Substrate processing method and substrate processing apparatus

Abstract

Provided are a substrate processing method and a substrate processing apparatus capable of making the boundary between a portion subjected to surface treatment and a portion not subjected to surface treatment uniform even when the surface treatment time is extended. In this substrate processing method, a processing liquid is discharged toward an outer peripheral portion of a rotating substrate (W). The method includes: performing heat treatment on the substrate (W) for a predetermined time to bring the substrate (W) into a fully warped state by the heat treatment; and discharging the processing liquid toward the outer peripheral portion of the substrate (W) in the fully warped state.

Description

Substrate processing method and substrate processing apparatus

[0001] The present disclosure relates to a substrate processing method and apparatus that process a peripheral edge portion of a substrate with a processing liquid. Here, the substrates include semiconductor wafers, glass substrates for liquid crystal display devices, glass substrates for plasma displays, optical disk substrates, magnetic disk substrates, magneto-optical disk substrates, glass substrates for photomasks, photovoltaic cell substrates, etc. (hereinafter simply referred to as "substrates"). The processing includes etching processing.

[0002] As substrate processing apparatuses that perform chemical processing, cleaning processing, and the like by supplying a processing liquid to a peripheral edge portion of a substrate such as a semiconductor wafer while rotating the substrate, for example, the apparatuses described in Patent Document 1 and Patent Document 2 are known. When performing surface processing of a substrate in the above-described substrate processing apparatus, it is required that a boundary between a surface-processed region and a non-surface-processed region at the peripheral edge portion of the substrate be continuous in a uniform state in the circumferential direction of the substrate.

[0003] Japanese Patent Application Laid-Open No. 2024-044286 Japanese Patent Application Laid-Open No. 2018-142677

[0004] However, the inventors of the present invention have found that when surface processing of a substrate is performed by heating the substrate, if the surface processing time becomes long, the boundary between a surface-processed region and a non-surface-processed region at the peripheral edge portion of the substrate may become non-uniform.

[0005] Accordingly, an object of one aspect of the present disclosure is to provide a substrate processing method and a substrate processing apparatus that can make a boundary between a surface-processed region and a non-surface-processed region uniform even when the surface processing time becomes long.

[0006] In order to solve the above problem, a substrate processing method according to one aspect of the present disclosure is a substrate processing method that discharges a processing liquid toward an outer peripheral portion of a rotating substrate, the method including: performing heat treatment on the substrate for a predetermined time to bring the substrate into a fully warped state by the heat treatment; and discharging the processing liquid toward the outer peripheral portion of the substrate in the fully warped state.

[0007] A substrate processing apparatus according to one aspect of the present disclosure is a substrate processing apparatus for discharging a processing liquid toward the outer periphery of a rotating substrate, comprising: a holding table on which the substrate is placed; a heater positioned opposite to the substrate placed on the holding table; a discharging mechanism for discharging the processing liquid; and a control unit for controlling the heater and the discharging mechanism, wherein the control unit controls the heater and the discharging mechanism to start discharging the processing liquid toward the outer periphery of the substrate after the heater has heated the substrate for a predetermined time.

[0008] According to one aspect of this disclosure, a substrate processing method and a substrate processing apparatus can be provided that make the boundary between the treated and untreated areas uniform, even if the surface processing time is extended.

[0009] This is a plan view showing the schematic configuration of a substrate processing system equipped with a processing unit according to the embodiment of this disclosure. This is a diagram showing the internal structure of the processing unit shown in Figure 1. This is a plan view schematically showing the configuration of the substrate processing unit provided in the processing unit shown in Figure 2. This is a flowchart showing a beveling process performed as an example of substrate processing operation by the processing unit shown in Figure 2. This is a schematic diagram showing a state in which the substrate is not fully warped and a state in which the substrate is fully warped. This is a photograph of the substrate taken from above, showing the result of an etching process in which the substrate is etched as an example of surface treatment of the substrate.

[0010] (Substrate Processing System) Figure 1 is a plan view showing the schematic configuration of a substrate processing system 100 equipped with a processing unit 1 according to the embodiment of this disclosure. This does not show the external appearance of the substrate processing system 100, but is a schematic diagram that clearly shows its internal structure by excluding the outer wall panels and some other components of the substrate processing system 100. The following description mainly concerns the substrate processing system 100, but also includes a description of a substrate processing method in which processing liquid is discharged toward the peripheral edge (outer periphery) of the substrate W.

[0011] The substrate processing system 100 is a single-wafer type device installed, for example, in a cleanroom, which processes substrates W on which circuit patterns, etc. (hereinafter referred to as "patterns") have been formed, one by one. The processing unit 1 equipped in the substrate processing system 100 performs substrate processing using a processing solution.

[0012] In this embodiment, both main surfaces of the substrate W are referred to as "surfaces." Furthermore, on the substrate W, the surface facing downwards is referred to as the "bottom surface," and the surface facing upwards is referred to as the "top surface." The following explanation will primarily use a processing unit 1, which is used for processing semiconductor wafers, as an example, with reference to the drawings, but the method is similarly applicable to processing various other substrates.

[0013] As shown in Figure 1, the substrate processing system 100 has a substrate processing area 110 for processing the substrate W. An indexer section 120 is provided adjacent to this substrate processing area 110. The indexer section 120 has a container holding section 121 that can hold a plurality of containers C for housing the substrate W.

[0014] Furthermore, the indexer unit 120 is equipped with an indexer robot 122 for accessing the container C held by the container holding unit 121 to remove unprocessed substrates W from the container C or to store processed substrates W in the container C. Each container C contains multiple substrates W in a nearly horizontal position.

[0015] The indexer robot 122 comprises a base portion 122a fixed to the device housing, a multi-joint arm 122b rotatably mounted on the base portion 122a around a vertical axis, and a hand 122c attached to the tip of the multi-joint arm 122b. The hand 122c is structured to hold the substrate W placed on its upper surface.

[0016] In the substrate processing area 110, a mounting table 112 is provided to allow substrates W from the indexer robot 122 to be placed on it. In a plan view, a substrate transport robot 111 is positioned approximately in the center of the substrate processing area 110. Furthermore, multiple processing units 1 are arranged to surround this substrate transport robot 111.

[0017] Specifically, multiple processing units 1 are arranged facing the space where the substrate transport robot 111 is located. The substrate transport robot 111 randomly accesses the mounting table 112 with respect to these processing units 1 and transfers the substrate W between the robot and the mounting table 112. Meanwhile, each processing unit 1 performs predetermined processing on the substrate W and corresponds to the substrate processing apparatus of this disclosure.

[0018] In this embodiment, these processing units 1 have the same function. Therefore, parallel processing of multiple substrates W is possible. Note that the substrate transfer robot 111 does not necessarily need the mounting table 112 if it is possible to directly receive the substrates W from the indexer robot 122.

[0019] (Inside the Processing Unit) Figure 2 shows the internal structure of the processing unit 1 shown in Figure 1. Figure 3 is a schematic plan view showing the configuration of the substrate processing unit SP included in the processing unit 1 shown in Figure 2. In Figure 2, the dimensions and number of each part may be exaggerated or simplified for ease of understanding.

[0020] As shown in Figures 2 and 3, the processing unit 1 has a structure in which a substrate processing unit SP is arranged in the internal space 12 within the chamber 11. The processing unit 1 comprises the substrate processing unit SP and a control unit 10. The processing unit 1 is a device that discharges processing liquid toward the peripheral Ws of a substrate W that rotates within the chamber 11.

[0021] Base support members 16, 16 are fixed to the upper surface of the bottom wall 11a of the chamber 11 by fastening components such as bolts, spaced apart from each other. A base member 17 is fixed to the upper ends of these base support members 16, 16 by fastening components such as bolts. The upper surface of this base member 17 is finished to allow the installation of a substrate processing unit SP for performing substrate processing on a substrate W, and the substrate processing unit SP is installed on this upper surface. Each part constituting this substrate processing unit SP is electrically connected to a control unit 10 that controls the entire apparatus and operates in accordance with instructions from the control unit 10. The control unit 10 corresponds to the control unit of this disclosure.

[0022] In Figure 1, the processing unit 1 has a transport opening in the side wall facing the substrate transport robot 111, connecting the internal space 12 with the outside of the chamber 11. Therefore, the handle (not shown) of the substrate transport robot 111 can access the substrate processing unit SP through the transport opening. In other words, the transport opening allows for the loading and unloading of substrates W into and out of the internal space 12. A shutter 15 for opening and closing this transport opening is also attached to the side wall.

[0023] A shutter opening / closing mechanism (not shown) is connected to the shutter 15, which opens and closes the shutter 15 in response to an opening / closing command from the control unit 10. More specifically, in the processing unit 1, when an unprocessed substrate W is brought into the chamber 11, the shutter opening / closing mechanism opens the shutter 15, and the unprocessed substrate W is brought into the substrate processing unit SP by the handle of the substrate transport robot 111. In other words, the substrate W is placed on the spin chuck 21 of the substrate processing unit SP with its top surface facing upwards.

[0024] Then, after the substrate is loaded, the handle of the substrate transport robot 111 retracts from the chamber 11, and the shutter opening / closing mechanism closes the shutter 15. Then, within the processing space 12a of the chamber 11, the substrate processing unit SP performs beveling on the peripheral Ws of the substrate W. After the beveling is completed, the shutter opening / closing mechanism opens the shutter 15 again, and the handle of the substrate transport robot 111 removes the processed substrate W from the substrate processing unit SP.

[0025] (Substrate Processing Unit) The substrate processing unit SP includes a holding and rotating mechanism 2, a splash prevention mechanism 3, an upper surface protection heating mechanism 4, a discharge mechanism 5, and an atmosphere separation mechanism 6. These mechanisms are mounted on the base member 17. The holding and rotating mechanism 2, the splash prevention mechanism 3, the upper surface protection heating mechanism 4, the discharge mechanism 5, and the atmosphere separation mechanism 6 are arranged in a predetermined relative position.

[0026] (Holding and Rotating Mechanism) The holding and rotating mechanism 2 includes a substrate holding section 2A that holds the substrate W in a substantially horizontal position with one main surface of the substrate W facing upward, and a rotating mechanism 2B that synchronously rotates the substrate holding section 2A holding the substrate W and a part of the scattering prevention mechanism 3. Therefore, when the rotating mechanism 2B is activated in response to a rotation command from the control unit 10, the substrate W and the rotating cup section 31 of the scattering prevention mechanism 3 are rotated around a rotation axis AX that extends parallel to the vertical direction.

[0027] The substrate holding section 2A is equipped with a spin chuck 21, which is a disc-shaped member smaller than the substrate W. The spin chuck 21 corresponds to an example of the holding table of this disclosure and is made of resin. The upper surface of the spin chuck 21 is substantially horizontal, and the spin chuck 21 is positioned so that its central axis coincides with the rotation axis AX.

[0028] The spin chuck 21 is installed inside the chamber 11 and on which the substrate W is placed. A cylindrical rotating shaft portion 22 is connected to the lower surface of the spin chuck 21. The rotating shaft portion 22 extends vertically with its axis aligned with the rotation axis AX. A rotating mechanism 2B is also connected to the rotating shaft portion 22.

[0029] The rotating mechanism 2B includes a motor 23 and a power transmission unit 24. The motor 23 generates rotational driving force to rotate the substrate holding unit 2A and the rotating cup unit 31 of the anti-scattering mechanism 3. The power transmission unit 24 transmits the rotational driving force generated by the motor 23 to the rotating shaft unit 22.

[0030] A through-hole (not shown) is provided in the center of the spin chuck 21, and this through-hole communicates with the internal space of the rotating shaft portion 22. A pump 26 is connected to the internal space via piping 25, which has a valve (not shown) interposed therein. The pump 26 and the valve are electrically connected to the control unit 10 and operate in response to commands from the control unit 10. This allows negative pressure and positive pressure to be selectively applied to the spin chuck 21.

[0031] For example, when the substrate W is placed on the upper surface of the spin chuck 21 in a nearly horizontal position and the pump 26 applies negative pressure to the spin chuck 21, the spin chuck 21 will attract and hold the substrate W from below. On the other hand, when the pump 26 applies positive pressure to the spin chuck 21, the substrate W becomes removable from the upper surface of the spin chuck 21. Also, when the pump 26 stops suction, the substrate W becomes able to move horizontally on the upper surface of the spin chuck 21.

[0032] A nitrogen gas supply unit 29 is connected to the spin chuck 21 via a pipe 28 located in the center of the rotating shaft portion 22. The nitrogen gas supply unit 29 supplies ambient temperature nitrogen gas, supplied from a utility in the factory where the substrate processing system 100 is installed, to the spin chuck 21 at a flow rate and timing corresponding to the gas supply command from the control unit 10. As a result, the nitrogen gas supply unit 29 circulates the nitrogen gas radially outward from the center on the underside of the substrate W. In this embodiment, nitrogen gas is used, but other inert gases may also be used.

[0033] The rotating mechanism 2B not only rotates the spin chuck 21 integrally with the substrate W, but also has a power transmission unit 27 to rotate the rotating cup portion 31 in synchronization with the rotation. The power transmission unit 27 has an annular member 27a made of a non-magnetic material or resin, a spin chuck-side magnet 27b built into the annular member 27a, and a cup-side magnet 27c built into the lower cup 32, which is a component of the rotating cup portion 31.

[0034] The annular member 27a is attached to the rotating shaft portion 22 and is rotatable together with the rotating shaft portion 22 around the rotating shaft AX. The lower cup 32 is positioned concentrically with the rotating shaft portion 22 and the annular member 27a, with the inner circumferential surface of the lower cup 32 separated from the outer circumferential surface of the annular member 27a by a predetermined distance.

[0035] An engagement pin and a connecting magnet (not shown) are provided on the upper outer edge of the lower cup 32, and these connect the upper cup 33 to the lower cup 32, and this connecting body functions as a rotating cup portion 31. The lower cup 32 is supported on the upper surface of the base member 17 by a bearing (not shown) so as to be rotatable around the rotation axis AX.

[0036] When the annular member 27a rotates together with the rotating shaft 22 by the motor 23, the lower cup 32 rotates in the same direction as the annular member 27a due to the magnetic force between the spin chuck-side magnet 27b and the cup-side magnet 27c, while maintaining the air gap with the annular member 27a. As a result, the rotating cup portion 31 rotates around the rotation axis AX. In other words, the rotating cup portion 31 rotates in the same direction as the substrate W and in synchronization with it.

[0037] (Splatter prevention mechanism) The splash prevention mechanism 3 has a rotating cup portion 31 that can rotate around the rotation axis AX while surrounding the outer circumference of the substrate W held by the spin chuck 21, and a fixed cup portion 34 that is fixedly provided so as to surround the rotating cup portion 31. The rotating cup portion 31 is provided so as to be able to rotate around the rotation axis AX while surrounding the outer circumference of the rotating substrate W by connecting the upper cup 33 to the lower cup 32. The droplets collected by the rotating cup portion 31 are recovered together with the gaseous components and collected in the fixed cup portion 34.

[0038] (Top surface protection heating mechanism) The top surface protection heating mechanism 4 comprises a disc portion 42, an internal heater 421, a heater drive unit 422, a support member 404, and a heating gas supply unit 47, and corresponds to an example of a heater of this disclosure. The disc portion 42 is positioned opposite to the substrate W placed on the spin chuck 21. That is, the disc portion 42 is positioned above the upper surface of the substrate W held by the spin chuck 21 and is held in a horizontal position.

[0039] The disc portion 42 incorporates an internal heater 421 that is driven and controlled by a heater drive unit 422. The disc portion 42 has a diameter slightly shorter than that of the substrate W. The disc portion 42 is supported by a support member 404 such that its lower surface covers the upper surface area of ​​the substrate W, excluding the peripheral edge Ws, from above.

[0040] The lower end of the support member 404 is attached to the center of the disc portion 42. A cylindrical through hole (not shown) is formed so as to penetrate vertically through the support member 404 and the disc portion 42. A central nozzle 45 is inserted vertically through this through hole. This central nozzle 45 is connected to a heating gas supply unit 47 via a pipe 46.

[0041] The heating gas supply unit 47 heats ambient temperature nitrogen gas supplied from the factory where the substrate processing system 100 is installed using a heater 471, and supplies it to the substrate W at a flow rate and timing corresponding to the heating gas supply command from the control unit 10. A ribbon heater 48 is attached to a part of the piping 46. The ribbon heater 48 generates heat in response to the heating command from the control unit 10, heating the nitrogen gas flowing through the piping 46.

[0042] The heated nitrogen gas (hereinafter referred to as "heated gas") is then pumped towards the central nozzle 45 and discharged from the central nozzle 45. For example, when the heated gas is supplied with the disc portion 42 positioned in a processing position close to the substrate W held by the spin chuck 21, the heated gas flows from the center of the space between the upper surface of the substrate W and the disc portion 42 toward the periphery.

[0043] The upper end of the support member 404 is fixed to a beam member 49 that extends horizontally. This beam member 49 is connected to a lifting mechanism (not shown) attached to the upper surface of the base member 17, and is raised and lowered by the lifting mechanism in response to a command from the control unit 10. For example, in Figure 2, when the beam member 49 is positioned downward, the disc portion 42 connected to the beam member 49 via the support member 404 is positioned in the processing position.

[0044] On the other hand, when the lifting mechanism lifts the beam member 49 in response to a lifting command from the control unit 10, the disc portion 42, the beam member 49, and the support member 404 rise integrally, and the upper cup 33 also interlocks to separate from the lower cup 32 and rise. This widens the space between the spin chuck 21, the upper cup 33, and the disc portion 42, making it possible to carry the substrate W into and out of the spin chuck 21.

[0045] (Processing Mechanism) As shown in the partially enlarged views of FIG. 2 and FIG. 3, the discharge mechanism 5 includes a processing liquid discharge nozzle 51D, a nozzle moving part 54, a nozzle head 56, and a processing liquid supply part 52. The nozzle head 56 includes processing liquid discharge nozzles 51A, 51B, 51C and a nozzle holder 53. The processing liquid discharge nozzles 51A to 51C are arranged on the upper surface side of the substrate W, and the processing liquid discharge nozzle 51D is arranged on the lower surface side of the substrate W.

[0046] It should be noted that the discharge mechanism 5 may include only the nozzle moving part 54 and the nozzle head 56 among the processing liquid discharge nozzle 51D, the nozzle moving part 54, and the nozzle head 56, or may include only the processing liquid discharge nozzle 51D.

[0047] The processing liquid supply part 52 supplies processing liquid to the processing liquid discharge nozzles 51A to 51D. The processing liquid discharge nozzles 51A to 51D discharge the processing liquid. In addition, although two processing liquid supply parts 52 are illustrated in FIG. 2, they are identical.

[0048] In this embodiment, three processing liquid discharge nozzles 51A to 51C are provided, and the processing liquid supply part 52 is connected thereto. In addition, the processing liquid supply part 52 is configured to be able to supply chemical liquids such as SC1 and DHF, and functional water (CO ２ such as water) as processing liquid, and SC1, DHF, and functional water can be independently discharged from the three processing liquid discharge nozzles 51A, 51B, and 51C respectively. Chemical liquids such as SC1 and DHF are etching liquids for etching the substrate W.

[0049] Each of the processing liquid discharge nozzles 51A to 51C is provided with a discharge port (not shown) for discharging the processing liquid on the lower surface of its tip. The lower parts of the processing liquid discharge nozzles 51A to 51C are positioned in the notches 425 of the disc portion 42, with each discharge port facing the upper surface of the peripheral edge Ws of the substrate W. The upper parts of the processing liquid discharge nozzles 51A to 51C are movably attached to the nozzle holder 53 in the radial direction D1. This nozzle holder 53 is connected to a nozzle moving unit 54. The nozzle moving unit 54 is attached to a lifting mechanism, which moves the nozzle moving unit 54 in the vertical direction Z.

[0050] In this embodiment, a processing liquid discharge nozzle 51D and a nozzle support portion 57 are provided below the substrate W held by the spin chuck 21 in order to discharge the processing liquid toward the lower surface of the peripheral edge Ws of the substrate W. The nozzle support portion 57 has a thin-walled cylindrical portion 571 extending in the vertical direction and a flange portion 572 having an annular shape that is folded outward radially at the upper end of the cylindrical portion 571.

[0051] The cylindrical portion 571 has a shape that allows it to be freely inserted into the air gap formed between the annular member 27a and the lower cup 32. The nozzle support portion 57 is fixedly positioned such that the cylindrical portion 571 is freely inserted into the air gap and the flange portion 572 is positioned between the substrate W held by the spin chuck 21 and the lower cup 32.

[0052] Three processing liquid discharge nozzles 51D are attached to the upper peripheral edge of the flange portion 572. Each processing liquid discharge nozzle 51D has a discharge port (not shown) that opens toward the lower surface of the peripheral edge Ws of the substrate W, and is capable of discharging processing liquid supplied from the processing liquid supply unit 52 via the piping 58.

[0053] (Atmosphere Separation Mechanism) The atmosphere separation mechanism 6 separates the internal space 12 within the chamber 11 into a processing space 12a in which beveling of the substrate W can be performed, and an outer space 12b outside the processing space 12a. The atmosphere separation mechanism 6 is positioned to completely surround the spin chuck 21, the substrate W held by the spin chuck 21, the rotating cup portion 31, and the upper surface protection heating mechanism 4 from above. The atmosphere separation mechanism 6 has a lower sealing cup member 61 and an upper sealing cup member 62. The lower sealing cup member 61 is provided to be movable in the vertical direction.

[0054] As the lower sealing cup member 61 descends and is positioned at its lower limit, the upper sealing cup member 62, the lower sealing cup member 61, and the fixed cup portion 34 are connected in the vertical direction. Thus, the upper sealing cup member 62, the lower sealing cup member 61, and the fixed cup portion 34 form a processing space 12a.

[0055] Furthermore, as the lower sealing cup member 61 rises and moves to the retracted position, the upper cup 33 also rises together with it by engaging with the lower sealing cup member 61. As a result, the upper cup 33 and the upper surface protection heating mechanism 4 move upward away from the spin chuck 21. The movement of the lower sealing cup member 61 to the retracted position creates a transport space for the hand of the substrate transport robot 111 to access the spin chuck 21.

[0056] (Distance Sensor) The processing unit 1 may further include a distance sensor 7. The distance sensor 7 is a sensor capable of measuring the distance between the distance sensor 7 and the substrate W. This distance is the distance along the vertical direction. The distance sensor 7 is positioned opposite the substrate W which is mounted on the spin chuck 21 and is fixed to the lower surface of the beam member 49. Specifically, the distance sensor 7 is positioned directly above the peripheral edge Ws of the substrate W.

[0057] The distance sensor 7 may be, for example, an optical sensor, and may include a light-emitting unit that emits light onto the substrate W and a light-receiving unit that receives the light reflected from the substrate W. Alternatively, the distance sensor 7 may be an imaging sensor that images the substrate W, and may be capable of measuring the distance between the distance sensor 7 and the substrate W based on the image of the substrate W. The distance sensor 7 may be positioned directly below the peripheral edge Ws of the substrate W.

[0058] (Control Unit) The control unit 10 includes an arithmetic processing unit 10A, a storage unit 10B, a reading unit 10C, a drive control unit 10D, and a communication unit 10E. The storage unit 10B is composed of a hard disk drive or the like and stores a program for the processing unit 1 to perform bevel processing.

[0059] The program is stored, for example, on a computer-readable recording medium RM (e.g., an optical disk, magnetic disk, magneto-optical disk, etc.), read from the recording medium RM by the reading unit 10C, and stored in the storage unit 10B. Furthermore, the provision of the program is not limited to the recording medium RM; for example, the program may be provided via a telecommunications line. The drive control unit 10D controls each drive unit of the processing unit 1. The communication unit 10E is for the arithmetic processing unit 10A to communicate with the substrate transport robot 111.

[0060] The arithmetic processing unit 10A is composed of a computer having a CPU (Central Processing Unit) and RAM (Random Access Memory), and controls each part of the processing unit 1 according to the program stored in the storage unit 10B, and performs bevel processing. The bevel processing by the processing unit 1 will be described below with reference to Figure 4.

[0061] (Substrate Processing Operation) Figure 4 is a flowchart showing a beveling process performed as an example of substrate processing operation by the processing unit 1 shown in Figure 2. First, the arithmetic processing unit 10A loads the substrate W (S1). Specifically, the arithmetic processing unit 10A requests the substrate transport robot 111 to load the substrate W via the communication unit 10E and waits until the unprocessed substrate W is brought into the processing unit 1 and placed on the upper surface of the spin chuck 21. Then, the substrate W is placed on the spin chuck 21. At this point, the pump 26 is stopped, and the substrate W is able to move horizontally on the upper surface of the spin chuck 21.

[0062] When the substrate W is placed on the upper surface of the spin chuck 21, the substrate transport robot 111 retracts from the processing unit 1. Subsequently, the arithmetic processing unit 10A uses the centering mechanism (not shown) provided in the substrate processing unit SP to center the substrate W. This eliminates the eccentricity of the substrate W relative to the spin chuck 21, so that the center of the substrate W coincides with the center of the spin chuck 21. After centering the substrate W, the arithmetic processing unit 10A operates the pump 26 to apply negative pressure to the spin chuck 21. As a result, the spin chuck 21 attracts and holds the substrate W from below.

[0063] Next, the calculation processing unit 10A prepares for the discharge of the processing liquid (S2). Specifically, the calculation processing unit 10A gives a downward command to the lifting mechanism (not shown). In response, the lifting mechanism lowers the lower sealing cup member 61, nozzle head 56, beam member 49, and upper surface protection heating mechanism 4 together. During this downward movement, the upper cup 33 is connected to the lower cup 32. This forms the rotating cup portion 31.

[0064] In this state, the lower surface of the disc portion 42 covers the upper surface area of ​​the substrate W, excluding the peripheral edge Ws, from above. In addition, the processing liquid discharge nozzles 51A to 51C are positioned within the notch 425 of the disc portion 42 with their discharge ports facing the upper surface of the peripheral edge Ws on the substrate W.

[0065] After the processing liquid discharge nozzles 51A to 51C are positioned, the calculation processing unit 10A gives a rotation command to the motor 23, and the spin chuck 21 and rotating cup section 31 that hold the substrate W start to rotate. The rotation speed of the substrate W and the rotating cup section 31 is set to, for example, 1800 revolutions per minute.

[0066] Next, the arithmetic processing unit 10A preheats the substrate W (S3). Specifically, the arithmetic processing unit 10A controls the heater drive unit 422 to raise the internal heater 421 to the desired temperature. The arithmetic processing unit 10A also issues a heating gas supply command to the heating gas supply unit 47. As a result, nitrogen gas heated by the heater 471, i.e., the heating gas, is pumped from the heating gas supply unit 47 towards the substrate W. This heating gas is heated by the ribbon heater 48 as it passes through the piping 46.

[0067] As a result, the heating gas is supplied to the top surface protection heating mechanism 4 while preventing a temperature drop during gas supply via the piping 46. In the top surface protection heating mechanism 4, the heating gas is heated by the internal heater 421. The heated gas is then discharged towards the space sandwiched between the substrate W and the disc portion 42 near the peripheral edge Ws of the substrate W. Therefore, the upper surface of the peripheral edge Ws of the substrate W is heated intensively.

[0068] Furthermore, the peripheral Ws of the substrate W are also heated by the internal heater 421. As a result, the temperature of the peripheral Ws of the substrate W rises over time, reaching a temperature suitable for beveling, for example, 90°C. In addition, the temperature of areas other than the peripheral Ws also rises to approximately the same temperature due to the heat from the internal heater 421. In other words, in this embodiment, the in-plane temperature of the upper surface of the substrate W is approximately uniform.

[0069] In step S3, the arithmetic processing unit 10A performs heat treatment on the substrate W for a first hour using the internal heater 421. The first hour corresponds to a predetermined time in this disclosure. The first hour is the time from the point in time when the arithmetic processing unit 10A controls the heater drive unit 422 to start raising the temperature of the internal heater 421 until the point in time when the arithmetic processing unit 10A controls the processing liquid supply unit 52 to supply processing liquid to the processing liquid discharge nozzles 51A to 51D.

[0070] The arithmetic processing unit 10A causes the substrate W to be fully warped by the first hour of heat treatment. At this time, the upper surface of the substrate W is heated by the internal heater 421, causing the upper surface of the substrate W to expand due to thermal expansion, and the substrate W becomes fully warped so that the peripheral edges Ws of the substrate W are directed downwards. In some cases, the substrate W may be fully warped so that the peripheral edges Ws are directed upwards.

[0071] In step S3, the arithmetic processing unit 10A may determine whether the substrate W has warped completely using a distance sensor 7 positioned opposite the substrate W. The arithmetic processing unit 10A determines that the substrate W has warped completely if the distance between the distance sensor 7 and the substrate W, as measured by the distance sensor 7, reaches a predetermined distance. Conversely, the arithmetic processing unit 10A determines that the substrate W has not warped completely if the distance between the distance sensor 7 and the substrate W, as measured by the distance sensor 7, does not reach a predetermined distance.

[0072] The memory unit 10B stores a predetermined distance. The arithmetic processing unit 10A obtains the predetermined distance from the memory unit 10B and determines whether the substrate W has warped completely. If the arithmetic processing unit 10A determines that the substrate W has warped completely, it executes the process of the next step S4. If the arithmetic processing unit 10A determines that the substrate W has not warped completely, it continues the process of determining whether the substrate W has warped completely.

[0073] Furthermore, the arithmetic processing unit 10A moves the processing liquid discharge nozzles 51A to 51D to the outermost position in the radial direction of the substrate W within the range in which the processing liquid discharge nozzles 51A to 51D can move, at any timing while the processing of step S3 is being performed. At this time, the discharge ports of the processing liquid discharge nozzles 51A to 51D are positioned between the substrate W and the upper cup 33 in a plan view from vertically above.

[0074] The arithmetic processing unit 10A controls the processing liquid supply unit 52 for any period of time while the processing in step S3 is being performed, to discharge the processing liquid from the processing liquid discharge nozzles 51A to 51D. This allows the old processing liquid and air bubbles in the processing liquid discharge nozzles 51A to 51D to be discharged outside the nozzles 51A to 51D without coming into contact with the substrate W. Here, the period for discharging the processing liquid is, for example, 5 seconds.

[0075] The arithmetic processing unit 10A heats the substrate W with the internal heater 421 for a first hour, and then processes the peripheral edge Ws of the substrate W with the processing liquid (S4). Specifically, the arithmetic processing unit 10A moves the processing liquid discharge nozzles 51A to 51C to a position where the discharge ports of the processing liquid discharge nozzles 51A to 51C are located above the peripheral edge Ws of the substrate W. The arithmetic processing unit 10A also moves the processing liquid discharge nozzle 51D to a position where the discharge port of the processing liquid discharge nozzle 51D is located below the peripheral edge Ws of the substrate W.

[0076] The processing unit 10A then controls the processing liquid supply unit 52 to supply processing liquid to the processing liquid discharge nozzles 51A to 51D. Specifically, a stream of processing liquid is discharged from the processing liquid discharge nozzles 51A to 51C so as to hit the upper surface of the peripheral edge Ws on the substrate W, and a stream of processing liquid is discharged from the processing liquid discharge nozzle 51D so as to hit the lower surface of the peripheral edge Ws on the substrate W. This performs beveling on the peripheral edge Ws of the substrate W.

[0077] Furthermore, while the processing in step S4 is being performed, the arithmetic processing unit 10A controls the heater drive unit 422 to continue driving the internal heater 421. Alternatively, the arithmetic processing unit 10A may discharge the processing liquid onto the upper surface of the peripheral edge Ws using the processing liquid discharge nozzles 51A to 51C, instead of discharging the processing liquid onto the lower surface of the peripheral edge Ws. Alternatively, the arithmetic processing unit 10A may discharge the processing liquid onto the lower surface of the peripheral edge Ws using the processing liquid discharge nozzle 51D, instead of discharging the processing liquid onto the upper surface of the peripheral edge Ws.

[0078] After heating the substrate W with the internal heater 421 for a first hour, the arithmetic processing unit 10A controls the processing liquid supply unit 52 in step S4 to discharge the processing liquid towards the peripheral edge Ws of the warped substrate W using the processing liquid discharge nozzles 51A to 51D. As described above, after heating the substrate W with the internal heater 421 for a first hour, the arithmetic processing unit 10A controls the internal heater 421 and the discharge mechanism 5 to start discharging the processing liquid towards the peripheral edge Ws of the substrate W.

[0079] Then, when the arithmetic processing unit 10A detects the elapsed processing time required for the beveling of the substrate W, it terminates the surface treatment of the substrate W (S5). Specifically, the arithmetic processing unit 10A issues a supply stop command to the processing liquid supply unit 52 and stops the discharge of the processing liquid.

[0080] Subsequently, the arithmetic processing unit 10A issues a command to stop supplying the heating gas to the heating gas supply unit 47, stopping the supply of heating gas from the heating gas supply unit 47 to the substrate W. The arithmetic processing unit 10A also issues a command to stop rotation to the motor 23, stopping the rotation of the spin chuck 21 and the rotating cup unit 31. Furthermore, the arithmetic processing unit 10A controls the heater drive unit 422 to stop the internal heater 421.

[0081] Next, the arithmetic processing unit 10A observes the peripheral Ws of the substrate W and checks the result of the beveling process (S6). Specifically, the arithmetic processing unit 10A positions the upper cup 33 in a retracted position, similar to when the substrate W is loaded, and forms a transport space. Then, the arithmetic processing unit 10A controls the observation head drive unit (not shown) to bring the observation head (not shown) closer to the substrate W.

[0082] The processing unit 10A illuminates the peripheral Ws of the substrate W via the observation head by turning on the light source unit (not shown). The imaging unit (not shown) receives the reflected light reflected from the peripheral Ws and adjacent areas and images the peripheral Ws and adjacent areas. In other words, while the substrate W is rotating around the rotation axis AX, the imaging unit acquires a peripheral image of the peripheral Ws along the rotation direction of the substrate W from multiple images of the peripheral Ws.

[0083] Then, the arithmetic processing unit 10A controls the observation head drive unit to retract the observation head from the substrate W. In parallel with this, the arithmetic processing unit 10A checks whether the beveling process has been performed well, based on the captured peripheral Ws and adjacent region images, i.e., the peripheral image. In this embodiment, as an example of this check, the processing width processed by the processing liquid from the edge face of the substrate W toward the center of the substrate W is checked from the peripheral image.

[0084] After inspection, the arithmetic processing unit 10A sends an unloading request for the substrate W to the substrate transport robot 111 via the communication unit 10E, and the processed substrate W is discharged from the processing unit 1 (S7). This series of steps is repeated.

[0085] (Regarding substrate warping) Figure 5 is a schematic diagram showing the state in which the substrate W is not fully warped and the state in which the substrate W is fully warped. Specifically, reference numeral 501 in Figure 5 shows the state in which the substrate W is not fully warped, and reference numeral 502 in Figure 5 shows the state in which the substrate W is fully warped.

[0086] As shown in Figure 5, consider the case where the surface of the substrate W is treated by discharging a processing liquid from processing liquid discharge nozzles 51A to 51C (processing liquid discharge nozzles 51B and 51C are not shown) toward the peripheral edge Ws of the substrate W. As shown by reference numeral 501 in Figure 5, the point of contact of the processing liquid on the substrate W when the substrate W is not fully warped is indicated by P1. Also, as shown by reference numeral 502 in Figure 5, the point of contact of the processing liquid on the substrate W when the substrate W is fully warped is indicated by P2.

[0087] As shown by reference numerals 501 and 502 in Figure 5, the liquid application positions P1 and P2 are different. In other words, the application position of the processing liquid to the substrate W differs depending on the degree of warping of the substrate W. Specifically, as the degree of warping of the substrate W increases, the liquid application position P2 is located closer to the peripheral edge Ws of the substrate W in the radial direction of the substrate W than the liquid application position P1.

[0088] Therefore, by fully curving the substrate W in step S3 and then discharging the treatment solution onto the peripheral edge Ws of the substrate W in step S4, the following effects can be obtained. In other words, even if the surface treatment time is extended, the boundary between the treated and untreated areas can be made uniform.

[0089] (Results of Etching Treatment) Figure 6 shows the results of etching treatment on substrate W as an example of surface treatment of substrate W, and is a photograph of substrate W taken from above. Reference numeral 601 in Figure 6 is a photograph showing the result of etching treatment on substrate W when it is not fully warped, and reference numeral 602 in Figure 6 is a photograph showing the result of etching treatment on substrate W when it is fully warped. In both cases of reference numeral 601 and 602 in Figure 6, the treatment was performed by dispensing the SC1 chemical solution onto substrate W for 60 seconds.

[0090] In Figure 6, W1 indicates areas on the substrate W where etching has been performed, and W2 indicates areas where etching has not been performed and the film remains. As shown by reference numeral 601 in Figure 6, when the substrate W is etched while it is not fully warped, bleeding occurs at the boundary between the etched areas W1 and the unetched areas W2. One possible reason for this bleeding at the boundary is that the substrate W warps as it heats up while the processing solution is being discharged onto it, as shown in Figure 5, and the contact position of the processing solution changes.

[0091] On the other hand, as shown by reference numeral 602 in Figure 6, when the substrate W is etched while it is fully warped, the boundary between the etched area W1 and the unetched area W2 can be made uniform. This is because, while the processing solution is being discharged onto the substrate W, the temperature of the substrate W is stable and the shape of the substrate W is also stable, resulting in a constant contact position of the processing solution on the substrate W in the radial direction.

[0092] Therefore, by discharging the processing solution onto the peripheral Ws of the warped substrate W, the boundary between the etched area W1 and the unetched area W2 can be made uniform. As a result, when the processing solution is an etching solution, the film is less likely to peel off from the substrate W, and the yield of the substrate W can be improved in subsequent processes.

[0093] Furthermore, as described above, the arithmetic processing unit 10A performs a determination using the distance sensor 7, which allows for accurate determination of whether or not the substrate W has warped completely, and ensures that the application position of the processing liquid to the substrate W in the radial direction of the substrate W remains constant.

[0094] (Modification 1) The substrate processing unit SP may be equipped with a heater for heating the lower surface of the substrate W held by the spin chuck 21, instead of the upper surface protection heating mechanism 4. In this case, the heater is located on the lower surface side of the substrate W.

[0095] In step S3, consider the case where the arithmetic processing unit 10A performs heat treatment on the substrate W for a first hour using this heater. In this case, since the heater heats the lower surface of the substrate W, the lower surface of the substrate W expands due to heat, and the substrate W warps to its limit, with the peripheral edge Ws of the substrate W pointing upwards.

[0096] (Modification 2) In step S3, when the arithmetic processing unit 10A determines whether the substrate W has warped completely using the distance sensor 7, it may determine whether a second time has elapsed since the point in time when the distance between the distance sensor 7 and the substrate W, as measured by the distance sensor 7, stopped changing over time and reached a steady state. In this case, the storage unit 10B stores the second time.

[0097] The arithmetic processing unit 10A obtains the second time from the storage unit 10B and performs this determination. The steady state is a state in which the distance between the distance sensor 7 and the substrate W is constant or approximately constant. Approximately constant means that the absolute value of the change in distance per unit time is less than or equal to a predetermined threshold.

[0098] The arithmetic processing unit 10A determines that the substrate W has fully warped if two hours have elapsed since the distance between the distance sensor 7 and the substrate W reached a steady state. Conversely, the arithmetic processing unit 10A determines that the substrate W has not fully warped if two hours have not elapsed since the distance between the distance sensor 7 and the substrate W reached a steady state.

[0099] The arithmetic processing unit 10A can accurately determine whether the shape of the substrate W is maintained by determining whether a second time has elapsed since the distance between the distance sensor 7 and the substrate W reached a steady state without changing over time. Therefore, the application position of the processing liquid to the substrate W in the radial direction can be reliably kept constant.

[0100] (Modification 3) In step S3, the first time for which the substrate W is heat-treated may be a time obtained in advance before the heat treatment as the heating time necessary to completely warp the substrate W. In this case, the storage unit 10B stores the first time. The arithmetic processing unit 10A obtains the first time from the storage unit 10B and performs the heat treatment on the substrate W. The first time stored in the storage unit 10B is, for example, 40 seconds.

[0101] The first time stored in the memory unit 10B is the time obtained by conducting an experiment in which a substrate of the same type as the substrate W to be processed is subjected to heat treatment, and measuring the time from the start of the heat treatment until the substrate is fully warped. Here, the state in which the substrate W is fully warped is the state in which the shape of the substrate W is maintained from the time when the deformation of the substrate W stops until a predetermined second time has elapsed. For example, the state in which the substrate W is fully warped may be the state in which the second time has elapsed from the time when the distance between the distance sensor and the substrate W, as measured by a distance sensor such as the distance sensor 7, reaches a steady state.

[0102] With the above configuration, the arithmetic processing unit 10A uses a first time pre-stored in the storage unit 10B, making it easy to determine whether or not the substrate W has warped completely. The storage unit 10B may store a first time for each type of substrate W. In this case, the arithmetic processing unit 10A obtains the first time corresponding to the type of substrate W held in the spin chuck 21 from the storage unit 10B and performs heat treatment on the substrate W. This makes it possible to appropriately determine whether or not the substrate W has warped completely, depending on the type of substrate W.

[0103] Furthermore, the storage unit 10B may store a first time for each processing content applied to the substrate W by the processing solution. In this case, the arithmetic processing unit 10A obtains the first time corresponding to the processing content applied to the substrate W held in the spin chuck 21 from the storage unit 10B and performs heat treatment on the substrate W. This makes it possible to appropriately determine whether or not the substrate W has warped completely, depending on the processing content applied to the substrate W. Examples of processing content applied to the substrate W include etching and cleaning.

[0104] Furthermore, the first time stored in the memory unit 10B may be based on the following correlation obtained in advance by conducting experiments in which heat treatment is performed on a substrate of the same type as substrate W. Specifically, this correlation is the correlation between the heating temperature of the substrate and the time from when the heat treatment is started on the substrate until the substrate is fully warped. The heating temperature of the substrate is the temperature of the internal heater 421. The first time is the time corresponding to the heating temperature of substrate W in this correlation.

[0105] [Summary] A substrate processing method according to one aspect of the present disclosure is a substrate processing method for which a processing liquid is discharged toward the outer periphery of a rotating substrate, wherein the substrate is subjected to heat treatment for a predetermined time, the substrate is made to be fully warped by the heat treatment, and the processing liquid is discharged toward the outer periphery of the fully warped substrate.

[0106] In one aspect of the present disclosure, a substrate processing method may be used to determine whether or not the substrate has warped completely, using a distance sensor positioned opposite the substrate.

[0107] In a substrate processing method according to one aspect of the present disclosure, the predetermined time is a time obtained in advance before the heat treatment as the heating time necessary to completely warp the substrate, and the heat treatment may be performed after obtaining the predetermined time from the storage unit.

[0108] In a substrate processing method according to one aspect of the present disclosure, the processing solution may be an etching solution for etching the substrate.

[0109] A substrate processing apparatus according to one aspect of the present disclosure is a substrate processing apparatus for discharging a processing liquid toward the outer periphery of a rotating substrate, comprising: a holding table on which the substrate is placed; a heater positioned opposite to the substrate placed on the holding table; a discharging mechanism for discharging the processing liquid; and a control unit for controlling the heater and the discharging mechanism, wherein the control unit controls the heater and the discharging mechanism to start discharging the processing liquid toward the outer periphery of the substrate after the heater has heated the substrate for a predetermined time.

[0110] A substrate processing apparatus according to one aspect of the present disclosure may further include a distance sensor capable of measuring the distance to the substrate at a position opposite to the substrate placed on the holding table.

[0111] In a substrate processing apparatus according to one aspect of the present disclosure, the predetermined time is a time obtained in advance before heating the substrate as the heating time necessary to completely warp the substrate, and the substrate processing apparatus may further include a storage unit for storing the predetermined time.

[0112] (Additional Notes) This disclosure is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the various technical means disclosed in the embodiments are also included in the technical scope of this disclosure.

[0113] 1 Processing unit (substrate processing device) 4 Top surface protection heating mechanism (heater) 5 Discharge mechanism 7 Distance sensor 10 Control unit (control unit) 10A Calculation processing unit 10B Storage unit 21 Spin chuck (holding table) W Substrate Ws Peripheral edge

Claims

1. A substrate processing method for discharging a processing liquid toward the outer periphery of a rotating substrate, comprising: performing a heat treatment on the substrate for a predetermined time; causing the substrate to be fully warped by the heat treatment; and discharging the processing liquid toward the outer periphery of the fully warped substrate.

2. The substrate processing method according to claim 1, wherein it is determined whether or not the substrate has warped completely using a distance sensor positioned opposite the substrate.

3. The substrate processing method according to claim 1, wherein the predetermined time is a time obtained in advance before the heat treatment as the heating time necessary to completely warp the substrate, and the heat treatment is performed after obtaining the predetermined time from the memory unit.

4. The substrate processing method according to claim 1, wherein the processing solution is an etching solution for etching the substrate.

5. A substrate processing apparatus for discharging a processing liquid toward the outer periphery of a rotating substrate, comprising: a holding table on which the substrate is placed; a heater positioned opposite to the substrate placed on the holding table; a discharging mechanism for discharging the processing liquid; and a control unit for controlling the heater and the discharging mechanism, wherein the control unit controls the heater and the discharging mechanism to start discharging the processing liquid toward the outer periphery of the substrate after the heater has heated the substrate for a predetermined time.

6. The substrate processing apparatus according to claim 5, further comprising a distance sensor capable of measuring the distance to the substrate at a position opposite to the substrate placed on the holding table.

7. The substrate processing apparatus according to claim 5, wherein the predetermined time is a time obtained in advance before heating the substrate as the heating time necessary to completely warp the substrate, and further comprises a storage unit for storing the predetermined time.

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