least a portion of the base member; and a biasing mechanism having a first end contacting the base member and a second end contacting the frame member, the biasing mechanism applying a biasing force in a direction to move the base member and the frame member closer to or farther from each other. According to aspect 1, a polishing profile can be made more uniform between the center of a polygonal substrate and the outer edge of the substrate.

[0048] According to the second aspect, the biasing mechanism includes a pneumatic actuator having the first end and the second end in the first aspect. The pneumatic actuator can be used to make the polishing profile more uniform between the center of the substrate and the outer edge of the substrate.

[0049] [Form 3] According to Form 3, in Form 2, the pneumatic actuator has a cylinder attached to the base member and capable of receiving a working fluid therein, a diaphragm disposed within the cylinder, and a piston in contact with the frame member and displaceable in accordance with movement of the diaphragm.

[0050] [Mode 4] According to Mode 4, the pneumatic actuator of Mode 2 or 3 further includes an elastic membrane configured to form a pressurizing chamber between the base member and the shielding member, and a fluid supply source that supplies working fluid to the pressurizing chamber, and the pneumatic actuator is operated by the working fluid from the fluid supply source. According to Mode 4, a biasing mechanism can be configured using the fluid supply source that supplies working fluid to the pressurizing chamber, thereby reducing the number of parts.

[0051] [Mode 5] According to Mode 5, in Mode 1, the biasing mechanism is an elastic body having the first end and the second end. According to Mode 2, by using the elastic body, the polishing profile can be made more uniform between the center side of the substrate and the outer edge side of the substrate.

[0052] According to the sixth aspect, in any one of the first to fifth aspects, the frame member includes a stopper that connects different portions of the frame member in an arch shape across the interior of the frame, the base member has a contact portion that contacts the stopper to limit the movement of the substrate suction member in the height direction relative to the base member, and the second end of the biasing mechanism contacts the stopper. According to the sixth aspect, the biasing mechanism can be configured using a stopper that limits the movement of the substrate suction member in the height direction.

[0053] [Mode 7] According to Mode 7, in Modes 1 to 6, the second end of the biasing mechanism contacts a corner region of the frame member when viewed from a direction perpendicular to the substrate suction surface.

[0054] [Eighth Mode] According to an eighth mode, in any one of the first to seventh modes, the second end of the biasing mechanism contacts a side region of the frame member when viewed from a direction perpendicular to the substrate suction surface.

[0055] [Mode 9] According to Mode 9, the apparatus of Modes 1 to 8 further includes an elastic membrane configured to form a pressure chamber between the base member and the shielding member. According to Mode 9, the pressure chamber can be pressurized to pressurize the substrate held by the top ring.

[0056] According to the tenth aspect of the present invention, in the ninth aspect, the elastic membrane is configured to form a plurality of concentric pressure chambers between the base member and the shielding member. According to the tenth aspect, the plurality of concentric pressure chambers can be pressurized to pressurize the substrate held by the top ring.

[0057] [Mode 11] According to Mode 11, in any of Modes 1 to 10, the first end and the second end are spaced apart from the substrate attracting body when viewed in a direction perpendicular to the substrate attracting surface.

[0058] [Mode 12] According to Mode 12, in any one of Modes 1 to 11, the substrate adsorbent is made of a porous material.

[0059] [Mode 13] According to Mode 13, in any of Modes 1 to 12, a band is provided connecting the outer side surface of the portion of the base member that is not surrounded by the frame member to the outer side surface of the frame member.

[0060] [Mode 14] According to Mode 14, there is provided a substrate polishing apparatus including the top ring according to any one of Modes 1 to 13 and a table configured to hold a polishing pad. Mode 14 can achieve the same effects as the above modes.

[0061] [Mode 15] According to Mode 15, there is provided a substrate polishing apparatus including the top ring according to Mode 9 or 10, a table configured to hold a polishing pad, and a controller that controls the supply of working fluid to the pressurizing chamber and the biasing force of the biasing mechanism so that the film thickness distribution of the substrate becomes a target film thickness distribution. According to Mode 15, by controlling the supply of working fluid to the pressurizing chamber and the biasing force by the biasing force with the controller, it is possible to make the polishing profile more uniform between the center side and the outer edge side of a rectangular substrate.

[0062] Although the embodiments of the present invention have been described above, the above-described embodiments are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The present invention may be modified or improved without departing from the spirit thereof, and the present invention naturally includes equivalents thereof. Furthermore, any combination of the embodiments and modifications is possible within the scope of solving at least part of the above-described problems or achieving at least part of the effects, and any combination or omission of the components described in the claims and specification is possible.

[0063] This application claims priority to Japanese Patent Application No. 2023-202452, filed November 30, 2023. The entire disclosure of Japanese Patent Application No. 2023-202452, including the specification, claims, drawings, and abstract, is incorporated herein by reference in its entirety. The entire disclosure of Japanese Patent Application No. 2023-57047 (Patent Document 1), including the specification, claims, drawings, and abstract, is incorporated herein by reference in its entirety.

[0064] 18...Top ring shaft (rotating shaft) 30...Pressure adjustment section 31...Decompression module 300...Polishing unit 301...Base member 302...Top ring 309...Pad 320...Elastic membrane 330...Substrate suction member 332...Shielding member 334...Substrate suction body 334a...Substrate suction surface 336...Elastic seal member 340...Elastic member 342...Upper frame member 343...Lower frame member 344...Frame member 345...Band 346...Stopper 350...Polishing table 352...Polishing pad 400, 400A...Biasing mechanism 401...Cylinder 402...Upper cylinder housing 404...Lower cylinder housing 406A, 408A...Collar 408...Diaphragm 410...Piston 410A...Elastic body 900...Controller 900a...Storage device 1000...Substrate polishing apparatus WF...Substrate

Claims

1. A top ring for holding polygonal substrates comprising: a base member connected to a rotating shaft; a substrate adsorption member including a substrate adsorption body having a substrate adsorption surface for adsorbing a substrate and communicating with a pressure reduction module, a shielding member configured to shield the surface of the substrate adsorption body opposite the substrate adsorption surface, and a frame member connected to the shielding member so as to surround at least a portion of the base member; and a biasing mechanism having a first end in contact with the base member and a second end in contact with the frame member, which applies a biasing force in a direction to bring the base member and the frame member closer together or apart.

2. The top ring of claim 1, wherein said biasing mechanism includes a pneumatic actuator having said first end and said second end.

3. The top ring according to claim 2, wherein the pneumatic actuator comprises: a cylinder attached to the base member and capable of receiving a working fluid therein; a diaphragm disposed within the cylinder; and a piston in contact with the frame member and capable of being displaced in response to movement of the diaphragm.

4. A top ring as described in claim 2, further comprising: an elastic membrane configured to form a pressurized chamber between the base member and the shielding member; and a fluid supply source that supplies a working fluid to the pressurized chamber, wherein the pneumatic actuator is operated by the working fluid from the fluid supply source.

5. The top ring according to claim 1, wherein said biasing mechanism is an elastic body having said first end and said second end.

6. A top ring as described in claim 1, wherein the frame member includes a stopper that connects different parts of the frame member in an arch shape spanning the inside of the frame, the base member has a contact portion that contacts the stopper to limit vertical movement of the substrate suction member relative to the base member, and the second end of the biasing mechanism contacts the stopper.

7. The top ring according to claim 1, wherein the second end of the biasing mechanism contacts a corner region of the frame member when viewed from a direction perpendicular to the substrate attracting surface.

8. The top ring according to claim 1, wherein the second end of the biasing mechanism contacts a side region of the frame member when viewed in a direction perpendicular to the substrate attracting surface.

9. The top ring of claim 1, further comprising an elastic membrane configured to define a pressurized chamber between said base member and said shield member.

10. The top ring of claim 9, wherein the elastic membrane is configured to define a plurality of concentric pressurized chambers between the base member and the shield member.

11. The top ring according to claim 1, wherein the first end and the second end are spaced apart from the substrate attracting body when viewed in a direction perpendicular to the substrate attracting surface.

12. The top ring according to claim 1, wherein the substrate attracting member is made of a porous material.

13. The top ring of claim 1, further comprising a band connecting an outer side surface of the portion of the base member not surrounded by the frame member to an outer side surface of the frame member.

14. A substrate polishing apparatus comprising: a top ring according to any one of claims 1 to 13; and a table configured to hold a polishing pad.

15. A substrate polishing apparatus comprising: a top ring as defined in claim 9 or 10; a table configured to hold a polishing pad; and a controller that controls the supply of working fluid to the pressure chamber and the biasing force applied by the biasing mechanism so that the film thickness distribution on the substrate becomes a target film thickness distribution.

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