Substrate processing equipment

Abstract

To provide a substrate processing device which suppresses the splashing of a process liquid and prevents liquid droplets from scattering to the surroundings of the substrate.SOLUTION: The substrate processing device comprises: nozzle arms 21, 22 that pivot around a pivot shaft A2, which is set to the outside of an edge of a horizontally held substrate W, so as to move nozzles slewing along the surface of the substrate W; a first nozzle 23 that is held by a nozzle arm and injects droplets of a first process liquid to the surface of the substrate W from top to bottom in the vertical direction; a second nozzle 24 that is held by a nozzle arm at a prescribed interval from the first nozzle 23 in a plan view and discharges a continuous stream of a second process liquid to the surface of the substrate W diagonally from top to bottom. The second nozzle 24 has a discharge direction that is set so as to incline at a prescribed angle of inclination toward the pivot shaft A2 of the nozzle arms.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a substrate processing apparatus that processes a substrate by supplying a processing liquid to the substrate while rotating the substrate. Substrates to be processed include, for example, semiconductor wafers, substrates for flat panel displays (FPDs) such as liquid crystal display devices and organic EL (Electro-luminescence) display devices, substrates for optical disks, substrates for magnetic disks, substrates for magneto-optical disks, substrates for photomasks, ceramic substrates, substrates for solar cells, and the like.

Background Art

[0002] Patent Document 1 below discloses a substrate processing apparatus that integrally moves a first nozzle that injects a jet of droplets of a processing liquid in a substantially vertical direction and a second nozzle that discharges a continuous flow of the processing liquid above a horizontally held and rotated substrate for use.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When ejecting a jet of droplets of a processing liquid from a first nozzle and simultaneously discharging a continuous flow of the processing liquid from a second nozzle while integrally moving these first and second nozzles to perform processing on the substrate surface, liquid splashing of the processing liquid may occur, and droplets may scatter around the substrate.

[0005] The substrate processing apparatus disclosed in Patent Document 1 provides a technology that can suppress the occurrence of liquid splashing from one perspective. One objective of the present invention is to provide a substrate processing apparatus that suppresses liquid splashing of the processing liquid and prevents or suppresses the scattering of liquid droplets around the substrate, based on a different perspective from the technology disclosed in Patent Document 1. [Means for solving the problem]

[0006] One embodiment of the present invention provides a substrate processing apparatus comprising: a substrate holding unit for holding a substrate horizontally; a substrate rotating unit for rotating the substrate held horizontally by the substrate holding unit in a horizontal plane such that the center of the substrate is the center of rotation; a first nozzle for injecting a jet of droplets of a first processing liquid vertically from top to bottom relative to the surface of the substrate; a second nozzle for discharging a continuous flow of a second processing liquid diagonally from top to bottom relative to the surface of the substrate; and a nozzle arm for holding the first nozzle and the second nozzle. The nozzle arm holds the first nozzle and the second nozzle so as to be separated by a predetermined distance in a plan view, and its rotation axis is set to be located outside the outer edge of the substrate, and by rotating around the rotation axis, the first nozzle and the second nozzle are rotated along the surface of the substrate. The second nozzle has a discharge direction set to be inclined at a predetermined angle toward the rotation axis of the nozzle arm as it moves downward.

[0007] In this device, the second nozzle has a discharge direction inclined at a predetermined angle toward the rotation axis, which is the center of rotation of the nozzle arm. Therefore, the continuous flow of the second processing liquid discharged from the second nozzle lands on the substrate surface in an oblique direction toward the rotation axis. That is, the continuous flow of the second processing liquid is incident on the substrate surface at the predetermined angle of inclination and lands on the substrate surface. Since an oblique discharge force acts on the landsted second processing liquid, the landsted second processing liquid flows across the substrate surface in a direction toward the rotation axis of the nozzle arm. Therefore, the second processing liquid is less likely to accumulate at the point of contact, and a thick liquid film of the second processing liquid is not widely distributed around the point of contact.

[0008] On the other hand, the first processing liquid sprayed from the first nozzle enters and lands on the substrate surface in a vertical direction. The jet of droplets of the first processing liquid sprayed from the first nozzle and landing on the substrate surface acts on the substrate surface with respect to the point of contact.

[0009] The first and second nozzles are positioned at a predetermined distance apart in a plan view and are rotated by a nozzle arm. As a result, the first nozzle may move to the vicinity of the point of impact of the second processing liquid discharged from the second nozzle. If a thick liquid film of the second processing liquid is widely present around the point of impact, the droplet jet ejected from the first nozzle may interfere with the thick liquid film of the second processing liquid, causing splashing of the second processing liquid and scattering of droplets.

[0010] In this embodiment, by directing the second processing liquid discharged from the second nozzle to flow from the point of contact across the substrate surface toward the rotation axis of the nozzle arm, it is possible to suppress the widespread distribution of the thick film portion of the second processing liquid near the point of contact. As a result, even when the first nozzle moves, a flow can be created on the substrate surface such that the second processing liquid does not pass directly beneath the droplet jet ejected from the first nozzle in a thick film state. In other words, the thick film portion of the second processing liquid can flow across the substrate surface while avoiding the point of contact of the droplet jet from the first nozzle.

[0011] Therefore, interference between the thick liquid film of the second processing solution and the droplet jet of the first processing solution on the surface of the substrate can be suppressed or prevented, liquid splashing that may occur due to such interference can be suppressed, and droplets can be prevented from scattering around the substrate.

[0012] In one embodiment of the present invention, the first nozzle and the second nozzle are held on the nozzle arm such that, by the rotational movement of the first nozzle and the second nozzle, the point of contact of the droplet jet of the first processing liquid on the surface of the substrate moves through the center of the substrate, and the point of contact of the continuous flow of the second processing liquid on the surface of the substrate passes through a position shifted by a certain amount relative to the center of the substrate in the direction toward the rotation axis.

[0013] In this configuration, when the first and second nozzles are rotated along the surface of the substrate by the nozzle arm, the trajectory of the impact point of the droplet jet ejected from the first nozzle and the trajectory of the impact point of the second processing liquid discharged as a continuous flow from the second nozzle do not overlap. Furthermore, compared to the arc-shaped trajectory of the impact point of the droplet jet of the first processing liquid, the trajectory of the impact point of the continuous flow of the second processing liquid is offset in the direction of the rotation axis and draws an arc with a radius that is a certain distance shorter. In addition, since the discharge direction of the second nozzle is inclined at a predetermined angle toward the rotation axis, the second processing liquid flows on the substrate in the direction toward the rotation axis from the impact point, moving away from the impact point of the droplet jet. Therefore, a flow of the second processing liquid can be created on the substrate such that the thick liquid film of the second processing liquid does not pass directly beneath the droplet jet, and the thick film portion of the second processing liquid is formed on the surface of the substrate while avoiding the impact point of the droplet jet. Furthermore, by suppressing splashing caused by the droplet jet interfering with the thick liquid film of the second processing solution, it is possible to suppress or prevent droplets from scattering around the substrate.

[0014] In one embodiment of the present invention, the nozzle arm rotates the first nozzle and the second nozzle together so that the point of impact of the droplet jet of the first processing liquid can scan the surface of the substrate from one edge of the substrate through the center of the substrate to the other edge of the substrate, and the point of impact of the continuous flow of the second processing liquid can scan the surface of the substrate from one edge of the substrate to the other edge of the substrate, passing through a position shifted by a certain distance from the center of the substrate toward the rotation axis.

[0015] In this configuration, the point of contact of the droplet jet discharged from the first nozzle moves in an arc passing over the center of rotation of the substrate, scanning the substrate surface. Meanwhile, the point of contact of the continuous flow of the second processing liquid discharged from the second nozzle moves in an arc with a shorter radius than the arc drawn by the droplet jet's point of contact, avoiding the center of rotation of the substrate, and scanning the substrate surface.

[0016] Therefore, the trajectory of the point of impact of the droplet jet ejected from the first nozzle and the trajectory of the point of impact of the second processing liquid discharged from the second nozzle do not overlap. Furthermore, since the discharge direction of the second nozzle is inclined at a predetermined angle relative to the surface of the substrate toward the axis of rotation, the second processing liquid flows on the substrate in the direction toward the axis of rotation from the point of impact, moving away from the point of impact of the droplet jet. As a result, interference between the liquid film of the second processing liquid and the droplet jet is more effectively suppressed or prevented, thereby suppressing splashing caused by the interference of the liquid film and preventing droplets from scattering around the substrate.

[0017] In one embodiment of the present invention, the first processing liquid injected by the first nozzle and the second processing liquid discharged by the second nozzle are the same type of processing liquid.

[0018] In this configuration, the same type of processing liquid is injected onto the substrate surface as a droplet jet from the first nozzle and discharged as a continuous flow from the second nozzle, thereby supplying the processing liquid to the substrate surface in different ways, and the processing liquid is supplied from the first and second nozzles simultaneously. As a result, the substrate surface can be efficiently and effectively treated with a single type of processing liquid.

[0019] In one embodiment of the present invention, the first nozzle includes a spray nozzle (a so-called two-fluid nozzle) that sprays the first processing liquid in a spray form by mixing the first processing liquid with an inert gas and releasing the mixture.

[0020] In this configuration, the first nozzle can be a spray nozzle with high physical cleaning capability. [Brief explanation of the drawing]

[0021] [Figure 1] Figure 1 is a schematic diagram showing an example of the general configuration of a processing unit of a substrate processing apparatus according to one embodiment, viewed from the side. [Figure 2] Figure 2 is a schematic diagram showing an example of the schematic configuration of a processing unit of a substrate processing apparatus according to one embodiment, in a plan view. [Figure 3]FIG. 3 is a diagram showing a configuration example of a second nozzle used in a processing unit of a substrate processing apparatus according to an embodiment. [Figure 4] FIG. 4 is a diagram schematically depicting the flow of a thick portion of a liquid film of a processing liquid discharged from a second nozzle onto the surface of a substrate. [Figure 5] FIG. 5 is a diagram showing in tabular form the number of droplets (particles) adhering to the ceiling of a chamber when the distance between a first nozzle and a second nozzle, the diameter of the second nozzle, and the offset amount of the liquid landing point of the second nozzle are changed in a processing unit of a substrate processing apparatus according to an embodiment.

Embodiments for Carrying Out the Invention

[0022] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0023] FIG. 1 is a schematic diagram showing an example of the schematic configuration of a processing unit 10 of a substrate processing apparatus according to an embodiment in a side view. FIG. 2 is a schematic diagram showing an example of the schematic configuration of the processing unit 10 in a plan view.

[0024] A substrate processing apparatus according to an embodiment includes a plurality of processing units 10 shown in FIGS. 1 and 2, and in each processing unit 10, processing of a substrate W is performed individually. Although detailed illustration is omitted, a substrate processing apparatus typically includes, in addition to a plurality of processing units 10, a carrier holding unit that holds a carrier for accommodating a substrate, and a substrate transfer mechanism that transfers the substrate between the carrier held by the carrier holding unit and the processing unit 10. The substrate transfer mechanism includes one or more substrate transfer robots. The substrate transfer robot includes a hand for holding the substrate and a hand drive mechanism that moves the hand in the horizontal and vertical directions and turns the hand in the horizontal direction.

[0025] The processing unit 10 is a single-wafer type unit that processes substrates W one at a time. In this example, the substrate W is a circular substrate such as a semiconductor wafer. The processing unit 10 is equipped with a spin chuck 11 that rotates a single substrate W in the horizontal plane around a rotation axis A1 extending vertically, while holding the substrate W in a horizontal position which is the processing position. The spin chuck 11 functions as both a substrate holder and a substrate rotater. The spin chuck 11 includes a rotating support shaft 12 and a spin base 13 connected and fixed to the upper end of the rotating support shaft 12. The spin base 13 is configured as a horizontally positioned disc. Multiple chuck pins 14 are erected near the periphery of the spin base 13 for gripping the periphery of the substrate W. Three or more chuck pins 14 are sufficient to securely hold the circular substrate W, and they are arranged at equal angular intervals along the periphery of the spin base 13.

[0026] Each chuck pin 14 includes a substrate support portion 141 that supports the peripheral edge of the substrate W from below, and a peripheral edge holding portion 142 that holds the substrate W by pressing the peripheral edge of the substrate W, supported by the substrate support portion 141, toward the center of the substrate W from its side. Each chuck pin 14 is configured to be switchable between a pressing state in which the peripheral edge holding portion 142 presses against the peripheral edge of the substrate W, and a release state in which the peripheral edge holding portion 142 moves away from the peripheral edge of the substrate.

[0027] When the substrate W is transferred to the spin base 13 by the handle of the substrate transfer robot, the processing unit 10 releases the multiple chuck pins 14, and when processing the substrate W with the processing liquid, it presses the multiple chuck pins 14. By pressing them, the multiple chuck pins 14 grip the peripheral edge of the substrate W and hold the substrate W in a horizontal position at a predetermined distance above the spin base 13. As a result, the substrate W is supported with its front surface facing upwards and its back surface facing downwards, with the rotation axis A1 passing through the center of the front and back surfaces.

[0028] The processing unit 10 rotates the substrate W at a predetermined rotational speed (for example, 500 rpm to 2000 rpm) by rotating the spin chuck 11, which holds the substrate W, using a chuck rotation mechanism 15. A guard 16 is provided around the spin chuck 11 to catch any liquid splashed from the substrate W. The guard 16 includes a cylindrical portion 161 that surrounds the spin chuck 11 and a canopy portion 162 that extends diagonally inward from the upper end of the cylindrical portion 161 and has an open top surface.

[0029] The processing unit 10 includes a rotating support base 17 and a holding base 18. In a plan view, the rotating support base 17 is erected on the outside of the guard 16. The rotating support base 17 may be cylindrical in shape, for example, and the holding base 18 is connected to its upper end. The holding base 18 may be cube-shaped, for example, and can rotate on the rotating support base 17 within a predetermined angle range about a rotation axis A2 that extends vertically through the center of the rotating support base 17. The rotation axis A2 is located outside the outer edge of the substrate W held by the spin chuck 11. That is, the distance between the rotation axis A1 of the spin chuck 11 and the rotation axis A2 is greater than the rotation radius of the substrate W. The rotation radius here refers to the radius of the circle traced by the outer edge of the substrate W when the substrate W rotates about the rotation axis A1, and is substantially equal to that radius when the substrate W is circular.

[0030] The retaining base 18 holds the base portions of the first nozzle arm 21 and the second nozzle arm 22, which extend horizontally from one side surface 19.

[0031] The first nozzle arm 21 has its base portion 211 fixed within the holding base 18. The first nozzle arm 21 extends horizontally from one side surface 19 of the holding base 18 and has a length such that its tip portion 212 reaches the rotation axis A1 of the substrate W when directed toward the rotation axis A1. The first nozzle arm 21 has an internal processing liquid channel for circulating the processing liquid. This processing liquid channel constitutes a processing liquid piping that guides the processing liquid from the base portion 211 to the tip portion 212 (it can also be said that the first nozzle arm 21 itself constitutes the processing liquid piping). A first nozzle 23 is connected to the tip portion 212 of the first nozzle arm 21, which discharges the processing liquid vertically from top to bottom onto the surface of the substrate W. That is, the processing liquid channel in the first nozzle 23 communicates with the processing liquid piping of the first nozzle arm 21. The first nozzle 23 may be formed integrally with the first nozzle arm 21 so as to communicate with the tip portion 212 of the first nozzle arm 21. The first nozzle 23 has a mixing unit 25 that mixes a gas, such as an inert gas, with the processing liquid supplied through the processing liquid piping contained in the first nozzle arm 21. The processing liquid discharged vertically downward from the first nozzle 23 forms a jet of liquid droplets (mist spray), and the processing liquid, mixed with the gas and turned into a mist, is sprayed from the first nozzle 23. In other words, the first nozzle 23 is a spray nozzle (a so-called two-fluid nozzle). The first nozzle 23 may be an internal mixing type in which the mixing of the processing liquid and gas occurs inside the nozzle housing (i.e., before discharge), or it may be an external mixing type in which the mixing of the processing liquid and gas occurs outside the nozzle housing (more specifically, near the discharge port).

[0032] The base portion 221 of the second nozzle arm 22 is fixed within the holding base 18. The second nozzle arm 22 has an internal processing liquid channel for circulating the processing liquid. This processing liquid channel constitutes a processing liquid piping that guides the processing liquid from the base portion 221 to the tip portion 222 (it can also be said that the second nozzle arm 22 itself constitutes the processing liquid piping). The second nozzle arm 22 extends horizontally from one side surface 19 of the holding base 18. The tip portion 222 of the second nozzle arm 22 is provided with a second nozzle 24 that is angled at a predetermined inclination angle with respect to the surface of the substrate W and folded back in the direction returning to the base portion 221 of the second nozzle arm 22. The processing liquid channel formed within the second nozzle 24 communicates with the processing liquid piping of the second nozzle arm 22. The second nozzle 24 may be formed integrally with the second nozzle arm 22 so that its channel communicates with the tip portion 222 of the second nozzle arm 22. The second nozzle 24 is a nozzle that discharges a continuous flow of processing liquid.

[0033] The processing unit 10 is provided with a processing liquid supply source 26 and a gas supply source 27. The processing liquid supply source 26 includes, for example, a processing liquid tank that stores the processing liquid inside or outside the substrate processing apparatus. In this embodiment, the case in which the surface of the substrate W is cleaned using DIW (DE-IONIZED WATER: pure water) as the processing liquid will be described as an example.

[0034] One end of the first pipe 28 is connected to the processing liquid supply source 26, and the other end of the first pipe 28 is connected to the base 211 of the first nozzle arm 21, communicating with the processing liquid piping of the first nozzle arm 21. A first valve 30 and a first flow rate adjustment valve 37 are interposed in the middle of the first pipe 28. The first valve 30 is an on / off valve that switches the supply / stop of the processing liquid supplied from the processing liquid supply source 26 to the first nozzle arm 21 and then to the first nozzle 23 via the first pipe 28. The flow rate of the supplied processing liquid can be adjusted by adjusting the opening of the first flow rate adjustment valve 37. The flow rate of the processing liquid supplied to the first nozzle 23 is, for example, about 0.1 liters / minute.

[0035] Looking at the direction of the processing liquid supply, a branch is formed upstream of the position where the first valve 30 is installed in the first pipe 28, and one end of the second pipe 29 is connected to it. The other end of the second pipe 29 is connected to the base 221 of the second nozzle arm 22 and communicates with the processing liquid piping of the second nozzle arm 22. A second valve 31 and a second flow rate adjustment valve 38 are installed in the middle of the second pipe 29. The second valve 31 is an on / off valve that switches the supply / stop of the processing liquid supplied from the processing liquid supply source 26 through the second pipe 29 to the second nozzle arm 22 and then to the second nozzle 24. By adjusting the opening of the second flow rate adjustment valve 38, the flow rate of the supplied processing liquid can be adjusted. The flow rate of the processing liquid supplied to the second nozzle 24 is, for example, about 0.5 liters / minute.

[0036] In this embodiment, the first processing liquid injected from the first nozzle 23 and the second processing liquid discharged from the second nozzle 24 are both DIW (Direct Injection Water), and therefore the processing liquid is supplied to the first nozzle 23 and the second nozzle 24 from a common processing liquid supply source 26. However, if different types of processing liquids are used for the first processing liquid injected from the first nozzle 23 and the second processing liquid discharged from the second nozzle 24, a separate processing liquid supply source can be provided for each type of processing liquid, and each processing liquid can be supplied to the first nozzle and the second nozzle from each processing liquid supply source via separate piping.

[0037] The gas supply source 27 is, for example, a processing gas supply facility installed in a factory equipped with a substrate processing device. In this embodiment, the case in which nitrogen gas (N2), an example of an inert gas, is used as the gas will be explained as an example.

[0038] One end of the third pipe 32 is connected to the gas supply source 27, and the other end of the third pipe 32 is connected to the mixing section 25 of the first nozzle 23. A third valve 33 and a third flow rate adjustment valve 39 are interposed in the middle of the third pipe 32. The third valve 33 is an on / off valve that switches the supply / stop of nitrogen gas supplied from the gas supply source 27 to the mixing section 25 of the first nozzle 23 via the third pipe. The flow rate of the supplied nitrogen gas can be adjusted by adjusting the opening of the third flow rate adjustment valve 39. The flow rate of nitrogen gas supplied to the mixing section 25 of the first nozzle is, for example, about 35 liters / minute.

[0039] The first nozzle arm 21 and the second nozzle arm 22, which extend horizontally from one side surface 19 of the holding base 18, are arranged parallel to each other with a predetermined distance D (for example, D = 30 mm to 50 mm) in a plan view, as shown in Figure 2. As previously described, the tip 212 of the first nozzle arm 21 is equipped with a first nozzle 23, and the tip 222 of the second nozzle arm 22 is equipped with a second nozzle 24. The vertical distance between the nozzle opening 231 of the first nozzle 23 (see Figure 1) and the surface of the substrate W is set to, for example, 5 to 10 mm. The vertical distance between the nozzle opening 241 of the second nozzle 24 (see Figures 1 and 3) and the surface of the substrate W is also set to, for example, 5 to 10 mm.

[0040] In Figure 1, the vertical height positions of the first nozzle arm 21 and the second nozzle arm 22, which extend horizontally from one side surface 19 of the holding base 18, are shown with the first nozzle arm 21 being relatively higher and the second nozzle arm 22 being relatively lower. However, the vertical height positions of both nozzle arms 21 and 22 may be equal, or the first nozzle arm 21 may be relatively lower and the second nozzle arm 22 may be relatively higher.

[0041] Referring to Figure 2, the holding base 18 rotates horizontally within a predetermined angular range, for example, about 90°, about the rotation axis A2. The rotational movement of the holding base 18 is controlled by the nozzle arm rotation control unit 35. The nozzle arm rotation control unit 35 controls the rotational movement of the holding base 18 by, for example, driving a rotational drive mechanism provided on the rotational support base 17. The rotational drive mechanism may include a rotation shaft coupled to the holding base 18, and a rotational actuator (such as an electric motor) that generates a driving force to rotate the rotation shaft.

[0042] When the holding base 18 rotates horizontally around the rotation axis A2, the first nozzle arm 21 and the second nozzle arm 22, which extend horizontally from one side surface 19 of the holding base 18, also rotate horizontally. The first nozzle 23, provided at the tip 212 of the first nozzle arm 21, pivots along the trajectory L1 shown by the dashed line and moves above the surface of the substrate W and along the surface of the substrate W. The second nozzle 24, provided at the tip 222 of the second nozzle arm 22, pivots along the trajectory L2 shown by the double dashed line and moves above the surface of the substrate W and along the surface of the substrate W.

[0043] More specifically, trajectory L1 is the trajectory of the point of impact where the droplet jet ejected by the first nozzle 23 reaches the surface (top surface) of the substrate W. The point of impact is the position where the center line (main discharge axis) of the discharge profile of the droplet jet from the first nozzle 23 intersects the surface of the substrate W. Since the first nozzle 23 discharges the droplet jet along the vertical direction, in a plan view, the movement trajectory of the first nozzle 23 coincides with the trajectory of the point of impact of the droplet jet. Therefore, for the sake of explanation, in this specification, the position of the first nozzle 23 in a plan view may sometimes mean the point of impact of the droplet jet discharged from the first nozzle 23. Trajectory L1 is an arc centered on the rotation axis A2, and its radius is equal to the distance from the rotation axis A2, which is the pivot center of the first nozzle arm 21, to the rotation axis A1 of the spin chuck 11.

[0044] Similarly, trajectory L2 is, more specifically, the trajectory of the point of contact where the continuous flow of processing liquid discharged from the second nozzle 24 reaches the surface (top surface) of the substrate W. The point of contact is the position where the centerline (main discharge axis) of the continuous flow of processing liquid discharged from the second nozzle 24 intersects the surface of the substrate W. The second nozzle 24 is inclined with respect to the vertical, and therefore its discharge direction is inclined with respect to the vertical, so in a plan view, the position of the discharge port of the second nozzle 24 and the point of contact do not coincide. However, for the sake of explanation, in this specification, the position of the second nozzle 24 in a plan view may mean the point of contact of the continuous flow of processing liquid discharged from the second nozzle 24. Trajectory L2 is a circular arc centered on the rotation axis A2, and its radius is shorter than the distance from the rotation axis A2, which is the pivot center of the second nozzle arm 22, to the rotation axis A1 of the spin chuck. In other words, trajectory L2 is a circular arc with a smaller radius than trajectory L1.

[0045] The rotation of the first nozzle 23 is set so that, in a plan view, the first nozzle 23 (more specifically its nozzle opening 231, and more specifically the point of impact of the droplet jet) can scan the surface of the substrate W along a trajectory L1 from one end edge E1 of the substrate W to the center of the substrate W, i.e., passing through the rotation axis A1, to the other end edge E2 of the substrate W.

[0046] The rotation of the second nozzle 24 is set so that the second nozzle 24 (more specifically its nozzle opening 241, or more precisely, the point of contact of the continuous flow of processing liquid) can scan the surface of the substrate W from one edge E3 to the other edge E4 along a trajectory L2. In this case, the scan path, i.e., trajectory L2, passes through a position shifted by a certain dimension S (for example, S = 2 mm to 10 mm) from directly above the center of the substrate W (rotation axis A1) toward the rotation axis A2.

[0047] In this embodiment, the scanning range on the surface of the substrate W by the first nozzle 23 and the second nozzle 24, which are provided at the tips of the first nozzle arm 21 and the second nozzle arm 22 extending horizontally from one side surface 19 of the holding base 18, is set to the entire range of the substrate W from one edge E1, E3 to the other edge E2, E4, which is called a full scan. The direction in which the first nozzle 23 and the second nozzle 24 scan the surface of the substrate W may be a right-hand full scan by rotating the holding base 18 clockwise, or a left-hand full scan by rotating the holding base 18 counterclockwise, as shown in Figure 2. Of course, a half scan may be performed, with the scanning range from the center of the substrate W (rotation axis A1) to the edge of the substrate W. The discharge of droplet jets by the first nozzle 23 and the discharge of continuous flow by the second nozzle 24 are started at the starting point, which is one end of the scan range, and stopped at the ending point, which is the other end. When repeating the scan, the first nozzle 23 and the second nozzle 24 rotate from the end point to the start point of the scan range with discharge stopped, and the next scan is performed.

[0048] Figure 3 shows a specific example of the configuration of a second nozzle 24 used in the processing unit 10. The second nozzle 24 is integrally configured with the second nozzle arm 22 so as to communicate with the tip 222 of the second nozzle arm 22 and connect to the flow path. The upper part of the second nozzle 24 is attached to the tip 222 of the second nozzle arm 22 which extends horizontally, and includes a curved portion 242 that curves downward in an arc shape, and an inclined portion 243 that extends from below the curved portion 242 with an inclination angle of 45° with respect to the horizontal direction (i.e., with respect to the surface of the substrate W) and toward the base portion 221 of the second nozzle arm 22. According to this shape, a nozzle flow path (processing liquid flow path) is formed inside the second nozzle 24. A nozzle opening 241 connected to the nozzle flow path is formed at the lower end of the inclined portion 243. As an example, the nozzle opening 241 has an inner diameter of 3 mm and an outer diameter of 4 mm.

[0049] In this example, the inclined portion 243 of the second nozzle 24 is shown to have an inclination angle of 45° with respect to the horizontal direction, but the inclination angle of the inclined portion 243 with respect to the horizontal direction may be within the range of 30° to 50°. The smaller the inclination angle of the inclined portion 243 with respect to the horizontal direction, the greater the flow velocity component of the processing liquid discharged from the nozzle opening 241 that tends to flow in the direction toward the rotation axis A2. Therefore, the processing liquid discharged from the second nozzle 24 can be made to flow away from the point of contact.

[0050] Furthermore, the vertical distance H between the nozzle opening 241 and the surface of the substrate W is set to, for example, H = 5 to 10 mm. In addition, the point T where the processing liquid is discharged diagonally from the nozzle opening 241 is set to be a certain distance S (for example, S = 5 mm) away from the rotation axis A1, which is the center of the substrate W, in the direction toward the base 221 of the second nozzle arm 22 (towards the rotation axis A2 of the holding base 18).

[0051] By configuring the second nozzle 24 as described above, the effects described below with reference to Figure 4 are achieved.

[0052] Figure 4 is a diagram illustrating how the processing liquid discharged by the second nozzle 24 of this embodiment flows and spreads on the surface of the substrate W.

[0053] The diagrams shown in Figures 4(A) to (D) illustrate the flow of the processing liquid discharged by the second nozzle 24 on the substrate W when the substrate W is rotated counterclockwise at 500 rpm and scanned from one edge E3 to the other edge E4 of the substrate W. As mentioned above, the scan path of the second nozzle 24 passes over the center of the substrate W (i.e., the rotation axis A1) and shifted by a certain distance S (S=5mm) toward the rotation axis A2. In Figures 4(A) to (D), the areas shown in light gray represent the thicker parts of the liquid film of the processing liquid discharged by the second nozzle 24.

[0054] As the substrate W rotates, the processing liquid is discharged from the second nozzle 24, forming a liquid film (protective film) of the processing liquid that covers the entire surface of the substrate W. With the entire surface of the substrate wet, processing is performed by a droplet jet from the first nozzle 23. The thickness of the liquid film of the processing liquid on the surface of the substrate W is not uniform, and a thick film portion is formed starting from the point of contact of the continuous flow of processing liquid discharged from the second nozzle 24. This thick film portion is shown in light gray in Figures 4(A) to (D). The shape of the thick film portion is mainly influenced by the point of contact of the continuous flow of processing liquid, the direction of incidence of the continuous flow of processing liquid onto the substrate surface (discharge direction of the second nozzle 24), and the rotation direction and rotation speed of the substrate W.

[0055] As shown in Figure 4(A), near one edge E3 of the substrate W, the continuous flow of the processing liquid (second processing liquid) discharged by the second nozzle 24 creates a liquid film distribution on the surface of the substrate W that curves downward in the figure from the point of contact to the right, due to the oblique discharge force of the second nozzle 24, the frictional force between it and the surface of the substrate W, and the centrifugal force acting on the processing liquid on the substrate W.

[0056] As shown in Figure 4(B), until the second nozzle 24 approaches the center of the substrate W (rotation axis A1), the thickest portion of the liquid film of the processing liquid discharged by the second nozzle 24 is distributed in a direction away from the first nozzle 23, which is rotating to follow the second nozzle 24.

[0057] As shown in Figure 4(C), after the second nozzle 24 passes the position closest to the center of the substrate W (rotation axis A1), the thickest portion of the liquid film discharged by the second nozzle 24 spreads across the surface of the substrate W in a counterclockwise spiral. However, even in this case, the thickest portion of the liquid film does not flow directly below the first nozzle 23 (i.e., the point of impact of the droplet jet).

[0058] As shown in Figure 4(D), when the second nozzle 24 approaches the other edge E4 of the substrate W, the processing liquid discharged by the second nozzle 24 is affected by the combination of the oblique discharge force of the second nozzle 24 and the outward force acting in the opposite direction to this discharge force (frictional force and centrifugal force). As a result, the thicker portion of the liquid film flows away from directly beneath the first nozzle 23.

[0059] As a result, regardless of the scanning position of the first nozzle 23 and the second nozzle 24, it is possible to create a flow of processing liquid on the substrate W in which a thick portion of the processing liquid film discharged by the second nozzle 24 is not distributed directly below the first nozzle 23, or is difficult to distribute.

[0060] Figure 5 is a diagram showing, in a table format, the number of droplets (particles) attached to the ceiling of the chamber of a processing unit when the distance between the first nozzle and the second nozzle, the diameter of the second nozzle (diameter of the nozzle opening 241), and the offset amount of the liquid contact point of the second nozzle (constant dimension S) are changed in a processing unit according to one embodiment.

[0061] As shown in Figure 5, it was verified that splashing was reduced by changing the second nozzle from a standard vertical nozzle (comparative example) to an inclined nozzle with a 45° inclination angle toward the rotation axis A2 (example). A standard vertical nozzle is a nozzle that supplies a continuous flow of processing liquid from top to bottom along the vertical direction to the surface of a substrate in a horizontal position.

[0062] The verification results in Figure 5 confirm that simply changing the second nozzle to an inclined nozzle with a 45° inclination angle toward the rotation axis A2 does not completely eliminate splashing. Furthermore, it can be confirmed that to further reduce splashing, it is effective to (1) make the diameter (nozzle opening) of the second nozzle narrow (for example, inner diameter of 3 mm or less, outer diameter of 4 mm or less), (2) hold the first and second nozzles so that the distance between them is narrow (for example, 35 mm or less), and (3) offset the point of liquid application of the second nozzle by a predetermined distance in the direction toward the rotation axis A2 from the center of the substrate (rotation axis A1).Therefore, if the effect of preventing splashing is insufficient by simply using an inclined nozzle as the second nozzle, it is preferable to take one or more (preferably all) of the above measures (1), (2), and (3) in combination.

[0063] The present invention is not limited to the embodiments described above, and can be implemented in other forms.

[0064] Another example of an embodiment is to use a single shared nozzle arm that holds both the first nozzle arm 23 and the second nozzle arm 24, instead of dividing the nozzle arm into a first nozzle arm 21 and a second nozzle arm 22 as in the above embodiment. In the case of a single shared nozzle arm, the processing liquid piping and gas piping connected to the first nozzle 23 can be arranged within the nozzle arm, and the processing liquid piping connected to the second nozzle 24 can also be arranged within the nozzle arm. The first nozzle 23 and the second nozzle 24 can then be provided at the tip of the shared nozzle arm in a configuration that satisfies the installation conditions of the above embodiment.

[0065] In another embodiment, the jet of droplets of the first processing liquid sprayed by the first nozzle 23 may be a jet of droplets of an etching solution, such as hydrogen peroxide (H2O2), hydrofluoric acid (HF), dilute hydrofluoric acid (DHF), buffered hydrofluoric acid (BHF), mixed acid, hydrochloric acid (HCl), ammonia water, tetramethylammonium hydroxide solution (TMAH solution), ammonia water hydrogen peroxide mixture (APM solution), etc. That is, the etching solution may be sprayed in a mist form.

[0066] In this specification, when a numerical range is indicated using "~", unless otherwise specifically stated, these ranges include both endpoints.

[0067] In addition, various modifications can be made within the scope of the claims. [Explanation of Symbols]

[0068] 10: Processing Unit 11: Spin Chuck 17: Rotating support base 18: Retaining base 19: One side 21: First nozzle arm 22: Second nozzle arm 23: Nozzle No. 1 24: Second nozzle 25: Mixing section 26: Source of processing liquid 27: Gas supply source 35: Nozzle arm rotation control unit 211, 221: Root part 212, 222: Tip 231, 241: Nozzle opening 242: Curved section 243: Inclined part W: Circuit board A1: Rotation axis of the circuit board A2: Rotation axis of the nozzle arm E1, E3: One edge E2, E4: Other edge

Claims

1. A substrate holding section that holds the substrate horizontally, A substrate rotating unit rotates the substrate, which is held horizontally by the substrate holding unit, in a horizontal plane such that the center of the substrate becomes the center of rotation. A first nozzle that sprays a jet of droplets of the first processing liquid vertically from top to bottom onto the surface of the substrate, A second nozzle discharges a continuous stream of the second processing liquid diagonally from top to bottom onto the surface of the substrate, A nozzle arm holds the first nozzle and the second nozzle so as to be separated by a predetermined distance in a plan view, and has a pivot axis set to be located outside the outer edge of the substrate, and rotates around the pivot axis to pivotally move the first nozzle and the second nozzle along the surface of the substrate, Includes, A substrate processing apparatus wherein the second nozzle has a discharge direction set to tilt at a predetermined angle toward the rotation axis side of the nozzle arm as it moves downward, and in a plan view, is held by the nozzle arm at a position closer to the rotation axis than the first nozzle is to the rotation axis.

2. The substrate processing apparatus according to claim 1, wherein the first nozzle and the second nozzle are held in the nozzle arm such that, by the rotational movement of the first nozzle and the second nozzle, the point of contact of the droplet jet of the first processing liquid on the surface of the substrate moves through the center of the substrate, and the point of contact of the continuous flow of the second processing liquid on the surface of the substrate passes through a position shifted by a certain amount relative to the center of the substrate in the direction toward the rotation axis.

3. The substrate processing apparatus according to claim 1, wherein the nozzle arm rotates the first nozzle and the second nozzle integrally so that the point of impact of the droplet jet of the first processing liquid can scan the surface of the substrate from one edge of the substrate through the center of the substrate to the other edge of the substrate, and the point of impact of the continuous flow of the second processing liquid can scan the surface of the substrate from one edge of the substrate to the other edge of the substrate, passing through a position shifted by a certain distance from the center of the substrate toward the rotation axis.

4. The substrate processing apparatus according to any one of claims 1 to 3, wherein the first processing liquid sprayed by the first nozzle and the second processing liquid discharged by the second nozzle are the same type of processing liquid.

5. The substrate processing apparatus according to claim 1, wherein the first nozzle includes a spray nozzle that sprays the first processing liquid in a spray form by mixing the first processing liquid with an inert gas and releasing the mixture.

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