SUBSTRATE PROCESSING METHOD, STORAGE MEDIUM, AND SUBSTRATE PROCESSING APPARATUS

Abstract

To reduce the swelling of the film thickness at the edge of a treatment liquid film after a peripheral region is removed.SOLUTION: A substrate processing method according to an embodiment of the present disclosure includes performing an intermittent removal process for removing a peripheral edge region of a film formed on the surface of the substrate by a treatment liquid. An intermittent removal process includes alternating performing a first process of supplying a removing liquid for removing a film from a nozzle to the peripheral area while rotating the substrate and a second process of maintaining a state in which the removal liquid is not supplied from the nozzles to the peripheral area while rotating the substrate after the execution of the first process.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present disclosure relates to a substrate processing method, a storage medium, and a substrate processing apparatus. [Background technology]

[0002] Patent Document 1 discloses a coating film removing device that uses a removing liquid to remove the peripheral edge of a coating film formed by supplying a coating liquid to the surface of a circular substrate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-121045 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a substrate processing method, a storage medium, and a substrate processing apparatus that are capable of reducing a rise in film thickness at an end of a processing liquid film after a peripheral area has been removed. [Means for solving the problem]

[0005] A substrate processing method according to an aspect of the present disclosure includes performing an intermittent removal process for removing a peripheral region of a film formed on a surface of a substrate by a processing liquid. The intermittent removal process includes alternately performing a first process for supplying a removing liquid for removing the film from a nozzle to the peripheral region while rotating the substrate, and a second process for maintaining a state in which the removing liquid is not supplied from the nozzle to the peripheral region while rotating the substrate after the first process is performed. Effect of the Invention

[0006] According to the present disclosure, there are provided a substrate processing method, a storage medium, and a substrate processing apparatus that are capable of reducing the rise in film thickness at the edge of the processing liquid film after the peripheral area has been removed. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram illustrating an example of a substrate processing system. [Diagram 2] FIG. 2 is a schematic diagram showing an example of a coating and developing apparatus. [Diagram 3] FIG. 3 is a schematic diagram showing an example of the liquid processing unit. [Figure 4] 4(a) and 4(b) are schematic diagrams showing an example of the nozzle arrangement during ejection. [Diagram 5] FIG. 5 is a block diagram illustrating an example of a hardware configuration of the control device. [Figure 6] FIG. 6 is a flowchart showing an example of a method for removing the peripheral region. [Figure 7] 7(a) and 7(b) are schematic diagrams showing an example of how the peripheral region is removed. [Figure 8] 8(a) and 8(b) are schematic diagrams showing an example of how the peripheral region is removed. [Figure 9] FIG. 9 is a flowchart showing an example of a method for removing the peripheral region. [Figure 10] 10(a) and 10(b) are schematic diagrams showing an example of how the peripheral region is removed. [Figure 11] 11(a) and 11(b) are graphs showing an example of the evaluation results of the film thickness in the peripheral region. [Figure 12] Fig. 12(a) is a graph showing an example of a measurement result of a film thickness distribution according to a comparative example, and Fig. 12(b) is a graph showing an example of a measurement result of a film thickness distribution according to an example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] First, an overview of the embodiment will be described.

[0009] A substrate processing method according to an aspect of the present disclosure includes performing an intermittent removal process for removing a peripheral region of a film formed on a surface of a substrate by a processing liquid. The intermittent removal process includes alternately performing a first process for supplying a removing liquid for removing the film from a nozzle to the peripheral region while rotating the substrate, and a second process for maintaining a state in which the removing liquid is not supplied from the nozzle to the peripheral region while rotating the substrate after the first process is performed.

[0010] When the peripheral region of the film of the processing liquid is removed by the removing liquid, a mixed layer is formed in the peripheral region of the substrate by mixing a part of the film of the processing liquid with the removing liquid. Therefore, the film thickness at the end of the film after the peripheral region is removed becomes thick. In contrast, in the above-mentioned substrate processing method, a state in which the removing liquid is supplied to the peripheral region and a state in which the removing liquid is not supplied to the peripheral region are alternately performed, so that the time for supplying the removing liquid to the peripheral region is shortened and the formation of the mixed layer is suppressed. In addition, the substrate is rotated in a state in which the removing liquid is not supplied, so that the mixed layer can be discharged outside the substrate. Therefore, it is possible to reduce the rise in film thickness at the end of the film of the processing liquid after the peripheral region is removed.

[0011] The substrate processing method may start at least one first process performed in the intermittent removal process by moving the nozzle so that the area where the removal liquid reaches from the nozzle in a state where the removal liquid is being discharged moves from a position outside the periphery of the substrate to the periphery area. In this case, the number of times that the nozzle that has stopped discharging the removal liquid is transitioned to a state where the removal liquid is being discharged in order to start the first process can be reduced. As a result, it is possible to reduce the frequency of occurrence of defects that may occur when the nozzle starts discharging the removal liquid.

[0012] The substrate processing method may start at least one first process performed in the intermittent removal process by switching an opening / closing valve that opens and closes a flow path that sends the removing liquid to the nozzle from a closed state to an open state with the nozzle disposed at a position where the removing liquid can be supplied to the peripheral region. In this case, it is possible to reduce a period during which the removal liquid is continuously discharged without being supplied to the film of processing liquid before the first process is started. As a result, it is possible to reduce the amount of removal liquid discharged in the intermittent removal process including the second process in which the removing liquid is not supplied.

[0013] The substrate processing method may start at least one second process performed in the intermittent removal process by moving the nozzle so that the area where the removal liquid reaches from the nozzle in a state where the removal liquid is being discharged moves from the peripheral area to a position outside the peripheral edge of the substrate. In this case, the number of times that the nozzle discharging the removal liquid is transitioned to a state where the discharge is stopped in order to start the second process can be reduced. As a result, it is possible to reduce the frequency of occurrence of defects that may occur due to the stop of the discharge of the removal liquid from the nozzle.

[0014] The substrate processing method may start at least one second process performed in the intermittent removal process by switching an opening / closing valve that opens and closes a flow path that sends the removing liquid to the nozzle from an open state to a closed state with the nozzle disposed at a position where the removing liquid can be supplied to the peripheral region. In this case, after the second process is started, the period during which the removal liquid is continuously discharged without being supplied to the film of processing liquid can be reduced. As a result, it is possible to reduce the amount of removal liquid discharged in the intermittent removal process including the second process in which the removing liquid is not supplied.

[0015] The substrate processing method may further include, after performing the intermittent removal process, continuing to supply the removal liquid to the peripheral region for a predetermined time while rotating the substrate. In this case, the time required to remove a target amount of the processing liquid film from the peripheral region is shortened. As a result, it is possible to achieve both reduction in the thickness of the film at the edge and processing efficiency.

[0016] The second process may include rotating the substrate so as to discharge a portion of the film softened by the removing liquid outside the substrate. A portion of the film softened by the removing liquid remains in the peripheral region of the substrate, which may cause a rise in the film thickness. In the above method, a portion of the film softened by the removing liquid is discharged outside the substrate, thereby making it possible to reduce a rise in the film thickness at the end of the film after the peripheral region is removed.

[0017] The second process may include rotating the substrate so as to discharge a mixture of the components of the film dissolved by the removal liquid and the removal liquid outside the substrate. The mixture may remain in the peripheral region of the substrate, causing a rise in the film thickness. In the above method, the mixture of the components dissolved by the removal liquid and the removal liquid is discharged outside the substrate, making it possible to reduce the rise in the film thickness at the edge after the peripheral region is removed.

[0018] A storage medium according to one aspect of the present disclosure is a computer-readable storage medium storing a program for causing an apparatus to execute any one of the substrate processing methods described above.

[0019] A substrate processing apparatus according to an aspect of the present disclosure includes a liquid processing unit having a spin holder that holds and rotates a substrate, a processing liquid supply unit that supplies a predetermined processing liquid to the substrate held by the spin holder, and a removing liquid supply unit that includes a nozzle and supplies a removing liquid from the nozzle to the substrate held by the spin holder, and a control unit that controls the liquid processing unit. The control unit executes the following: controlling the liquid processing unit to form a film of the processing liquid on the surface of the substrate, and controlling the liquid processing unit to execute an intermittent removal process that removes a peripheral region of the film. The intermittent removal process includes alternately executing a first process in which the removing liquid supply unit supplies the removing liquid from the nozzle to the peripheral region while rotating the substrate by the spin holder, and a second process in which the removing liquid supply unit maintains a state in which the removing liquid is not supplied from the nozzle to the peripheral region while rotating the substrate by the spin holder after the first process is executed. In this substrate processing apparatus, as in the above-mentioned substrate processing method, it is possible to reduce the rise in film thickness at the end of the film of the processing liquid after the peripheral region is removed.

[0020] The removing liquid supplying unit may further include a driving unit that moves the nozzle along the surface of the substrate, and an opening / closing valve that opens and closes a flow path that supplies the removing liquid to the nozzle. The control unit may cause the liquid processing unit to start at least one first process performed in the intermittent removing process by moving the nozzle with the driving unit so that a region where the removing liquid reaches from the nozzle in a state where the removing liquid is being discharged moves from a position outside the periphery of the substrate to the periphery region. In this case, as in the above-mentioned substrate processing method, it is possible to reduce the frequency of occurrence of malfunctions that may occur when the nozzle starts discharging the removing liquid.

[0021] The removing liquid supplying section may further include a driving section that moves the nozzle along the surface of the substrate, and an opening / closing valve that opens and closes a flow path that supplies the removing liquid to the nozzle. The control unit may cause the liquid processing unit to start at least one first process executed in the intermittent removal process by switching the opening / closing valve from a closed state to an open state, with the nozzle disposed at a position that allows the removing liquid to be supplied to the peripheral region. In this case, as in the above-described substrate processing method, it is possible to reduce the amount of removal liquid discharged in the intermittent removal process including the second process in which the removing liquid is not supplied.

[0022] The control unit may cause the liquid processing unit to start at least one second process performed in the intermittent removal process by moving the nozzle with the drive unit so that the arrival area of ​​the removal liquid from the nozzle in a state where the removal liquid is being discharged moves from the peripheral area to a position outside the peripheral edge of the substrate. In this case, as in the above-mentioned substrate processing method, it is possible to reduce the frequency of occurrence of malfunctions that may occur due to the stop of the discharge of the removal liquid from the nozzle.

[0023] The control unit may cause the liquid processing unit to start at least one second process performed in the intermittent removal process by switching the on-off valve from an open state to a closed state while the nozzle is disposed at a position where the removing liquid can be supplied to the peripheral region. In this case, as in the above-described substrate processing method, it is possible to reduce the amount of removal liquid discharged in the intermittent removal process including the second process in which the removing liquid is not supplied.

[0024] An embodiment will be described below with reference to the drawings. In the description, the same elements or elements having the same functions are given the same reference numerals, and duplicated descriptions will be omitted. Some drawings show an orthogonal coordinate system defined by an X-axis, a Y-axis, and a Z-axis. In the following embodiment, the Z-axis corresponds to the vertical direction, and the X-axis and the Y-axis correspond to the horizontal direction.

[0025] [Substrate processing system] The substrate processing system 1 (substrate processing apparatus) shown in FIG. 1 is a system that forms a photosensitive coating on a workpiece W, exposes the photosensitive coating, and develops the photosensitive coating. The workpiece W to be processed is, for example, a substrate, or a substrate on which a film, circuit, or the like has been formed by performing a predetermined process. One example of the substrate is a silicon wafer. The workpiece W (substrate) may be circular. The workpiece W may also be a glass substrate, a mask substrate, or an FPD (Flat Panel Display), etc. The photosensitive coating is, for example, a resist film.

[0026] 1 and 2, the substrate processing system 1 includes a coating and developing apparatus 2, an exposure apparatus 3, and a control device 100 (control unit). The exposure apparatus 3 is an apparatus that exposes a resist film (photosensitive coating) formed on a workpiece W (substrate). Specifically, the exposure apparatus 3 irradiates an exposure target portion of the resist film with an energy beam by a method such as immersion exposure.

[0027] (Coating and developing equipment) The coating and developing apparatus 2 applies resist (chemical solution) to the surface of the workpiece W to form a resist film before the exposure process by the exposure device 3, and develops the resist film after the exposure process. The coating and developing apparatus 2 includes a carrier block 4, a processing block 5, and an interface block 6.

[0028] The carrier block 4 introduces the workpiece W into the coating and developing apparatus 2 and removes the workpiece W from the coating and developing apparatus 2. For example, the carrier block 4 can support multiple carriers C for the workpiece W and has a built-in transport device A1 including a delivery arm. The carrier C accommodates, for example, multiple circular workpieces W. The transport device A1 removes the workpiece W from the carrier C and delivers it to the processing block 5, and receives the workpiece W from the processing block 5 and returns it to the carrier C. The processing block 5 has processing modules 11, 12, 13, and 14.

[0029] The processing module 11 incorporates a liquid processing unit U1, a heat processing unit U2, and a transport device A3 that transports the workpiece W to these units. The processing module 11 forms an underlayer film on the surface of the workpiece W using the liquid processing unit U1 and the heat processing unit U2. The liquid processing unit U1 applies a processing liquid for forming the underlayer film onto the workpiece W. The heat processing unit U2 performs various heat treatments associated with the formation of the underlayer film.

[0030] The processing module 12 incorporates a liquid processing unit U1, a heat processing unit U2, and a transport device A3 that transports the workpiece W to these units. The processing module 12 forms a resist film on the underlayer film using the liquid processing unit U1 and the heat processing unit U2. The liquid processing unit U1 applies a processing liquid for forming a resist film onto the underlayer film. The processing liquid applied by the liquid processing unit U1 may be a resist liquid having a medium viscosity or higher (for example, a viscosity of 50 cP or higher). The liquid processing unit U1 removes the peripheral region of the film formed by the processing liquid, which is applied (supplied) with the processing liquid for forming the resist film, by using a chemical liquid different from the above processing liquid. The heat processing unit U2 performs various heat treatments associated with the formation of the resist film.

[0031] The processing module 13 incorporates a liquid processing unit U1, a heat processing unit U2, and a transport device A3 that transports the workpiece W to these units. The processing module 13 forms an upper layer film on the resist film using the liquid processing unit U1 and the heat processing unit U2. The liquid processing unit U1 applies a processing liquid for forming the upper layer film onto the resist film. The heat processing unit U2 performs various heat treatments associated with the formation of the upper layer film.

[0032] The processing module 14 incorporates a liquid processing unit U1, a heat processing unit U2, and a transport device A3 that transports the workpiece W to these units. The processing module 14 uses the liquid processing unit U1 and the heat processing unit U2 to perform development processing of the resist film that has been subjected to exposure processing and heat processing associated with the development processing. The liquid processing unit U1 supplies a developer onto the surface of the exposed workpiece W, and then washes it away with a rinsing liquid to form a resist pattern (development processing of the resist film). The heat processing unit U2 performs various heat processing associated with the development processing. Specific examples of heat processing include a heat processing before development (PEB: Post Exposure Bake) and a heat processing after development (PB: Post Bake), etc.

[0033] A shelf unit U10 is provided on the carrier block 4 side in the processing block 5. The shelf unit U10 is divided into multiple cells arranged in the vertical direction. A transport device A7 including a lifting arm is provided near the shelf unit U10. The transport device A7 lifts and lowers the workpiece W between the cells of the shelf unit U10.

[0034] A shelf unit U11 is provided on the interface block 6 side in the processing block 5. The shelf unit U11 is partitioned into a plurality of cells arranged in the vertical direction.

[0035] The interface block 6 transfers the workpiece W to and from the exposure apparatus 3. For example, the interface block 6 has a built-in transport device A8 including a transfer arm, and is connected to the exposure apparatus 3. The transport device A8 transfers the workpiece W placed on the shelf unit U11 to the exposure apparatus 3. The transport device A8 receives the workpiece W from the exposure apparatus 3 and returns it to the shelf unit U11.

[0036] The control device 100 is configured to partially and entirely control the coating and developing apparatus 2. The control device 100 controls the coating and developing apparatus 2 to execute a coating and developing process, for example, in the following procedure. First, the control device 100 controls the transport device A1 to transport the workpiece W in the carrier C to the shelf unit U10, and controls the transport device A7 to place the workpiece W in a cell for the processing module 11.

[0037] Next, the control device 100 controls the transport device A3 to transport the workpiece W on the shelf unit U10 to the liquid treatment unit U1 and heat treatment unit U2 in the processing module 11. The control device 100 also controls the liquid treatment unit U1 and heat treatment unit U2 to form an underlayer film on the surface of the workpiece W. Thereafter, the control device 100 controls the transport device A3 to return the workpiece W on which the underlayer film has been formed to the shelf unit U10, and controls the transport device A7 to place the workpiece W in a cell for the processing module 12.

[0038] Next, the control device 100 controls the transport device A3 to transport the workpiece W on the shelf unit U10 to the liquid processing unit U1 and the heat processing unit U2 in the processing module 12. The control device 100 also controls the liquid processing unit U1 and the heat processing unit U2 to form a resist film on the underlying film of the workpiece W.

[0039] In detail, the control device 100 controls the liquid processing unit U1 to form a film of a processing liquid for forming a resist film on the surface of the workpiece W, and then to remove the peripheral area of ​​the film of the processing liquid. Then, the control device 100 controls the heat processing unit U2 to heat the workpiece W having the film of the processing liquid from which the peripheral area has been removed, to form a resist film. After the resist film is formed, the control device 100 controls the transport device A3 to return the workpiece W to the shelf unit U10, and controls the transport device A7 to place the workpiece W in a cell for the processing module 13.

[0040] Next, the control device 100 controls the transport device A3 to transport the workpiece W on the shelf unit U10 to each unit in the processing module 13. The control device 100 also controls the liquid processing unit U1 and the heat processing unit U2 to form an upper layer film on the resist film of the workpiece W. Thereafter, the control device 100 controls the transport device A3 to transport the workpiece W to the shelf unit U11.

[0041] Next, the control device 100 controls the transport device A8 to send the workpiece W on the shelf unit U11 to the exposure device 3. Thereafter, the control device 100 controls the transport device A8 to receive the workpiece W that has been subjected to the exposure process from the exposure device 3 and place it in a cell for the processing module 14 in the shelf unit U11.

[0042] Next, the control device 100 controls the transport device A3 to transport the workpiece W on the shelf unit U11 to each unit in the processing module 14, and controls the liquid processing unit U1 and the heat processing unit U2 to perform a developing process on the resist film of the workpiece W. By performing the developing process on the resist film, a resist pattern is formed on the surface Wa of the workpiece W.

[0043] Thereafter, the control device 100 controls the transport device A3 to return the workpiece W to the shelf unit U10, and controls the transport device A7 and the transport device A1 to return the workpiece W into the carrier C. This completes the coating and developing process for one workpiece W. The control device 100 causes the coating and developing device 2 to perform the coating and developing process for each of the subsequent workpieces W in the same manner as described above.

[0044] The specific configuration of the substrate processing apparatus is not limited to the above-described configuration of the substrate processing system 1. The substrate processing apparatus may be any type as long as it includes a device for removing a peripheral region of a film formed by a processing liquid for forming a resist film and a control device capable of controlling the device.

[0045] <Liquid processing unit> Next, an example of the liquid processing unit U1 in the processing module 12 will be described in detail with reference to Figures 3 and 4. In the following, unless otherwise specified, "processing liquid" means a processing liquid (resist liquid) for forming a resist film. "Processing liquid film" means a film of the processing liquid formed on the surface Wa of the workpiece W. In addition, the surface of the workpiece W is referred to as "surface Wa" and the periphery of the workpiece W is referred to as "periphery Wb". The peripheral area on the surface Wa of the workpiece W is the periphery Wb on the surface Wa and the area nearby.

[0046] The liquid processing unit U1 forms a film of processing liquid on the surface Wa of the workpiece W. For example, the liquid processing unit U1 supplies processing liquid to the surface Wa while rotating the workpiece W, and then continues rotating the workpiece W for a predetermined time while stopping the supply of processing liquid. This forms a film of processing liquid on the surface Wa of the workpiece W. The liquid processing unit U1 performs a process of removing the peripheral region of the processing liquid film using a chemical liquid for removing the processing liquid film (hereinafter referred to as a "removal liquid").

[0047] The peripheral region of the film of the processing liquid refers to the peripheral region of the film and the region in its vicinity. Note that, before the peripheral region of the film of the processing liquid is removed, the peripheral region of the surface Wa of the workpiece W corresponds to the peripheral region of the film of the processing liquid formed on the surface Wa. The removal liquid is a solvent that can remove (dissolve) the film formed by the processing liquid. Specific examples of the removal liquid include organic solvents such as thinner. As shown in FIG. 3, the liquid processing unit U1 has a spinning holder 20, a processing liquid supply unit 30, and a removal liquid supply unit 40.

[0048] The rotating holding unit 20 holds and rotates the workpiece W. The rotating holding unit 20 has, for example, a holding unit 21 and a rotation drive unit 22. The holding unit 21 supports the center of the workpiece W arranged horizontally with the surface Wa facing upward, and holds the workpiece W by suction (for example, vacuum suction). The rotation drive unit 22 includes a power source such as an electric motor, and rotates the holding unit 21 around a vertical axis Ax, thereby rotating the workpiece W. The rotating holding unit 20 may hold and rotate the workpiece W such that the center CP of the workpiece W (see FIG. 4(a)) approximately coincides with the axis Ax.

[0049] The processing liquid supply unit 30 supplies the processing liquid to the surface Wa of the workpiece W held by the rotating holder 20. The processing liquid supply unit 30 has, for example, a nozzle 31, a liquid source 32, a liquid delivery unit 33, and a drive unit 34. The nozzle 31 ejects the processing liquid toward the surface Wa of the workpiece W. The liquid source 32 contains the processing liquid and pressure-feeds the processing liquid to the nozzle 31. The liquid delivery unit 33 guides the processing liquid from the liquid source 32 to the nozzle 31. The liquid delivery unit 33 has, for example, a liquid delivery pipe L1 and an opening / closing valve V1. The liquid delivery pipe L1 connects the liquid source 32 and the nozzle 31, and forms a flow path that delivers the processing liquid to the nozzle 31.

[0050] The on-off valve V1 opens and closes the flow path in the liquid supply pipe L1 based on an operational command from the control device 100. When the on-off valve V1 is in an open state, the processing liquid is discharged from the nozzle 31, and when the on-off valve V1 is in a closed state, the discharge of the processing liquid from the nozzle 31 is stopped. The on-off valve V1 is, for example, an air operation valve. The drive unit 34 includes a power source such as an electric motor, and moves the nozzle 31 along the surface Wa of the workpiece W based on an operational command from the control device 100. The drive unit 34 moves the nozzle 31, for example, between the axis Ax (above the center CP of the workpiece W) and an area outside the workpiece W.

[0051] The removing liquid supplying unit 40 supplies the removing liquid to the workpiece W held by the rotating holder 20. The removing liquid supplying unit 40 is configured to be able to supply the removing liquid to the peripheral region of the film of the processing liquid formed on the surface Wa of the workpiece W. The removing liquid supplying unit 40 has, for example, a nozzle 41, a liquid source 42, a liquid delivery unit 43, and a drive unit 44. The nozzle 41 ejects the removing liquid toward the peripheral region of the surface Wa of the workpiece W rotated by the rotating holder 20. The nozzle 41 is disposed above the surface Wa of the workpiece W. The nozzle 41 may eject the removing liquid in a direction perpendicular to the surface Wa of the workpiece W (vertically downward), or may eject the removing liquid in a direction inclined from the perpendicular direction.

[0052] The liquid source 42 contains the removal liquid and pressure-feeds the removal liquid to the nozzle 41. The liquid delivery unit 43 guides the removal liquid from the liquid source 42 to the nozzle 41. The liquid delivery unit 43 has, for example, a liquid delivery tube L2 and an opening / closing valve V2. The liquid delivery tube L2 connects the liquid source 42 and the nozzle 41 and forms a flow path for delivering the removal liquid to the nozzle 41. The opening / closing valve V2 opens and closes the flow path in the liquid delivery tube L2 based on an operation instruction from the control device 100. When the opening / closing valve V2 is in an open state, the removal liquid is discharged from the nozzle 41, and when the opening / closing valve V2 is in a closed state, the discharge of the removal liquid from the nozzle 41 is stopped. The opening / closing valve V2 is, for example, an air-operated valve.

[0053] The drive unit 44 includes a power source such as an electric motor, and moves the nozzle 41 along the surface Wa of the workpiece W based on an operation command from the control device 100. As the nozzle 41 moves along the surface Wa, the area reached by the removal liquid discharged from the nozzle 41 changes. Here, the reach area AR of the removal liquid discharged from the nozzle 41 is defined as follows (see FIG. 4(a)). The reach area AR is an area including the intersection point of an imaginary line extending in the direction in which the removal liquid is discharged from the nozzle 41 (for example, a direction perpendicular to the discharge port of the nozzle 41) and an imaginary plane including the surface Wa of the workpiece W, and the vicinity thereof. The outer edge (shape) and size of the reach area AR change depending on the shape and size of the discharge port of the nozzle 41.

[0054] When the reach area AR overlaps with the surface Wa of the workpiece W (located inside the periphery Wb), the removal liquid discharged from the nozzle 41 reaches the surface Wa and is supplied onto the surface Wa. When the reach area AR does not overlap with the surface Wa of the workpiece W (located outside the periphery Wb), the removal liquid discharged from the nozzle 41 is not supplied to the surface Wa of the workpiece W. In this case, for example, the removal liquid discharged from the nozzle 41 is received in a cup (not shown) surrounding the rotating holder 20.

[0055] The drive unit 44 moves the nozzle 41 so that the arrival area AR changes along a virtual line rL corresponding to one radial direction of the workpiece W. The drive unit 44 moves the nozzle 41 so that the arrival area AR changes at least between the peripheral area of ​​the film of the treatment liquid (the peripheral area of ​​the surface Wa) and a position outside the peripheral edge Wb of the workpiece W. In the example shown in FIG. 4(a), the virtual line rL is set to extend along the Y-axis direction. In this case, the drive unit 44 moves the nozzle 41 so that the movement direction of the nozzle 41 is along the Y-axis direction.

[0056] In a top view (when the surface Wa of the workpiece W is viewed from the axis Ax), the ejection direction VD of the removal liquid from the nozzle 41 may be inclined with respect to a virtual reference line SL perpendicular to the virtual line rL. Unlike the example of FIG. 4(a), the ejection direction VD may be along the reference line SL. The reference line SL perpendicular to the virtual line rL is parallel to a tangent at the intersection of the virtual line rL and the periphery Wb of the surface Wa. The angle α between the ejection direction VD of the removal liquid from the nozzle 41 and the reference line SL may be -30° to +30°, -15° to +15°, or -10° to +10°.

[0057] The angle α has a negative value when the ejection direction VD of the removal liquid from the nozzle 41 is inclined toward the center CP of the surface Wa with respect to the reference line SL. In this case, the component of the ejection direction VD along the imaginary line rL faces the center CP of the surface Wa. The angle α has a positive value when the ejection direction VD of the removal liquid from the nozzle 41 is inclined toward the center CP of the surface Wa with respect to the reference line SL. In this case, the component of the ejection direction VD along the imaginary line rL faces in a direction away from the center CP of the surface Wa.

[0058] When the arrival area AR overlaps with the surface Wa, the direction of the component along the reference line SL of the discharge direction VD of the removal liquid from the nozzle 41 and the direction of rotation RD of the workpiece W by the spin holder 20 may be opposite to each other in the arrival area AR. In FIG. 4(a), the rotation direction RD is shown clockwise, and is downward on the paper in the arrival area AR, and the component along the reference line SL of the discharge direction VD is upward on the paper. Unlike the example of FIG. 4(a), when the arrival area AR is included within the surface Wa, the direction of the component along the reference line SL of the discharge direction VD and the direction of rotation RD of the workpiece W by the spin holder 20 may be the same in the arrival area AR.

[0059] 4(b), in a side view (when the peripheral edge Wb is viewed from the radial direction of the workpiece W), the angle β between the ejection direction VD of the removal liquid from the nozzle 41 and the surface Wa of the workpiece W may be smaller than 90°. The angle β may be 5° to 40°, 8° to 35°, or 10° to 30°.

[0060] (Control device) After the workpiece W with the underlayer film formed thereon is carried into the liquid treatment unit U1, the control device 100 controls the liquid treatment unit U1 to form a film of the treatment liquid on the surface Wa of the workpiece W. In detail, the control device 100 supplies the treatment liquid to the surface Wa by the treatment liquid supply unit 30 while rotating the workpiece W by the spin holder 20. Then, the control device 100 rotates the workpiece W by the spin holder 20 for a predetermined drying time while stopping the supply of the treatment liquid to the treatment liquid supply unit 30. As a result, part of the solvent contained in the treatment liquid on the surface Wa volatilizes, and a film of the treatment liquid is formed on the surface Wa of the workpiece W.

[0061] The control device 100 controls the liquid processing unit U1 to perform a process for removing the peripheral region of the processing liquid film (hereinafter, referred to as a "removal process") after the processing liquid film is formed on the surface Wa. The removal process includes at least an intermittent removal process. The intermittent removal process includes alternately performing the following first and second processes. The first process is a process for supplying the removing liquid from the nozzle 41 by the removing liquid supply unit 40 to the peripheral region of the processing liquid film while rotating the workpiece W by the spin holder 20. The second process is a process for maintaining the removing liquid supply unit 40 in a state in which the removing liquid is not supplied from the nozzle 41 to the peripheral region of the processing liquid film while rotating the workpiece W by the spin holder 20 after the first process is performed. In the second process, the removing liquid is not supplied from any nozzle to the peripheral region of the processing liquid film.

[0062] In the present disclosure, alternately executing the first process and the second process means at least executing the first process and the second process in sequence, and then executing the first process again. In the intermittent removal process, the control device 100 alternately executes the first process multiple times and at least one second process, one at a time. In addition to the intermittent removal process, the removal process may include a process of continuously supplying the removal liquid to the peripheral region of the treatment liquid film (hereinafter referred to as a "continuous removal process"). Specific examples of the intermittent removal process and the continuous removal process will be described later.

[0063] The control device 100 is composed of one or more control computers. The control device 100 has, for example, a circuit 120 shown in FIG. 5. The circuit 120 has one or more processors 122, a memory 124, a storage 126, an input / output port 128, and a timer 132. The storage 126 has a computer-readable storage medium, such as a hard disk. The storage medium stores a program for causing the control device 100 to execute a substrate processing method, which will be described later. The storage medium may be a removable medium, such as a non-volatile semiconductor memory, a magnetic disk, or an optical disk. The memory 124 temporarily stores the program loaded from the storage medium of the storage 126 and the calculation result by the processor 122.

[0064] The processor 122 executes the above programs in cooperation with the memory 124. The input / output port 128 inputs and outputs electrical signals between the spin holder 20, the processing liquid supply unit 30, the removal liquid supply unit 40, etc., in accordance with commands from the processor 122. The timer 132 measures the elapsed time, for example, by counting reference pulses at a constant cycle. The hardware configuration of the control device 100 may be configured with a dedicated logic circuit or an ASIC (Application Specific Integrated Circuit) that integrates the same.

[0065] [Substrate processing method] 6 to 8, a method for removing a film of a processing liquid performed on one workpiece W in the liquid processing unit U1 of the processing module 12 (more specifically, a removal process for removing a peripheral area of ​​the film of the processing liquid) will be described as an example of a substrate processing method. FIG. 6 is a flow chart showing an example of a series of processes performed by the control device 100 in the removal process. In this removal process, the control device 100 performs step S11 while the workpiece W having a film of the processing liquid formed on its surface Wa is being rotated by the spin holder 20 at a predetermined first rotation speed.

[0066] In step S11, for example, the control device 100 moves the nozzle 41, which is arranged so that the arrival area AR of the removal liquid is located outside the peripheral edge Wb of the workpiece W, by the drive unit 44 so that the arrival area AR overlaps the peripheral area. Hereinafter, in step S11, the position of the nozzle 41 arranged so that the arrival area AR is located in the peripheral area is referred to as the "first discharge position". FIG. 7(a) illustrates an example of an operation in which the nozzle 41, which is not discharging the removal liquid Lr, moves to the first discharge position. The nozzle 41 arranged in the first discharge position can discharge the removal liquid toward the peripheral area PA of the film R of the processing liquid (the peripheral area of ​​the surface Wa of the workpiece W held by the rotating holder 20). For the sake of explanation, the peripheral area PA is shown enlarged from its actual size.

[0067] In the processes after step S11, the control device 100 causes the spin holder 20 to continue rotating the workpiece W at the first spin speed until the rotation speed is adjusted. The first spin speed is preset to a spin speed at which the removal liquid does not excessively splash when supplied (discharged) to the surface Wa of the workpiece W. The first spin speed may be 500 rpm to 2000 rpm, 700 rpm to 1800 rpm, or 1000 rpm to 1500 rpm.

[0068] Next, the control device 100 executes step S12. In step S12, for example, the control device 100 controls the liquid delivery unit 43 of the removal liquid supply unit 40 to start discharging the removal liquid toward the peripheral region of the film of the processing liquid. Specifically, the control device 100 switches the opening / closing valve V2 of the liquid delivery unit 43 from a closed state to an open state. As a result, the removal liquid starts to be discharged from the nozzle 41 arranged at the first discharge position, and the removal liquid starts to be supplied to the peripheral region. That is, the first process described above is started.

[0069] Next, the control device 100 executes step S13. In step S13, for example, the control device 100 waits until a predetermined discharge time has elapsed since starting the discharge of the removal liquid. The discharge time is determined in advance, and is set to, for example, about 0.3 to 3.0 seconds. FIG. 7(b) illustrates an example in which the removal liquid Lr is supplied from the nozzle 41 to the peripheral area PA of the film R of the processing liquid while the workpiece W is rotating. As the removal liquid Lr is supplied to the peripheral area PA, the peripheral area PA of the film R of the processing liquid is softened (begins to dissolve) by the removal liquid.

[0070] Next, the control device 100 executes step S14. In step S14, for example, the control device 100 moves the nozzle 41 by the drive unit 44 so that the arrival area AR of the removal liquid from the nozzle 41 in a state where the removal liquid is discharged moves from the peripheral area of ​​the film of the processing liquid to a position outside the peripheral edge Wb of the workpiece W. By moving the arrival area AR to a position outside the peripheral edge Wb, a state in which the removal liquid is not supplied to the peripheral area of ​​the film of the processing liquid is started (the above-mentioned second process is started). As a result, the process executed by the control device 100 transitions from the first process to the second process. FIG. 8(a) illustrates a state in which the removal liquid Lr from the nozzle 41 is discharged outside the workpiece W while the workpiece W is rotating, and the removal liquid is not supplied to the peripheral area PA of the film R of the processing liquid.

[0071] Next, the control device 100 executes steps S15 and S16. In step S15, for example, the control device 100 waits until a predetermined waiting time has elapsed. The waiting time is predetermined and is set to, for example, about 0.5 to 3.0 seconds. The waiting time may be set to the same value as the discharge time, or may be set to a value different from the discharge time. In step S16, for example, the control device 100 determines whether or not the number of repetitions of one loop of processing (one set of processing) including the first process and the second process has reached a predetermined number. This predetermined number is set in advance to a value of 2 or more.

[0072] In step S16, if it is determined that the number of repetitions of the process of one loop has not reached the predetermined number (step S16: NO), the process executed by the control device 100 proceeds to step S17. In step S17, for example, the control device 100 moves the nozzle 41 by the drive unit 44 so that the arrival area AR of the removal liquid from the nozzle 41 in a state in which the removal liquid is being discharged moves from a position outside the workpiece W to the peripheral area of ​​the film of the treatment liquid (so as to overlap with the peripheral area). As the arrival area AR moves to the peripheral area of ​​the film of the treatment liquid, a state in which the removal liquid is supplied to the peripheral area of ​​the film of the treatment liquid is started (a state in which the removal liquid is supplied is resumed). As a result, the process executed by the control device 100 transitions from the second process to the first process.

[0073] After step S17, the process executed by controller 100 returns to step S13. Thereafter, controller 100 repeats the series of processes from steps S13 to S16 (S17) until one loop of processes has been executed the predetermined number of times. As a result, one loop of processes including the first process and the second process is executed twice or more times. In this case, controller 100 controls liquid processing unit U1 to execute a plurality of first processes and a plurality of second processes alternately, one at a time. In this control, the number of times the plurality of first processes are executed is the same as the number of times the plurality of second processes are executed.

[0074] From the viewpoint of processing efficiency, the number of times the processing of one loop is repeated may be set to 30 times or less, 25 times or less, 20 times or less, or 15 times or less. From the viewpoint of suppressing the influence of the intermittent removal process on the film thickness distribution, the number of times the processing of one loop is repeated may be set to 2 times or more, 4 times or more, 6 times or more, or 8 times or more. The number of times the processing of one loop is repeated is set to, for example, 2 to 30 times, or 4 to 20 times.

[0075] By supplying the removal liquid to the peripheral region of the film of the processing liquid, the peripheral region is softened and dissolved. As the supply of the removal liquid to the peripheral region continues, the removal liquid and the components in the processing liquid mix to form a mixed layer in the peripheral region of the workpiece W. Then, since the workpiece W is rotating, a part of the processing liquid film that has not solidified moves toward the periphery and the mixed layer builds up. As a result, a phenomenon in which the film thickness rises at the end of the processing liquid film after the peripheral region is removed may occur. In the first process of the intermittent removal process, a mixed layer is also formed in the peripheral region of the surface Wa of the workpiece W.

[0076] Then, in the second process following the first process, the workpiece W rotates without being supplied with the removing liquid, so that the mixed layer is discharged outside the workpiece W. By executing the second process, the height of the piled-up mixed layer can be reduced. In the first stage of the intermittent removal process, the control device 100 may rotate the workpiece W by the rotating and holding unit 20 in the second process so that a part of the film of the processing liquid softened by the removing liquid is discharged outside the workpiece W. In the second stage of the intermittent removal process, since the dissolution (softening) of the film progresses, a liquid in which the component of the film of the processing liquid dissolved by the removing liquid and the removing liquid are mixed may be formed. Therefore, the control device 100 may rotate the workpiece W by the rotating and holding unit 20 in the second process so that the mixed liquid is discharged outside the workpiece W.

[0077] In step S16, if it is determined that the number of times the process of one loop has been executed has reached a predetermined number (step S16: YES), the process executed by the control device 100 proceeds to step S18. In step S18, the control device 100 causes the drive unit 44 to move the nozzle 41 in a state in which the removal liquid is being discharged so that the arrival area AR overlaps the peripheral region. Hereinafter, in step S18, the position of the nozzle 41 arranged so that the arrival area AR is located in the peripheral region is referred to as the "second discharge position." The arrival area AR of the removal liquid from the nozzle 41 arranged in the second discharge position may be located outside the arrival area AR of the removal liquid from the nozzle 41 arranged in the first discharge position in the first process included in the intermittent removal process, or may be approximately the same.

[0078] Next, the control device 100 executes step S19. In step S19, for example, the control device 100 waits until a predetermined supply time (predetermined time) has elapsed since the control device 100 moved the nozzle 41 to the second discharge position. The supply time is preset to a time that allows the removal liquid to dissolve the undissolved portion of the peripheral region of the film of the treatment liquid in the intermittent removal process in which the first process and the second process are alternately repeated. The predetermined supply time may be longer than the above-mentioned discharge time (the execution time of the first process) during which the control device 100 waits in step S13. The supply time may be about 2 to 30 times the above-mentioned discharge time (the execution time of the first process).

[0079] Next, the control device 100 executes step S20. In step S20, for example, the control device 100 controls the liquid delivery unit 43 of the removal liquid supply unit 40 to stop the ejection of the removal liquid from the nozzle 41. Specifically, the control device 100 switches the on-off valve V2 of the liquid delivery unit 43 from an open state to a closed state to stop the ejection of the removal liquid from the nozzle 41. As described above, after the execution of the intermittent removal process, the control device 100 causes the liquid processing unit U1 to execute a continuous removal process in which the removal liquid is supplied to the peripheral region of the film of the processing liquid (the peripheral region of the surface Wa of the workpiece W) while rotating the workpiece W, for a predetermined supply time.

[0080] Next, the control device 100 executes steps S21 and S22. In step S21, for example, the control device 100 controls the spin holder 20 to increase the rotation speed of the workpiece W from the first rotation speed to the second rotation speed. In step S22, for example, the control device 100 accelerates the rotation of the workpiece W to the second rotation speed and then waits until a predetermined shake-off time has elapsed. The second rotation speed and the shake-off time are each preset to a value that allows the removal liquid and dissolved material remaining on the surface Wa of the workpiece W to be discharged outside the workpiece W. The second rotation speed is higher than the first rotation speed, and is, for example, about 1500 rpm to 3000 rpm. FIG. 8(b) illustrates the rotation of the workpiece W after the discharge of the removal liquid Lr from the nozzle 41 has stopped.

[0081] Next, the control device 100 executes step S23. In step S23, for example, the control device 100 controls the spin holder 20 to stop the rotation of the workpiece W. By executing the above series of processes, the peripheral region of the film R of the processing liquid on the surface Wa of the workpiece W is removed as shown in Fig. 8(b). In other words, a film R of the processing liquid with the peripheral region removed is formed on the surface Wa of the workpiece W.

[0082] The above-mentioned series of processes is an example and can be changed as appropriate. In the above-mentioned series of processes, the control device 100 may execute one step and the next step in parallel, or may execute each step in an order different from the above-mentioned example. The control device 100 may execute step S11 after executing step S12, for example. That is, the control device 100 may also cause the liquid processing unit U1 to start the first process for the first process executed in the first time by moving the nozzle 41, which has discharged the removal liquid outside the periphery Wb of the workpiece W, to the first discharge position by the drive unit 44.

[0083] The control device 100 may omit any step, or may execute a process different from the above-mentioned example in any step. The control device 100 may omit, for example, step S21. The control device 100 may omit, for example, steps S18 and S19 (the continuous removal process may be omitted). In this case, the control device 100 may control the liquid processing unit U1 to continue stopping the discharge of the removal liquid from the nozzle 41 and rotate the workpiece W for the shake-off time following the intermittent removal process.

[0084] The control device 100 may switch between the first process and the second process by switching the open / close state of the on-off valve V2 of the liquid delivery unit 43 while maintaining the nozzle 41 in a state in which the removal liquid can be discharged toward the peripheral region of the film of the treatment liquid. FIG. 9 is a flowchart showing another example of a series of processes executed by the control device 100 to remove the peripheral region of the film of the treatment liquid. In this series of processes, the control device 100 executes steps S31 to S33, similar to steps S11 to S13 of the series of processes shown in FIG. 6. FIG. 10(a) illustrates an example in which the removal liquid Lr is supplied to the peripheral region PA of the film R of the treatment liquid after execution of step S32.

[0085] When a predetermined discharge time has elapsed in step S33, the control device 100 executes step S34. In step S34, for example, the control device 100 controls the liquid delivery unit 43 of the removal liquid supply unit 40 to stop the discharge of the removal liquid from the nozzle 41 while maintaining the nozzle 41 at the first discharge position. Specifically, the control device 100 stops the discharge of the removal liquid from the nozzle 41 by switching the opening and closing valve of the liquid delivery unit 43 from an open state to a closed state while the nozzle 41 is located at the first discharge position where the removal liquid can be supplied to the peripheral area of ​​the film of the processing liquid. Then, the control device 100 executes steps S35 and S36, similar to steps S15 and S16. While step S35 is being executed, the control device 100 may cause the drive unit 34 to maintain the state in which the nozzle 41 is located at the first discharge position. FIG. 10(b) illustrates a state in which the nozzle 41 is located at the first discharge position and the removal liquid Lr is not supplied to the peripheral area PA of the film R of the processing liquid.

[0086] In step S36, if it is determined that the number of repetitions of the intermittent removal process has not reached the predetermined number (step S36: NO), the process executed by the control device 100 returns to step S32. In step S32, for example, the control device 100 controls the liquid delivery unit 43 of the removal liquid supply unit 40 to start (resume) the discharge of the removal liquid from the nozzle 41 while maintaining the nozzle 41 at the first discharge position. Specifically, the control device 100 switches the opening / closing valve V2 of the liquid delivery unit 43 from a closed state to an open state while the nozzle 41 is placed at the first discharge position where the removal liquid can be supplied to the peripheral region of the film of the treatment liquid, thereby starting the discharge of the removal liquid from the nozzle 41.

[0087] Thereafter, the control device 100 repeats a series of processes from step S32 to S36 until the number of times that one loop of processes including the first process and the second process is executed reaches a predetermined number. In step S36, when it is determined that the number of times that one loop of processes is repeated reaches a predetermined number (step S36: YES), the control device 100 executes steps S37 and S38. In step S37, for example, the control device 100 moves the nozzle 41, in a state in which the ejection of the removal liquid is stopped, to the above-mentioned second ejection position by the drive unit 44. In step S38, for example, the control device 100 switches the opening / closing valve V2 from a closed state to an open state, thereby starting the ejection of the removal liquid from the nozzle 41. Then, the control device 100 executes steps S39 to S43 in the same manner as steps S19 to S23. By executing the above series of processes, the peripheral region of the film of the treatment liquid on the surface Wa of the workpiece W is removed.

[0088] In the intermittent removal process included in the series of processes shown in Fig. 6, the process executed by the control device 100 transitions from the second process to the first process as the arrival area AR of the removal liquid from the nozzle 41 that discharges the removal liquid moves from the outside of the periphery Wb of the workpiece W to the peripheral area of ​​the film of the treatment liquid. On the other hand, in the intermittent removal process included in the series of processes shown in Fig. 9, the arrival area AR (the area where the discharged removal liquid is expected to reach) remains located in the peripheral area, and the opening / closing valve V2 that opens and closes the flow path to the nozzle 41 transitions from a closed state to an open state, and the process executed by the control device 100 transitions from the second process to the first process.

[0089] In the intermittent removal process included in the series of processes shown in Fig. 6, the process executed by the control device 100 transitions from the first process to the second process as the arrival area AR moves from the peripheral area of ​​the film of the treatment liquid to the outside of the peripheral area Wb of the workpiece W. On the other hand, in the intermittent removal process included in the series of processes shown in Fig. 9, the process executed by the control device 100 transitions from the first process to the second process as the opening / closing valve V2 transitions from an open state to a closed state with the arrival area AR located in the peripheral area. The above-mentioned modified example of the series of processes shown in Fig. 6 may also be applied to the series of processes shown in Fig. 9.

[0090] A part of the series of processes shown in FIG. 9 may be applied to a part of the series of processes shown in FIG. 6. In all of the second processes included in the intermittent removal process shown in FIG. 6, the control device 100 may switch the opening / closing valve V2 from an open state to a closed state when starting (resuming) the second process with the nozzle 41 disposed at the first discharge position. In this case, the control device 100 may move the nozzle 41 by the drive unit 44 so that the arrival area AR is located outside the periphery Wb before starting the first process (during the execution of the second process) and cause the removal liquid supply unit 40 to start discharging the removal liquid from the nozzle 41. In some of the second processes, the control device 100 may move the arrival area AR of the removal liquid to the outside of the periphery Wb to start the second process, and in the remaining part, the control device 100 may switch the opening / closing valve V2 from an open state to a closed state with the nozzle 41 disposed at the first discharge position to start the second process.

[0091] In all of the first processes included in the intermittent removal process shown in FIG. 6, the control device 100 may switch the on-off valve V2 from a closed state to an open state when starting (resuming) the first process with the nozzle 41 disposed at the first discharge position. In this case, in order to end the first process, the control device 100 moves the nozzle 41 to the drive unit 44 so that the arrival area AR of the removing liquid is outside the periphery Wb. Then, before starting the first process, the control device 100 may move the nozzle 41 to the first discharge position by the drive unit 44 after stopping the discharge of the removing liquid from the removing liquid supply unit 40. In some of the first processes, the control device 100 may start the first process by moving the arrival area AR of the removing liquid to the periphery area of ​​the film of the treatment liquid, and in the remaining part, the control device 100 may start the first process by switching the on-off valve V2 from a closed state to an open state with the nozzle 41 disposed at the first discharge position.

[0092] Next, the influence of the intermittent removal process in which the first process and the second process are alternately performed on the film thickness distribution will be described with reference to Figures 11 and 12. The film thickness distribution is a distribution that indicates the change in the thickness (film thickness) of the film of the treatment liquid with respect to the measurement position on the diameter on the surface Wa of the workpiece W. Comparative Example 1, Comparative Example 2, Example 1, and Example 2 were each prepared under the following conditions.

[0093] In Comparative Example 1, the intermittent removal process was not performed, and the removal liquid was continuously discharged onto the peripheral region of the film of the treatment liquid for only 20 seconds. Also, in Comparative Example 1, in the stage of forming a film of the treatment liquid on the surface Wa before removing the peripheral region, the treatment liquid on the surface Wa was dried by rotating for only 120 seconds after the supply of the treatment liquid was stopped. In Comparative Example 2, similar to Comparative Example 1, the intermittent removal process was not performed, and the removal liquid was continuously discharged onto the peripheral region of the film of the treatment liquid for only 20 seconds. Also, in Comparative Example 2, in the stage of forming a film of the treatment liquid, the treatment liquid on the surface Wa was dried by rotating for only 70 seconds after the supply of the treatment liquid was stopped.

[0094] In Example 1, one loop of processing including the first process and the second process was repeated three times, and then a continuous removal process was performed in which the removal liquid was continuously supplied to the peripheral area of ​​the film of the processing liquid for 10 seconds. The execution time of each of the first process and the second process was 1 second. In Example 1, a film of the processing liquid was formed in the same manner as in Comparative Example 1. In Example 2, one loop of processing including the first process and the second process was repeated 10 times, and then a continuous removal process was performed in which the removal liquid was continuously supplied to the peripheral area of ​​the film of the processing liquid for 5 seconds. The execution time of each of the first process and the second process was 1 second. In Example 2, a film of the processing liquid was formed in the same manner as in Comparative Example 2.

[0095] To evaluate the rise in film thickness at the edge of the treatment liquid film after the peripheral region was removed, the "hump height" and "edge bounce" defined as follows were evaluated. The hump height is the maximum film thickness between radial positions of 148 mm and 150 mm on the surface Wa of the workpiece W, which has a diameter of 300 mm. The edge bounce is the difference between the film thickness at a radial position of 147 mm and the film thickness at a radial position of 145 mm.

[0096] In Fig. 11(a), the evaluation results of the hump height in each of Comparative Example 1, Comparative Example 2, Example 1, and Example 2 are shown in a bar graph. In the graph of Fig. 11(a), the evaluation results are shown as relative values ​​when the hump height in Comparative Example 1 is set to 100%. In Fig. 11(b), the evaluation results of the edge bounce in each of Comparative Example 1, Comparative Example 2, Example 1, and Example 2 are shown in a bar graph. In the graph of Fig. 11(b), the evaluation results are shown as relative values ​​when the edge bounce in Comparative Example 1 is set to 100%.

[0097] From the results of Comparative Example 1 and Comparative Example 2, it can be seen that when the drying time when forming the film of the treatment liquid is shortened, the film thickness may be more swollen at the end of the film after the peripheral region is removed. This is thought to be due to the fact that when the drying time is short, the film of the treatment liquid contains more solvent when performing the process of removing the peripheral region compared to when the drying time is long. From the results of Comparative Example 1 and Example 1, it can be seen that by alternately performing the first process and the second process, the swollen film thickness is reduced at the end of the film after the peripheral region is removed.

[0098] From the results of Comparative Example 1 and Example 2, it can be seen that even if the drying time is shortened (even if a large amount of solvent is contained in the film of the processing liquid when the peripheral region is removed), the intermittent removal process reduces the rise in film thickness at the end of the film after the peripheral region is removed. Also, in Comparative Example 1, the total of the drying process time and the process (removal process) time for removing the peripheral region is 140 seconds, whereas the corresponding total time in Example 2 is 95 seconds. In other words, it can be seen that the rise in film thickness at the end of the film of the processing liquid after the peripheral region is removed can be reduced while shortening the total process time for forming the film of the processing liquid and the execution time of the removal process.

[0099] FIG. 12(a) shows the measurement results of the film thickness distribution in Comparative Example 1, and FIG. 12(b) shows the measurement results of the film thickness distribution in Example 2. In FIG. 12(a) and FIG. 12(b), the measurement results are plotted so that the scale of the vertical axis is the same. In FIG. 12(a) and FIG. 12(b), the difference between the maximum value and the minimum value of the film thickness distribution is shown as "Ra". The difference Ra in the measurement result shown in FIG. 12(b) is about 0.8 times the difference Ra in the measurement result shown in FIG. 12(a). That is, it can be seen that the difference Ra indicating the difference between the maximum value and the minimum value in the film thickness distribution is reduced by alternately repeating the state in which the removing liquid is supplied and the state in which the removing liquid is not supplied.

[0100] [Effects of the embodiment] The substrate processing method according to the above embodiment includes performing an intermittent removal process to remove a peripheral region of a film formed by a processing liquid on the surface Wa of the workpiece W. The intermittent removal process includes alternately performing a first process in which a removing liquid for removing the film is supplied from the nozzle 41 to the peripheral region while rotating the workpiece W, and a second process in which, after performing the first process, a state in which the removing liquid is not supplied from the nozzle 41 to the peripheral region while rotating the workpiece W.

[0101] In order to remove the peripheral region of the film of the processing liquid, conventionally, the peripheral region is removed by continuously supplying the removing liquid to the peripheral region. While the removing liquid is being supplied to the peripheral region, the components in the film of the processing liquid and the removing liquid mix to form a mixed layer in the peripheral region of the substrate, and the mixed layer builds up. In this state, as the drying of the film of the processing liquid progresses, the film thickness at the end of the film after the peripheral region is removed becomes thicker than other regions. In contrast, in the above-mentioned substrate processing method, a state in which the removing liquid is supplied to the peripheral region and a state in which the removing liquid is not supplied to the peripheral region are alternately repeated, so that the time for supplying the removing liquid to the peripheral region is shorter than when the removing liquid is continuously supplied, and the formation of the mixed layer is suppressed. In addition, by rotating the workpiece W in a state in which the removing liquid is not supplied, the mixed layer can be discharged outside the workpiece W during the process of removing the peripheral region, so that the buildup of the mixed layer can be suppressed. Therefore, it is possible to reduce the buildup of the film thickness at the end of the film of the processing liquid after the peripheral region is removed.

[0102] In the above substrate processing method, at least one first process performed in the intermittent removal process may be started by moving the nozzle 41 so that the arrival area AR of the removal liquid from the nozzle 41 in a state where the removal liquid is being discharged moves from a position outside the periphery Wb of the workpiece W to the peripheral area of ​​the film of the treatment liquid. In this case, the number of times that the nozzle 41, which has stopped discharging, is transitioned to a state where the removal liquid is discharged in order to start the first process can be reduced. As a result, it is possible to reduce the frequency of occurrence of malfunctions that may occur when the nozzle 41 starts discharging the removal liquid. For example, it is possible to reduce the frequency of occurrence of malfunctions in which the treatment liquid is discharged from the nozzle 41 in an unintended direction when the opening / closing valve V2 is transitioned to an open state to start discharging.

[0103] In the above substrate processing method, at least one first process executed in the intermittent removal process may be started by switching the on-off valve V2, which opens and closes the flow path for sending the removing liquid to the nozzle 41, from a closed state to an open state, with the nozzle 41 disposed at a position where the removing liquid can be supplied to the peripheral region. In this case, the period during which the removal liquid is continuously discharged without being supplied to the film of processing liquid before the first process is started can be reduced. As a result, it is possible to reduce the amount of removal liquid discharged (total amount of discharged) in the intermittent removal process including the second process in which the removing liquid is not supplied.

[0104] In the above substrate processing method, at least one second process performed in the intermittent removal process may be started by moving the nozzle 41 so that the arrival area AR of the removal liquid from the nozzle 41 in a state where the removal liquid is being discharged moves from the peripheral area of ​​the film of the treatment liquid to a position outside the peripheral edge Wb of the workpiece W. In this case, the number of times that the nozzle 41 discharging the removal liquid is transitioned to a state where the discharge is stopped in order to start the second process can be reduced. As a result, it is possible to reduce the frequency of occurrence of malfunctions that may occur due to the stop of the discharge of the removal liquid by the nozzle 41. For example, it is possible to reduce the frequency of occurrence of malfunctions in which the treatment liquid is discharged from the nozzle 41 in an unintended direction when the opening and closing valve V2 is transitioned to a closed state in order to stop the discharge.

[0105] In the above substrate processing method, at least one second process performed in the intermittent removal process may be started by switching the on-off valve V2, which opens and closes the flow path for sending the removing liquid to the nozzle 41, from an open state to a closed state, with the nozzle 41 disposed at a position where the removing liquid can be supplied to the peripheral region. In this case, after the start of the second process, the period during which the removal liquid is continuously discharged without being supplied to the film of processing liquid can be reduced. As a result, it is possible to reduce the amount of removal liquid discharged (total amount of discharged) in the intermittent removal process including the second process in which the removing liquid is not supplied.

[0106] The substrate processing method may further include continuing to supply the removing liquid to the peripheral region for a predetermined time while rotating the workpiece W after performing the intermittent removal process. In this case, by continuing to supply the removing liquid for a predetermined time after performing the intermittent removal process, the time required to remove a target amount of the peripheral region of the processing liquid film is shortened. As a result, it is possible to achieve both reduction in the swelling of the film thickness at the end and processing efficiency.

[0107] The second process may include rotating the workpiece W so as to discharge a portion of the film of the processing liquid softened by the removing liquid outside the workpiece W. A portion of the film softened by the removing liquid remains in the peripheral region of the workpiece W, which may cause a rise in the film thickness. In the above method, a portion of the film softened by the removing liquid is discharged outside the workpiece W, thereby suppressing the build-up of the mixed layer in the peripheral region of the surface Wa. As a result, it is possible to reduce the rise in the film thickness at the end of the film after the peripheral region is removed.

[0108] The second process may include rotating the workpiece W so that a liquid obtained by mixing the components of the film of the processing liquid dissolved by the removing liquid with the removing liquid is discharged outside the workpiece W. If the mixed liquid remains in the peripheral region of the workpiece W, a rise in the film thickness may occur. In the above method, the mixed liquid obtained by mixing the components dissolved by the removing liquid with the removing liquid is discharged outside the workpiece W, so that the buildup of the mixed layer in the peripheral region of the surface Wa is suppressed. As a result, it is possible to reduce the rise in the film thickness at the end of the film after the peripheral region is removed. [Explanation of symbols]

[0109] 1...substrate processing system, 2...coating and developing apparatus, U1...liquid processing unit, 20...rotating holder, 30...processing liquid supply section, 40...removal liquid supply section, 41...nozzle, 44...drive section, L2...liquid delivery pipe, V2...opening / closing valve, 100...control device, W...workpiece, Wa...surface, Wb...periphery, AR...reach area.

Claims

1. performing a removal process for removing a peripheral region of a film formed by a processing liquid on a surface of a substrate so as to expose an area underneath the film; The removal process includes an intermittent removal process, a continuous removal process, and a shake-off process, The intermittent removal process includes: a first process of supplying a removal liquid for removing the film from a nozzle onto the peripheral region while rotating the substrate; and alternately performing a second process in which, after the first process is performed, the removing liquid is not supplied from the nozzle to the peripheral region while rotating the substrate, the removal liquid is a solvent capable of dissolving the film, When the execution of the second process is completed, the intermittency removal process is completed, the continuous removal process includes, after performing the intermittent removal process, continuing to supply the removing liquid to the peripheral region for a predetermined time while rotating the substrate, The substrate processing method includes rotating the substrate at a rotational speed greater than the rotational speed of the substrate in each of the second processes of the intermittent removal process after the continuous removal process, without ejecting the removal liquid.

2. 2. The substrate processing method according to claim 1, wherein the removal liquid continues to be ejected from the nozzle at least during a period during which the intermittent removal process is performed, from the start of a first cycle of the first process until the end of a final cycle of the first process.

3. The substrate processing method according to claim 1 , wherein the predetermined time is longer than a duration of each of the first steps in the intermittent removal processes.

4. The substrate processing method according to any one of claims 1 to 3, wherein a reach area of ​​the removing liquid in the continuous removal process is set at a position farther from the center of the substrate than a reach area of ​​the removing liquid in each of the first processes of the intermittent removal process.

5. 5. The substrate processing method according to claim 1, wherein the second process includes rotating the substrate so as to discharge a portion of the film softened by the removing liquid outside the substrate.

6. The substrate processing method according to any one of claims 1 to 5, wherein the second process includes rotating the substrate so as to discharge a liquid, which is a mixture of the component of the film dissolved by the removing liquid and the removing liquid, outside the substrate.

7. A computer-readable storage medium storing a program for causing an apparatus to execute the substrate processing method according to any one of claims 1 to 6.

8. a liquid processing unit including a spin holder that holds and rotates a substrate, a processing liquid supplying unit that supplies a predetermined processing liquid to the substrate held by the spin holder, and a removing liquid supplying unit that includes a nozzle and supplies a removing liquid from the nozzle to the substrate held by the spin holder; a control unit for controlling the liquid processing unit; the control unit controls the liquid processing unit to form a film of the processing liquid on the surface of the substrate, and controls the liquid processing unit to perform a removal process to remove a peripheral region of the film so as to expose an area below the film; The removal process includes an intermittent removal process, a continuous removal process, and a shake-off process, The intermittent removal process includes: a first process of supplying the removing liquid from the nozzle by the removing liquid supply unit to the peripheral region while rotating the substrate by the spin holder; and a second process in which the removing liquid supply unit maintains a state in which the removing liquid is not supplied from the nozzle to the peripheral region while rotating the substrate by the spin holder after the first process is performed, the removal liquid is a solvent capable of dissolving the film, When the execution of the second process is completed, the intermittency removal process is completed, the continuous removal process includes, after performing the intermittent removal process, continuing to supply the removing liquid to the peripheral region for a predetermined time while rotating the substrate, The shake-off process is a process of rotating the substrate at a rotational speed higher than the rotational speed of the substrate in each of the second processes of the intermittent removal process without ejecting the removal liquid, separate from the continuous removal process, in a substrate processing apparatus.

9. 9. The substrate processing apparatus of claim 8, wherein the control unit controls the liquid processing unit so that the removal liquid continues to be ejected from the nozzle at least during a period during which the intermittent removal process is performed, from the start of a first run of the first process to the end of the last run of the first process.

10. The substrate processing apparatus according to claim 8 , wherein the predetermined time is longer than a duration of each of the first processes in the intermittent removal process.

11. The substrate processing apparatus according to any one of claims 8 to 10, wherein a reach area of ​​the removing liquid in the continuous removal process is set at a position farther from the center of the substrate than a reach area of ​​the removing liquid in each of the first processes of the intermittent removal process.

12. The substrate processing apparatus according to any one of claims 8 to 11, wherein the second process includes rotating the substrate by the rotating holder so as to discharge a portion of the film softened by the removing liquid outside the substrate.

13. The substrate processing apparatus according to any one of claims 8 to 12, wherein the second process includes rotating the substrate by the rotating holder so as to discharge a liquid mixture of the component of the film dissolved by the removing liquid and the removing liquid outside the substrate.

Images