Top ring

Abstract

The purpose is to improve the adhesion of the substrate using the top ring. [Solution] A top ring for holding a substrate, comprising: a base member connected to a rotating shaft; and an elastic membrane attached to the base member, the elastic membrane having a substrate adsorption surface for adsorbing a substrate and one or more suction ports for drawing air from between the substrate and the substrate adsorption surface, wherein the elastic membrane comprises rubber and a sheet-like member encased in the rubber and having a higher rigidity than the rubber, and an air passage to the suction port is formed on the substrate adsorption surface of the elastic membrane by irregularities, and the air passage terminates spaced apart from the outer edge of the area on the substrate adsorption surface where the substrate is placed.

Description

[[Technical Field]]

[0001] The present application relates to a top ring. [[Background Art]]

[0002] CMP polishing is performed on panels such as CCL (Copper Clad Laminate) substrates, PCB (Printed Circuit Board) substrates, photomask substrates, and display panels. In panel CMP polishing, when polishing thin or brittle panels, the panel may shift during polishing and collide with the retainer of the top ring, causing the panel to bend or crack. To solve such problems, a top ring combining a porous vacuum chuck and a pressurization mechanism using an air bag has been proposed to prevent damage (see, for example, Japanese Patent Application Laid-Open No. 2024-57926 (Patent Document 1)).

[0003] In addition, Japanese Patent Application Laid-Open No. 2009-539626 (Patent Document 2) and Japanese Patent Application Laid-Open No. 2004-119809 (Patent Document 3) describe a top ring in which an elastic film serving as a substrate installation surface is disposed on a base member provided with a plurality of recesses, and the inside of the elastic film is set to negative pressure through a through hole in the base member to deform the elastic film so as to conform to the recesses, thereby causing the recesses to function as suction cups to adsorb the substrate onto the elastic film. Further, in the top ring of Patent Document 3, after cleaning the substrate installation surface formed of the elastic film, the substrate is suction-held on the substrate installation surface, and the cleaning liquid remaining between the elastic film and the substrate when the top ring rotates is discharged through grooves provided in the elastic film, thereby preventing the substrate from idling. Japanese Patent Application Laid-Open No. 2021-122896 (Patent Document 4) describes a top ring in which an elastic film forming a single sealed space with the top ring main body is composed of three layers, and an intermediate layer formed of a material having higher rigidity than the inner layer and the outer layer is provided in the elastic film, thereby achieving uniform pressing force of the substrate against the polishing pad via the elastic film. [[Prior Art Literature]] [[Patent Documents]]

[0004] [Patent Document 1] Japanese Patent Publication No. 2024-57926 [Patent Document 2] Japanese Patent Publication No. 2009-539626 [Patent Document 3] Japanese Patent Publication No. 2004-119809 [Patent Document 4] Japanese Patent Publication No. 2021-122896 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] In the top ring described in Patent Document 1, if there is a notch on the outer periphery of the panel and / or an area on the back surface of the panel that is not coated, vacuum leakage may occur between the panel and the vacuum chuck, preventing suction. Of course, small panels cannot be suctioned as is. Furthermore, in current top rings, soft materials such as lip seals are placed on the outer periphery of the vacuum chuck to prevent vacuum leakage, so the surface pressure on the outer periphery of the panel differs significantly from that on the center, which may worsen the polishing profile. In addition, because the material of the vacuum chuck plate has poor flexibility, the unevenness of the vacuum chuck may be transferred during polishing, which may worsen the polishing profile. The top rings described in Patent Documents 2 to 4 also have one or more of the above problems.

[0006] The object of the present invention is to solve at least some of the above-mentioned problems. For example, one object of the present invention is to improve the adsorption of the substrate by the top ring. Another object of the present invention is to improve the polishing profile in CMP. Another object of the present invention is to improve the polishing profile by the difference in surface pressure between the outer periphery and the center of the substrate during polishing. One of the objectives of the present invention is to suppress the deterioration of the polishing profile during polishing, which is caused by the transfer of irregularities of the vacuum chuck to the panel. [Means for solving the problem]

[0007] According to one embodiment, a top ring for holding a substrate is disclosed, comprising: a base member connected to a rotating shaft; and an elastic membrane attached to the base member, the elastic membrane having a substrate adsorption surface for adsorbing the substrate and one or more suction ports for drawing air from between the substrate and the substrate adsorption surface, wherein the elastic membrane comprises rubber and a sheet-like member encased in the rubber and having a higher rigidity than the rubber, and an air passage to the suction port is formed on the substrate adsorption surface of the elastic membrane by irregularities, and the air passage terminates spaced apart from the outer edge of the region on the substrate adsorption surface where the substrate is placed. [Brief explanation of the drawing]

[0008] [Figure 1] This is a plan view showing the overall configuration of a substrate processing apparatus according to one embodiment. [Figure 2] This is a perspective view illustrating the configuration of a polishing unit according to one embodiment. [Figure 3] This is a schematic cross-sectional view showing the configuration of the top ring according to one embodiment. [Figure 4] This is a schematic cross-sectional view showing the structure of an elastic membrane according to one embodiment. [Figure 5] This is a bottom view schematicly showing the structure of an elastic membrane according to one embodiment. [Figure 6] This is a bottom view diagram illustrating the structure of the elastic film along with the substrate adsorption region. [Modes for carrying out the invention]

[0009] Embodiments of the top ring and substrate processing apparatus according to the present invention will be described below with reference to the accompanying drawings. In the accompanying drawings, identical or similar elements are denoted by identical or similar reference numerals, and redundant descriptions of identical or similar elements may be omitted in the description of each embodiment. Furthermore, the features shown in each embodiment are applicable to other embodiments insofar as they do not contradict each other.

[0010] Figure 1 is a plan view showing the overall configuration of a substrate processing apparatus 1000 according to one embodiment. Here, a polishing apparatus, more specifically a CMP apparatus, will be used as an example to describe the substrate processing apparatus 1000.

[0011] The substrate processing 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. In one embodiment, each of these units can be formed independently. By forming these units independently, substrate processing apparatus 1000s with different configurations can be easily formed by arbitrarily combining the number of each unit. The substrate processing apparatus 1000 also includes a control device 900, and each component of the substrate processing apparatus 1000 is controlled by the control device 900. In one embodiment, the control device 900 can be composed of a general computer including an input / output device, an arithmetic unit 900a, a storage device 900b, etc. The arithmetic unit 900a may include a CPU, MPU, etc. The storage device 900b may include any non-volatile memory and / or volatile memory.

[0012] <Road Unit> The load unit 100 is a unit for introducing substrate WF into the substrate processing apparatus 1000 before processing such as polishing and cleaning. In one embodiment, the load unit 100 is a machine of SMEMA (Surface Mount Equipment Manufacturers Association) The device is configured to conform to the IPC-SMEMA-9851 mechanical interface standard. The substrate WF may be a Copper Clad Laminate (CCL) substrate, a Printed Circuit Board (PCB) substrate, a photomask substrate, a display panel, or any other rectangular substrate. Some substrates have multiple wiring units formed on them, each of which has a wiring pattern. IC chip dies or the like may be mounted on each of the multiple wiring units of the polished substrate. Rectangular substrates are often larger than circular substrates such as wafers. The disclosures herein are particularly effective for polishing such large substrates.

[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, they should be positioned 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 being 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 it. In one embodiment, the load unit 100 may be provided with an ionizer (not shown) to prevent the substrate WF from becoming charged.

[0014] <Conveyor Unit> The substrate processing apparatus 1000 shown in FIG. 1 includes two transfer units 200A and 200B. Since the two transfer units 200A and 200B may have the same configuration, they will be collectively described as the transfer unit 200 below.

[0015] The illustrated transfer unit 200 includes a plurality of transfer rollers 202 for transferring a substrate WF. By rotating the transfer rollers 202, the substrate WF on the transfer rollers 202 can be transferred in a predetermined direction. The transfer rollers 202 of the transfer unit 200 may be formed of a conductive polymer or a non-conductive polymer. The transfer rollers 202 are driven by a motor (not shown). The substrate WF is transferred to a substrate transfer position by the transfer rollers 202.

[0016] In one embodiment, the transfer 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 cleaning liquid to the substrate WF transferred by the transfer rollers 202.

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

[0018] As shown in FIG. 2, the polishing unit 300 includes a polishing table 350, and a top ring 302 constituting a top ring that holds a substrate WF as an object to be polished and presses the substrate WF 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) disposed below the polishing table 350, and is rotatable around the table shaft 351. On the upper surface of the polishing table 350, a polis A polishing pad 352 is attached, and the surface 352a of the polishing pad 352 constitutes the polishing surface for polishing the substrate. In one embodiment, the polishing pad 352 may be attached via a layer to facilitate removal from the polishing table 350. Such a layer may be, for example, a silicone layer or a fluororesin layer.

[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 there may be one or more openings 355 of the polishing table 350 and through holes 357 of the polishing pad 352. The positions of the opening 355 of the polishing table 350 and the through hole 357 of the polishing pad 352 are arbitrary, but in one embodiment they are located near the center of the polishing table 350.

[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 (more specifically, the base member 400 described later) 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 for positioning. 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 designed to hold a rectangular substrate WF (as described above) on its underside. The oscillating arm 360 is configured to pivot around a pivot shaft 362. By pivoting 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 WF 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 located above the polishing table 350 and / or from an opening 355 located in the polishing table 350. In this way, the substrate WF can be pressed against the polishing surface 352a of the polishing pad 352 and its surface can be polished. During polishing of the substrate WF, the oscillating arm 360 may be fixed or oscillated 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 for moving the top ring shaft 18 and 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 mounted on the support base 29. The support base 29 that supports 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, which in turn 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. In this polishing apparatus, the amount of wear of the polishing pad 352 is measured using this dresser 50. That is, the dressing unit 356 is equipped with a displacement sensor 60 that measures the displacement of the dresser 50. This displacement sensor 60 constitutes a wear amount detection means for detecting the amount of wear of the polishing pad 352 and is provided on the upper surface of the oscillating arm 55. A target plate 61 is fixed to the dresser shaft 51 and moves up and down in accordance with the up and down movement of the dresser 50. The displacement sensor 60 is positioned to pass through the target plate 61, and the displacement of the dresser 50 is measured by measuring the displacement of the target plate 61. Any type of sensor can be used as the displacement sensor 60, such as a linear scale, laser sensor, ultrasonic sensor, or eddy current sensor. The displacement sensor 60 and the target plate 61 may be omitted.

[0027] Dressing the polishing surface 352a of the polishing pad 352 is performed as follows. The dresser 50 is pressed against the polishing surface 352a by the 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). Alternatively, instead of or in addition to the pure water from the pure water supply nozzle (not shown), the passage 353 and / or polishing fluid supply nozzle 354 for supplying polishing fluid may be switched to supply pure water and pure water may be supplied to the polishing surface 352a. In this state, the dresser 50 is rotated around the dresser shaft 51 and the oscillating arm 55 is oscillated 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] The polishing unit 300 may include a film thickness sensor 42 for measuring the film thickness of the substrate WF on the polishing surface 352a. The film thickness sensor 42 is configured to generate a film thickness index value that directly or indirectly indicates the film thickness of the substrate WF. This film thickness index value changes according to the film thickness of the substrate WF. The film thickness index value may be a value that represents the film thickness of the substrate WF itself, or it may be a physical quantity or signal value before it is converted to film thickness.

[0029] Examples of the film thickness sensor 42 include eddy current sensors and optical film thickness sensors. The film thickness sensor 42 is installed in the polishing table 350 and rotates integrally with the polishing table 350. More specifically, the film thickness sensor 42 is configured to measure the film thickness at multiple measurement points on the substrate WF on the polishing surface 352a as the polishing table 350 completes one rotation. The film thickness at the multiple measurement points is output from the film thickness sensor 42 as a film thickness index value, and this film thickness index value is sent to the control device 900. The control device 900 may be configured to control the operation of the top ring 302 based on the film thickness index value.

[0030] The control device 900 creates a film thickness profile of the substrate WF from the film thickness index values ​​output from the film thickness sensor 42. The film thickness profile of the substrate WF is a distribution of the film thickness index values. The control device 900 controls the operation of the top ring 302 to eliminate the difference between the obtained current film thickness profile of the substrate WF and the target film thickness profile. The target film thickness profile of the substrate WF is pre-stored in the storage device 900b of the control device 900. Examples of the current film thickness profile of the substrate WF include the initial film thickness profile of the substrate WF before polishing by the substrate processing device 1000 (polishing unit 300) shown in Figure 1, and the film thickness profile created from the film thickness index values ​​output from the film thickness sensor 42 while the substrate WF is being polished by the substrate processing device 1000 shown in Figure 1. The initial film thickness profile is created, for example, from film thickness measurements obtained by a standalone film thickness measuring device (not shown), or from film thickness measurements obtained by another substrate processing device 1000 equipped with a film thickness sensor. The initial film thickness profile is stored in the storage device 900b of the control device 900.

[0031] <Drying Unit> The drying unit 500 is a device for drying the substrate WF. In the substrate processing apparatus 1000 shown in Figure 1, the drying unit 500 dries the substrate WF that has been polished in the polishing unit 300 and then washed 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 nozzles 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.

[0032] <Unloading Unit> The unloading unit 600 is a unit for transporting the substrate WF out of the substrate processing apparatus 1000 after processing such as polishing and cleaning. In the substrate processing 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 located downstream of the SMEMA (Surface Mount Equipment Manufacturers Association) machinery interface It is configured to comply with the IPC-SMEMA-9851 standard.

[0033] The configuration of the substrate processing apparatus 1000 (polishing apparatus) described above is just one example, and other configurations can also be adopted.

[0034] <Top Ring> Next, the top ring 302 constituting the polishing head in the polishing unit 300 according to one embodiment will be described. Figure 3 is a schematic cross-sectional view showing the configuration of the top ring 302 according to one embodiment. Figure 4 is an enlarged cross-sectional view of region IV in Figure 3, and schematicly shows the configuration of the membrane (elastic film) 410 according to one embodiment. Figure 5 is a schematic bottom view showing the configuration of the membrane (elastic film) 410 according to one embodiment. Figure 6 is a schematic bottom view showing the configuration of the elastic film together with the substrate adsorption region.

[0035] The top ring 302 comprises a base member 400, an elastic membrane 410, and an airbag 420. The base member 400 is a bottomed cylindrical or box-shaped structure with an opening at the bottom. The top ring shaft 18 is connected to the upper surface of the base member 400. As shown in Figure 3, the elastic membrane 410 is attached to the lower part of the base member 400, i.e., to close the opening of the base member 400. Inside the base member 400 (referred to as the internal space 400A), the airbag 420 is provided on the back side (upper surface 414 side) of the elastic membrane 410. The airbag 420 is inflated by the supply of air and presses the substrate WF against the polishing surface 352a (Figure 2) during substrate polishing. The airbag 420 may be formed integrally with the elastic membrane 410 or may be formed separately from the elastic membrane 410. Furthermore, the airbag 420, which is formed separately from the elastic membrane 410, may or may not be joined to the elastic membrane 410.

[0036] The elastic membrane 410 is a component that forms a vacuum adsorption mechanism for vacuum adsorption of the substrate WF. The elastic membrane 410 satisfies the conditions of being able to withstand lateral forces (shear forces) during polishing, being flexible, and transmitting the force of the airbag 420. As shown in Figure 3, a suction port 418 is provided in the center of the elastic membrane 410, penetrating from the bottom surface 413 to the top surface 414. The suction port 418 is connected to a pressure reduction source 432 such as a vacuum pump via a fluid line 431. When the elastic membrane 410 and the substrate WF are in contact, the pressure between the elastic membrane 410 and the substrate WF is reduced (vacuumed), causing the substrate WF to be vacuum-adsorbed to the elastic membrane 410. Note that in Figure 3, for the sake of explaining that air is drawn in from between the elastic membrane 410 and the substrate WF, a gap is shown between the elastic membrane 410 and the substrate WF. However, in reality, with the substrate WF in contact with the elastic membrane 410, a vacuum is drawn from the suction port 418 between the elastic membrane 410 and the substrate WF, causing the substrate WF to be vacuum-adsorbed to the elastic membrane 410.

[0037] The elastic membrane 410 has a rectangular shape in plan view, for example, as shown in Figure 5. The elastic membrane 410 has a bottom surface 413 and a top surface 414, as shown in Figures 3 and 4, and a groove 415 is formed in the bottom surface 413. The bottom surface 413 of the elastic membrane 410 constitutes the substrate adsorption surface. The elastic membrane 410 is constructed by wrapping a sheet-like member 412, which has higher rigidity / strength than the rubber 411, with rubber 411. In other words, the elastic membrane 410 has rubber 411 and a sheet-like member that is wrapped by rubber 411 and has higher rigidity / strength than rubber 411. The sheet-like member 412 can be, for example, a cloth member with high rigidity / strength. As a cloth member with high rigidity / strength, for example, a woven fabric made of aramid fibers can be used. As an aramid fiber, for example, Kevlar® can be used. The sheet-like member 412 can be made of fabric, SUS plate, resin plate, or other sheet-like member having the desired rigidity / strength. A member with high rigidity / strength can also be described as a member with low elasticity / high hardness.

[0038] As shown in Figure 5, the groove 415 formed in the bottom surface 413 of the elastic membrane 410 has a plurality of annular grooves 415A arranged concentrically from the center of the bottom surface 413, and a radial groove 415B extending radially (for example, diagonally) from the center of the bottom surface 413. The plurality of annular grooves 415A are fluidically connected to each other and to the suction port 418 by the radial groove 415B. As shown in Figure 5, the suction port 418 of the elastic membrane 410 is formed in the radial groove 415B (the bottom surface of the radial groove 415B) at the center of the bottom surface 413 of the elastic membrane 410.

[0039] In one example, the region where the grooves 415 (annular groove 415A and radial groove 415B) connected to the suction port 418 are located is smaller than the region where the substrate WF is adsorbed (substrate adsorption region) Swf (Figure 6). The grooves 415 (annular groove 415A and radial groove 415B) connected to the suction port 418 are not connected to the outer edge of the substrate adsorption region Swf at the bottom surface 413 of the elastic film 410. (The grooves are not formed up to the outer edge of the substrate adsorption region Swf). That is, grooves 415 (annular groove 415A and radial groove 415B) that connect to the suction port 418 are not formed on the outer edge and outside of the substrate adsorption region Swf on the bottom surface 413 of the elastic film 410. This makes it possible to suppress or prevent vacuum leakage from between the substrate WF and the elastic film 410. The substrate adsorption region Swf can be a region whose outer edge is, for example, outside the outermost edge of the grooves 415 (annular groove 415A and radial groove 415B) that connect to the suction port 418 in Figure 5, and inside (or on) the outer edge 413A of the bottom surface 413.

[0040] In the example shown in Figure 5, a further second annular groove 416 is provided outside the outermost annular groove 415A of the multiple annular grooves 415A, and is not connected to the groove 415 (annular groove 415A and radial groove 417) that is connected to the suction port 418. This second annular groove 416 is located on the outer periphery of the substrate adsorption region Swf (the outer edge of the substrate adsorption region Swf in the example shown in Figure 6) on the bottom surface 413 of the elastic film 410. The second annular groove 416 functions as a stiffness adjustment groove and is provided to make the stiffness / strength of the entire bottom surface 413 of the elastic film 410 uniform, including the region where the groove 415 (annular groove 415A and radial groove 417) connected to the suction port 418 is formed and the region outside of it, so that the elastic film 410 presses the substrate WF against the polishing surface 352a with uniform force. The second annular groove 416 may be omitted.

[0041] In this configuration, with the elastic membrane 410 and the substrate WF in contact, the air in the groove 415 of the elastic membrane 410 is sucked out from the suction port 418, thereby reducing the pressure (creating a vacuum) between the elastic membrane 410 and the substrate WF, and causing the substrate WF to be vacuum-adsorbed to the elastic membrane 410. The groove 415 is not open to the outer edge of the substrate adsorption region Swf of the elastic membrane 410, and the space within the groove 415 is sealed while the elastic membrane 410 and the substrate WF are in contact.

[0042] The airbag 420 is provided within the internal space 400A of the base member 400 so as to be in contact with the upper surface 414 of the elastic membrane 410. The airbag 420 is connected to a gas supply source 434 via a fluid line 433. The airbag 420 is inflated by the gas supplied from the gas supply source 434 via the fluid line 433, causing the elastic membrane 410 to press against the substrate WF on the polishing surface 352a. The airbag 420 may be composed of a plurality of concentrically arranged pressurized chambers, with a fluid line 433 connected to each pressurized chamber, so that gas is supplied to each pressurized chamber individually and independently.

[0043] According to the above embodiment, the elastic membrane 410 has a structure in which a sheet-like member 412 is covered with rubber 411, so that the elastic membrane 410 is flexible while being able to withstand the shear force from the substrate during polishing. In addition, the presence of a sheet-like member 412 with high rigidity / strength allows the pressing force of the substrate WF against the polishing surface 352a to be made uniform.

[0044] According to the above embodiment, grooves are made in the contact portion of the elastic film 410 with the substrate WF, and when the elastic film 410 and the substrate WF are in contact, the air in the grooves 415 of the elastic film 410 is sucked out from the suction port 418, thereby efficiently creating a vacuum between the elastic film 410 and the substrate WF while suppressing or preventing vacuum leakage, and enabling the substrate WF to be vacuum-adsorbed to the elastic film 410.

[0045] According to the above embodiment, the groove 415 for vacuum adsorption is not carved into the bottom surface (substrate adsorption surface) 413 of the elastic film 410 up to the outermost edge (peripheral edge) of the substrate adsorption region Swf. Therefore, vacuum leakage (vacuum leakage between the substrate WF and the elastic film 410) due to notches on the outer periphery of the substrate WF, irregularities in the plating film, etc., can be suppressed or prevented.

[0046] According to the above embodiment, the polishing profile of the substrate WF can be improved because there are no foreign materials or shapes such as lip seals on the outer periphery of the substrate adsorption surface, and the elastic film 410 has high flexibility. That is, there are no foreign materials such as lip seals on the outer periphery of the substrate adsorption surface of the elastic film 410, Because there are no irregularly shaped components, the difference in surface pressure between the outer periphery and the center of the substrate WF can be suppressed, improving the polishing profile. In addition, since the elastic film 410 is more flexible than porous vacuum check, the transfer of irregularities of the elastic film 410 to the panel during polishing can be suppressed or prevented, improving the polishing profile.

[0047] (Other embodiments) (1) Although a rectangular substrate was used as an example above, the above embodiment may also be applied to a top ring (polishing head) used for polishing a circular wafer. (2) In the above, an air passage was provided on the substrate adsorption surface by grooves (recesses), but an air passage may also be provided by protrusions (between the protrusions). (3) In the above description, one suction port 418 is provided at the center of the substrate adsorption region Swf, but multiple suction ports 418 may be provided at various locations on the substrate adsorption region Swf. When multiple suction ports 418 are provided at various locations on the substrate adsorption region Swf, it is preferable to include the suction port 418 provided at the center of the substrate adsorption region Swf. When multiple suction ports 418 are provided at various locations on the substrate adsorption region Swf (whether or not there is a suction port 418 at the center of the substrate adsorption region Swf), it is preferable that the arrangement of the multiple suction ports 418 is symmetrical with respect to the shape of the substrate Wf.

[0048] [1] According to one embodiment, a top ring for holding a substrate is provided, comprising: a base member connected to a rotating shaft; and an elastic membrane attached to the base member, the elastic membrane having a substrate adsorption surface for adsorbing a substrate and one or more suction ports for drawing air from between the substrate and the substrate adsorption surface, wherein the elastic membrane comprises rubber and a sheet-like member wrapped by the rubber and having a higher rigidity than the rubber, and an air passage to the suction port is formed on the substrate adsorption surface of the elastic membrane by irregularities, and the air passage terminates spaced apart from the outer edge of the region on the substrate adsorption surface where the substrate is placed.

[0049] In this configuration, the elastic membrane is made of a sheet-like material with high rigidity / strength covered with rubber, allowing the elastic membrane to be flexible while withstanding the shear force received from the substrate during polishing. Furthermore, the presence of the sheet-like material with high rigidity / strength allows for uniform pressure on the substrate against the polishing pad. Furthermore, by drawing air through the suction port via air passages created by irregularities on the substrate adsorption surface of the elastic film, the substrate can be vacuum-adsorbed to the elastic film. Furthermore, since the air passage terminates at a distance from the outer edge of the substrate adsorption area (substrate adsorption area) and does not extend to the outer edge of the substrate, vacuum leakage due to notches or unevenness in the plating on the outer edge of the substrate can be suppressed or prevented, thereby improving the substrate adsorption performance of the top ring. With this configuration, substrates significantly smaller than the area of ​​the substrate adsorption surface can also be adsorbed. Furthermore, the absence of dissimilar materials or irregularly shaped components such as lip seals on the outer periphery of the substrate adsorption surface of the elastic film, and the high flexibility of the elastic film, can improve the polishing profile.

[0050] [2] In one embodiment, the one or more suction ports include a suction port provided at the center of the substrate adsorption surface.

[0051] In this configuration, the uneven surface of the substrate adsorption surface creates air passages, resulting in high adhesion between the elastic film and the substrate, and the suction port located in the center of the substrate adsorption surface allows the substrate to be efficiently adsorbed onto the elastic film.

[0052] [3] In one embodiment, grooves are formed by the irregularities, and the grooves include a plurality of annular grooves arranged concentrically with respect to the suction port of the elastic membrane, and one or more radial grooves extending radially from the suction port and connecting the plurality of annular grooves to each other and to the suction port, It holds.

[0053] In this configuration, air passages for vacuuming can be evenly distributed across almost the entire surface of the substrate, and the entire surface of the substrate can be vacuum-suctioned with uniform force.

[0054] [4] In one embodiment, the substrate is rectangular, and the plurality of annular grooves are rectangular in plan view.

[0055] This configuration provides a top ring suitable for vacuum adsorption of rectangular substrates.

[0056] [5] In one embodiment, the radial grooves are provided along the diagonals of the rectangular substrate adsorption surface.

[0057] This configuration allows for a uniform arrangement of radial grooves while keeping the number of grooves to a minimum.

[0058] [6] In one embodiment, the groove further has a second annular groove outside the plurality of annular grooves connected to the suction port, the second annular groove is not connected to the plurality of annular grooves connected to the suction port and terminates spaced apart from the outer edge of the area on the substrate adsorption surface where the substrate is placed.

[0059] This configuration allows for uniform flexibility across the entire region of the elastic film that contacts the substrate. Furthermore, this improves the adhesion between the elastic film and the substrate on the outside of the multiple annular grooves connected to the suction port for vacuuming, thereby improving the sealing performance of the multiple annular grooves connected to the suction port for vacuuming.

[0060] [7] In one embodiment, an airbag is provided on the side of the elastic film opposite to the substrate adsorption surface.

[0061] In this configuration, the substrate can be pressed against the polishing surface via an elastic membrane by the inflation of the airbag.

[0062] [8] In one embodiment, the sheet-like member is a woven fabric.

[0063] This configuration makes it easy to give the sheet-like member the desired strength / rigidity.

[0064] [9] In one embodiment, the sheet-like member is a woven fabric of aramid fibers.

[0065] This configuration allows the sheet-like member to have high strength and rigidity.

[0066]

[10] In one embodiment, the sheet-like member is a SUS plate or a resin plate.

[0067] This configuration makes it easy to give the sheet-like member the desired strength / rigidity.

[0068]

[11] In one embodiment, the rubber is Si rubber.

[0069] This configuration makes it easy to give the rubber the desired strength / rigidity.

[0070]

[12] In one embodiment, a substrate processing apparatus is provided, comprising any of the above top rings and a polishing table having a polishing pad.

[0071] This configuration makes it possible to provide a substrate processing apparatus that exhibits the effects described above.

[0072]

[13] In one embodiment, a method is provided for holding a substrate on a top ring, comprising: preparing a top ring having an elastic membrane having a substrate adsorption surface for adsorbing a substrate and one or more suction ports for drawing air from between the substrate and the substrate adsorption surface, wherein the elastic membrane comprises rubber and a sheet-like member wrapped by the rubber and having a rigidity higher than the rubber, and an air passage to the suction port is formed on the substrate adsorption surface by irregularities, the air passage terminating spaced apart from the outer edge of the area on the substrate adsorption surface where the substrate is placed; and bringing the substrate into contact with the substrate adsorption surface of the top ring, and vacuum adsorbing the substrate to the substrate adsorption surface by drawing air through the air passage provided on the substrate adsorption surface by irregularities and the one or more suction ports.

[0073] This form produces the effects described above with respect to [1].

[0074]

[13] In one embodiment, an elastic membrane is provided which is attached to a top ring for holding a substrate, comprising: an elastic membrane body having rubber and a sheet-like member wrapped by the rubber and having a higher rigidity than the rubber; a substrate adsorption surface provided on one surface of the elastic membrane body for adsorbing the substrate; and one or more suction ports provided on the elastic membrane body for drawing air from between the substrate and the substrate adsorption surface, wherein an air passage to the suction port is formed on the substrate adsorption surface of the elastic membrane body by irregularities, and the air passage terminates spaced apart from the outer edge of the region on the substrate adsorption surface where the substrate is placed.

[0075] This embodiment provides an elastic membrane that constitutes the top ring of [1]. The top ring composed of this elastic membrane exhibits the effects described above with respect to [1].

[0076] Although several embodiments of the present invention have been described above, the embodiments 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, equivalents thereof are included in the present invention. Furthermore, any combination or omission of the components described in the claims and specification 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.

[0077] All disclosures, including the specifications, claims, drawings, and abstracts, of Japanese Patent Publication No. 2024-57926 (Patent Document 1), Japanese Patent Publication No. 2009-539626 (Patent Document 2), Japanese Patent Publication No. 2004-119809 (Patent Document 3), and Japanese Patent Publication No. 2021-122896 (Patent Document 4) are incorporated into this application as a whole by reference. [Explanation of Symbols]

[0078] 18 Top Ring Shaft 300 polishing units 302 Top Ring 350 Polishing Table 351 Table shaft 352 Polishing Pads 400 Base Member 410 Elastic membrane 411 Rubber 412 Sheet-like member 413 Bottom surface (board adsorption surface) 413A Outer edge 414 Top surface 415 Groove 415A Annular groove 415B Radial Groove 416 Second annular groove 418 Suction port 420 Airbags 431 Fluid line 432 Pressure Source 433 Fluid lines 434 Gas supply source 900 Control Unit 1000 Substrate Processing Equipment Swf substrate adsorption area WF board

Claims

1. A top ring for holding a substrate, A base member connected to a rotating shaft, An elastic membrane attached to the base member, having a substrate adsorption surface for adsorbing a substrate and one or more suction ports for drawing air from between the substrate and the substrate adsorption surface, Equipped with, The elastic membrane comprises rubber and a sheet-like member that is encased in the rubber and has higher rigidity than the rubber. A top ring having an air passage to the suction port formed by irregularities on the substrate adsorption surface of the elastic film, wherein the air passage terminates spaced apart from the outer edge of the region on the substrate adsorption surface where the substrate is placed.

2. The top ring according to claim 1, The top ring includes one or more suction ports, each located at the center of the substrate adsorption surface.

3. The top ring according to claim 2, Grooves are formed by the aforementioned irregularities, The groove is The elastic membrane comprises a plurality of annular grooves arranged concentrically with respect to the suction port, A top ring having one or more radial grooves extending radially from the suction port, which connect the plurality of annular grooves to each other and to the suction port.

4. The top ring according to claim 3, The aforementioned substrate is rectangular, The aforementioned multiple annular grooves are rectangular in shape when viewed from above, forming a top ring.

5. The top ring according to claim 4, The radial grooves are provided along the diagonals of the rectangular substrate adsorption surface, forming a top ring.

6. The top ring according to claim 3, The groove further has a second annular groove outside the plurality of annular grooves connected to the suction port, the second annular groove is not connected to the plurality of annular grooves connected to the suction port, and terminates spaced apart from the outer edge of the area on the substrate adsorption surface where the substrate is placed.

7. The top ring according to claim 1, A top ring in which an airbag is provided on the side of the elastic film opposite to the substrate adsorption surface.

8. The top ring according to claim 1, The aforementioned sheet-like member is a woven fabric, a top ring.

9. The top ring according to claim 8, The aforementioned sheet-like member is a top ring, which is a woven fabric of aramid fibers.

10. The top ring according to claim 1, The sheet-like member is a SUS plate or a resin plate, which is used for the top ring.

11. The top ring according to claim 1, The rubber is Si rubber, in the top ring.

12. A top ring according to any one of claims 1 to 11, A polishing table having a polishing pad, A substrate processing apparatus comprising:

13. A method for holding a substrate in a top ring, The steps of preparing a top ring comprising an elastic membrane having a substrate adsorption surface for adsorbing a substrate and one or more suction ports for drawing air from between the substrate and the substrate adsorption surface, wherein the elastic membrane comprises rubber and a sheet-like member encased in the rubber and having a higher rigidity than the rubber, and the substrate adsorption surface has air passages formed by irregularities to the suction ports, the air passages terminating spaced apart from the outer edge of the region on the substrate adsorption surface where the substrate is placed, The steps include bringing the substrate into contact with the substrate adsorption surface of the top ring, and vacuum adsorbing the substrate to the substrate adsorption surface by drawing air through the air passages provided by the irregularities on the substrate adsorption surface and the one or more suction ports, Methods that include...

14. An elastic membrane attached to a top ring for holding a substrate, An elastic membrane body having rubber and a sheet-like member that is encased in the rubber and has higher rigidity than the rubber, A substrate adsorption surface for adsorbing the substrate is provided on one surface of the elastic film body, The elastic membrane body is provided with one or more suction ports for drawing air from between the substrate and the substrate adsorption surface, Equipped with, An elastic membrane having an air passage to the suction port formed by irregularities on the substrate adsorption surface of the elastic membrane body, wherein the air passage terminates at a distance from the outer edge of the region on the substrate adsorption surface where the substrate is placed.

Images