Substrate polishing device, substrate processing apparatus, substrate polishing method, and program

Abstract

To improve the accuracy of detecting projection of a substrate from a top ring or the like.SOLUTION: A substrate polishing device comprises a top ring for holding a substrate and pressing the substrate against a polishing pad, and a control unit. The top ring includes at least one elastic membrane configured to form at least one pressurizing chamber for pressing the substrate. The at least one elastic membrane has at least one opening on a surface that contacts the substrate. The substrate polishing device further comprises a measuring unit that is disposed in a flow path fluidly connected to the pressurizing chamber in which the opening is formed, and measures pressure or flow rate of the flow path. The control unit determines abnormality of polishing on the basis of a measurement value obtained through measurement by the measuring unit while the polishing of the substrate is being performed. The abnormality of the polishing includes at least one of projection of the substrate from the top ring and breakage of the substrate.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a substrate polishing apparatus, a substrate processing apparatus, a substrate polishing method, and a program. [Background technology]

[0002] CMP (Chemical Mechanical Polishing) equipment is one type of substrate processing equipment used in semiconductor processing. CMP equipment can be broadly categorized into "face-up type" (where the surface to be polished of the substrate faces upward) and "face-down type" (where the surface to be polished of the substrate faces downward) depending on the direction in which the surface to be polished of the substrate faces.

[0003] A face-down chemical mechanical polishing apparatus includes a polishing head (also called a top ring) that holds the substrate, and a polishing table with a polishing pad attached, and is configured to polish the substrate by pressing the substrate against the polishing pad while rotating the polishing head and polishing table. During polishing of the substrate, the substrate may come off the polishing head and fly out of the polishing head, or may be damaged by cracking or other reasons.

[0004] In response to this, for example, Patent Document 1 discloses detecting whether a substrate has popped out of a polishing head based on the rotation torque of an arm or the flow rate of fluid supplied to a retainer member pressurizing chamber. Patent Document 2 discloses detecting the pressure or flow rate of pressurized fluid supplied to the backside of a substrate to determine whether the substrate is damaged. Patent Document 3 discloses that if two sensors installed in two adjacent pressurizing chambers detect the same flow rate of fluid from the one with higher pressure to the one with lower pressure, it is determined that a leak has occurred at the boundary between the two pressurizing chambers. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2022-010795 [Patent Document 2] Patent No. 3705670 [Patent Document 3] Japanese Patent Application Laid-Open No. 2004-349340 Summary of the Invention [Problem to be solved by the invention]

[0006] The device of Patent Document 1 may not be able to detect protrusion of a substrate sufficiently accurately under certain conditions during polishing, for example, because the rotation torque changes significantly when the direction of arm movement changes during arm swing. Furthermore, the device of Patent Document 2 does not have a configuration in which a pressure chamber is formed by an elastic membrane. If a pressure chamber were formed by an elastic membrane, fluctuations in pressure or flow rate may prevent sufficiently accurate detection of protrusion of a substrate.

[0007] The present invention has been made in consideration of the above-mentioned circumstances, and one of its objects is to provide a substrate polishing apparatus, a substrate processing apparatus, or a substrate polishing method that improves the accuracy of detecting polishing abnormalities such as a substrate protruding from a top ring. [Means for solving the problem]

[0008] According to one embodiment of the present invention, a substrate polishing apparatus includes a polishing table that supports a polishing pad for polishing a substrate, a top ring that holds the substrate and presses it against the polishing pad, and a control device, wherein the top ring includes at least one elastic membrane configured to form at least one pressure chamber for pressing the substrate, and the at least one elastic membrane has at least one opening in a surface that comes into contact with the substrate, The apparatus further includes a measurement unit disposed in a flow path fluidly connected to the pressurized chamber in which the opening is formed, for measuring the pressure or flow rate of the flow path, and the control device is configured to determine abnormalities in the polishing based on measurements obtained by the measurement unit while the substrate is being polished, the abnormalities in the polishing including at least one of the substrate popping out of the top ring and damage to the substrate. According to one embodiment of the present invention, a substrate polishing method comprises polishing a substrate held by a top ring by pressing the substrate against a polishing pad supported on a polishing table, the top ring comprising at least one elastic membrane configured to form at least one pressure chamber for pressing the substrate, the at least one elastic membrane comprising at least one opening in a surface that contacts the substrate, the substrate polishing method comprising: measuring the pressure or flow rate of the flow path by a measuring unit arranged in a flow path fluidly connected to the pressure chamber in which the opening is formed while the substrate is being polished; and determining a polishing abnormality based on the measurement value obtained by the measurement unit, the polishing abnormality including at least one of the substrate popping out of the top ring and the substrate being damaged. According to one embodiment of the present invention, a program is provided for causing a processing device of a substrate polishing apparatus to perform a process, the processing device comprising a polishing table that supports a polishing pad for polishing a substrate, and a top ring that holds the substrate and presses it against the polishing pad, the top ring comprising at least one elastic membrane configured to form at least one pressure chamber for pressing the substrate, the at least one elastic membrane comprising at least one opening on a surface that contacts the substrate, the substrate polishing apparatus further comprising a measurement unit disposed in a flow path fluidically connected to the pressure chamber in which the opening is formed, the measurement unit measuring the pressure or flow rate of the flow path, and during the process, a polishing abnormality is determined based on measurement values ​​obtained by measurement by the measurement unit while the substrate is being polished, and the polishing abnormality includes at least one of the substrate popping out of the top ring and damage to the substrate. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a plan view showing an overall configuration of a substrate processing apparatus according to one embodiment; [Figure 2] FIG. 2 is a perspective view schematically illustrating a configuration of a polishing unit according to one embodiment. [Figure 3] FIG. 1 is a cross-sectional view schematically illustrating a top ring according to an embodiment. [Figure 4] FIG. 2 is a view of a top ring viewed from the polishing table side according to an embodiment. [Figure 5] 10A-10C illustrate the shape of a retainer member according to one embodiment. [Figure 6A] FIG. 2 is a plan view illustrating the structure of an elastic membrane according to one embodiment. [Figure 6B] FIG. 6B is a cross-sectional view taken along the arrow BB shown in FIG. 6A. [Figure 6C] FIG. 6B is a cross-sectional view taken along the arrow CC shown in FIG. 6A. [Figure 7] FIG. 10 is a conceptual diagram illustrating the placement of a measurement device in a flow path connected to a ripple chamber according to one embodiment. [Figure 8] FIG. 2 is a cross-sectional view showing a substrate, a polishing pad, and a top ring during polishing. [Figure 9] FIG. 10 is a cross-sectional view schematically showing the protrusion of a substrate. [Figure 10] FIG. 10 is a cross-sectional view showing the polishing pad and the top ring after the substrate has been ejected. [Figure 11] 10 is a graph showing the relationship between the torque of the swing arm, the pressure on the secondary side of the pressure regulator, and the pressure measured by the pressure gauge, and time. [Figure 12] 10 is a graph showing the relationship between the position and torque of the swing arm and time. [Figure 13] 10 is a graph showing the relationship between time and the pressure on the secondary side of the pressure regulator and the pressure measured by a pressure gauge, schematically illustrating each state of the pressurizing chamber. [Figure 14] 1 is a flowchart showing a substrate polishing method according to an embodiment. [Figure 15]1 is a flowchart showing a substrate polishing method according to an embodiment. [Figure 16] 1 is a flowchart showing a substrate polishing method according to an embodiment. [Figure 17] 1 is a flowchart showing a substrate polishing method according to an embodiment. [Figure 18] FIG. 10 is a conceptual diagram showing the arrangement of a measurement device in a flow path connected to a pressurizing chamber according to another embodiment. [Figure 19] FIG. 10 is a conceptual diagram showing the arrangement of a measurement device in a flow path connected to a pressurizing chamber according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of a substrate polishing apparatus, a substrate processing apparatus, a substrate polishing method, and a program according to the present invention will be described with reference to the accompanying drawings. In the accompanying drawings, identical or similar elements are designated by identical or similar reference symbols, and duplicate descriptions of identical or similar elements may be omitted in the description of each embodiment. Furthermore, features shown in each embodiment can also be applied to other embodiments as long as they are not mutually inconsistent.

[0011] FIG. 1 is a plan view showing the overall configuration of a substrate processing apparatus 1000 according to a first embodiment. The substrate processing apparatus 1000 shown in FIG. 1 includes a load unit 100, a transfer unit 200, a polishing unit 300, a drying unit 500, and an unload unit 600. In the illustrated embodiment, the transfer unit 200 includes two transfer units 200A and 200B, and the polishing unit 300 includes two polishing units 300A and 300B. In one embodiment, each of these units can be formed independently. By forming these units independently, substrate processing apparatuses 1000 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, which controls each component of the substrate processing apparatus 1000. In one embodiment, the control device 900 can be configured as a general computer including an input / output device, a calculation device, a storage device, and the like.

[0012] <Load unit> The load unit 100 is a unit for introducing a substrate WF before processing such as polishing and cleaning into the substrate processing 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).

[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 Fig. 1, three transport rollers 202 are attached to each roller shaft 204. The substrate WF is placed on the transport rollers 202, and is transported by the rotation of the transport rollers 202.

[0014] <Transport unit> 1 includes two transport units 200A and 200B. The two transport units 200A and 200B can have the same configuration, and therefore will be collectively referred to as the transport unit 200 in the following description.

[0015] The illustrated transport unit 200 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 are driven by a motor (not shown). The substrate WF is transported by the transport rollers 202 to a substrate transfer position.

[0016] 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.

[0017] <Drying unit> The drying unit 500 is a device for drying the substrate WF. In the processing apparatus 1000, 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 blowing away water droplets on the transported substrate WF with the gas sprayed from the nozzle 530.

[0018] <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 processing apparatus 1000. In the substrate processing 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 Mechanical Device Interface Standard (IPC-SMEMA-9851) of the SMEMA (Surface Mount Equipment Manufacturers Association).

[0019] <Polishing unit> Fig. 2 is a perspective view schematically illustrating 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. 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.

[0020] 2, the polishing unit 300 includes a polishing table 350 that supports a polishing pad 352, and a top ring 302 that constitutes a polishing head that holds a substrate WF, which is an object to be polished, and presses it against the polishing surface of the polishing pad 352. The polishing table 350 is connected to a polishing table rotation motor (not shown) disposed below it via a table shaft 351, and is rotatable about the table shaft 351. A polishing pad 352 is attached to the upper surface of the polishing table 350, and the surface of the polishing pad 352 constitutes a polishing surface 352a that polishes the substrate WF.

[0021] 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 , a passage 353 for supplying a polishing liquid is provided in the polishing table 350 and the table shaft 351. 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. 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. Note that the opening 355 in the polishing table 350 and the through-hole 357 in the polishing pad 352 may be one or more. Furthermore, the opening 355 in the polishing table 350 and the through-hole 357 in the polishing pad 352 may be located at any position, but in one embodiment, they are located near the center of the polishing table 350.

[0022] 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.

[0023] The top ring 302 is connected to the top ring shaft 18. The top ring shaft 18 is movable up and down relative to the 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. The top ring 302 is capable of holding a rectangular substrate WF on its underside. A rotary joint 323 is attached to the upper end of the top ring shaft 18.

[0024] The swing arm 360 is configured to be rotatable around a support shaft 362. The swing arm 360 is connected to an arm rotation motor 364 disposed below the swing arm 360 via the support shaft 362 and is rotatable about the support shaft 362. The arm rotation motor 364 is provided with an arm ammeter 365 capable of measuring the drive current of the arm rotation motor 364 as an arm torque detector for detecting a physical quantity correlating with the swing torque (rotation torque) of the swing arm 360. When the arm rotation motor 364 is a servo motor, the arm rotation motor 364 serves as the arm torque detector. The top ring 302 can be moved between the substrate transfer position of the transport unit 200 and above the polishing table 350 by swinging the swing arm 360. 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 from an opening 355 provided in the polishing table 350. In this manner, the surface of the substrate WF can be polished by pressing the substrate WF against the polishing surface 352a of the polishing pad 352. During polishing of the substrate WF, the swing arm 360 may be fixed or swingable 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).

[0025] 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 a 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.

[0026] 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.

[0027] 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 dresser 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 dresser swing arm 55.

[0028] The dresser swing arm 55 is driven by a motor (not shown) and rotates around a support shaft 58. The dresser shaft 51 is rotated by a 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.

[0029] 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.

[0030] <Top ring> Next, the top ring 302 in the polishing unit 300 according to one embodiment will be described. Fig. 3 is a schematic cross-sectional view of the top ring 302 according to one embodiment, which holds a substrate WF, which is an object to be polished, and presses the substrate WF against the polishing surface 352a of the polishing pad 352. Fig. 3 shows only the main components of the top ring 302.

[0031] As shown in FIG. 3, the top ring 302 includes a top ring body 2 that presses the substrate WF against the polishing surface 352a, and a retainer member 3 that surrounds the periphery of the top ring body 2 and directly presses the polishing surface 352a. The top ring body 2 is made of a roughly rectangular, flat plate, and the retainer member 3 is attached to the outer periphery of the top ring body 2. The top ring body 2 is made of a resin such as engineering plastic (e.g., PEEK (polyether ether ketone)). An elastic membrane 4 that contacts the backside of the substrate WF is attached to the bottom surface of the top ring body 2. In one embodiment, the elastic membrane 4 is made of a rubber material with excellent strength and durability, such as ethylene propylene rubber (EPDM), polyurethane rubber, or silicone rubber.

[0032] FIG. 4 is a view of the top ring 302 according to one embodiment, as seen from the polishing table 350 side. In one embodiment, the retainer member 3 has multiple grooves 3a as shown in FIG. 4. The retainer member 3 shown in FIG. 4 has grooves 3a extending from the inside to the outside of the top ring 302. In the embodiment shown in FIG. 4, there are areas at the corners of the top ring body 2 where no retainer member 3 is present. The substrate WF does not have to be rectangular; for example, it may be circular. The top ring 302 can be formed in a shape that corresponds to the shape of the substrate WF.

[0033] Fig. 5 is a diagram showing the shape of a retainer member 3 according to one embodiment. The retainer member 3 shown in Fig. 5 has a fan-shaped end portion of the elongated retainer member 3 shown in Fig. 4. Therefore, by combining four retainer members 3 as shown in Fig. 5, it is possible to surround almost the entire top ring body 2, including the corners, with the retainer members 3.

[0034] FIG. 6A is a top view showing the structure of an elastic membrane 4 according to one embodiment. FIG. 6B is a cross-sectional view taken along arrow BB in FIG. 6A. FIG. 6C is a cross-sectional view taken along arrow CC in FIG. 6A. As shown in FIG. 4 and FIGS. 6A to 6C, the elastic membrane 4 is formed with a plurality of vacuum suction holes 315 that communicate with the ripple chamber 6 and that vacuum-suck the substrate WF to the top ring 302. In one embodiment, as shown in FIG. 4 and FIG. 6A, eight vacuum suction holes 315 are provided. The vacuum suction holes 315 are not shown. The vacuum suction holes 315 communicate with a passage and are connected to a vacuum source. The substrate WF can be vacuum-sucked to the elastic membrane 4 of the top ring 302 through the vacuum suction holes 315. The number of vacuum suction holes 315 is not particularly limited, and the vacuum suction hole 315 can be at least one opening.

[0035] The elastic membrane 4 has multiple concentric partition walls 4a, which define a circular center chamber 5, a square-frame-shaped ripple chamber 6 surrounding the center chamber 5, a square-frame-shaped intermediate chamber 7 surrounding the ripple chamber 6, a square-frame-shaped outer chamber 8 surrounding the intermediate chamber 7, and a square-frame-shaped edge chamber 9 surrounding the outer chamber 8, between the upper surface of the elastic membrane 4 and the lower surface of the top ring body 2. That is, the center chamber 5 is formed in the center of the top ring body 2, and the ripple chamber 6, intermediate chamber 7, outer chamber 8, and edge chamber 9 are formed concentrically in this order from the center toward the periphery. As shown in FIG. 3 , the top ring body 2 is provided with a flow path 11 communicating with the center chamber 5, a flow path 12 communicating with the ripple chamber 6, a flow path 13 communicating with the intermediate chamber 7, a flow path 14 communicating with the outer chamber 8, and a flow path 15 communicating with the edge chamber 9. Flow paths 11, 12, 13, 14, and 15 are connected to flow paths 21, 22, 23, 24, and 25, respectively, via rotary joint 323. Flow paths 21, 22, 23, 24, and 25 are connected to fluid supply source 30 via valves V1-1, V2-1, V3-1, V4-1, and V5-1 and pressure regulators R1, R2, R3, R4, and R5, respectively. Flow paths 21, 22, 23, 24, and 25 are connected to vacuum source 31 via valves V1-2, V2-2, V3-2, V4-2, and V5-2, respectively, and can communicate with the atmosphere via valves V1-3, V2-3, V3-3, V4-3, and V5-3.

[0036] A retainer member pressurizing chamber 10 made of an elastic membrane is also formed on the retainer member 3. The retainer member pressurizing chamber 10 is connected to a flow path 26 via a flow path 16 formed in the top ring body 2 and a rotary joint 323. The flow path 26 is then connected to a fluid supply source 30 via a valve V6-1 and a pressure regulator R6. The flow path 26 is also connected to a vacuum source 31 via a valve V6-2 and is connected to the atmosphere via a valve V6-3. The pressure regulators R1, R2, R3, R4, R5, and R6 each have a pressure adjusting function for adjusting the pressure of a pressurized fluid, such as compressed air, supplied from the fluid supply source 30 to the center chamber 5, ripple chamber 6, intermediate chamber 7, outer chamber 8, edge chamber 9, and retainer member pressurizing chamber 10. This structure allows the pressing force with which the substrate WF is pressed against the polishing pad 352 to be adjusted for each region of the substrate WF, and the pressing force with which the retainer member 3 presses the polishing pad 352 to be adjusted. The pressure regulators R1, R2, R3, R4, R5, and R6 and the valves V1-1 to V1-3, V2-1 to V2-3, V3-1 to V3-3, V4-1 to V4-3, V5-1 to V5-3, and V6-1 to V6-3 are connected to a control device 900 (see FIG. 1) so that their operation is controlled. In addition, pressure gauges P1, P2, P3, P4, P5, and P6 and flow meters F1, F2, F3, F4, F5, and F6 are installed in the flow paths 21, 22, 23, 24, 25, and 26, respectively.

[0037] FIG. 7 is a conceptual diagram showing the arrangement of measurement devices in a flow path 22 connected to a ripple chamber 6 according to one embodiment. The ripple chamber 6 is a pressurized chamber in which vacuum suction holes 315, which are openings, are formed. Each measurement device functions as a measurement unit 70 that measures the pressure or flow rate of the flow path 22. This embodiment mainly assumes a case in which the ripple chamber 6 is pressurized via the flow path 22, and therefore the ripple chamber 6 side is referred to as the downstream side. The flow path 22, which fluidly connects the fluid supply source 30 (FIG. 3) and the ripple chamber 6, has an upstream flow path 90, a first flow path 91, a second flow path 92, and a downstream flow path 93.

[0038] The upstream flow path 90 is connected to the fluid supply source 30 and has a pressure regulator R2 disposed therein. In the upstream flow path 90, the pressure regulator R2 is configured to adjust the pressure on the downstream side (secondary pressure) when a pressure (primary pressure) higher than that on the downstream side is applied to the upstream side. The pressure regulator R2 is preferably configured to measure the pressure at least downstream thereof using a pressure gauge provided therein and to transmit a signal or data indicative of the pressure to the control device 900. The upstream flow path 90 is fluidly connected to a first flow path 91 and a second flow path 92 downstream of the pressure regulator R2.

[0039] The first flow path 91 and the second flow path 92 are arranged in parallel and are fluidly connected to the downstream flow path 93 on the downstream side. A compression valve V20 is arranged in the first flow path 91. A flow meter F2 and a leak check valve V2-12 are arranged in the second flow path 92. The flow meter F2 and the leak check valve V2-12 are arranged in series in the second flow path 92. As will be described later, when increasing the pressure in the ripple chamber 6, it is preferable that the compression valve V20 is opened and the pressurized fluid is introduced into the ripple chamber 6 via the first flow path 91. At this time, the leak check valve V2-12 may be opened or closed. On the other hand, during polishing, it is preferable that the compression valve V20 is closed and the leak check valve V2-12 is opened, and the flow rate in the second flow path 92 is monitored by the flow meter F2.

[0040] The downstream flow path 93 is fluidly connected to the ripple chamber 6 at a further downstream side. A downstream valve V2-11 is disposed in the downstream flow path 93. The pressure gauge P2 is disposed in the flow path so as to measure the pressure at a position upstream of the downstream valve V2-11 and downstream of the compression valve V20 and the leak check valve V2-12. The pressure gauge P2 is disposed downstream of the pressure regulator R2 and can measure the pressure in the ripple chamber 6 more accurately than the pressure gauge of the pressure regulator R2.

[0041] <Control device> As shown in FIG. 2, the polishing unit 300 and the control device 900 constitute a substrate polishing apparatus. The control device 900 includes a storage medium 910 and a processing device 920. The storage medium 910 includes a storage device such as a solid-state drive. The storage medium 910 stores various data used in the substrate processing apparatus 1000, as well as a program for causing a computer (control device 900) of the substrate processing apparatus 1000 to execute each step of a substrate polishing method described below. The CPU (Central Processing Unit) of the control device 900 can read and execute the program stored in the storage medium 910. For example, the CPU can store the program stored in the storage medium 910 in a memory (not shown) and read and execute the program from the memory. The program can be recorded in a computer-readable storage medium and provided to the control device 900 via the storage medium. Alternatively, the program can be provided to the control device 900 via a communication network such as the Internet. The storage medium 910 and the processing device 920 constituting the control device 900 may be distributed.

[0042] The processing apparatus 920 includes a first determination unit 921, a second determination unit 922, and an apparatus control unit 923. The apparatus control unit 923 controls the operation of each unit of the substrate processing apparatus 1000. For example, the apparatus control unit 923 is configured to send a control signal to each unit of the substrate processing apparatus 1000.

[0043] The first determination unit 921 determines whether or not a first polishing abnormality occurs while the substrate WF is being polished. Hereinafter, this determination will be referred to as the first determination. Hereinafter, the first polishing abnormality refers to at least one of the substrate WF jumping out of the top ring 302 and damage such as cracks in the substrate WF. The first determination unit 921 makes the first determination based on the measurement value obtained by the measurement unit 70.

[0044] FIG. 8 is a cross-sectional view of the top ring 302 containing the substrate WF being polished. The ripple chamber 6 is formed with vacuum suction holes 315. During polishing, a pressure fluid is introduced into the elastic membrane 4. , a ripple chamber 6, an intermediate chamber 7, an outer chamber 8, and an edge chamber 9 are formed. These pressure chambers are configured to press the substrate WF against the polishing pad 352. Furthermore, pressurized fluid is introduced into the retainer member pressure chamber 10, which presses the retainer member 3 against the polishing pad 352, and the retainer member 10 restricts movement of the substrate WF along the polishing surface 352a. During polishing, the substrate WF is pressed against the elastic membrane 4 that defines the ripple chamber 6, so that leakage of pressurized fluid from the vacuum suction holes 315 formed in the ripple chamber elastic membrane 4b that defines the surface of the ripple chamber 6 facing the substrate WF does not occur unless there is an abnormality.

[0045] 9 is a cross-sectional view of the top ring 302 and other components, schematically illustrating the protrusion of the substrate WF being polished from the top ring 302. A portion of the substrate WF protrudes outside the top ring 302, and the substrate WF is no longer located below the ripple chamber 6. At this time, a gap is formed at least temporarily between the polishing pad 352 and the ripple chamber elastic membrane 4b, causing leakage of pressure fluid from the ripple chamber 6. If the substrate WF is damaged, such as by cracking, during polishing, a similar gap may also be formed, potentially causing leakage of pressure fluid from the ripple chamber 6.

[0046] FIG. 10 is a cross-sectional view of the top ring 302, etc., schematically showing the grooves 352b in the polishing pad 352. The grooves 352b are formed in the polishing surface 352a of the polishing pad 352 to supply or discharge a liquid such as a polishing liquid onto the polishing pad 352. This facilitates distributing an appropriate amount of liquid on the polishing surface 352a, enabling more uniform polishing of the substrate WF. The polishing pad 352 may also have holes for discharging a liquid such as a polishing liquid from above the polishing pad 352. Even if the ripple chamber 6 is in close contact with the polishing pad 352 after the substrate WF has been ejected from the top ring 302, the grooves 352b or holes in the polishing pad 352 communicate with the vacuum suction holes 315, which can still cause leakage of pressure fluid.

[0047] FIG. 11 is a graph illustrating the change in pressure in the ripple chamber 6 when the substrate WF pops out. The horizontal axis represents time. The solid line plot shows the relationship between time and the change in torque of the swing arm 360 (vertical axis). The dashed line plot shows the relationship between time and the pressure value measured by the pressure gauge P2 (FIG. 7). The pressure value at the bottom of the graph is atmospheric pressure. The dot-dash line plot shows the relationship between time and the pressure value on the secondary side of the pressure regulator R2. The torque of the swing arm 360 can be calculated from the drive current of the arm ammeter 365, etc.

[0048] 11, the substrate WF pops out at time T1, and the swing arm 360 stops swinging after a while. The torque of the swing arm 360 before time T1 fluctuates periodically due to the swing. The jumping out of the substrate WF causes leakage of pressurized fluid from the ripple chamber 6, and after the pressure value measured by the pressure gauge P2 drops, the pressure value on the secondary side of the pressure regulator R2 upstream of the pressure gauge P2 drops. Hereinafter, the pressure value measured by the pressure gauge P2 will be referred to as the first pressure value, and the pressure value on the secondary side of the pressure regulator R2 will be referred to as the second pressure value.

[0049] In this embodiment, the first determination unit 921 performs the first determination based on the first pressure value, which is less susceptible to changes in polishing conditions than when detecting the protrusion of the substrate WF based on the torque of the swing arm 360 or the like, and can improve the accuracy of detecting an abnormality in the first polishing, at least when the polishing conditions change.

[0050] The first determination unit 921 can be configured to refer to a reference value for the change in the first pressure value stored in the storage medium 910, and if the change in the first pressure value exceeds the reference value, to determine that a first polishing abnormality has been detected and to execute error processing. This error processing is not particularly limited, but can be configured such that the device control unit 923 stops the operation of the top ring 302, the swing arm 360, the polishing table 350, etc. so as to stop polishing, or to display a message or image, etc., on a display unit (not shown) to notify of the first polishing abnormality. In this way, when the control device 900 detects an abnormality in polishing, it can control the top ring 302, the swing arm 360, the polishing table 350, etc. so as to stop polishing. The first determination unit 921 can control at least one of the top ring 302, the swing arm 360, and the polishing table 350. This can prevent damage to the top ring 302, etc., and prevent unnecessary polishing when an abnormality occurs. The algorithm of the first determination unit 921 is not particularly limited as long as it performs the first determination based on the first pressure value and the reference value. For example, the first determination unit 921 may perform processing to suppress variations in the first pressure value, or may perform error processing when the change in the first pressure value is equal to or greater than the reference value.

[0051] 12 is a graph illustrating the position and torque of the swing arm 360. The horizontal axis represents time. The solid line plot shows the relationship between time and the change in torque of the swing arm 360 (vertical axis). The dashed-dotted line plot shows the relationship between time and the position of the swing arm 360 in the swing direction. Circles CL1 schematically show both ends of the path along which the swing arm 360 swings.

[0052] In the conventional method of detecting the protrusion of the substrate WF based on changes in the torque of the swing arm 360, as shown in the graph in FIG. 12, the torque changes when the swing arm 360 changes its movement direction, making it difficult to detect the protrusion of the substrate WF for a certain period of time after the movement direction is changed. Therefore, it is desirable to, for example, control the swing arm 360 so that detection of the substrate WF is not performed for a certain period of time. This period of time during which detection is not performed is schematically indicated by arrow Ar1. Even when detecting the protrusion of the substrate WF using the rotational torque of the polishing table 350 or the top ring 302, changes in polishing conditions, such as the rotation speed of the polishing table 350 or the top ring 302, can reduce the accuracy of detecting the protrusion of the substrate WF. Similar to such changes in polishing conditions, detection accuracy can also be reduced at the start of polishing the substrate WF.

[0053] In the substrate polishing method of this embodiment, the first determination is performed based on the first pressure value, thereby suppressing the influence of the swinging of the swing arm 360 or changes in other polishing conditions on the detection of abnormalities in the first polishing, thereby improving detection accuracy. The control device 900 is preferably configured to perform the first determination simultaneously with the start of polishing of the substrate WF, or to perform the first determination even when the rotation speed of the polishing table 350 or the top ring 302 is changed during polishing of the substrate WF. This allows detection of protrusion of the substrate WF, etc., even when the polishing conditions are changed, thereby preventing damage to the substrate WF, the top ring 302, etc. For example, the control device 900 can perform the first determination intermittently or continuously during polishing, and preferably performs the first determination without interruption when the rotation speed of the polishing table 350 or the top ring 302 is changed. Here, "at the time of change" refers to a predetermined time period immediately after or at the moment of the change. This predetermined time period can be set as appropriate, for example, to 5 seconds or less, 4 seconds or less, 3 seconds or less, 2 seconds or less, 1 second or less, etc. When the pressure in the pressurizing chamber inside the top ring 302 is changed, the first determination may be suspended for a predetermined time to wait for the pressure to stabilize, or may be suspended until the pressure reaches a target pressure value.

[0054] The first determination unit 921 may perform the first determination based on the first pressure value and at least one of the torque of the swing arm 360, the flow rate of the pressurized fluid into the retainer member pressurizing chamber 10, the rotational torque of the polishing table, and the rotational torque of the top ring 302. This can further improve the detection accuracy.

[0055] As shown in FIG. 7, the top ring 302 has a measurement unit 70 arranged in the flow path 22 that fluidly communicates with a single pressurizing chamber (ripple chamber 6). The measurement unit 70 has a pressure gauge P2 and a pressure regulator R2, which are multiple pressure gauges arranged in the flow path 22. The first determination unit 921 preferably makes a first determination based on a first pressure value obtained by measurement with the pressure gauge P2 and a second pressure value on the secondary side of the pressure regulator R2. By using multiple measurement values, the accuracy of detecting protrusion of the substrate WF can be further improved. The first determination unit 921 may also make a first determination based on pressure values ​​at three or more locations in the flow path 22. The second pressure value may be obtained by measurement using a pressure gauge arranged inside the pressure regulator R2. Alternatively, the second pressure value may be obtained by measuring the pressure at a position on the downstream side of the pressure regulator R2 using any type of pressure gauge not included in the pressure regulator R2. In this embodiment, the pressure gauge P2 is used as the first pressure gauge 71 used in the first determination, and the pressure gauge inside the pressure regulator R2 is used as the second pressure gauge 72.

[0056] FIG. 13 is a graph illustrating the changes in the first and second pressure values ​​from the start of polishing until the substrate WF pops out. The horizontal axis represents time. The dashed line plots the first pressure value (vertical axis) measured by the pressure gauge P2 versus time. The dashed-dotted line plots the relationship between time and the second pressure value on the secondary side of the pressure regulator R2. The pressure values ​​at the bottom of the graph represent atmospheric pressure. Arrow A1 indicates the period before polishing has started and the top ring 302 is in a standby state. Arrow A2 indicates the period after polishing has started, when the ripple chamber 6 is pressurized toward the set pressure and the top ring 302 is in a pressurization standby state. Arrow A3 indicates the period during which polishing is being performed while monitoring for any abnormalities in the polishing process and the top ring 302 is in a leak monitoring state.

[0057] In the illustrated example, in the leak monitoring state, after the substrate WF pops out at time T1, the first pressure value obtained by measurement by the pressure gauge P2 drops, while the second pressure value on the secondary side of the upstream pressure regulator R2 remains unchanged for a while and then drops after the polishing stop operation at time T2. Therefore, it was found that the first pressure value reacts quickly to the popping out of the substrate WF, while the second pressure value fluctuates relatively little.

[0058] In this embodiment, the first determination unit 921 preferably performs the first determination based on the difference between the first pressure value and the second pressure value. This makes it possible to suppress a decrease in the accuracy of detecting protrusion of the substrate WF, etc., even if the pressure in the ripple chamber 6 changes during polishing due to changes in polishing conditions, vibrations, etc. For example, if the set pressure of the pressure regulator R2 is reduced during polishing, this difference is relatively insensitive. Hereinafter, this difference will be referred to as the pressure difference.

[0059] The first determination unit 921 may be configured to refer to a reference value for the pressure difference stored in the storage medium 910, and if the pressure difference exceeds the reference value, to determine that a first polishing abnormality has been detected and to execute error processing. The algorithm used by the first determination unit 921 is not particularly limited as long as it performs the first determination based on the pressure difference and the reference value. For example, the first determination unit 921 may perform processing to suppress variations in pressure values ​​or execute error processing when the pressure difference is equal to or greater than the reference value. The first determination unit 921 may also refer to multiple reference values, and may be configured to execute error processing if, for example, the arithmetic mean of the pressure differences over a predetermined period of time exceeds a second reference value, even if the pressure difference at a certain time does not exceed the first reference value.

[0060] By making a first judgment based on the difference between the first pressure value of the pressure gauge P2, which is fluidly connected between the pressure regulator R2 and the ripple chamber 6, and the second pressure value on the secondary side of the pressure regulator R2, the relatively stable second pressure value can be used as the basis for pressure changes, thereby further improving the detection accuracy of the substrate WF popping out, etc.

[0061] The second determination unit 922 (FIG. 2) determines whether or not a second polishing abnormality exists while the substrate WF is being polished. Hereinafter, this determination will be referred to as the second determination. Hereinafter, the second polishing abnormality refers to a leak in the pressure chamber that does not involve the substrate WF protruding or being damaged, such as cracked, of the substrate WF. The second polishing abnormality is a microleak, which can be defined as a leak with an extremely small flow rate compared to the first polishing abnormality that causes the substrate WF to protrude or be damaged. The second polishing abnormality includes a leak in the elastic film 4 itself, and includes, for example, a microleak caused by the movement of a fluid, such as compressed air, between the ripple chamber 6 and another pressure chamber, such as the center chamber 5 or the intermediate chamber 7, due to damage to the partition wall 4a (FIG. 6B). The second polishing abnormality may also be a leak in the pressure chamber that does not involve the substrate WF protruding or being damaged, such as cracked, of the substrate WF. This includes minute leaks due to poor airtightness between the elastic membrane 4 and the casing 1.

[0062] The second determination unit 922 performs a second determination based on the flow rate value obtained by measurement with the flow meter F2 (FIG. 7). As shown in FIG. 7, this embodiment is configured so that pressurized fluid can be introduced into the ripple chamber 6 via the first flow path 91 or the second flow path 92 via the pressure regulator R2. Here, when increasing the pressure in the ripple chamber 6 to a set pressure, it is preferable to introduce the pressurized fluid into the ripple chamber 6 via the first flow path 91. For example, when increasing the pressure in the ripple chamber 6 to a set pressure based on user input or the like, the equipment control unit 923 preferably controls the compression valve V20 and the downstream valve V2-11 to open. At this time, it is preferable, but not limited to, to also open the leak check valve V2-12 in order to increase conductance. Furthermore, when polishing the substrate WF based on user input or the like, it is preferable that the equipment control unit 923 controls the compression valve V20 to close and the leak check valve V2-12 and the downstream valve V2-11 to open. When increasing the pressure, the pressurized fluid is efficiently introduced through the first flow path 91, while during polishing, the conductance of the second flow path 92 can be configured to be lower than the conductance of the first flow path 91, from the viewpoint of being able to detect even minute leaks using the flow rate value of the flow meter F2. Even in this case, since the pressure meter P2 is fluidly connected downstream of the flow meter F2, the pressure in the ripple chamber 6 can be accurately measured by the pressure meter P2. The measurable flow rate range of the flow meter F2 can be set appropriately depending on the level of leak to be detected. To detect smaller leaks, a narrower measurable range is preferable.

[0063] The second determination unit 922 may be configured to refer to a reference value for the second determination stored in the storage medium 910, and if the magnitude or change in the flow rate measured by the flow meter F2 exceeds the reference value, it may determine that an abnormality in the second polishing has been detected and execute error processing. This error processing is not particularly limited, but may include the device control unit 923 stopping the operation of the top ring 302, the swing arm 360, the polishing table 350, etc. to stop polishing, or displaying a message or image on a display unit (not shown) informing the user of the abnormality in the second polishing. The algorithm of the second determination unit 922 is not particularly limited as long as it performs the second determination based on the flow rate value and the reference value for the second determination.

[0064] 7, in this embodiment, a flow meter F2 is disposed between the pressure gauge P2 and the pressure regulator R2 in the flow path 22, and the device control unit 923 is configured to switch the compression valve V20, the leak check valve V2-12, etc. so that the measurement position of the pressure gauge P2, the flow meter F2, and the measurement position of the pressure on the secondary side of the pressure regulator R2 are fluidly connected in series during polishing. As a result, during polishing, the pressure in the ripple chamber 6 can be more accurately measured by the pressure gauge P2 disposed downstream of the flow meter F2, while the flow meter F2 detects leakage in the ripple chamber 6.

[0065] The processing device 920 can use any value to indicate whether the top ring 302 is in a standby state, a pressurization waiting state, or a leak monitoring state, and store the value in the storage medium 910 or the like. For example, the processing device 920 can determine that the top ring 302 is in a standby state when the instruction to pressurize the ripple chamber 6 using the pressure regulator R2 is released, when the processing device 920 receives an instruction to depressurize the ripple chamber 6 for vacuum suction of the substrate WF, or when the processing device 920 detects that the ripple chamber 6 is at atmospheric pressure, and can reflect the determination result in the above-mentioned value in the storage medium 910 or the like. The processing device 920 can determine that the processing device has transitioned to a pressurization waiting state when pressurization of the ripple chamber 6 begins in the standby state. The processing device 920 can determine that the processing device has transitioned to a pressurization waiting state when the set pressure of the ripple chamber 6 increases in the leak monitoring state. The processing device 920 can determine that the processing device has transitioned to a leak monitoring state when the first pressure value of the pressure gauge P2 reaches the set pressure in the pressurization waiting state.

[0066] For example, in the same polishing unit 300, if polishing using a polishing liquid is performed, and then polishing using pure water is performed by lowering the set pressure of the ripple chamber 6, both polishing operations can be performed consecutively while remaining in the leak monitoring state. Alternatively, the unit may be opened to the atmosphere between the two polishing operations. In this case, the unit transitions from the leak monitoring state to a standby state by opening to the atmosphere, a pressurization wait state, and a leak monitoring state. If polishing using a polishing liquid is performed again by increasing the set pressure of the ripple chamber 6, the unit transitions from the leak monitoring state to a pressurization wait state by pressurization, and a leak monitoring state.

[0067] In the standby state, it is preferable that the first determination unit 921 does not perform the first determination, and the second determination unit 922 does not perform the second determination. In the pressurization waiting state, it is preferable that the first determination unit 921 performs the first determination, and the second determination unit 922 does not perform the second determination. The processing device 920 can perform error processing if an abnormality in the first polishing is detected in the first determination. Furthermore, in the pressurization waiting state, the processing device 920 can perform error processing if the first pressure value measured by the pressure gauge P2 drops. These error processing methods are not particularly limited, but can include stopping pressurization or displaying a message or image on a display unit (not shown) notifying of the pressurization abnormality. In determining a drop in the first pressure value, for example, the processing device 920 can perform error processing if the first pressure value drops from the peak pressure value during pressurization to exceed the reference value for the pressurization waiting state. Furthermore, even if the first pressure value does not drop, the processing device 920 can similarly perform error processing if a predetermined time has passed without the set pressure being reached. Note that the algorithm for determining an abnormality in pressurization is not particularly limited. In the leak monitoring state, a first determination and a second determination are preferably performed.

[0068] 14 to 17 are flowcharts illustrating an example of the substrate polishing method of this embodiment. This substrate polishing method is executed by the processing device 920. In this example, it is determined whether the top ring 302 is in a standby state, a pressurization waiting state, or a leak monitoring state. However, the substrate polishing method of this embodiment is not particularly limited as long as the first determination is performed, and it is not necessary to detect each state.

[0069] In step S101, the processing device 920 determines whether the operating conditions for monitoring abnormalities in the polishing of the substrate WF are satisfied. The operating conditions are not particularly limited. For example, the operating conditions may be satisfied when a user inputs an instruction to start polishing while monitoring abnormalities in the polishing of the substrate WF. If the operating conditions are satisfied, a positive determination is made in step S101, and step S102 is initiated. If the operating conditions are not satisfied, a negative determination is made in step S101, and step S103 is initiated. In step S103, the processing device 920 sets the top ring 302 to be in a standby state. After step S103 is completed, the processing is terminated, or the processing is restarted from step S101 immediately or at a preset timing. The processing of the flowcharts in FIGS. 14 to 17 is preferably repeated in a loop when the first determination unit 921 is operating. Although the following flowcharts use loop start and loop end symbols, the first determination, etc., may be performed without looping.

[0070] In step S102, the processing device 920 references a value indicating the state of the top ring 302 stored in the storage medium 910 or the like to detect the state of the top ring 302. If the top ring 302 is in a standby state, step S200 is performed. If the top ring 302 is in a pressurization waiting state, step S300 is performed. If the top ring 302 is in a leak monitoring state, step S400 is performed.

[0071] 15 is a flowchart showing the process S200 performed in the standby state. After step S102, step S201 is started. In step S201, the processing device 920 determines whether the pressurizing chamber (ripple chamber 6) is pressurized. The processing device 920 This determination can be made by referring to a value that indicates whether the pressure regulator R2 is pressurizing, which is stored in the storage medium 910 or the like. If the ripple chamber 6 is pressurized, an affirmative determination is made in step S201, and step S202 is started. If the ripple chamber 6 is not pressurized, a negative determination is made in step S201, and the process is either ended or started again from step S101 at a preset timing.

[0072] In step S202, the processing device 920 sets the top ring 302 to be in a pressurization waiting state. After step S202 is completed, the processing is either terminated or restarted from step S101 at a preset timing.

[0073] 16 is a flowchart showing process S300 performed in the pressurization waiting state. After step S102, step S301 is started. In step S301, the processing device 920 determines whether the pressurization chamber (ripple chamber 6) is pressurized. The processing device 920 can make this determination by referring to a value that indicates whether the pressure regulator R2 is pressurizing, which is stored in the storage medium 910 or the like. If the ripple chamber 6 is pressurized, an affirmative determination is made in step S301, and step S302 is started. If the ripple chamber 6 is not pressurized, a negative determination is made in step S301, and step S305 is started.

[0074] In step S302, the processing device 920 determines whether the pressure in the pressurizing chamber (ripple chamber 6) has reached a set value. If the first pressure value measured by the pressure gauge P2 is equal to or greater than the set pressure, an affirmative determination is made in step S306, and step S306 is initiated. If the first pressure value is less than the set pressure, step S303 is initiated.

[0075] In step S303, the processing device 920 determines whether or not there is a leak in the pressurizing chamber (ripple chamber 6). In the pressurization waiting state, the processing device 920 can determine whether or not there is a leak based on whether or not the pressure in the ripple chamber 6 has dropped below its peak value, as described above. If it is determined that there is a leak in the ripple chamber 6, a positive determination is made in step S303, and step S307 is initiated. If it is determined that there is no leak in the ripple chamber 6, a negative determination is made in step S303, and step S304 is initiated.

[0076] In step S304, the processing device 920 determines whether a predetermined time has elapsed since the start of pressurization. If the predetermined time has elapsed since the start of pressurization, a positive determination is made in step S304, and step S307 is started. If the predetermined time has not elapsed since the start of pressurization, a negative determination is made in step S304, and the processing is either ended or started again from step S101 at a preset timing.

[0077] In step S305, the processing device 920 sets the top ring 302 to be in a standby state. In step S306, the processing device 920 sets the top ring 302 to be in a leak monitoring state. In step S307, the device control unit 923 controls the pressure regulator R2 and other components to stop polishing of the pressurizing chamber (ripple chamber 6). After steps S305, S306, and S307, the processing ends, or is restarted from step S101 immediately or at a preset timing.

[0078] 17 is a flowchart showing process S400 performed in the leak monitoring state. After step S102, step S401 is started. In step S401, the processing device 920 determines whether the pressurized chamber (ripple chamber 6) is pressurized. If the ripple chamber 6 is pressurized, an affirmative decision is made in step S401, and step S402 is started. If the ripple chamber 6 is not pressurized, a negative decision is made in step S401, and step S405 is started.

[0079] In step S402, the processing device 920 determines whether the set value of the pressure in the pressurizing chamber (ripple chamber 6) has been changed to increase. For example, the processing device 920 references the set value of the pressure in the ripple chamber 6 stored in the storage medium 910 or the like, and makes this determination based on whether the set value has increased compared to the last time it was referenced. If the set value of the pressure in the ripple chamber 6 has been changed to increase, an affirmative decision is made in step S402, and step S406 is initiated. If the set value has not increased, a negative decision is made in step S402, and step S403 is initiated.

[0080] In step S403, the first determination unit 921 determines whether or not a first polishing abnormality has occurred (first determination). If a first polishing abnormality has occurred, an affirmative determination is made in step S403, and step S407 is started. If a first polishing abnormality has not occurred, a negative determination is made in step S403, and the process is either ended or restarted from step S101 immediately or at a preset timing.

[0081] In step S405, the processing device 920 sets the top ring 302 to be in a standby state. In step S406, the processing device 920 sets the top ring 302 to be in a pressurization waiting state. In step S407, the device control unit 923 controls the pressure regulator R2 and other components to stop pressurizing the pressurizing chamber (ripple chamber 6). After steps S405, S406, and S407, the processing ends, or starts again from step S101 immediately or at a preset timing.

[0082] In the above embodiment, an example has been shown in which the first or second determination is made for the ripple chamber 6 having the vacuum suction holes 315. However, alternatively or additionally, the first or second determination may be made by forming the vacuum suction holes 315 in a pressure chamber formed by the elastic membrane 4 other than the ripple chamber 6. Furthermore, the top ring 302 may have multiple elastic membranes 4, and some pressure chambers and other pressure chambers may be defined by multiple different elastic membranes 4.

[0083] <Variation 1> Fig. 18 is a conceptual diagram showing the arrangement of the measurement device in the flow path 22 connected to the ripple chamber 6 according to this modified example. The arrangement of the measurement device in this modified example has a configuration similar to that of Fig. 7, but differs from the arrangement in Fig. 7 in that the pressure gauge P2 is not provided and a flow meter F20 is provided between the flow meter F2 and the leak check valve V2-12.

[0084] In this modification, the processing device 920 is configured to determine whether or not there is an abnormality in the polishing based on a plurality of measurement values ​​obtained by a plurality of flow meters (flow meter F20 and flow meter F2). Hereinafter, the flow meter F20 will be referred to as the first flow meter 81, and the flow meter F2 will be referred to as the second flow meter 82, as appropriate.

[0085] The first determination unit 921 performs a first determination to detect whether or not there is a first polishing abnormality based on the first flow rate value obtained by measurement by the first flow meter 81. The first determination unit 921 may be configured to refer to a reference value for the first flow rate value stored in the storage medium 910, and if a change in the first flow rate value exceeds the reference value, the first determination unit 921 may detect a first polishing abnormality and execute error processing. This error processing is not particularly limited, but may be configured such that the apparatus control unit 923 stops operation of the top ring 302, the swing arm 360, the polishing table 350, etc. to stop polishing, or may be configured to display a message or image on a display unit (not shown) notifying of the first polishing abnormality. Note that the algorithm used by the first determination unit 921 is not particularly limited as long as it performs the first determination based on the first flow rate value and the reference value.

[0086] The second determination unit 922 performs a second determination to detect whether or not there is an abnormality in the second polishing based on the second flow rate value obtained by measurement by the second flow meter 82. The second determination may be performed in the same manner as the second determination in the above-described embodiment.

[0087] The upper limit of the measurable flow rate of the first flow meter 81 is preferably higher than the upper limit of the measurable flow rate of the second flow meter 82. This makes it possible to detect a relatively large leak caused by the substrate WF protruding or the like in the first determination, and to accurately detect an abnormality in the second polishing, such as a minute leak, in the second determination. Note that the position of the first flow meter 81 is not particularly limited to the example shown in the figure, as long as the flow rate can be measured during polishing.

[0088] <Variation 2> 19 is a conceptual diagram showing the arrangement of the measurement device in the flow path 22 connected to the ripple chamber 6 according to this modification. The arrangement of the measurement device in this modification has a similar configuration to that in the first modification, but differs from that in the first modification in that the pressure gauge P2 of the above-described embodiment is provided.

[0089] In this modification, the first determination unit 921 may perform the first determination based on a pressure value obtained by at least one of the pressure gauge P2 and the pressure gauge on the secondary side of the pressure regulator R2, as in the above-described embodiment, or may perform the first determination based on a first flow rate value obtained by measurement by the first flow meter 81. Alternatively, the first determination unit 921 may perform the first determination based on the at least one pressure value and the first flow rate value. This further improves the detection accuracy of the first determination. For example, the first determination unit 81 may determine that a first polishing abnormality has occurred when the pressure difference between the first pressure value and the second pressure value exceeds a reference value for the pressure difference or when a change in the first flow rate value exceeds a reference value for the first flow rate value. Alternatively, the first determination unit 81 may determine that a first polishing abnormality has occurred when the pressure difference between the first pressure value and the second pressure value exceeds the reference value and when a change in the first flow rate value exceeds the reference value. The second determination unit 922 can perform a second determination to detect whether or not there is an abnormality in the second polishing based on the second flow rate value obtained by the measurement of the second flow meter 82.

[0090] The above-described embodiments can also be described as the following embodiments. [Embodiment 1] According to embodiment 1, a substrate polishing apparatus is provided, the substrate polishing apparatus comprising: a polishing table supporting a polishing pad for polishing a substrate; a top ring for holding the substrate and pressing it against the polishing pad; and a control device. The top ring comprises at least one elastic membrane configured to form at least one pressure chamber for pressing the substrate, the at least one elastic membrane having at least one opening in a surface that contacts the substrate. The substrate polishing apparatus further comprises a measurement unit disposed in a flow path fluidically connected to the pressure chamber in which the opening is formed, the measurement unit measuring the pressure or flow rate of the flow path. The control device is configured to determine an abnormality in the polishing based on a measurement value obtained by measurement by the measurement unit while the substrate is being polished. The abnormality in the polishing includes at least one of the substrate popping out of the top ring and damage to the substrate. According to embodiment 1, a substrate polishing apparatus can be provided with improved accuracy in detecting an abnormality in the polishing, such as a substrate popping out of the top ring.

[0091] [Mode 2] According to Mode 2, in Mode 1, the measurement unit includes a plurality of pressure gauges or a plurality of flow meters arranged in the flow path fluidly connected to a single pressurizing chamber, and the control device is configured to make the determination based on a plurality of measurement values ​​obtained by the plurality of pressure gauges or the plurality of flow meters. According to Mode 2, by using a plurality of measurement values, it is possible to further improve the accuracy of detecting polishing abnormalities such as the substrate popping out of the top ring.

[0092] [Form 3] According to Form 3, in Form 2, the measurement unit includes a first pressure gauge and a second pressure gauge, and the control device is configured to make the judgment based on the difference between the first pressure value obtained by measurement with the first pressure gauge and the second pressure value obtained by measurement with the second pressure gauge. According to the third aspect, it is possible to further improve the accuracy of detecting abnormalities in polishing, such as the substrate jumping out of the top ring.

[0093] [Mode 4] According to Mode 4, in Mode 3, the second pressure gauge is configured to measure the pressure on the secondary side of a pressure regulator that adjusts the pressure in the flow path, and the first pressure gauge is fluidly connected between the second pressure gauge and the pressurizing chamber. According to Mode 4, since the relatively stable second pressure value can be used as a reference for pressure changes, the detection accuracy of substrate protrusion, etc. can be further improved.

[0094] [Mode 5] According to Mode 5, in Mode 3 or 4, a valve and a flow meter are arranged in the flow path between the first pressure gauge and the second pressure gauge, and the control device is configured to switch the valve so that the measurement position of the first pressure gauge, the flow meter, and the measurement position of the second pressure gauge are fluidly connected in series during polishing. According to Mode 5, while measuring the flow rate with the flow meter, the pressure in the pressurizing chamber can be measured more accurately with the pressure gauge arranged downstream of the flow meter during polishing.

[0095] [Mode 6] According to Mode 6, in any of Modes 1 to 5, the measurement unit includes a first flow meter and a second flow meter, the first flow meter has a higher upper limit of measurable flow rate than the second flow meter, and the control device is configured to detect at least one of a protrusion of the substrate and damage to the substrate based on a first flow rate value obtained by measurement with the first flow meter, and to detect a leak in the pressurizing chamber that does not involve a protrusion of the substrate or damage to the substrate based on a second flow rate value obtained by measurement with the second flow meter. According to Mode 6, various abnormalities such as a protrusion of the substrate and a minute leak can be detected during polishing, and the user can be notified of the abnormality and adverse effects such as damage to the substrate or the device due to these abnormalities can be reduced.

[0096] [Mode 7] According to Mode 7, in any one of Modes 1 to 6, the control device is configured to control at least one of the top ring and the polishing table to stop the polishing when an abnormality in the polishing is detected. According to Mode 7, damage to the top ring or the like can be prevented, and unnecessary polishing during an abnormality can be prevented.

[0097] [Feature 8] According to feature 8, in any one of features 1 to 7, the polishing pad has at least one of grooves and holes for supplying or discharging a liquid onto the polishing pad. According to feature 8, the substrate can be polished more uniformly.

[0098] [Mode 9] According to Mode 9, in any of Modes 1 to 8, a swing arm for swinging the top ring is provided, and the control device is configured to be able to make the determination simultaneously with the start of polishing of the substrate, or to be able to make the determination intermittently or continuously during polishing of the substrate, and to be able to make the determination without interruption when the rotation speed of the polishing table or the top ring is changed. According to Mode 9, even when these polishing conditions are changed, protrusion of the substrate, etc. can be detected, and damage to the substrate, top ring, etc. can be prevented.

[0099] [Mode 10] According to mode 10, a substrate processing apparatus is provided, which further comprises a substrate polishing apparatus according to any one of modes 1 to 9. According to mode 10, it is possible to provide a substrate processing apparatus with improved accuracy in detecting polishing abnormalities, such as a substrate protruding from a top ring during polishing.

[0100] [Embodiment 11] According to embodiment 11, there is provided a substrate polishing method, the substrate polishing method comprising: A substrate polishing method for polishing a substrate by pressing the substrate held by a top ring against a polishing pad supported on a polishing table, wherein the top ring has at least one elastic membrane configured to form at least one pressure chamber for pressing the substrate, the at least one elastic membrane having at least one opening in a surface that contacts the substrate, the method including, while the substrate is being polished, measuring the pressure or flow rate of the flow channel by a measurement unit disposed in a flow channel fluidly connected to the pressure chamber in which the opening is formed, and determining a polishing abnormality based on the measurement value obtained by the measurement unit, the polishing abnormality including at least one of the substrate popping out of the top ring and damage to the substrate. According to aspect 11, the accuracy of detecting polishing abnormalities such as the substrate popping out of the top ring during substrate polishing can be improved.

[0101] [Mode 12] According to Mode 12, a program is proposed for causing a processing device of a substrate polishing apparatus including a polishing table supporting a polishing pad for polishing a substrate and a top ring for holding the substrate and pressing it against the polishing pad, the top ring including at least one elastic membrane configured to form at least one pressure chamber for pressing the substrate, the at least one elastic membrane including at least one opening in a surface that contacts the substrate, the substrate polishing apparatus further including a measurement unit disposed in a flow path fluidically connected to the pressure chamber in which the opening is formed and measuring the pressure or flow rate of the flow path, the program determining a polishing abnormality based on a measurement value obtained by the measurement unit while the substrate is being polished, the polishing abnormality including at least one of the substrate popping out of the top ring and damage to the substrate. According to Mode 12, the accuracy of detecting a polishing abnormality such as a substrate popping out of the top ring during substrate polishing can be improved.

[0102] Although several embodiments of the present invention have been described above, the above-described embodiments of the present invention 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 or omission of the components described in the claims and specification is possible within the scope of solving at least part of the above-described problems or achieving at least part of the effects. [Explanation of symbols]

[0103] 4...Elastic membrane 4a…Bulkhead 4b...Ripple chamber elastic membrane 11, 12, 13, 14, 15, 16, 21, 22, 23, 24, 25, 26...Flow path 30…Fluid supply source 70...Measuring part 71...First pressure gauge 72...Second pressure gauge 81...1st flow meter 82…Second flow meter 300...Polishing unit 302...Top ring 315...Vacuum suction hole 350...Polishing table 352...Polishing pad 352a…Polished surface 352b…Groove 357...Through hole 360...swing arm 900...Control device 910...Storage medium 920...Processing equipment 921...1st judgment section 922...Second judgment section 923...Device control section 1000 Substrate Processing Equipment F1,F2,F3,F4,F5,F6…Flowmeter P1, P2, P3, P4, P5, P6...Pressure gauges R1, R2, R3, R4, R5, R6...Pressure regulators V2-11: Downstream valve V2-12...Leak check valve V20...Compression valve WF board

Claims

1. a polishing table supporting a polishing pad for polishing a substrate; a top ring for holding the substrate and pressing it against the polishing pad; Control device and A substrate polishing apparatus comprising: the top ring includes at least one elastic membrane configured to form at least one pressure chamber for pressing the substrate, the at least one elastic membrane including at least one opening on a surface that contacts the substrate; The substrate polishing apparatus includes: a measuring unit disposed in a flow path fluidly connected to the pressure chamber in which the opening is formed, the measuring unit measuring a pressure or a flow rate of the flow path; the control device is configured to determine an abnormality in the polishing based on a measurement value obtained by the measurement unit while the substrate is being polished, The abnormality in polishing includes at least one of the substrate jumping out of the top ring and the substrate being damaged.

2. the measurement unit includes a plurality of pressure meters or a plurality of flow meters arranged in the flow path fluidly connected to a single pressurizing chamber, 2. The substrate polishing apparatus according to claim 1, wherein the control device is configured to make the determination based on a plurality of measurement values ​​obtained by the plurality of pressure gauges or the plurality of flow meters.

3. the measuring unit includes a first pressure gauge and a second pressure gauge, 3. The substrate polishing apparatus of claim 2, wherein the control device is configured to make the determination based on a difference between a first pressure value obtained by measurement of the first pressure gauge and a second pressure value obtained by measurement of the second pressure gauge.

4. 4. The substrate polishing apparatus of claim 3, wherein the second pressure gauge is configured to measure the pressure on the secondary side of a pressure regulator that adjusts the pressure of the flow path, and the first pressure gauge is fluidly connected between the second pressure gauge and the pressurizing chamber.

5. a valve and a flow meter are disposed in the flow path between the first pressure gauge and the second pressure gauge; 4. The substrate polishing apparatus of claim 3, wherein the control device is configured to switch the valve so that the measurement position of the first pressure gauge, the flow meter, and the measurement position of the second pressure gauge are fluidly connected in series during polishing.

6. the measuring unit includes a first flow meter and a second flow meter; the first flow meter has a higher upper limit of a measurable flow rate than the second flow meter; 6. A substrate polishing apparatus as described in any one of claims 1 to 5, wherein the control device is configured to detect at least one of the substrate popping out and damage to the substrate based on a first flow rate value obtained by measurement of the first flow rate meter, and to detect a leak in the pressure chamber that does not involve the substrate popping out or damage to the substrate based on a second flow rate value obtained by measurement of the second flow rate meter.

7. 6. The substrate polishing apparatus according to claim 1, wherein the control device is configured to control at least one of the top ring and the polishing table to stop the polishing when an abnormality in the polishing is detected.

8. The polishing pad has grooves and holes for supplying or draining liquid onto the polishing pad. The substrate polishing apparatus according to claim 1 , further comprising at least one.

9. a swing arm for swinging the top ring, The control device The determination can be made simultaneously with the start of polishing of the substrate, or 6. A substrate polishing apparatus according to claim 1, wherein the judgment can be made intermittently or continuously during polishing of the substrate, and the judgment can be made without interruption when the rotation speed of the polishing table or the top ring is changed.

10. A substrate processing apparatus comprising the substrate polishing apparatus according to claim 1 .

11. 1. A substrate polishing method for polishing a substrate by pressing a substrate held by a top ring against a polishing pad supported on a polishing table, comprising: the top ring includes at least one elastic membrane configured to form at least one pressure chamber for pressing the substrate, the at least one elastic membrane including at least one opening on a surface that contacts the substrate; The substrate polishing method includes: measuring a pressure or a flow rate of the flow channel by a measuring unit disposed in the flow channel fluidly connected to the pressurizing chamber in which the opening is formed while the substrate is being polished; determining whether there is an abnormality in polishing based on the measurement value obtained by the measurement of the measuring unit; Including, The method for polishing a substrate, wherein the abnormality in the polishing includes at least one of the substrate jumping out of the top ring and the substrate being damaged.

12. a polishing table supporting a polishing pad for polishing a substrate; a top ring for holding the substrate and pressing it against the polishing pad; A program for causing a processing device of a substrate polishing apparatus to perform processing, the top ring includes at least one elastic membrane configured to form at least one pressure chamber for pressing the substrate, the at least one elastic membrane including at least one opening on a surface that contacts the substrate; The substrate polishing apparatus includes: a measuring unit disposed in a flow path fluidly connected to the pressure chamber in which the opening is formed, the measuring unit measuring a pressure or a flow rate of the flow path; In the process, while the substrate is being polished, a determination is made as to whether there is an abnormality in the polishing based on the measurement value obtained by the measurement unit; The polishing abnormality includes at least one of the substrate popping out of the top ring and the substrate being damaged.

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